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08-03-2010 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,130
Joined on 10-12-2006

Post #: 1
Post ID: 14173
Reply to: 14173
Natural Remedies for Sick Speakers?
fiogf49gjkf0d
Haralanov, I've spun this thread off the "Speakers for a Powerful SET" thread, as you suggested. I took a couple of pictures, but I can't figure out how to upload them, just yet. I'm also not sure what you could see from the outside, anyway.

As for the Reps R1 driver, I used to know Frank Reps over 40 years ago, when we both lived in LA. He was/is a very bright guy and a tireless self-promoter of the "Secret Society" variety. The R1 is Frank's "perfected" Lowther. He uses all premium parts and serious, close-tolerance machining, along with touches like a Cobalt "Flux Funnel" that is supposed to make optimum focus in the gap. I took out the phase plug, and the gap is truly tiny!

I think I remember that Frank got/gets his cones from AER, or their OEM; very stiff, light, treated paper, and it appears that the paper cone "continues" to make the (paper) former. There is a standard red coated fabric "billows" around the otherwise-open front of the magnet. The cone surround is soft foam. In case you care, Frank lists the Qts as .1048 (!), and the "flux density" as 20,000 Gauss, which is a lot against the Qts, but less, numerically, than Lowther claims for their DX4, for instance. Frank intends for his R1 to be used FR in a back horn, like the complete units he offers (very discretely) for > $20k/pair...  Again, I presently high-pass my OB-mounted units 1st order at 400 Hz.

So far, I have not measured anything, and I lack the lab-type equipment to do serious investigations, anyway. So far, I have just used my ears and related that back to the well-documented Lowther numbers.  Although the ~2k Hz resonance does seem common with the light 8" drivers, this spike has got to be every bit the Lowther's 6 dB. Basically, it's mostly what you hear when you listen au natural.

I hope this gets the ball rolling. I'll keep after the pictures, if you still want them.

Best regards,
Paul S
08-04-2010 Post does not mapped to Knowledge Tree
haralanov


Bulgaria
Posts 130
Joined on 05-20-2008

Post #: 2
Post ID: 14178
Reply to: 14173
Who knows for sure...
fiogf49gjkf0d
 Paul S wrote:
I took a couple of pictures, but I can't figure out how to upload them, just yet.

Hi, Paul. Take a look here http://www.goodsoundclub.com/Forums/ShowPost.aspx?PostID=1120

 Paul S wrote:
I took out the phase plug, and the gap is truly tiny!

The very tiny magnetic gaps always have some nonlinearities in order to have high efficiencies.

 Paul S wrote:
The cone surround is soft foam. I presently high-pass my OB-mounted units 1st order at 400 Hz. Frank lists the Qts as .1048 (!)

Wow, that value is really on the very low side. I suppose the voice coil has at least two or may be more layers in order to get more turns in the gap which cause high BL factor (low Qes). As a downside there is a big increase in VC inductance, which can be calculated as the inductance of one layer get multiplied by the number of layers plus the mutual inductance of the layers because they are magnetically coupled. So the inductance modulation will be very high despite the driver does not make high excursions because of the high pass filter you use with it. So that may be part of the reason for the peak, but I cannot be sure about that.
You use a driver with very strong motor designed for horn use in open baffle. Soft foam surrounds never have good midrange reproduction, especially with OBs - you need some not so soft suspension an not so overdamped motor in order to get proper sound but I don't want to exercise my moronity making assumptions based on nothing...




"If you can't explain it simply, you don't understand it well enough." -A.E.
08-04-2010 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,130
Joined on 10-12-2006

Post #: 3
Post ID: 14179
Reply to: 14178
Un-Done by Eyes, Ears and Numbers
fiogf49gjkf0d

Petar, thanks for the pic posting link (which I've read over and over), but my problem posting pictures is my ancient browser, so that's another task. Again, there's really not much of what one would like to see that I can show, short of disassembly, as you will see for yourself, eventually.

I am not sure about the double coil windings. My guess is, "optimized" single winding, since Frank's aim was to keep it as light as possible, and he would be all over mutual inductance and that sort of thing, as part of his intellectual excercise. And, clearly, he did not use the most powerful magnet possible but sought to "optimize" that, too. As a point of interest, Frank refers to the bonding of the former to the cone as "an elaborate interlaced bandline" using "adhesives specifically selected for their low mass and exceptional bond strength". He also says the coil is a "perfect lay" Aluminum on a .003" bobbin, and he cites power handling at 55 W.

I have played around with two different Lowthers, but this is my first experience with the Reps.  None of these drivers move much, at least not the way I've used them. I am aware of conventional wisdom regarding Qts and the usual applications. While I would not choose an OB driver - including this one - because it had soft Qts, neither will I give up on it for that reason, at least not until I get the stupid spike tamed so I can hear what else it can do with my ears rather than my eyes. I suppose I could dope the foam (being careful not to degrade it chemically...), come to that.  But I am not there yet, and anything like this will come as a direct response to listening rather than a preemptive strike based on supposed TS numbers.

Again, unless one of us is siezed with inspiration in the meantime, I will at least try the (damned) notch filter, if only out of curiosity. Any suggestions for [foam] dope? I used to use a mix of good Damar varnish and highly-filtered beeswax that never completly set up; but if I ever settled on an exact recipe, I no longer remember it. In any case, I won't change the mechanics of the driver without having aurally targeted reasons to do so, and I would start with things I could un-do.

Best regards,
Paul S

08-14-2010 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,130
Joined on 10-12-2006

Post #: 4
Post ID: 14240
Reply to: 14179
Arf 'n Arf
fiogf49gjkf0d
I still have no solid idea how to naturally tame the wild upper-mid/lower-treble I have heard.  I went ahead and soldered in the guestimated notch filter yesterday, very sharp, 6 dB, and by this morning the (removable) silicone stick-um was dry, so I put the speakers back together and gave a listen today.

MUCH better!  Issues remain, but at least I can enjoy listening to music while I continue to think about it.

I always planned to add short sails on the ceiling over the speaker baffles, and some experiments this morning indicate that this would help with some aspects of more refined sound shaping with the Reps.  Also, way back when I made the speakers I included provisions for separate "dust covers" for all drivers, including the Lowther (Reps...) driver.  The Lowther/Reps is my only OB driver, so it is the only one that might need front and "rear" dust covers.  Back when, I drilled some holes in the rear part of the baffle wings so I could insert dowels that would support cloth covers over the back of the winged baffle, and even then then I had in mind I might wind up leaving some sort of sound "screen" in place while listening.  I am thinking now that I will start with some sort of "gossamer" that would be about useless for dust or lower frequencies but might be just about right for tuning the rear-firing upper-mid/lower-treble.

At this point, sound is differnet that it was with the Lowthers, but it is on par, overall.

Speaking of "Natural Solutions", I hate to belly up so soon, but at this point it looks like I may have to bust out the meters and crunch more numbers to get where I want to go (though I hope not...). 


Paul S
08-15-2010 Post does not mapped to Knowledge Tree
haralanov


Bulgaria
Posts 130
Joined on 05-20-2008

Post #: 5
Post ID: 14242
Reply to: 14240
Flat cone geometry?
fiogf49gjkf0d

Paul, the problem could be unsolvable if this peak is due to cone geometry. Flat cones in general behave very good up to a certain frequency, but they have strong standing wave mode (its magnitude depends of the internal damping in the cone) above that frequency which is dependent of the cone size and it’s thickness. If your Reps driver uses the same paper as the original Lowthers – you are in trouble (I wish I was kidding, but I’m not). It is very thin and weak and it can’t resist the fast acceleration of the voice coil above 2-3kHz. The ribs of the cone improve the situation, but not much. I took a photo of a friend’s lowther – is the main cone the same like yours?


lowther flat cone.JPG


Best regards,

Haralanov


"If you can't explain it simply, you don't understand it well enough." -A.E.
08-15-2010 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,130
Joined on 10-12-2006

Post #: 6
Post ID: 14246
Reply to: 14242
Pulling the Problem Up By Its Roots
fiogf49gjkf0d

Petar, I believe I remember reading somewhere that Reps sources his cones from the German firm, AER, or their OEM, whoever that is.  Perhaps you know of AER's Lowther-alike drivers?   However, the Reps cone is still very similar to the Lowther - different treatment, but similar, with very similar ribs, and also very thin paper; perhaps thinner than the Lowther.  I can't say for sure, but the Reps' "too-soft" surround might make movement easier on the paper than it is for the DX4.  It sounds as if this is the case.  Since my Reps are without whizzers, straight comparisons with my Lowther DX4s are not really possible, but the Reps I have sound generally more "calm" than the DX4s.  Of course, the DX4s also suffer from whizzer cone break-up ("roll" notwithstanding), which the Reps I have (obviously...) do not...

And now that I have had more time to reflect on it, I suppose it is likely that the Reps' voice coil has at least 2 layers - hence the "perfect lay" reference in Reps' flyer.

The thing is, one can't avoid hearing the Reps' spike.  Although I admit I have not actually measured it for myself yet, the very sharp 2.1k Hz notch filter I just put in improved the situation considerably, so I must have gotten close.  I am not sure about problems in the "drum range", but I presently think it has as much to do with the room, etc. as it does with the Reps.

As you know, the problem with all the thin paper drivers is the cone break-up that effectively "converts" the pure tones into mostly higher frequencies.

And the problem with the heavier paper drivers is that they are so slow and "homoginized" by comparison to the  lighter cones.

Based on past experience, I know I prefer a nice 10" driver as the aural pivot for my speakers.  But I have no idea where to turn for a 10" driver today.  I have thought about trying the Supervox 285 GMF (obviously, it's larger than 10"...), but that would force me to x/o in the voice range.  I am not sure if I would change the fundamental pitch much with Supravox's 215.  I also had old Peerless 8" drivers that were "nice", but I always preferred the 10", in context.  I can say from memory that the Lowther is much faster than any "comparable" Peerless!

All I want is wide-range drivers as fast as a Lowther DX4 or Reps R1 with the tone of the old (late 70s/early 80s) 10" Peerless!  Is that asking too much?

Best regards,
Paul S

08-15-2010 Post does not mapped to Knowledge Tree
haralanov


Bulgaria
Posts 130
Joined on 05-20-2008

Post #: 7
Post ID: 14249
Reply to: 14246
Fastness and good drivers
fiogf49gjkf0d
 Paul S wrote:
All I want is wide-range drivers as fast as a Lowther DX4

Paul, I have listened DX4 driver.  In my view this fastness that you report is completely artificial and absolutely non-musical as it does not have any relation to the dynamic acceleration of real instruments. Let me explain – DX series are made for people which doesn’t listen acoustical music. They intentionally use neodymium magnets, which force the drivers to sound "impressive" but this impressiveness is good only for electronic music. The feeling is like the driver has build in blaster in the place of its phase plug and shoots right in your face with small pieces of glass. This is due to the highly nonlinear behavior of neodymium when it’s field is stressed by the voice coil, even with very low currents. I can’t stand that type of sound for more than 5 seconds. There is another reason for that fastness – any acoustic system with rolled off low bass tend to sound "fast". Bring the bass back and the fastness will loose its speed. Any widerange driver which produces enough high frequencies used in backloaded horn sound fast, but again – it has nothing to do with the unforced and ultra dynamic sound of real instruments.


 Paul S wrote:
All I want is wide-range drivers as fast as .... with the tone of the .... Is that asking too much?

No, you are not asking for too much, but I’m afraid there is no commercial 10” driver which meets you requirements. There isn’t even 8”! All of them are not good enough and if some particular driver shows strength in one category, it is bad in another – that’s because no manufacturer does have stimulation to produce frequency optimized widerange drivers – all of them want their drivers operating 20-20000Hz which is absolutely ridiculous! I think you need some custom extended midrange drivers, something like this:

http://community.webshots.com/photo/fullsize/2554912450048111837MRntIi

Best regards from Europe,

Haralanov




"If you can't explain it simply, you don't understand it well enough." -A.E.
08-21-2010 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,130
Joined on 10-12-2006

Post #: 8
Post ID: 14281
Reply to: 14249
Can You Even Get There From Here?
fiogf49gjkf0d
Petar, I looked at the "custom" driver you posted the address for.  It is interesting to look at, all right, but I am not set up to build drivers from scratch.  Since I pretty much have to buy something that is either useable as-is or something that needs only minimal, easy modification, I guess I am stuck trying things that seem "likely" to me in order to hear how they actually sound in my application, according to my ability to shape them to my needs.

You may remember that I have presently high-passed the Reps 1st order at 400 Hz, with the 15" Audax coming up, so the Reps does not need to go down.  Listening to it again today, even with the notch filter the Reps sounds tilted up tonally with a sharp-ish trough around 2.5 - 3k Hz, whether this is the actual case or not.  I will have to meditate on this.

Based on what I can see (I have not heard them), I am curious about the  Supravox 285 GMF with 165 GMF, and I am thinking to x/o somewhere around 2.5 - 3k Hz.  These driver are about 1.4T in the gap, all paper cones and suspension, with ceramic magnets.  Like most mid drivers made today, they are touted by the manufacturer for their "extended range".  Supravox does give response curves, however, and at least these drivers are obviously not intended to be used "full range"- at all.  I do not know it for sure, but I think the GMF series are more or less "production" drivers, ie, I do not believe they are "hand made" like Supravox's "boutique" drivers, many of which are intended to be used in "extended range" applications.

http://www.supravox.fr/anglais/haut_parleurs/285_GMF.htm
http://www.supravox.fr/anglais/haut_parleurs/165_GMF.htm

Another potential issue with these: I am not at all sure these could play decently loud, even if they might sound good played at low volume.

Best regards,
Paul S
08-23-2010 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,130
Joined on 10-12-2006

Post #: 9
Post ID: 14291
Reply to: 14281
Updating the Gray Matter
fiogf49gjkf0d
OK, Petar, I was finally able to take some time yesterday to focus and meditate on this.  I remembered a host of "old" drivers from my past (not old at the time...) that, if memory serves, sounded rather muffled and slow, with humped response, as "heard" in my present situation, according to my present demands.  Where does one find data sheets (response and impedance curves, efficiency ratings, etc.) for this stuff, to at least be able to separate the wheat from the chaff ahead of time? It seems overwhelming to just round up stuff and install everything if it is not necessary.  If you are worried about a stampede, feel free to e-mail me.

I also went back to look at the pictures you posted, and those drivers look rather like some of the old radio speakers, most of which I remember as soft, with a decidedly humped response.  Also, many of these drivers only rate 5 Watts, and/or they are at or under 4 Ohms, and most are closer to 90 dB than 98 dB.  I realize there were much more powerful "pro" drivers, as well, but I have not heard many of those, apart from some American made, and in any case more power seems to fly in the face of what you have been preaching, so far.  I can imagine using, say, a 4" driver over a 10" and not asking anything under 2.5k or so from the 4".  But even the 4" drivers of that time did not really go all that high, or they did not do it well, as I recall, so even with a 4" mid there would remain the need for a real tweeter. Looking at the "ragged tweeter" you shared, I am curious how you keep the cone/coil centered in the gap.  You say the cone is now 55mm.  What size did it start out?

Now that I have thought about it, I can also recall the noisy frames on many of those drivers.  I guess that's something else to deal with...

Best regards,
Paul S
08-24-2010 Post does not mapped to Knowledge Tree
haralanov


Bulgaria
Posts 130
Joined on 05-20-2008

Post #: 10
Post ID: 14297
Reply to: 14291
Gray matter is not so grey
fiogf49gjkf0d
 Paul S wrote:
I remembered a host of "old" drivers from my past (not old at the time...) that, if memory serves, sounded rather muffled and slow, with humped response

Yes, Paul, that's exactly the way they sound in their original condition. Most of them are totally unlistenable. I don't think you will "find" an old driver with satisfying enough sound.

 Paul S wrote:
Where does one find data sheets (response and impedance curves, efficiency ratings, etc.) for this stuff, to at least be able to separate the wheat from the chaff ahead of time?

Nowhere... You must recognize the good drivers by just looking at their construction. I know it's not easy, but unfortunately that's the only way if you don't have a chance to listen to them.

 Paul S wrote:
It seems overwhelming to just round up stuff and install everything if it is not necessary.

You must define exactly what type of sound you want to get from your extended midrange driver and then to look at available options.

 Paul S wrote:
I also went back to look at the pictures you posted, and those drivers look rather like some of the old radio speakers, most of which I remember as soft, with a decidedly humped response.

That's why I do not use original drivers. My drivers might look like the old radio drivers, but their sound is very different compared to the old radio speaker crap. There is only visual similarity, but the principles and ideas are actually quite diffrent.

 Paul S wrote:
Also, many of these drivers only rate 5 Watts, and/or they are at or under 4 Ohms, and most are closer to 90 dB than 98 dB.

That is correct. But if they are reworked and used properly, they could sound really loud without burning the voice coil.

 Paul S wrote:
But even the 4" drivers of that time did not really go all that high, or they did not do it well, as I recall, so even with a 4" mid there would remain the need for a real tweeter.

If the voice coil and the way it's energy is transmitted to the cone is done properly, there will be extremely good high frequencies with much better tonal and dynamic potential compared to one of the "best" tweeters offered by the industry but only to 12-13kHz. Above that the transients loose their "speed" because of the cone mass, no matter the driver could measure almost linear up to 16-17 or just hypothetical to 30kHz. The tweeters are used not because the widerange drivers don't have enough HF extension, but because their upper HFs are not good enough. So a real tweeter is needed, because it has much better dispersion, its small cone has different and much more interesting tone at HF and it has extremely delicate and nuanced sound that no widerange driver is ever dreamed about.



 Paul S wrote:
Looking at the "ragged tweeter" you shared, I am curious how you keep the cone/coil centered in the gap.  You say the cone is now 55mm.  What size did it start out?

The original size was 80mm if I remember correctly. It is centered by two pairs of double fibers which are streched at slightly different vertical planes and everything is centered and balanced almost perfectly. It's voice coil does not have electrical phase shift up to 82kHz and because of that it has very fast and in the same time very natural sound (aka the Sound). The key is that my tweeter do not have back chamber and reflective surfaces behind it's cone - it gives an extremely open and delicate sound with tons of refinement that according to my listening experience no other tweeter on this planet could offer. And as a bonus - it could be integrated very easy to any good MF driver.

 Paul S wrote:
Now that I have thought about it, I can also recall the noisy frames on many of those drivers.  I guess that's something else to deal with...

Yep, most of the old drivers have extremely ringy steel frames, which response horribly when you knock at them. I personally use thick wooden frames because of multiple sonic reasons.



"If you can't explain it simply, you don't understand it well enough." -A.E.
08-24-2010 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,130
Joined on 10-12-2006

Post #: 11
Post ID: 14301
Reply to: 14297
Finding and Using What Works
fiogf49gjkf0d

The main "technique" I use in "problem solving" involves a sort of Hegelian turning and re-turning of/to the object of attention (or, my perspective...) to get as many "views" of the object as possible.  This sort of reflection has recently brought to mind some potentially useful memories/observations:

For all the problems of the old radio speakers, some of that old paper was very nice tonally and very stable and well-damped at certain frequencies.  Cone shape is also a factor, and the straight-faced "piston" is prone to some avoidable troubles by concept/design. It is all well and good to "control break-up"... in theory; in practice, it may work at least as well to simply avoid break-up by limiting stress, and/or even to"distribute" break-up over the cone and/or operating range.

For all the fact that Alnico tends to pull tone upwards as the demands on it are increased, yet it is quite "calm" (like silver wire...) in a way that might be put to good use.

My objective is not to use a full-range or wide-range driver but to wind up with acceptable performance from the system.  I know what I want, and I am not stuck on how to get it.

Recently, looking at and thinking about what real drivers I am aware of actually do, I have been "modeling"  3 drivers to fill in for my present 8" Lowther or Reps: A 10"; a 4"; a paper tweeter that can meet my ribbon in a good place.  I do not know it yet, but I suspect a "good" 4" will probably not go from, say,  2k to 12k.  If it can, then I am always happy to eliminate a driver/crossover!

If I "remember the response curves" of the old drivers correctly, the "hump" is probably at or close to the optimum portion of the coil/gap stroke.  If so, this would make my "objective" to somehow limit each driver to what it "prefers" to do, in the first place.  Or, a given driver might be refitted and/or "trained" to operate in its optimal range...

But the starting point is tough (impossible...) without some sort of mental "inventory" of available drivers.  Yes, it's too bad that the "market" is controlled by name-worshiping clowns with too much free time and money to spend on their fetishes.  So, to avoid stimulating these Bozos, perhaps you can say in more-or-less generic terms what sort of  * rough *  relationships you have worked out with respect to cone diameter, frequency response, SPL, gap and motor size/force?  In my case, I would not try for less than about 150 - 200 Hz from my 10" "pivot" driver, and I am not stuck on pushing it higher than, say 2 - 3 k; wherever the 4" does better.  The old-ish "theater" speakers mostly have rather large magnet/motors, regardless of cone size; the old "radio" speakers have relatively smaller magnet/motors, and narrower voice coils, regardless of cone size.  I do need over 100 dB SPL in my room with orchestras, that's for sure.  Basically, how does one "proportionally" relate the appearance of the driver to its purpose?

Petar, it has been some time since I have "spoken" of this stuff in this way with someone who basically takes the words out of my mouth and says/shows me things I "already knew", even though it is certainly "new" to me in terms of the rote, practical applications you present.  And so, based on your rather guarded/coded revelations so far, I suppose you re-wind at least some of your coils?

I guess I have to do what I have to do; but, as I have mentioned before, I am a VERY reluctant DIY guy!  I am still after results, not process, itself.

Best regards,
Paul S

08-25-2010 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,130
Joined on 10-12-2006

Post #: 12
Post ID: 14315
Reply to: 14297
SOS (same old shit) Redux
fiogf49gjkf0d
Petar, I might have just been tired, but I thought I saw a pair of "likely" 3.5" paper tweeters, and I played the hypnotized consumer and bought them, to start with my adaption education.  It might be a while before they get here, but in the meantime I am still wondering about a couple of things you have said regarding "custom" drivers.  Again, I am NOT a collector - at all.  I am only in it for the music; it's just that I am very picky about sound, and after 45 years at this I am still looking, although with a MUCH better idea of what I'm after. If there is really no "source" for the "completed" drivers I need, I suppose I am ready to go the DIY/mod route with the "selected" drivers, themselves, too, just as I have done with most of the rest of my gear, in order to wind up with sound I find acceptable. But where is the information about selecting and re-fitting the drivers? Must one start from absolute scratch here, too, or can/will you share some of your practical experience?

Best regards,
Paul S
08-26-2010 Post does not mapped to Knowledge Tree
haralanov


Bulgaria
Posts 130
Joined on 05-20-2008

Post #: 13
Post ID: 14326
Reply to: 14315
Two options only - to go for the road or to reject it
fiogf49gjkf0d
 Paul S wrote:
Again, I am NOT a collector - at all.  I am only in it for the music

I am not a collector too. I collect some very specific drivers only to take some good parts out of them which are not available anywhere else. I do not construct drivers for fun, but to get very specific sound and very specific music intonation out of them. Just like you, I have very clear vision what kind of sound I am looking for (it is still only in my head) and I am trying to materialize exactly that kind of sound in my listening room. No more, no less.

 Paul S wrote:
If there is really no "source" for the "completed" drivers I need, I suppose I am ready to go the DIY/mod route with the "selected" drivers, themselves, too, just as I have done with most of the rest of my gear, in order to wind up with sound I find acceptable.

Paul, that is really really difficult. Let me explain - for instance one of the most important parts of a speaker driver is the voice coil, especially for tweeters. Mine are produced by an extremely skilled master here in Bulgaria because I am completely disabled to wind them by myself with that degree of precision. So you need different people who are able to manufacture specific parts that you can't take form the old drivers, and which are essential for the performance of your "new" drivers. The other even more important part is your "know-how" - to know exactly what kind of materials to use for different parts, to know the right proportions between different elements, to know what kind of glue is appropriate here and there and many many other things. And the more you know, the more you realize there is a whole new world to explore. So you need to spend a lot of time (and money) to get progressively closer to the sound you wish to achieve, but anyway - I wish you luck if you choose to go for that road.

Edit: BTW, which are there 3,5" paper tweeters you bought?

Best regards,
Petar Haralanov



"If you can't explain it simply, you don't understand it well enough." -A.E.
08-26-2010 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,130
Joined on 10-12-2006

Post #: 14
Post ID: 14329
Reply to: 14326
First Guaranteed Failure, Coming Up
fiogf49gjkf0d
I did not shoot for the Collectors' Holy Grail to start, but I looked for and bought a +/- "generic" version.  The 3.5" I bought are unusual only with respect to their atypical (smaller than the usual 4") cone. They are 88.9 mm, as I recall.  Otherwise, they look like typical MagnetFabrik, etc., shaped and proportioned very much like the remaining parts of the tweeter in the photo you shared. Magnet shell is not gigantic, but larger than typical "radio" stuff, and they have the usual shitty, stamped, steel frames, "ventilated", in this case, rather than closed back.  They have the so-called "Tigges" iteration of MFW magnet.  Whoop-ee.

Of course I am going to try to listen to the tweeters stock, hopefully without blowing them up.  I suppose I should strap resistors across the terminals?

By your experience, are any of these guys ever made underhung, to start with, and/or must they all be re-wound?

You may remember I told you I knew Frank Reps WAY back, and he obviously has good sources for most of this stuff today.  However, he is not the easiest guy to talk to, because he always has an agenda, and he also hides out in a fairly remote part of the desert, with no phone or computer, so all communication must be written (he writes everything by hand...).  Anyway, I wish me luck, too, finding help with this and that.  Stuff like spec'd flat wire and the thin-body, light, hi-temp glue does not grow on trees aroud here, let alone proper diameter formers, etc.  As you know, dealing with hard-core tweaks can take all one's energy for not much net gain, not to mention all the blind alleys.

Ironically, I actually started seriously in hi-fi in much this same way, but VERY reluctantly, mostly hoping to save money, as much as tailoring the sound.  In every case, if I thought I could buy my way out, I took that option.  And not much has changed, in over 45 years, except a much much better idea of the Sound...  Maybe "too good" for my own good...

For future European stuff, once I have some idea what I'm talking about, perhaps you might give me some referrals?  My contact info is listed.

Best regards,
Paul S

08-27-2010 Post does not mapped to Knowledge Tree
haralanov


Bulgaria
Posts 130
Joined on 05-20-2008

Post #: 15
Post ID: 14337
Reply to: 14329
Email
fiogf49gjkf0d
Paul, I just send you an email.



"If you can't explain it simply, you don't understand it well enough." -A.E.
05-04-2011 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,130
Joined on 10-12-2006

Post #: 16
Post ID: 16206
Reply to: 14337
The Long and Winding Road
fiogf49gjkf0d

It is one thing to swap caps in a pre-amp, or ICs; it is another thing entirely to swap transducers.  Nothing brings change like a speaker, and it may be that nothing is less understood in terms of the pure sound that is - ultimately - the only thing that defines it.

It's been a long time since I thought I could just buy a better speaker system, and I did not start out thinking I would be "done" in 6 months, or anything like that.  Still, now that I have gotten into this "natural sound" thing, it is just as well that I held my expectations in check, because it looks like the months will be piling up while I develop the truly useful working knowledge I will need to continue, based on my current level of sonic and musical "expectations".  Sure, everyone else already gets it, but I never stop being surprised by how profoundly ignorant I am about the recurring relationships between what I will call for now "the various interactive elements" of the speaker system.  No matter what we hear about these things, the actual hearing and systematizing of sonic results for ones self is another matter, entirely.

To state the obvious: If to truly begin to understand them, just like any other component, each driver must be singled out, analyzed and developed on its own and then re-evaluated in the context of a system that is, per force, changing.  I have already gone through a pile of candidates that I have heard about, and I have kept some stuff for further development.  "Development" might mean exact placement with or near other drivers, or it might mean keeping only one part of the driver to build another one with.  If I were't married, I'm afraid my house might be full of speakers and speaker PARTS, since there are plenty enough lying around, as it is.

One thing I have learned so far is that while there is some truth to some rumors about some drivers, none I have heard so far is anything like a ready-to-go, stand-alone unit.  If I can be objective about this, ALL the drivers I have heard so far want some sort of special "consideration" in order for me to get what I want from them and, more importantly, no single "treatment" will certainly "fix" any particular driver, according to what I have heard so far.  I can say at this point that there are certain markers that rule certain drivers out entirely, at least for my purposes.

I remember writing the "It Takes Balls to Shop" thread, thinking about obtaining "parts" in general.  And so far it looks like it is possible to learn from the various speaker and driver cults... as long as one keeps it all in the context of personal experience.

Paul S

05-29-2011 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,130
Joined on 10-12-2006

Post #: 17
Post ID: 16354
Reply to: 16206
Pitch, Timbre, and Scale; Transients and Perspective
fiogf49gjkf0d
So little free time, so much to listen to and decide...  Today I listened again to a close variant of the previous set-up, using several large-ish drivers basically piled +/- in place, along with a tweeter that will not make the cut.  Even though all of the drivers are old, I suppose all of them have also sat around for a long time, and all of them have benefitted from recent use, in terms of tone and timbre, and also in terms of "transient behavior".  The last item is something we have already kicked around in general terms at this site, and it's also something that I started to think about differently as I listened mostly for pitch, tone and timbre today.  I can already hear how the "event" and the "impact" that calls it to our attention might be improved from how I've long heard it done,  and it now appears that there might be some sort of "convergence" for tone, scale and soundfield that will "include" these qualities with a better rendering of "transients", and I am pretty sure it will also include a sort of "re-shaping" of what we call "perspective", a variation on the more usual "3-D" "sound field".  I will say more about it when I learn more.

All the methods for testing these drivers have already been discussed elsewhere in this site, so I won't re-hash it all here; suffice it to say that the basics remain the same. Pre-evaluations are visual; early sound tests do not require a signal; and progress with signals is very slow.   After all this time, I have one for-sure "keeper" driver, one likely candidate for a major re-working, and one possibility that will need at least moderate re-working before being re-evaluated.  As far as my processes, I have also spoken about drivers in general in the "Speakers for a Powerful SET" thread and in the "Lowther" thread, and elsewhere, and all this thinking still comes to bear.  "Enclosures" are yet another variable (or, set of variables...) that I have just begun to include in the evaluations.

Another very interesting thing happened today that served as another sort of wake-up call.  Since I am finally beginning to listen to things I have only heard about before, I got some cold water in my face when I realized that that the balance of this particular pile of drivers improved steadily as I increased the volume, not in the usual way but in moving closer and closer toward the sort of sound I had hoped for and even expected to hear, perhaps sooner.  I have to say, it gave me pause to think that the weight and scale I recognize and really enjoy would only come to fruition at truly live volumes, way off-axis!  People, you may think that you listen at live volume, but if you have never been arrested, then perhaps or even probably there is "something missing" in your "version" of "live sound" (just as there is in my own set-up).  And the sudden, stark awareness of this possibility "woke me up" to realize, be careful what you ask for!

Paul S
06-19-2011 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,130
Joined on 10-12-2006

Post #: 18
Post ID: 16496
Reply to: 16354
Old vs. New Drivers; Tuning vs. Modern Expectations
fiogf49gjkf0d

By the time I got seriously involved in hi-fi, in the early 60s, speakers and their drivers were already undergoing significant changes from which they would never "recover".  Basically, for reasons that are no longer clear to me now, drivers and speakers alike - in general - began to be built to absorb and withstand more and more power from amps that seemed to double in power, annually at first, and then, monthly.  One thing that my friends and I took for granted at that time was "Tone", that any and every speaker would have more or less of it, and, if necessary, we could either restore or imbue a speaker with Tone by various means.  Whether "dope", cabinet "tuning" or X/Os, I don't remember ever doubting my own ability to find a driver and make a speaker to sound the way I wanted it to.  But as power came to the front, Tone dropped to the rear and, finally, it was gone, and somehow Tone became less important than "transients" and "detail", and "clarity", until it became pretty much a non-issue, as though it either did not matter, or it was there all along (although it was not), or it was just a minor sacrifice for better "detail" and more aggressive "transients".

Fast forward to 2011.  "Tone" is definitely a lost art, tossed in at the last minute like a handful of salt or pepper when it is considered at all.  And, annoyingly, nothing seems to sound like it used to, back in the day, anyway, according to my experience.  The crux for me now is to find and nurture Tone, then to push it beyond GWB (girl with balalaika), into the realm of Serious Music.  Of course, part of the "problem" is expectations, that we can somehow make new the best of what is now - in fact -  quite old.  Also, as I described in the previous post, there is the "problem" that tuning too "true to life" requires true-to-life SPLs to finally bring it home.

This is, I think, another good reason to take it slow: to take in and process the "paradoxical" information in a way that will yield actual (as opposed to idealized) results.  Yes, I insist that a violin is not a viola, etc., etc. But in my own case I think I can back off sustained 120 dB in order to have Tone, if this becomes necessary.  OTOH, I am not going through all this merely to re-create an idea whose time has already come and gone.


Paul S

07-31-2011 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,130
Joined on 10-12-2006

Post #: 19
Post ID: 16745
Reply to: 16496
Cold, Hard Facts (or are they...?)
fiogf49gjkf0d
Lots of good, relevant information lately in the new "Basic Guide to Advanced Audio" thread!  But I don't want to orphan this thread because it is specific to speakers, which at this point means, drivers.

So, germane to drivers, where should one start if everything that is commonly available is "not good enough"?  How about a 10" direct driver, searched out and chosen only for its paper cone?  As I have often said, I like the "size" of images presented by a good 10", and I +/- like its MF.  OTOH, as Haralanov has pointed out, the 10" gives away NEEDED "HF" to the 8", and it gives away "soundscape" to the 12".  I hate these compromises, but at some point one has to decide.  I will make a new former and VC that I hope to adapt to the very old Alnico motor that I have had re-magnetized.  Already for months I have agonized over paper and glue for this project, buying and trying former paper and glue for various applications, like the psycho that I am!  Make no mistake, this stuff "matters", and if it is not "at the heart" of this project, yet it certainly stems from the sort of discrimination that is required to "heal" the sick speakers in the first place.  In other words, it's not what you see or what you hear about, it's about steering and shaping the project with your ears and your aural aesthetics, bit by bit.

As to what is expected of this 10", it will be the WR "axis" of the system. I wish I could afford  a better motor for it.  But, even with a better motor, a 10" that goes up needs help as it goes down.  I have already tried phasing into a 12" and a 15" as frequencies drop, with plenty of overlap.  Cabinets for the bigger drivers are meant to bring out their best at the frequencies they will be limited to.  The 12" is  a "rare bird" that is well-known to cultists.  While they typically run it FR or WR, I will use it only for lower MF, with its "optimized" cabinet.  I have at this time only candidates for the 15", which will support lower MF and upper LF, along with its "special" cabinet.  For some time now I have had a sort of "mad scientist" idea for LF that involves 4 large paper cones I have stashed away and motors from "another source".  I have a boatload of already-culled paper tweeters on hand, and eventually I will make new VCs for them, etc.  Based on experiments to date, I will run these tweeters "hot" on top on-axis, but I will aim them away from my listening area.

Easy enough?  Don't forget about new chasses, and re-configuring/dialing in the surrounds!  I suspect at this point that the chasses need not be anvils; but surrounds matter, a lot.

This is as close as I plan to get to a "formula", and, as Haralanov continues to demonstrate, everything is subject to change at a moment's notice, according to experience. Basically, if you can't figure out and correct for "errors", then don't even start.  While this is NOT a matter of "Latest and Greatest", any given "solution" might be supreceded, according to experience.

Paul S
08-14-2011 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,130
Joined on 10-12-2006

Post #: 20
Post ID: 16827
Reply to: 16745
The "too big" Cones
fiogf49gjkf0d

Again, not to make a "formula", but I was thinking about the possible roles of the speaker in "offsetting" the typical upward-tending tone/harmonics of hi-fi.  Sure, there are lots of strategies to "deal with" the upward tendency.  These ideas might range from using tubes, to plate loading, or electronically adjusting gain according to frequency.  But what about the speaker's - or driver's - rote role in this?

Something that has slowly dawned on me is that if I can somehow "naturally" control/limit "large driver" "issues", then "bigger" paper cones tend to "sound better'..  "Too big" means, larger than what is typically chosen by "high-end" designers or DIY copycats.  Again, OTHER FACTORS BEING EQUAL.  I put that in caps because there are WAY too many other factors at work to simply derive from this a working "large cone" axiom.  Rather, it is more of a "reflective" observation, and one that I think is worth making, or I wouldn't have made it.  Some typical "big cone" "issues" to chew on are response spikes, falling-off and/or suddenly-disappearing upper harmonics and/or tone, image bloat, muffling...

Any sort of cause and effect "reasoning" on this is vague speculation, but this does not bother me.  I would speculate in any case that the "bigger cone" can either "offset typical hi-fi frequency imbalance" or that it simply "presents it better", at least in terms of tone and harmonics, GIVEN that the particular "too big' cone in question can none the less go "as high as it needs to" to "do its job", etc.  And, believe me, this last is no "gimmie".  In fact, dealing with these issues is what healing the drivers is all about.

Paul S

09-28-2011 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,130
Joined on 10-12-2006

Post #: 21
Post ID: 17093
Reply to: 16827
When the Listener is Ready,
fiogf49gjkf0d
...the Driver Will Appear

With appologies to the Buddha, and notwithstanding the fact that all the "action" on hi-fi forums centers around what to buy and where to buy it, success with speakers more often than not stems from lessons learned from "mistakes".  As for which drivers to buy, no one has asked on this thread (yet...), but I think that the mid-range is the place to start with drivers, then the tweeter(s), then work down from there.  Then, start over with the assembled drivers.  YMMV.  As for which particular drivers to buy, honestly, this can only draw circular "answers" that are more in line with the Zen koans than venal intentions will suffer.  Whether MF, HF, LF or ULF, any driver is only a machine, and it is not being facetious to say that any intelligence found to inhere in any driver must be so mirrored by its appreciator. This is not just a truism, it's The Truth.

FWIW, I see/hear LF as no different than "the rest of the sound spectrum" with respect to the need for "musical" drivers.  Even at LF, if you can get Music out of any "long-throw woofer" I have ever seen/heard, you must know something I don't about Sound or about Music, or you must possess a canny knowledge of physics that you ought not keep to yourself.

As for finding drivers: Probably, if to "hear the appearance", if it looks like a cast iron spaceship, then it sounds like a cast iron spceship. OTOH, one ought not assume that leather and wood, etc. are good because they are "natural", or that anything is anything else because it is fill-in-the-blank.  It's not that the indicators aren't good, but it's how they are used, of course. Eg, again, my "Best Driver" (according to prices) will be allocated to very limited (although critical...) duty in my system, because that's how it "works" for me in my idea of a system.  Sorry to disappoint, but it's my driver now, and it is NOT going WR on a large OB to play Motorhead.

Still on my "To Do" list: I would love to hear what others think of as "sonic indicators" that one sees/finds in various speakers/drivers, as opposed to the usual fraternal elbow to the ribs, "wouldja lookit that!".  The bald, fat and naked truth is, "seeing is hearing" is true only for those who are simply gifted or - generally - those who have learned by doing.

Paul S
10-03-2011 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,130
Joined on 10-12-2006

Post #: 22
Post ID: 17114
Reply to: 17093
The Price of a Good Education
fiogf49gjkf0d
What is it, abiout a year simce I started down this road?  Time is such a swirl.  During most of this time I have listented to music mostly in terms of driver "evaluations", with very little of my usual deep listening just for pleasure.  Ugh.  But this is necessary, I'm afraid.  Yes, I have enjoyed some music from some drivers on occasion. But I it seems like the more I learn about materials versus sound, the more there is to learn; and so it goes.

I hesitate to say how many drivers I have "acquired" over the past year, not to mantion boxes and closets (and a garage...) full of papers, glues and parts. As for cost, I absolutely do not recommend this path as a way to "save money" via DIY!

As Haralanov has said, you will not find "suitable" drivers among the ready-made items.  In fact looking for "likely" candidates is like looking for hen's teeth in haystacks, in terms of liklihood of success and also hours spent versus "reward".  The "cost/benefit" here is not "off the charts", it is not even on the charts...

So, why continue?  Well, it might be like any addiction, where the "high" is (necessarilly...) very much the least of it.  In fact, this is likely the case.  OTOH, there actually are "highs". It turns out there is actually something to learn, and it turns out you can find situationally-good-sounding drivers if you keep after the search.  Now, getting these drivers to work with the other drivers, in a coherent, cohesive system, is something else again...  More often than not, one has to re-think even the good-sounding drivers.

Paul S
11-09-2011 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,130
Joined on 10-12-2006

Post #: 23
Post ID: 17354
Reply to: 17114
Why So Long Between Posts?
fiogf49gjkf0d
How great it would be if there was some kind of "breakthrough" every so often, in order to make linear "progress" with the driver evaluations and speaker development! In fact, it is almost impossible to keep meaningful "controls" in place between evaluation sessions, for lots of reasons, so most of what I am learning must be processed "sub-consciously" and then "re-evaluated", often with repeat listening, to "confirm" findings.

One interesting thing I can share is that many of the old "manufacturers" actually did do some things "right", on occasion.  However, their "making the right choice" was not something that can be relied upon today when it comes time to choose drivers for "development". For one thing, significant physical changes do not always correspond to serial numbers or model designations; some drivers from the same "manufacturer" are simply different than others that bear exactly the same numbers!  This is not only confusing, it is costly!  Also, while some processes were obviously developed to improve response and sound, it seems like other changes were made solely to facilitate production.  Also, like I already said, as time passed, more and more changes were about making the drivers tougher, as opposed to making them sound better.

I finally have a re-built cone and a useable trial motor, and I have the raw materials at hand for a new chassis (I think...).  I am excited to hear the "new" WR driver, but I am also quite weary and disgusted with DIY in general!

Paul S
12-22-2011 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,130
Joined on 10-12-2006

Post #: 24
Post ID: 17564
Reply to: 17354
Determined Listening (and the ongoing cost of success)
fiogf49gjkf0d

I suppose I gave up fairly quickly on the 12" WR drivers, for reasons I cited earlier.  But good things I've continued to hear from them, and Haralanov's shared experience, have kept me coming back to the 12", doing a sort of focused listening that I have used for driver development, as opposed to making initial selections.  In this case, I keep in mind the sorts of things I want to hear and I continue to mess with the drivers until I start to hear more of what I want.  Basically, I try to add good things without losing the earlier benefits.  If this sounds simple, it is time consuming, and it is exhausting.  I have gotten some breaks when the sound was good enough to simply enjoy the music; but mostly it has been about keeping track of drivers, changes, situations and sound, not to lose any benefits nor repeat any mistakes.

Finally, while fiddling with the 12" WR in my "stack", and the other drivers adjusted accordingly, I have gotten much better "glimpses" of a sort of presentation that I do not want to give up, and it includes (finally...) proper image size.  Haralanov has gone on at some length about the acoustic effects in other threads, but I have not yet heard for myself all that he describes.  Lately I have been listening mostly to "smaller" works, in order to establish initial voicing, and the 12" defintely makes appropriate "space" in these cases.  Last weekend, I upped the ante with Mozart's Clarinet Concerto, and it blew my mind to think of this sound, including the "space" I got, as coming from only one speaker (4 drivers).  Now I have some very nice 10'" drivers that I will not use, including the recently re-built one I referred to in the previous post...

Oh, well... Chalk it up to experience, and add them to the pile...

Paul S

06-27-2012 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,130
Joined on 10-12-2006

Post #: 25
Post ID: 18332
Reply to: 17564
The Part of the Amp(s) (yet again)
fiogf49gjkf0d
How many times have we heard the mantra, speakers/amps/room?  Over the past few months I have listened to many non-musical private and salon installations, amazed that the owners have in every case seemed generally happy with the sound from their expensive systems.  Because of consistently bad overall sound, finding amps has been difficult, and driver/speaker testing bogged down for want of suitable amps.  Well, things hi-fi have finally changed for the better for me.

It should be obvious that to get specific sound in one's room requires specific speakers driven by specific amps.  Sure, an acceptable "range" might be established; but mix-n-match is very definitely out, given clear sonic objectives going in.  In my case, it quickly became apparent that I needed quite a lot of power to cleanly drive any stack I tried.  And I just as quickly established (what I suspected initially), that [clean] power alone was not nearly enough.  Now, while I don't really need to start over, I do have to re-evaluate some drivers and combinations of drivers in light of the sonic advances that suitable amplification has brought me.  Looking back, I'm glad I did not succumb to the PP SET hybrids, despite their wonderful sound, since the more I reflect, the more I realize that they were, indeed, struggling on tutti with less in the way of a "load" than my present amps will see, despite these PP SETs sported a 140W "rating", and so "shouldn't" be as far off the mark as they are, as a matter of fact.

Driver Development 101A makes it clear: While building up ones own drivers, keep the amp(s) in mind all the while.  Although there might be several ways to approach driver and system development, sooner or later the speaker/amp/room path will become a single track.

Paul S
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