GoodSoundClub - Romy the Cat's Audio Site - The another day of midbass.

03-12-2012

Post does not mapped to Knowledge Tree

twogoodears

Italy
Posts 116
Joined on 03-26-2008

Post #:	427
Post ID:	17950
Reply to:	17946

Music halls and recording venues low-end bloom and reproducing it at home

My five cents, folks... find nothing wrong in a flexible ULF, as it, sort-of, makes honour to any audio system and music and audio lover, as this "flexibility" strongly reminds me to various music and concert halls and venues around, where their "personality" is GREATLY supporting and enhancing music, from orchestral to solo lute and viceversa.

What would be Gregorian music without an old church or Strauss without Musikverein or Wagner without Sofiensaal, both in Wien?

Call it ULF, low-end or - poetically - "bloom", it gives character to any music and it's NEVER the same... every orchestra and hall, and to a larger extent, recording, should sound different... if any given system isn't able to "change" and follow and serve different music personalities, it's a flawed system whose own personality is stronger than its transparency and humble strength in bowing to music and recording own personalities.

On my part, I'm currently playing with my TVCs active crossover, and like when I was playing and fiddling with TacT's RCS 2.2 XP, where I had seven pre-sets, NOT an equalizer, BUT nonetheless obtaining different low-ends and highs curves, only to better tailor music to more satisfying final result and to my wishes and musical tastes.

I don't believe a complex system should not be able to be finely tuned to different musics through (carefully performed with skill) proper technical means, whatever: my beloved lute, as the most polyphonic of solo instruments, when properly reproduced, blooms in a seldom heard way... something audible also to any distract, occasional listener... and on and on, same as a large orchestra.

"Use your ears as your eyes" - Gertrude Stein

Stefano

12-04-2012

Post does not mapped to Knowledge Tree

Romy the Cat

Boston, MA
Posts 10,160
Joined on 05-28-2004

Post #:	428
Post ID:	18794
Reply to:	13597

Surprising and Interesting development …

A few days back an audio guy from Mexico-city visited me from. We did listen some music, talk a bit about audio. As usually I interrogated him about the problem he hears in my sound. The people who were in my room know that I do it with absolutely anybody and I am very disappointed if my visitors not able to criticize what they hear. As I asked my guy about critiques of my playback sound he suggested that he feel that somewhere in midbass the sound become heavy and does not decay as fast as he would like it to be. I know that it is absolutely imposable in my playback and the proper balance of sound across the whole range is my very much signature source of pride. Regardless what kind music is being played, regardless of volume and anything else imaginable my playback maintain is very high integrity and to have those kindergarten mistakes with crossovers, decays, under or over performing specific segment of range is absolutely imposable in my installation. So, using my “authority” opinion (wink-wink) I begin to convince my guest that he is wrong and if he is hearing something is it is just result of his corrupted perception.

Last night I got home early and Amy was staying overnight in Portsmouth. I kind of semi-persuaded her to stay in New Hampshire as I would like to have some “audio quality” time on my own. Since we redid hardwood floors 3 month back in listening room I just reassembled the playback as it use to be but I never invested any time for critical listening. I played playback all time but I did not do that fine sonic equilibristic that I use to do in past. A few day back I was visited my local audio friend and it gave me an inspiration to experiment with audio again:

http://www.goodsoundclub.com/Forums/ShowPost.aspx?PageIndex=1&postID=18791#18791

So, as Amy was out I decided to dedicate evening for fine moving of Macondo across the new floors, fine position it and perhaps to begin looking for the DPoLF. I did move horn a bit and I was able to get much more interesting imaging with the new floors and with new areal rags. However, as I sat to listen in sweat spot and turned not my typical Bruckner-like music, life recording in large churches but rather well regulated and calibrated by my hearing reference trucks that I know for years I instantly felt that something was wrong. To my fear and shame I recognized that my Mexican visitor was absolutely spot on – it was some kind of strange fattiness in midbass region. I felt like an idiot, not because the playback has developed some kind of problem (it might always happen and particularly with the multiamping topology I use) but because my over-confidence made me completely discard those very lucid and very accurate comments of my visitor.

Anyhow, now is an interesting technical question: what happened? At this point I have no idea. I check the Macondo calibration in accordance with my “Macondo calibration check sheet”:

http://www.GoodSoundClub.com/TreeItem.aspx?PostID=14994

Everything was perfect. Sonically it sounded as midbass horn are the problem but in my “Macondo calibration check sheet” I specified only way to drive the horns not the way to measure the horns output. So, I took a dBa muter and plunged it to the Milq’s bass channel output. The left channel has 7dB more output them right channel (!!!). Holly shit, how THAT might happens. Milq’s bass channel is DSET and there is absolutely no way SET suddenly will give over 2 times more gain. Perhaps something freaky happen with the crossover for left midbass. The Midbass crossover in my estimation is impossible to go down. Take a look for this second order:

http://www.GoodSoundClub.com/TreeItem.aspx?PostID=14666

In addition I have one more order on speaker level – a huge toroidal air-core coil in series with the drivers – they also can’t go down. So, now I need to bring RTA back to the room and begin to sweep the midbass also with the rest of the system, find the problem and recalibrate the left midbass. I did measure the DCR of the driver’s voice coils and it looks that it was not the driver problems. I truly have no idea what it is and I hoped that I would not do it ever again in my listening room. Well, never say nether as they said and never to be too confident with multiamping…

Rgs,
Romy the Cat

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

12-27-2012

Post does not mapped to Knowledge Tree

Romy the Cat

Boston, MA
Posts 10,160
Joined on 05-28-2004

Post #:	429
Post ID:	18841
Reply to:	13597

What could I say?

I was wondering what would I say or do with my house-build in horns if I move from this home? No, no not, the horror of married life that audio people love to tell to each other are very much not applied to me. There is no problem with computability between my new wife and my audio, instead we call it our audio and use it happily together. I kind of feel very horny what Amy turns Milqs, the ULF on and play the whole playback. Still, there are some very distant conversations about the school districts, the size of closets, the number of bathrooms, the social environment, commute distance and the rest things that comes with married territory. It is NOT oppressive and NOTurgent at all and if the subject rises then I see it in 5-7 years.

Nevertheless, if the subject does hit our horizon I will have a LOT of fun to envision what I would do with my current room setup. I love the room immensely but if I move out then the Midbass horns for sure will be left behind. So, what would I explain to the new home owners about the purpose of our Midbass horns?

The current leading ideas are following:
1)   Ventilation shafts for central AC
2)   Gest room for our gardener
3)   Storage closet
4)   A location to hide moonshine machine
5)   A location to store winter pickling
6)   A devise to punish kids

Does anybody has any more intelligent idea?

The caT

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

01-02-2013

Post does not mapped to Knowledge Tree

rickmcinnis
Posts 60
Joined on 10-18-2010

Post #:	433
Post ID:	18847
Reply to:	18846

Congratulations

I learned of the union from the posts sent to my email box. Sorry to have to admit I have been lackadaisical about checking in. You had not been posting much the months previous and now I understand why.

Wrote a note to Clark and he confirmed to me that it was true.

The fact that she enjoys music is not a surprise. I cannot imagine you giving up that.

I thought I had detected a change in the infamous gruff mask you enjoy wearing. The man behind the mask is a fine fellow when he wants to betray that public persona.

I would bet there is someone in the Boston area who would want the house as is. Whether they "hate" you or not. Surely there are enough people interested in audio in the area that the horns would be an attraction. I know it would be to me but I am 1100 miles away. Of course, you might be required to help them assemble a system to go with what is already there. I would bet if they were interested in the horns they would probably want to follow your examples of "how it is done".

I can imagine the pain it would cause you when the potential buyer brings over AEROSMITH cd's. Oy, ve ...

After all of the work you put in this room/house it is sad to think you might have to begin again. How many times do you think you can do that? Then again you might already have a grander scheme in mind ...

Take care,

01-02-2013

Post does not mapped to Knowledge Tree

Romy the Cat

Boston, MA
Posts 10,160
Joined on 05-28-2004

Post #:	434
Post ID:	18848
Reply to:	18847

A grander scheme in mind…

rickmcinnis wrote:
I learned of the union from the posts sent to my email box. Sorry to have to admit I have been lackadaisical about checking in. You had not been posting much the months previous and now I understand why.

Wrote a note to Clark and he confirmed to me that it was true.

The fact that she enjoys music is not a surprise. I cannot imagine you giving up that.

I thought I had detected a change in the infamous gruff mask you enjoy wearing. The man behind the mask is a fine fellow when he wants to betray that public persona.

I would bet there is someone in the Boston area who would want the house as is. Whether they "hate" you or not. Surely there are enough people interested in audio in the area that the horns would be an attraction. I know it would be to me but I am 1100 miles away. Of course, you might be required to help them assemble a system to go with what is already there. I would bet if they were interested in the horns they would probably want to follow your examples of "how it is done".

I can imagine the pain it would cause you when the potential buyer brings over AEROSMITH cd's. Oy, ve ...

After all of the work you put in this room/house it is sad to think you might have to begin again. How many times do you think you can do that? Then again you might already have a grander scheme in mind ...

Hey, Rick

The relation between Amy’s charm and prolificness of my output to my audio site is an interesting subject and it is something that I have been trying to express for a while in a dedicated thread that is brewing in my computer. For sure there is SOME relation between it but not as straight as it appears at superficial surface. I will be taking about it more what I feel so.

The idea do dump the house on the laps of another audio guy why would appreciate HOW this listening room is organized is a super sweet idea but it think it is unfortunately too much in the realms of fantasy. In the realms if absolute fantasy would be to sell the house with Macondo/Melquides installed, charging a good chunk of money for it. I did told to Amy that I need drop for her a few contact points that help her to sell my equipment in case of my sudden death as for right people the context of my entire installation would be a good down payment for a new house and free annual Costco supply for new 10 years of her and her new men.

There is behind all of it much more interesting question. One might see in my desire to sell Macondo/Melquides along with the house (if we move) as a subconsciousness expression of my dissatisfaction with audio. The reality is different. If we do move then I do envision us to have very much similar listening room as we have now. The hypothetic organization of the room is a very interesting subject and it might be beneficial to start from a white sheet of paper.

I doubt that in a new place I would invest as much efforts as I invested in accommodation of Macondo/Melquides here. But again… who knows. I do not think that in 10 years you will see me watching 30” TV with single driver speaker. Still, Macondo/Melquides is an ultimate expression that I found that represents 1990s and 2000s. It is good 15 years past and it is very possible that I will find new audio expressive forms. I do sometimes think what kind forms they might be. Sometimes, I might share my thoughts if I feel so.

Nevertheless, the whole notion of moving for us is not more than a metal exercise at my web site. I do think that we will be here for at least 7-10 years, so I will be a able to observe the rotting of my midbass horns at attic…

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

01-03-2013

Post does not mapped to Knowledge Tree

rickmcinnis
Posts 60
Joined on 10-18-2010

Post #:	435
Post ID:	18849
Reply to:	18848

The mind boggles ...

Since I am living with the assumption that the technology you have used is far from dated I have cannot wait to hear what you have in mind for your audio future.

Since my selfish nature longs to hear what you have acheived, assuming you would allow me to hear the system in its somewhat final state; adjustments being a constant, I might have a chance when I can finagle an excuse to make my way to Boston again.

I doubt those horns are going to rot, not with your standards for construction.

I know you hate gushing and I suffer from the disease when I am in awe of someone (I can hear you laughing at me) but I am sure Amy is quite an extraordinary woman and I hope I get to meet her one of these days.

I am not complaining about the number of posts. I am glad you have found an even more important system to tweak, your relationship with Amy. Hearing you speak of school systems made me smile. Some young Besnow's would be good for the world in my unhumble opinion.

It never occurred to me that you would sell the WHOLE THING with the house. Maybe there are a few folks in the Boston area that would take a page from the legend of the Japanese audiophile who built a house for his system. It is possible someone would buy the house JUST FOR THE SYSTEM and leave it as a separate listening house, Some of us can have dedicated rooms there are few who can have whole houses for this absurd, but noble, hobby, but they are out there!

One should always be disatisfied with audio. How can we proceed when satisfaction stifles our imagination? I am without a working system at the moment. In the midst of quite a few projects. It is funny how much pleasure I can derive from just listening to a table radio in my kitchen. One thing I have found is that I am (since I do not have any choice) far more adventurous in my listening to this kitchen radio. Since I have the rock affliction I find it interesting that I listen to orchestral music on the radio, not that I listen to rock exclusively. Could it be (yes, I am sure it is) that with the radio one does not bother comparing it to a real orchestra you just listen to the music. Of course, you are hearing only the surface of the music - not a chance of "inner detail", etc. - but most of the point of it comes across, amazingly.

Is this what you are getting at with your dissatisfaction? With great music with complicated textures (your beloved Bruckner and Mahler, expecially) even systems at a high level are hinting at the sound of an orchestra and we chase after incremental improvement only to find that we still have a long way to go? Kind of like the old saw, "the more you know you the more you find you don't know".

With pop records there is no standard and we can relax, well, those of us who enjoy that kind of thing.

Hope the new year is good to you and Amy.
Take care,

01-03-2013

Post does not mapped to Knowledge Tree

Romy the Cat

Boston, MA
Posts 10,160
Joined on 05-28-2004

Post #:	436
Post ID:	18850
Reply to:	18849

Audio as an interactive subject.

rickmcinnis wrote:
It is possible someone would buy the house JUST FOR THE SYSTEM and leave it as a separate listening house…

Yes, that would be very gratifying for sure and my ego will be dramatically enlarged but in reality we all know that it never happens. Also, the only unmovable elements of my playback are midbass horns, so I rather would like to have someone who recognizes the midbass horns as positive addition to the house. I might pull the trick with sound reinforce the piano in the room and if a perspective buyer is musician then it will be certainly be very imprecise for them to learn and to consider. First I need to learn how to reinforce piano with playback however. Nevertheless, sine we nowhere near or any real-estate projects I think all that is no more than strategic sinking.

rickmcinnis wrote:
One should always be disatisfied with audio…

Yes and no. Dissatisfaction with audio needed to be understood from a proper perspective. I have no dissatisfaction with audio as object but I do not like audio as an interactive subject. I have this dissatisfaction for many years. Audio, as I perceive it, is very personal and very individualistic mater and extremely happy with what it does in my life. What could be better than on X-mass days sit in our listening room with Amy, watch the 8” snow developing in the forest behind the window and to listen the fist pressing of Bernstein taking NY philharmonic on the ride across Mahler 4’s sleigh… The audio as interactive subject is totally different thing. I have absolutely no interest to explain to majority audio idiots what to buy, what not to buy what to do, what not to do, defend what I do from moronic public attacks. This gives me no personal or professional gratification of any king. Unfortunately very view audio people are able engage the subject at the level that would be interested and therefore I mostly have no interest to deal with audio people. It might for external observer looks like a “dissatisfaction with audio” but in reality it is just my desire to protect what I value from stupid pop-consumption and uninformed scrutiny.

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

06-02-2013

Post does not mapped to Knowledge Tree

Romy the Cat

Boston, MA
Posts 10,160
Joined on 05-28-2004

Post #:	438
Post ID:	19419
Reply to:	17133

Midbass horns, latest story.

A few months back a audio guy visited me and after a listening session I asked him if he can report any problems with sound. He reported that he hears a slightly more prolonging decay at upper bass then what he suspect to be. I knew about this effect but I felt that it was in very minor scale. As the larger picture I have observe this effect many times, for instance here.

http://www.goodsoundclub.com/Forums/ShowPost.aspx?PostID=16461

… where effect was part of a larger picture.

It did not bother me so much as with my type of music I feel that slight longer decay at upperbass helps to get an illusion of larger concerts halls, never bad, isn’t it? The effect was very minor and in my view negligible.

As time goes by I observed that the effect was growing and growing and last 2-3 month it become some kind of almost a conspicuous boomines at upper bass… I tested many times all calibration and filtration and I am very confident that the amps, filters and driver are operating where they shall be. It is not too unpleasant but notably. I was not in a rash to fix it, not to mention that I have no idea what to fix. I was not in a rash as nowadays I turn my large playback only to blast my Bruckner at full power and the rest I tend to play on Pilot playback – it is summer and it is hot.

Two week or so a local audio guy visited me, listened my playback and insisted that the problem that he hears I did not have it before. This was quantifiable evidence that something is objectively wrong. I knew it but I was not willing to knowledge it as there is no explanation for it.

I spend whole nigh trying to figure out, listening, experimenting. I discover that if I go for third order filter on Midbass then I get appropriate sound but I do not understand why after two year of operation the midbass horns started to sound more extended to higher knee. The softening of the suspension and even paper would not be responsible for it as not primary resonance slid away but HF extension. I did short my 18mF coil with 100uF electrolytic and I get the OK sound but still I need some explanation.

The leading idea is ugly and I hope it is not true. The idea is the drivers in midbass hors get demagnetized and this lead to HF extension. Usually as the LF drivers demagnetized then we lose definition in lower knee. It does not feel that it happens. However, perhaps as the driver is locked in back chamber then it is not so obvious that it lost the magnetic force. I do not know and I never heard the fully charged and then discharged Alnico driver in properly operating horns. The whole presumption is ugly as I do not see myself removing the driver from horns and send them out to recharge each 2 years. Perhaps I needed to put the magnet charging wire in the back chamber and recharge them right there in attic? Well, if I go for this then I need to be sure that it WAS the problem.

Rgs,
Romy the Cagt

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

06-02-2013

Post does not mapped to Knowledge Tree

Paul S
San Diego, California, USA
Posts 2,658
Joined on 10-12-2006

Post #:	439
Post ID:	19421
Reply to:	19419

Magnet Discharge and/or Chemical Warfare

Romy, it is rare for Alinco magnets to drop a charge "just like that", although time and/or physical shocks can diminish the magnetism considerably. If you happen to know how much charge your drivers started out with, then you already know more than 99.99% of audio people. Knowing this, you might be able to determine how far gone the charge is now, although finding out the reasons for the "sudden" discharge is another matter. Whatever the reasons for any discharge, at some point the charge gets too low for proper driver operation.

I also wonder if there have been changes in the foam (or whatever) in the chambers that house the drivers? I do know that some caulks, foams, and glues are chemically "incompatible", which can lead to degradation over time. This might cause shrinkage, hardening, leak(s), or ???, and who knows what the sonic results of any of this might be?

Best regards,
Paul S

06-02-2013

Post does not mapped to Knowledge Tree

jessie.dazzle

Paris, France
Posts 456
Joined on 04-23-2006

Post #:	440
Post ID:	19422
Reply to:	19419

Simulated suspension evolution

Give yourself time and let your unconscious work on it; you might have overlooked a cause originating in the electronics.

Romy wrote: "...The softening of the suspension and even paper would not be responsible for it as not primary resonance slid away but HF extension..."

I seem to remember that you fitted "new old stock" AK drivers... It's totally counter-intuitive but is it possible that the suspension has become stiffer with time? No, but is there something else that might simulate such a condition? Yes... A stiffening of the back chamber foam as Paul suggested... If that were the case, assuming you used the same foam in both these and your upper-bass horns, then logically you would have a similar issue with the smaller, older horns. If so, it may not be audible in the smaller horns or may have resulted in an improvement.

If this is what's happening with your mid-bass horns, you may be able to correct the issue by increasing rear chamber volume (digging out some foam).

Perhaps I needed to put the magnet charging wire in the back chamber and recharge them right there in attic?

Are you imagining wrapping the magnets with coils?
I was told by a guy who offered to remagnetize mine via a large remagnetizing "apparatus", that it is quite a violent process and requires removal of the membranes to prevent their destruction. I have not yet done it. I assume what you are proposing is a more gradual charge.

jd*

How to short-circuit evolution: Enshrine mediocrity.

06-03-2013

Post does not mapped to Knowledge Tree

Romy the Cat

Boston, MA
Posts 10,160
Joined on 05-28-2004

Post #:	442
Post ID:	19426
Reply to:	19422

Trying to do it with less blood.

Paul, Alinco magnets perfectly able to drop a charge "just like that" and I presume that it is what happened. If cause the environmental difficulties would not do it alone, at least for that time. Over winter I had output tubes worn up on both amps and as 6C33C begin to die they did the “pinging”. The pinging is outburst of energy that mostly likely near DC signal and DC discharges Alinco very aggressively. Saying that, I’ve been observing this behavior of 6C33C for years I need to say that I did not see that impact the pinging had to drivers. However in my past the drivers were MF driver and I never had Alinco on bass. So, it very much might be that my drivers got demagnetized. I can’t to be sure however and I can stick as now my gaussmeter to anywhere and I do not know how a discharged Vitavox sound. It feels like the long decay from discharged driver but I it is mostly because I have no other explanation and because I did observed somewhat similar effect with other driver, not bass drives, however.

Jessie, to re-magnetize the drivers is very simple, in my case the key would be to do it in place as to remove driver from attic is pain in ass. I would need to figure out the polarity, wind some 1-2GA wires around the magnets and lead those wires outside the back chamber. Then get some 3-4 Farad, high discharge current capacitors bank and run the capacitors through the wires with some kind SS or mechanical switch. There are no needs to remove any membranes; all you need to do is to disconnect VC to make sure that any inductive current would not have room to flow.

For sure it is perfectly doable but that itself would be a big project, not to mention that I am sure that the re-magnetizing has some own kinks about which I am not informed and that takes time to learn. So if I chose to do so then I would need some kind of objective evidence that the de-magnetizing allegations are correct. I do not have that evidence as now. A friend sent me email suggesting that it could it be just that the decay time for the room has changed for a frequency range. It is possible but why it did it with upper knee of my midbass horn but did not affected anything in lower knee of upperbass horn?

Well, there is another option - try to find another non- Alinco driver, let say ceramic or Neodymium that would be more or less immune to de-magnetizing. Well, this is whole different subject as to addition of those driver is figure out how they would behave in my horn would take literally half-life.

The Cat

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

06-03-2013

Post does not mapped to Knowledge Tree

Romy the Cat

Boston, MA
Posts 10,160
Joined on 05-28-2004

Post #:	443
Post ID:	19428
Reply to:	19426

Recharging the Alnico

Well I was thinking how I can verify that my midbass drivers had sunk magnets. I can take one of the drivers off; take them apart and compare them with another of my Vitavox 15 inchers. I can measure the magnetic force in the gap and it will be objective. However, no one knows if the other drivers that I have are fully charged and I do not know how much it has to be: 12.5T, 1.4T, 1.6T? who knows, I might call to Vitavox Mike to ask perhaps…

Another option would be to get a devise to read BL, a weak magnet will lower value.

http://www.daytonaudio.com/index.php/dats-dayton-audio-test-system.html

Usually 15-17 would consider low BL and 21-24 high BL. What would be the right BL for the 50 year old driver? Hmmm, who knows…
The most that piss me off in this whole story is that I might get all over it and recharge the driver but the reason why I have more HF from horns then I used to have will be some kind of other little stupid thing the I overlooked…. The recharging the Alnico after 50 year would never hurt however…

The Cat

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

06-03-2013

Post does not mapped to Knowledge Tree

Romy the Cat

Boston, MA
Posts 10,160
Joined on 05-28-2004

Post #:	446
Post ID:	19431
Reply to:	19430

Planning and wishing..

Well, there are a few places that can re-charge the drivers, GPA can do it for sure but it is not practical in my view as to remove the drivers from attic horns and to ship them is more pain then to pay to GPA $20 to re-charge them. The re-charging is truly not so difficult posses and I would like to do it in place. I do not see myself to send the drivers each year but I do not mind to do once a year in house firework and to re-charge the midbass magnets. Also, there is an attitude thing: the assholes who recharge the drivers never give you the measurable data of magnetic force before and after. I call them assholes as the last time I sent my S2 to be recharged I did explicitly requested the numbers before and after and I did paid extra to do the measurement. The guy who did it told me that he “just forgot to measure it before”. Thank you very much, the moron! I wonder if he goes under knife to a medical procedure he ask his doc some evidence that he is in fact sick?

Anyhow, I need to find at some old supply sale some used chip device like this:

http://www.magnet-physik.de/fileadmin/Mediendatenbank/1_Produkte/1_Magnetisiertechnik/IM-M_e_2121.pdf

Then I will be able to do something like this but skipping the ugly part with caps, charges, and commutation…

http://www.audioheritage.org/vbulletin/showthread.php?6406-Loudspeaker-magnets-magnetizing-fixture&highlight=magnet+charger

The Vitavox magnets are well exposed and I will wire 20-30 turns of thick wire and I think I will be fine. All that I will need to do is figure out the polarity of the coil, I am still thinking about it. BTW, would it be possible to rent such a magnetizing devise? It probably cost 2-3K it means that it might be rentable for $50 a day. That would be phenomenal!

Meow?

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

06-03-2013

Post does not mapped to Knowledge Tree

rickmcinnis
Posts 60
Joined on 10-18-2010

Post #:	447
Post ID:	19432
Reply to:	19431

Well, if anyone could ever do this ...

It would be you!
I should have known you had researched this more than the posts revealed.
I know I would not want to wrestle those drivers out of the attic, either. I figure you have replacements to use temporarily so you would not be without, but ...! Now one must consider wrestling that contraption up there ...
It is amazing how people will tell you they will do something and then, after you have received them back you get the "Oh, well, we forgot" response.
I got some chokes from SOWTER to be used as a passive low pass filter and asked them to measure them before shipping since I do not have the equipment to do it. "OH, YES, that is no problem", they say at the time of the order. Of course, when I got them I had to write and ask what the values were and, well, ...
When you master this process, and I am lucky enough to make a pilgrimage I will bring a pair of drivers that need the treatment. I would love to see this!
(Have you watched THE VANISHED EMPIRE? It has become one of my favorites. I am curious what you might think of it. Not as cerebral (by a long shot) as Tarkovsky but a very honest film)
Take care,

06-03-2013

Post does not mapped to Knowledge Tree

Romy the Cat

Boston, MA
Posts 10,160
Joined on 05-28-2004

Post #:	448
Post ID:	19434
Reply to:	19419

What was absolute wonderful…

I would like to share that wonderful experience I had 2 nights back when I spent the whole night to juts to listening my midbass horns. I did not do it for two year or so and to hear juts the midbass back as I did it during the post-contraction was very didactic. There is nothing as educational as to play one or two horn with just 40- to 107 Hz and think about the colors, density, shape, structure, texture of the sound they create. I would live all the rest observation of what I observed with me but there was one that strikes me as never before – the direction. Again and again I am applauding to myself with that super kinky decision to put the midbass in the hidden view above and behind the listening position. As I was listening the low octave coming from the horns I did very clearly hear them as the direct source FROM the front of loudspeakers. There was some room diffusion of chose but the main midbass image was coming from front. Apparently the longer wave were shooting across my 27 feet room and bounce back to me. What was a brilliant idea to hide the horns where they do not bother anybody and where they secretly do their duty! If I even move and will be ever rebuilding my room then I would very much try to mimic something like this. The living experience in listening room will be VERY much different if I has even single 7-8 feet horn sitting on my laps.

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

06-04-2013

Post does not mapped to Knowledge Tree

Romy the Cat

Boston, MA
Posts 10,160
Joined on 05-28-2004

Post #:	450
Post ID:	19438
Reply to:	19434

God, what a remarkable idiot I am!!!

Unbelievable idiot!

Last night an audio guy visited me and I played to him some music. I was not sitting in the listening spot but what stroked me was now stringent and how shallow the playback sounded. I was waling around the listening room, scratching my back a wondering what the hell is going on. The electricity is great recently but sound is not elegant as I am accustomed to. Listening more and more I suddenly realized that I do not have my bass. I have my soft and nice midbass but I did not have my last exhale of Macondo that I am so proud off. Then to my shame I realized that that meters on my ULF power amp are not moving. Reaching back and tracing the cables I learned that the ULF crossover was just disconnected. A month or two back, when I connected the small Pilot speakers with own amps I did not have empty output on my preamp and I unplugged the ULF crossover to use the Pilots. So, I do not use ULF for good tow months.

Putting back the ULF was like coming back home. The long decay of my midbass does not sound so horrible anymore, apparently the ULF, kicking at 20Hz does moderated the midbass decay. I still feel that there is a very very minor midbass decay issue but it no nears close to what I am experienced lately.

The playback again sound spectacularly and the re-charging of the drivers project is not at my radar anymore.

I need to look further into the midbass and ULF interaction as it is very interesting subject.

The Cat

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

	Target	Threads for related reading	Most recent post in related threads	Forum	Replies	Views	Started
»	New	45Hz Bass Horn..	Can We Ever be Saved From Ourselves?...	Horn-Loaded Speakers Forum	23	315655	09-19-2006
»	New	8" Goto Woofer for 60Hz Horn..	It's not a Goto 8in driver...	Horn-Loaded Speakers Forum	5	87526	11-03-2008
»	New	The Macondo’s Upper Bass Channel: what is next?..	Görlich again...	Horn-Loaded Speakers Forum	30	290947	10-28-2007
»	New	Jessie Dazzle Project..	Will this better to be auditable?...	Horn-Loaded Speakers Forum	172	1564818	08-03-2007
»	New	Romy The Cat's new Listening Room..	Won't be the last time he makes that trip!...	Audio Discussions Forum	478	2929764	03-28-2010
»	New	Problems with horns: upper bass ..	Must it be about loading?...	Horn-Loaded Speakers Forum	109	1171730	03-25-2005
»	New	Midbass Horns and Real Estate...	Just a youtube video......	Horn-Loaded Speakers Forum	247	2146961	07-26-2009
»	New	Macondo’s lowest channel...	What truly are you tryin to accomplish?...	Horn-Loaded Speakers Forum	150	1398735	09-15-2010
»	New	Practical Guide for Back Chambers Tuning...	Back chamber’s cost-benefit....	Horn-Loaded Speakers Forum	5	76065	10-21-2006
»	New	Superbly interesting effect: Suspended decoupled floor ..	Superbly interesting effect: Suspended decoupled floor ...	Playback Listening Forum	0	18120	10-08-2010
»	New	Midbass impedance bumps -- why and what to do?..	You need to stop deceive yourself....	Horn-Loaded Speakers Forum	18	194290	10-21-2010
»	New	Mystery of bass horn calibration: Radiating Surface Dee..	Mystery of bass horn calibration: Radiating Surface Dee...	Horn-Loaded Speakers Forum	0	17302	02-03-2011
»	New	Impulse response, short notes and midbass horns...	A possible solution to better impulse?...	Horn-Loaded Speakers Forum	14	128452	06-13-2011
»	New	My new “New” listening room, 2024..	That is not enough efforts in this direction....	Audio Discussions Forum	31	18416	05-08-2024

	Target	Threads for related reading	Most recent post in related threads	Forum	Replies	Views	Started
»	New	45Hz Bass Horn..	Can We Ever be Saved From Ourselves?...	Horn-Loaded Speakers Forum	23	315655	09-19-2006
»	New	8" Goto Woofer for 60Hz Horn..	It's not a Goto 8in driver...	Horn-Loaded Speakers Forum	5	87526	11-03-2008
»	New	The Macondo’s Upper Bass Channel: what is next?..	Görlich again...	Horn-Loaded Speakers Forum	30	290947	10-28-2007
»	New	Jessie Dazzle Project..	Will this better to be auditable?...	Horn-Loaded Speakers Forum	172	1564818	08-03-2007
»	New	Romy The Cat's new Listening Room..	Won't be the last time he makes that trip!...	Audio Discussions Forum	478	2929764	03-28-2010
»	New	Problems with horns: upper bass ..	Must it be about loading?...	Horn-Loaded Speakers Forum	109	1171730	03-25-2005
»	New	Midbass Horns and Real Estate...	Just a youtube video......	Horn-Loaded Speakers Forum	247	2146961	07-26-2009
»	New	Macondo’s lowest channel...	What truly are you tryin to accomplish?...	Horn-Loaded Speakers Forum	150	1398735	09-15-2010
»	New	Practical Guide for Back Chambers Tuning...	Back chamber’s cost-benefit....	Horn-Loaded Speakers Forum	5	76065	10-21-2006
»	New	Superbly interesting effect: Suspended decoupled floor ..	Superbly interesting effect: Suspended decoupled floor ...	Playback Listening Forum	0	18120	10-08-2010
»	New	Midbass impedance bumps -- why and what to do?..	You need to stop deceive yourself....	Horn-Loaded Speakers Forum	18	194290	10-21-2010
»	New	Mystery of bass horn calibration: Radiating Surface Dee..	Mystery of bass horn calibration: Radiating Surface Dee...	Horn-Loaded Speakers Forum	0	17302	02-03-2011
»	New	Impulse response, short notes and midbass horns...	A possible solution to better impulse?...	Horn-Loaded Speakers Forum	14	128452	06-13-2011
»	New	My new “New” listening room, 2024..	That is not enough efforts in this direction....	Audio Discussions Forum	31	18416	05-08-2024