GoodSoundClub - Romy the Cat's Audio Site

11-03-2024

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Paul S
San Diego, California, USA
Posts 2,797
Joined on 10-12-2006

Post #:	26
Post ID:	27672
Reply to:	27670

Back to Sound Shaping?

While I agree with the "Musical Instrument Theory", you have made clear your intentions to try to get a working understanding and control of those speakers, And that sounds like something "sound engineers" do all the time, getting the effects they want with DSP. For LF there are D amps that allow you to dial phase or delay to taste. If your horn goes down to 640 Hz, then the woofer probably goes up that high, right? Add a "board" and you can do the woofer top to bottom, in as narrow bands as the board allows, to hear the effects per octave, or whatever you choose. For "purists" there are still analog versions around, gathering dust.

Paul S

11-04-2024

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Paul S
San Diego, California, USA
Posts 2,797
Joined on 10-12-2006

Post #:	27
Post ID:	27675
Reply to:	27672

Tuning Made Easy?

Perhaps you have already tried this, Romy, but I was just thinking you could experiment by simply moving the speakers in relation to the corners, whether evenly from both walls or more or less from one side of the cabinet or the other, to try to determine how the "last leg of the horn" affects the sound. As for the sonic contributions of the cabinets themselves, short of drilling holes or butchery, you can add mass to the cabinet panels and/or +/- obstruct the passageways anywhere inside the cabinets. All of this being easy, cheap, and reversable.

Paul S

11-07-2024

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Romy the Cat

Boston, MA
Posts 10,400
Joined on 05-28-2004

Post #:	30
Post ID:	27680
Reply to:	27679

Yes, it is Klipsch Rebel but I think it is not where this Sound comes from...

Yes, it is exactly the replica of Klipsch Rebel horn. I did not see it before you mentioned it but you are right, it is the Rebel.

http://images.klipsch.com/Brochure_540100_RB_635164773054556000.pdf

In my case, I use an unfiltered LF section from 605A for the horn and for FH Vitavox S2 at 640Hz. I needed to go with a deeper HF horn as Vitavox S2 needs some low-pass filtration to work in a short horn. I need to admit that I am having a very surprising result that made me very much question what is going on. The sound is marvelous, truly marvelous and I do not use this word lightly. It should be like I need to sing admirations to Rebel Horn, 605A, S2 this little room but it is much more complex than this. I have been thinking and experimenting with it a lot. I have another 3 amplifiers including my very much tested Melquiades driving the corner horns, let's call it Rebel++, and I got garbage sound. Truly disgusting Sound. I have 2 other good Dacs taking digital out from the transport and I have not disgusting but boring sound. I have other transports, DAW, and multiple amps driving the thing, and I do not have a near-close sound compared to when I drive the thing from that super cheap table radio device. Dima and I were looking into schematics and build of that cheap table radio and it is laughable: class B, integrated IC amplifier with huge distortions. What I am saying is that while my Rebel++ might not be so bad it is not the reason why I have such a strangely positive result. I do not know the reason and I am digging into it now.

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

11-08-2024

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Romy the Cat

Boston, MA
Posts 10,400
Joined on 05-28-2004

Post #:	31
Post ID:	27682
Reply to:	27679

A question.

I was looking about this Klipsch Rebel concept. It's looks like Klipsch dived into that Rebel configuration out of financial desperation. Is there more complex horns was too expensive to manufacture and sell and they come up with simplify version that they sell super cheap. In fact they reportedly selling many kits for Rebel. What I have is a larger version of C5 kit. Back in 1957 the kit was selling for $42. It is possible that this horn was built from original kit and they may have a lot of your versions and C5. Or maybe it was custom made by a furniture maker as my right and left horn have slightly different dimensions, like 2-3 in here and there.

anagnost, I have a question to ask. How can I methodologically accurate measure a percentage of acoustic output which coming from back home. The back Horn signal obviously will be delayed but I cannot truly do it in time domain as at those low frequencies it is a completely mess and only God knows where is direct signal and where is reflections.

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

11-09-2024

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a.anagnost

Greece
Posts 8
Joined on 10-16-2024

Post #:	32
Post ID:	27683
Reply to:	27682

Rebel and answer

Rebel:
It seems that the Rebel was licensed to companies such as Cabinart (offering 3 sizes of the Rebel):
https://www.preservationsound.com/wp-content/uploads/2012/06/Cabinart_1957_part2.pdf
https://www.preservationsound.com/wp-content/uploads/2012/06/Cabinart_1957_part3.pdf

Apparently, all of them follow FIG.1 of the Klipsch Patent https://patentimages.storage.googleapis.com/f0/9b/b3/3d80597554398e/US2731101.pdf, but Rebel++ is more refined at the back providing a more sensible throat geometry.
Unsurprisingly, it was common those years to license designs to other companies (for example, Vitavox CN-191 was using the Klipschorn, Vitavox Scouts were using the bogus JBL 4530)

Measurements:
The obvious answer is: move the horn to your backyard, place it firing to the sky (and... call your doctor to fix your broken back).
I usually use MLS (Maximum length sequence) pseudorandom signal to extract the impulse response of the device under test. (The FFT of the impulse is the frequency response) The methodology is explained at https://www.audiomatica.com/wp/wp-content/uploads/cliomls.pdf - example section.

(A few 100y ago, when I was developing an RTA app I sent you a prototype that supported MLS generation/measurements. I suppose it may still run under windows 11 - I will check if you wish)

It might also be useful to measure the resistance of the Rebel++, as a possible hint to why various amps fail.

BR, Antonis

11-09-2024

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Romy the Cat

Boston, MA
Posts 10,400
Joined on 05-28-2004

Post #:	33
Post ID:	27684
Reply to:	27683

There is much more to it.

Yes, Antonis. I do understand how to measure the back response anechoically but the whole idea of doing it in place, factoring in the effectiveness of the corners. I do not know how to do it.

Regarding the Rebel++ impedance, yes it was my initial reaction but there is so much more to it that keeps my mind occupied for a while and I do not have the answer as of now. You see, the fact the tube Milq was objectively falling is a good indication impedance drop beyond where Milq can handle. Still, 2 other amplifiers were B2 and B3 that have no problem with low impedance. The failure with B2/3 aps was not so catastrophic but the “great” sound was not there.
My focus now is ironically not on Rebel++ , the speaker is good but no better than it might be. At this point I feel that the exceptionalism is not coming from the Rebel++ but from this shitty Denon table radio that I drive Rebel++. I have had this unit for 17 years and it was very good for my office, bedroom etc. I have not had a good full range speakers for over 20 years and the story with Rebel++ was a first time I was driving my little table radio against a “serious” speaker. I am more than impressed. Some of the things I am getting is would be VERY rare for any amplifier of any class and I am getting it from $100 CD/DAC/AMP combo!!!

The last night I was listening to Ivan Fisher’s Maler 2 with Budapest festival. I am not kidding, the Rebel++ overperformed my main system. Was sound better with Rebel++ then Macondo? No, it was even remotely close. Still, I feel that Rebel++ was advantageous in my view. You see, Fisher’s Maler 2 is good performance but not consistent. There are some moments that are spectacular with very sensible personal touch but there are some moments when the orchestra just run through the score and make music boring and not expressive enough. Macondo, being the system that does very good audio, slightly masks out the boring moment of the performance by showing off a remarkable audio expressiveness. The Rebel++ and this shitty Denon do not do it at all and the boring parts are truly deep-boring. This is VERY advanced characteristics of a playback, and it is VERY hard to get. The fact that this shitty Denon and Rebel++ somehow do it is a huge mystery for me.

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

11-09-2024

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Paul S
San Diego, California, USA
Posts 2,797
Joined on 10-12-2006

Post #:	34
Post ID:	27685
Reply to:	27684

A Silly Thought

Though it seems quite unlikely, I have to ask, does the Denon have some kind of buffering at the output stage? I mean, that's a 15" woofer you're driving there... Perhaps the waters are muddied enough by the "horn" that it eats some other problems, in line with the smoothing approach? Do you high pass it? Do you low pass it under the S2?

Paul S

11-10-2024

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a.anagnost

Greece
Posts 8
Joined on 10-16-2024

Post #:	35
Post ID:	27687
Reply to:	27685

The silly rebel thoughts

My experience with cheap/chip amps:
Around y2k, bored with the bass of those loudspeakers with <=8" bass drivers that my fiends where so proud about, I decided to experiment with a BR box using a 15" driver (irrelevant: a Beyma 15K200). Immediately, I discovered that my 300B amp was unsatisfactory, and decided to test the LM3886 chip amp. I used inverting feedback topology just 2 resistors without any caps in the signal & feedback path: a simple DC amp. I thought that it will fail miserably, but I was smiling for months...

The pic with the FR Melquiades:
My first sentiment was envy. The second thought was: It will fail. Fine... but why? Maybe the load is too low. But the 605A is not a 4ohm driver. In fact it is more like a 16ohm driver! Yes, the output transformer has amorphous core as opposed to the heavy iron core+inductance of the bass channel of the multichannel Melq. Are we done?

Freqs of interest:
I will arbitrary assume that the observed phenomena are involving freqs <=60Hz (wavelength >=19ft/6m)

The silly rebel thoughts:
The Rebel is a two cell horn where the 2 cell's mouths are not close to each other (as opposed to all multicell horns I know of). Physics ensures that at low frequencies/high wavelengths this distance is irrelevant. Fine, but the listening spot distance may be quite less than the 60Hz wavelength. At 30Hz (605A fs) the wavelengths are x2.
How many wavelengths are needed to ensure summation of the 2 cells + the driver? I don't know, by I suspect >= 1x wavelength...
This means that at listening position, one is exposed to much lower freqs than those predicted by the summation (a typical 4th order high-pass).
But, can the amps support this? For sure the FR Melq can not. A DC amp with feedback and high OpenLoop gain (chip amp) on the other hand can!

Measurements:
I wish I knew the anechoic response of the Rebel's mouths and the anechoic response of driver (with the mic at less 1 inch distance).
The same at listening position (the supposed summed response).
Using for sure the Denon, and, whatever other amp.

BR, Antonis

11-10-2024

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Romy the Cat

Boston, MA
Posts 10,400
Joined on 05-28-2004

Post #:	36
Post ID:	27688
Reply to:	27687

I feel there is much much more to it

Antonis, as I said above, it might be more sinister than it looks. It might well explain why SET with no feedback cannot drive it. Howevers it does not explain why another solid state amplification driven by way more sophisticated front end can drive it fine but does not sound as appealing. As I said above my leading hypothesis that in this specific unit something completely accidentally was made right and I even with very high certain she can predict that what was made right is proper balance between volume and distortions. This unit very accurately depict musical content, the spiritual anesthetical definition of musicality which is outrageously rare and complex parameter, which was properly rendered according to my knowledge only in the first productions of Lamm ML2. This little unit should not have intelligence to observe musical complexity. During the last month I bought 3 other units of the same period from the same company bought this slightly different schematics. All of them were okay but none of them can differentiate good music from bad., This little stinky device somehow does and I feel it's nothing to do with speakers it drives, I never had any more or less capable of full range and it happens that my recent Rebel ++ were the accidental first.

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

11-10-2024

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Romy the Cat

Boston, MA
Posts 10,400
Joined on 05-28-2004

Post #:	38
Post ID:	27692
Reply to:	27689

It's might be coming.

I never have Valenca. I have Altec 19, I still own them but they are still in Amy's house. I actually would like very much to drive this my little Denon but not Altec 19 but some very capable full range system, something of Wilson Grand Slams or alike. There's only full range system I have are Dunalevy II with my custom tweeters and they are truly great. However, they do not play classical music and they sitting in my smoking room driven by very same Denon and I typically play there my blues that I like so much.

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

11-11-2024

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Romy the Cat

Boston, MA
Posts 10,400
Joined on 05-28-2004

Post #:	39
Post ID:	27694
Reply to:	27680

Rebel of Macondo or Some sense of reality

I have tonight heated cop up Macondo and decided to do some listening. I need to admit that over a month I did explicitly listening to my new Rebel++. I pulled Karajan Bruckner 7, this typically unfortunate DG pressing, lit up nice cigar come and listening it.

Well, I kind of forgot how starting Macondo and Milq are. The way how multichannel system run across inner workings of instruments and sections is truly cannot be compatible with any two-way system. I truly detect that I kind of missing that insultingly wonderful base that I have from that vintage Rebel but everything else is just I completely different dimension. If I can point one thing only then it is obviously size that absolutely not obtainable from any small speakers. The Brunner's crescendos, until you heard it at time align multichannel system with properly tuned channels is completely different exceptional entity. Normal audio just cannot do it. You need multichannels, you need reverberation injections, it is not that you're entire room should sound, it is not Brahms it is not Beethoven. It is Bruckner. With Bruckner that orchestral crush Christ to that dimension of universe. It is like you entering a magnetic field of magnetar and eat shreds you to the atoms. It is like a fireball of thermonuclear weapon, which is growing up and you feel it will never stop. I literally did not hear not multi amp and not multichannel system able to present this size. And it should not be an acoustic pressure it should be a tonal pressure.

I just shut down the Macondo and my stupid brain begin to ask if I want to introduce more channels to Rebel. Of course I will not, but if you hear Macondo you know what I mean....

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

12-05-2024

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Romy the Cat

Boston, MA
Posts 10,400
Joined on 05-28-2004

Post #:	40
Post ID:	27743
Reply to:	27694

It will be very tricky but it migh be very beneficial.

Oh, God. I did something very very cool. I found a way to incorporate my Rebel++ INTO my main system!!! I “might” have my Rebel++ bass in Macondo. I have addressed the room and furniture problem very effectively but now I have properly integrated Rebel++ with Macondo. It will be very tricky. >>

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

12-08-2024

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Romy the Cat

Boston, MA
Posts 10,400
Joined on 05-28-2004

Post #:	41
Post ID:	27748
Reply to:	27743

The evidence that God does not exist.

I made an effort to integrate the Rebel++ in my main listening system. I changed the room and created good corners for corner-loaded horns, and they were time-aligned in my listening position. The result is not good. However, when I am listening to the Rebel++ they are very nice, and the whole presentation is very good come along at a distance of 15-20 feet and they sound VERY nice in that listening location. A completely not useable in the context of Macondo. The Macondo listening spot a feet before the middle of the carpet.

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

12-09-2024

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Romy the Cat

Boston, MA
Posts 10,400
Joined on 05-28-2004

Post #:	42
Post ID:	27750
Reply to:	27748

Very very added addictive this astonishingly low efforts

I play for the last 3 days my Rebel++ in different configuration and to my huge surprise they actually might perform better that I expected in new position and listening exam from 12 ft. They certainly need a larger room to breathe and to develop full body sound. I kind of settled this idea that I will not be able to integrate them with Macondo but I also feel that I can convert them to astonishingly good loudspeaker. It is not the time needed but I like to teach speaker how to sound good and the Rebel ++ really threw potentials and a wonderful playgrounds to start from. In the larger room I feel I would need to high pass the subwoofer somewhere. I also need to make the S2 drivers to sound less like S2. I know how I need to play with it little bit. It is kind of insulting that so little money I will be able to come up with acoustic system which significantly overperforms the garbage they sell for 100s thousands. It is not truly monetary ego. It gives me actually a pleasure to discover what possible to dig out from this topology. I always did not take serious the corner loaded horns as I failed that they are lying on the wall and never have any debth. That depth that my corner horns do in this location is kind of stunning. It is certainly different presentation but it is very addictive.

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

12-18-2024

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Romy the Cat

Boston, MA
Posts 10,400
Joined on 05-28-2004

Post #:	43
Post ID:	27765
Reply to:	27750

To be contineu.

In the end, the Rebel++ turned out to be a completely different project and it so far delivered more results than I ever expected. I am disbelieving about what I am observing here. The quality of the sound that so much impressed me in the end did not come from the Rebel++ topology, the Klipsch design, from the good vintage driver, or the magic of Vitavox S2. It turned out that it all came from that shitty table radio that I used to drive the Rebel++. I do a lot of experiments down here and I have discovered something truly interesting. From the direction that I absolutely did not expect.

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

12-18-2024

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Paul S
San Diego, California, USA
Posts 2,797
Joined on 10-12-2006

Post #:	44
Post ID:	27766
Reply to:	27765

Teaching a Stone to Talk

...with deference to Annie Dillard...

I hope everyone who follows along looking for tips is watching closely because this thread as it has evolved is a terrific exposition of the "applied theory" of high-end audio practices. The subject here is not only old quasi-complimentary SS amps but it shows how evolved listening skills and derived techniques can guide the paractitioner to Good Sound like a heat seeking missile. Even if one misses out on this particular amp, "the gear is out there". One needs to stay detatched from the fog of hype that enshrouds it and listen for what is important to ones self. When The Listener is ready, the System will appear.

Paul S

12-24-2024

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Romy the Cat

Boston, MA
Posts 10,400
Joined on 05-28-2004

Post #:	45
Post ID:	27789
Reply to:	27586

It is getting better and better.

I really like to work with the speaker as it responds very kindly. The next is to make S2 driver to work the way how it works in Macondo- with high frequency low pass. It will take probably around .1 to .03 if to slightly top off the S2 driver. And of course to complimented this insightly beautiful twitter from Red driver. After I did very same in Macondo I do see a better combination. Trying to figure out how to do it time alignment with exact positioning. So far a threaded rod dose fine but I need to come up with a better frame solution.

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

12-25-2024

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Paul S
San Diego, California, USA
Posts 2,797
Joined on 10-12-2006

Post #:	46
Post ID:	27790
Reply to:	27789

Nested Tweeter

No doubt you will find better looking support for your (super) tweeter, starting with less material. I see and appreciate that you have resisted any urges to remove the woofer cone, dust cover, etc. from around the tweeter. During my own manic experiments some years back I came to the conclusion that a "nested" tweeter "sounded better" than the same tweeter in free air. I never did figure out why. I also thought the largest cone (I am talking paper drivers) that could "do" the desired frequencies "sounded best". Of course, I took another direction in order to up the power potential. Of course I still have dozens of paper tweeters...

How are you liking the cellular horn, as opposed to your big, heavy turned horns? I remember preferring the Altec "500Hz" horn at 800Hz, but I did not like the 515s at 800Hz, and my wife hated the A7s, no peace until I sold them.

Happy Holidays,
Paul S

12-25-2024

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Romy the Cat

Boston, MA
Posts 10,400
Joined on 05-28-2004

Post #:	47
Post ID:	27791
Reply to:	27790

I do not know what nested Twitter is

I do not have any big prejudices and do not invest too much into specific type of horn. In my view at home form a very unique combination between compression driver and Horn, making compression driver to sound the best. I have two original different Vitavox horns. I do not make claim that a larger multisell is better I just would like to drive that compression driver slightly lower in my configuration and I need just a larger horn. I do not like Altec 7 design. I think some of Altec 7 I had large 2" Altec drivers and those drivers in my view are very usable. I heard a few months ago those large Altec drivers with custom strictly paper cones loaded into large horn similar to mine and they were sensationally good,

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

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	Target	Threads for related reading	Most recent post in related threads	Forum	Replies	Views	Started
»	New	Rebel++ first blood, AmpX and many other subjects..	Rebel++ first blood, AmpX and many other subjects...	Playback Listening Forum	0	2464	12-29-2024