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  »  New  Problems with horns: mid-range horns...  First or second order for 1" driver....  Horn-Loaded Speakers Forum     8  73055  07-21-2004
  »  New  Evaluation of tractrix curves based on visual surface r..  Re: The Delay of Time Delay...  Horn-Loaded Speakers Forum     17  119838  06-20-2006
  »  New  Earl Geddes: Horny Book..  Horns, Earl, bottomeaters Sound and confidence of ignor...  Horn-Loaded Speakers Forum     10  87656  07-19-2006
  »  New  Does horn surface porosity influence sound ?..  other possible materials that might be used....  Horn-Loaded Speakers Forum     11  60389  02-11-2007
  »  New  Adding one more non-spherical to Macondo...  Horn suggestions for 300Hz-1000Hz channel...  Horn-Loaded Speakers Forum     23  161564  12-15-2010
01-25-2008 Post does not mapped to Knowledge Tree
op.9
Planet Earth
Posts 68
Joined on 01-26-2007

Post #: 1
Post ID: 6436
Reply to: 6436
Open cell foam in horns and MF drivers
Ok. I have some very good results to report.
I've been stuffing my midrange horn (250hz lecleach with BMS4592nd-midrangeonlyversion) with some 20-hole-per-inch open cell foam. As per Mr. Geddes.
Its not coming out.

1. I can now play louder with no shreiking in the upper mids. In fact I'm not very good at setting a reasonable playback volume now.
2. I've now been able to move my crossover much higher - 5k at the moment. Was a problem there before.
3. Much more coherant musical-space effect.
4. Near field listening has improved (its very exciting)
5. no loss of dynamics. as far as I remember.
6. fantastic 'ease'
7. Can't stop listening to music...

did anyone else here try this?

(I'm sorry if this should be attatched to another thread - )


cheers op.9


everybody used to call me James in my past other-worldly life.
01-26-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,540
Joined on 05-28-2004

Post #: 2
Post ID: 6439
Reply to: 6436
To look at the problem from different angle

op.9,

to put your comment I perspective it is necessary to know what surface you had on your Lecleach horns before. If you search the site (use world textured or structured) then you would know that I am a vocal opponent of smooth surfaces on horns. When I see those manufactures sell their glossy and shiny horns I truly smile. Somewhere in this site I pitched enter theory that sound shell be scratched off the surface of the horn instead of sliding and slipping from the walls of the horns. Pretty much an abrasive sand paper is one of the greatest surfaces… In the time when John Hasquin was still in business he taught me to finish the horn surface with textured paint, it is what I do and moderating the dryiness of the pains it is possible to moderate the granularity of painting. Alternately you might use hairy wood of rough plaster surface as Jessie might do with his plaster horns.

Now about the Mr. Gedde’s idea of open cell foam.  It would work but I do not like the solution as foam instead of demanding diffusion does also absorption. I did use foam for experiment in past and I have seen HOW it works. Well, properly if to use very fine and very thin (a few mm) sheet of foam and to cover the horn very accurately then it will created the necessary boundary effect of surface randomanization however I would propose a slightly different angle.

Would it be possible that overly-absorbing characteristics of the Geddes foam redeem the upper range problem of your BMS 4592ND driver? In my past I did corrected the problem with some on my compression drivers by foaming the horns, then I learned that it is preferable to get a better driver. Sure, I have an agenda and I sweepingly do not like the BMS drivers. The improvements that you repost do suggest that the BMS did not work out well before in your horn. So, it might be an opportunity to look at the problem from different perspective.

Rgs, 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
01-26-2008 Post does not mapped to Knowledge Tree
jessie.dazzle


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

Post #: 3
Post ID: 6447
Reply to: 6439
Finish & texture
Romy wrote :

"...Alternately you might use hairy wood of rough plaster surface as Jessie might do with his plaster horns..."

I'm currently using Hammerite textured paint to seal the plaster. This stuff (originally designed to prevent rust) has an automatic fish-eye bumpy finish... I further increase the texture by applying all coats of this finish using a big sponge and a "stippling" technique while it dries (dabbing it on, instead of stroking). This also makes it very easy to repair damaged areas (in case of accidents during transport and set up).

Also, the subtle dark bronze color of Hammerite "hammered finish" looks fab.

jd*


How to short-circuit evolution: Enshrine mediocrity.
01-26-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,540
Joined on 05-28-2004

Post #: 4
Post ID: 6451
Reply to: 6447
The John Hasquin's schooling.
It should be read: "...Alternately you might use hairy wood OR rough plaster surface as Jessie might do with his plaster horns..." Anyhow if you use textured paint then there is an easy was to increase size. When you spray the paint do not spay from default 10”-12” but from I would say 30”. Yes, it is too far and it will waste a lot of paint but it has own merit as the paint when it arrives to target surface will be already dried out and will pile itself up instead of gluing to older layer of pain and turning into a liquid. The further you go in distance between stray can and the horn the larger paint texture. The larger texture I was able to get was when I painted in a very cold day and used a very hot paint. I usually warm the paint to 60-65C before spraying….


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
01-26-2008 Post does not mapped to Knowledge Tree
yoshi
Jefferson (MA), United States
Posts 69
Joined on 05-04-2005

Post #: 5
Post ID: 6455
Reply to: 6451
Auto Air Color Candy colors
I do a lot of spray painting on my other job.  One particular paint that gives rough texture is Auto Air Color's candy colors.

http://www.autoaircolors.com/

They are supposed to be used diluted with their Transparent Extender and coat it with thick layers of clear coat afterwards to give it a transparent candy effect, but when used directly from the bottle without diluting, it bulds up to a coarse texture.  You may need a thin layer of clear coat afterwards just to bind them to prevent crambling off.  The roughness of the surface can be adjusted by the amout of paint you apply.

Auto Air Color is water based so it's very easy to use.  I usually buy them through TCP Grobal in San Diego.

http://www.tcpglobal.com/autoaircolor/

Yoshi
01-28-2008 Post does not mapped to Knowledge Tree
N-set
Gdansk, Poland
Posts 454
Joined on 01-07-2006

Post #: 6
Post ID: 6462
Reply to: 6447
Oil paint?
guys, i was thinking of oil paint. i mean the one that artists use.
one can create structures from sub-mm to cm.
the application is surely a paint in the ass---painting a big horn
would take days, then weeks or months to dry, but...might be worth a
try?

cheers,
jk




Cheers,
Jarek
01-28-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,540
Joined on 05-28-2004

Post #: 7
Post ID: 6463
Reply to: 6455
How to create a rough horn surface.

Sure, it is a matter of personal preference but to my taste anything shiny of glossy should not be used in horn or in audio… unless you are French of course :-)  As far as I concern everything should be absolutely black, completely not glittery, have no reflection of any link and provide as less as possible visual impact. In my past even experimented with large drapes of black nylon covering the speakers. But it is me…

Anyhow, if to insists to use oil paints then it would worth to consider to pre-texture the surface before paint in order to have the defuseable surface instead of smooth one. A good solution would be to spay the horn with a layer of polyutherene and then while it is still wet to blow sand against the horn from air machine. The sand would randomly stick to the horn surface and then it might be painted above… Juts an idea…


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
01-28-2008 Post does not mapped to Knowledge Tree
el`Ol
Posts 225
Joined on 10-13-2007

Post #: 8
Post ID: 6465
Reply to: 6463
Acrylate spray
There are acrylate colour sprays with various kinds of texture. Most of them however have visual impact.
01-30-2008 Post does not mapped to Knowledge Tree
op.9
Planet Earth
Posts 68
Joined on 01-26-2007

Post #: 9
Post ID: 6488
Reply to: 6465
Rough

The surface of my fiberglass horns is quite rough. The mould was sprayed from a distance with some water based paint - so it all landed in fine globules. Maybe this is too fine a rough texture though. I like the idea of thick artists oil paint…

One more variable: The meeting of the driver to the horn throat seems very critical. I think I previously had a leak on one side. . . .and the centering of the driver seems to be very critical too. If I place a small piece of absorbent foam right after the driver, these problems disappear, but that is no fix, as then the sound loses dynamic quality. How do you all mate your drivers to the horn? Just a rubber gasket? I now understand why those screw threads were so popular.

I need to do more research, but I'm pretty sure that the foam filling has a different effect from that of the rough horn texture. For example I've now been quite shocked at the sound of live applause. There is now 'wetness' to the texture, and the sound seems to ‘hang’ all around the room.

As to those horrible BMS's, its all I've got at the moment, I’d love to have some other 2'’s to compare one day... But why care if their problems can be successfully controlled by this foam?!

Question, can you tell me what difference open foam has on a 'good' driver in a rough horn?

Cheers, op.9


everybody used to call me James in my past other-worldly life.
01-30-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,540
Joined on 05-28-2004

Post #: 10
Post ID: 6490
Reply to: 6488
BMS drivers, MD
 op.9 wrote:
As to those horrible BMS's… why care if their problems can be successfully controlled by this foam?!
Well, if you have diabetes and pump up own body with insulin then it might make you glucose-balance but does it make your state of being healthy? Let me to put it other way: does your insulin-induced sugar health has any advantages of disadvantages in relation to a person whos body takes care about the whole sugar  ceremony naturally?


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
01-30-2008 Post does not mapped to Knowledge Tree
op.9
Planet Earth
Posts 68
Joined on 01-26-2007

Post #: 11
Post ID: 6493
Reply to: 6490
What else?
good point well made.
Funny, i have tried to give up coffee many times. sometimes sucsessful even for 6 months at a time. But somehow, life with coffee is just better.
Anyhow, what are the 2" comp drivers that ARE any good and are available comercially? I didnt go with any JBLs because I had a very bad time with the 2427 1" version, could never get any music out of it.
I was going to try a selenium 405 with the phenolic diaphragm, but they discontinued it. Everything else seemed a gamble.
maybe I missed a trick...
cheers, james


everybody used to call me James in my past other-worldly life.
01-30-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,540
Joined on 05-28-2004

Post #: 12
Post ID: 6495
Reply to: 6493
The JBL one-inchers are no better then BMS crap.

 op.9 wrote:
Anyhow, what are the 2" comp drivers that ARE any good and are available comercially? I didnt go with any JBLs because I had a very bad time with the 2427 1" version, could never get any music out of it.

I would be surprised if you get any reasonable sound out of 2427 driver. I do not had it but I true a number of the drivers from the same family. My observation is that those drivers with small cones are very-very poor, unless you use them somewhere above 3kHz, but still the do very bad sound. The 1” Altecs were better, the older 802 or 808 with the 802 cones (not with the 808 cones). Still the Altecs were slow and had very small/ stiff-suspended cone to sound reasonably. The large Altecs were more fun and the 2” JBL were way more sophisticated, particularly with put aluminum cones. You might try the 2440/375 but do not bite into the newest titanium diaphragms. With all cones and pros of 2440 they will have VERY different sound then even a dozen BMS drivers. BMS juts do not go where Sound lives and no foam will help them. The entire reputation of the BMS driver is based upon the hype that a half dozens of idiots- manufacturers blow up abound the BMS driver but in reality it is all very-very third-rate drivers and any single product built around the BMS drivers is a testimony of nothingness.  You might stop by in your local pro audio shop and lease for a weekend a speaker with 2440/375. It will cost you ~$60 over a weekend. At home you would need to clean and to align the driver and give it time to play. It will be very different then JBL one-inchers. There are other options but it is would be an easy way to learn how much you do not get with BMS....

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
01-31-2008 Post mapped to one branch of Knowledge Tree
horny
Posts 28
Joined on 11-19-2007

Post #: 13
Post ID: 6501
Reply to: 6495
Some 2" alternatives
JBL 2441 also seems interesting candidate, perhaps "smoother" than 2440:
2441.JPG
Duke LeJeune of Audiokinesis recommends them as a "poor man`s TAD"

Beyma CP755ND/AL 1.4"

http://profesional.beyma.com/ENGLISH/pdf/descarga.php?pdf=CP755NdAL.pdf

Some interesting alu compression drivers, that Romy never tried:

eighteensound ND1460A 1.4" for the 800-10000 Hz range:

http://www.eighteensound.com/index.aspx?mainMenu=view_product&pid=253

eighteensound ND2060A 2" for the 600-6000 Hz range

http://www.eighteensound.com/index.aspx?mainMenu=view_product&pid=252

regards

horny
01-31-2008 Post mapped to one branch of Knowledge Tree
be
Copenhagen, Denmark
Posts 86
Joined on 02-12-2007

Post #: 14
Post ID: 6502
Reply to: 6501
2" drivers

The best driver I have heard is the TAD 4003.

It does not use the secondary resonance of the suspension, as described by Duke LeJeune above for the TAD 4001-4002, to extend the response towards 20 kHz, but has a natural roll off from app. 15 kHz.

Interestingly the sound of the 4003 is much better than the 4001-4002, the density of information and ability to articulate, also in the treble, is on a different level.

The sound of the TAD 4001-4002 might impress for a few notes until you realise that everything they do in the high frequencies have the same monotonous character and is not able to express the "smell" of the instruments very well.

If one looks at the AES paper for the 4001 it can be seen that their response over 8-10 kHz is due to deliberately placed resonances.

The JBL 375 was also made with the same trick, it is generally more coloured than the TAD 4001, but in a pleasing way.

All these drivers where designed by Bart Locanthi, the 4003 was, if I am not mistaken, his last completed driver before he died, apparently he realised his mistake with the others.
01-31-2008 Post does not mapped to Knowledge Tree
horny
Posts 28
Joined on 11-19-2007

Post #: 15
Post ID: 6503
Reply to: 6502
2" drivers
 be wrote:

The best driver I have heard is the TAD 4003.

It does not use the secondary resonance of the suspension, as described by Duke LeJeune above for the TAD 4001-4002, to extend the response towards 20 kHz, but has a natural roll off from app. 15 kHz.

Interestingly the sound of the 4003 is much better than the 4001-4002, the density of information and ability to articulate, also in the treble, is on a different level.

The sound of the TAD 4001-4002 might impress for a few notes until you realise that everything they do in the high frequencies have the same monotonous character and is not able to express the "smell" of the instruments very well.

If one looks at the AES paper for the 4001 it can be seen that their response over 8-10 kHz is due to deliberately placed resonances.

The JBL 375 was also made with the same trick, it is generally more coloured than the TAD 4001, but in a pleasing way.

All these drivers where designed by Bart Locanthi, the 4003 was, if I am not mistaken, his last completed driver before he died, apparently he realised his mistake with the others.


Couldn`t agree more. If you look at the cross section view of the 4003 you will notice it has the smoothest transition from the chamber to the throat (curved)
and taking into account the recommendations by various folks to replace the original Be diaphragm with the Radian alu replacement diaphragm, one could get
something interesting ("merely interesting", some will point out). Judging from my experience, compression drivers (or any drivers, for that matter) that have abrupt frequency roll off at the upper range, mostly sound lazy to me (non transparent). It is like with filters; the steeper they are, the more overshot they produce, the nastier they sound. The gradually falling upper range of the 2441 and 4003 simplyfies crossover integration with the tweeter above 8 khz or so.
Of course, this is no guarantee for the end result.
01-31-2008 Post does not mapped to Knowledge Tree
horny
Posts 28
Joined on 11-19-2007

Post #: 16
Post ID: 6504
Reply to: 6503
Correctio
 horny wrote:
be wrote: It does not use the secondary resonance of the suspension, as described by Duke LeJeune above for the TAD 4001-4002, to extend the response towards 20 kHz, but has a natural roll off from app. 15 kHz.
I am sorry, what I meant was that Duke LeJeune recommends the Beyma CP755ND/AL 1.4" driver as a cheap TAD alternative.

regards
horny
01-31-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,540
Joined on 05-28-2004

Post #: 17
Post ID: 6505
Reply to: 6503
Do not forget the damping the cones with amplifier

 be wrote:
The best driver I have heard is the TAD 4003.

It does not use the secondary resonance of the suspension, as described by Duke LeJeune above for the TAD 4001-4002, to extend the response towards 20 kHz, but has a natural roll off from app. 15 kHz.

Interestingly the sound of the 4003 is much better than the 4001-4002, the density of information and ability to articulate, also in the treble, is on a different level.

The sound of the TAD 4001-4002 might impress for a few notes until you realise that everything they do in the high frequencies have the same monotonous character and is not able to express the "smell" of the instruments very well.

If one looks at the AES paper for the 4001 it can be seen that their response over 8-10 kHz is due to deliberately placed resonances.

The JBL 375 was also made with the same trick, it is generally more coloured than the TAD 4001, but in a pleasing way.

All these drivers where designed by Bart Locanthi, the 4003 was, if I am not mistaken, his last completed driver before he died, apparently he realised his mistake with the others.

Very interesting comments about TAD 4003, thanks, Be. I had in past the 2001 and 4001, did not like them for their “over oily salad sound” and I dismissed TADs all together. 

The concept of the deliberately placed resonances is complicated and I would never feel that any driver might not suffer from it. They are all hugely resonating, some of them do it in “right way” and some of them now, go figure…  From what I remember when I was trying the 2440 and 375 (had them both) I god a feeling that they probably were the most neutral but at the same time the most capable in term of “discrimination” among the common drivers.

There is another aspect that I did not research in 2000-2001 what I was doing over many compression drivers – the control the drivers by amplification. In 2001 I used Lamm SET that cared everything above 100Hz. I did try to use different taps on the compression drivers that I used. It changed the harmonic envelop of the MF drivers but it also changed a lot my upperbass channel.  The upperbass channel is a bone of a compression MF driver so, it was not realty intuitive what was doing on. Also, at that time I had less evolved listing assessment skills then I have now and I presume that I did not give to some of the tried drivers the chance that they might needed.

What I feel the MF horn drivers need is to be driven by a dedicated SET where the effect of variable loading of the SET might be observed at the MF driver only. I know that MF compression driver have very little reactance back to amp but still, their sound very much might be moderated by SET’s plate loading. Particularly the drivers that use the “deliberately placed resonances” mish be very much comforted by loading the out stage of SET slightly heavier. Under other circumstances I would try some better drivers again, with my progressed understanding how to deal with compression drivers but I am not on the MF drivers market. If I begin to lose satisfaction and would detect some specific annoyances with the MF driver that I am using then it might open opportunities for further try. I would then try your TAD 4003…

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
02-01-2008 Post does not mapped to Knowledge Tree
el`Ol
Posts 225
Joined on 10-13-2007

Post #: 18
Post ID: 6516
Reply to: 6493
Selenium
 op.9 wrote:

I was going to try a selenium 405 with the phenolic diaphragm, but they discontinued it. Everything else seemed a gamble.
maybe I missed a trick...
cheers, james


http://cgi.ebay.de/SELENIUM-D-405-2-PHENOLIC-DRIVER-1-PAAR_W0QQitemZ290175513183QQihZ019QQcategoryZ21993QQtcZphotoQQcmdZViewItem
02-01-2008 Post does not mapped to Knowledge Tree
op.9
Planet Earth
Posts 68
Joined on 01-26-2007

Post #: 19
Post ID: 6517
Reply to: 6516
Interesting
Thanks. It would be interesting to try these. I heard some a while back in a rectangular tractrix and I remember being very impressed.  Has anyone had any experiance of these?
james


everybody used to call me James in my past other-worldly life.
02-01-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,540
Joined on 05-28-2004

Post #: 20
Post ID: 6519
Reply to: 6517
Phenolic diaphragms, Debussy and Ormandy

I never had that Selenium 405 driver. Generally the phenolic diaphragms are very tricky and might have some excessive softness and some luck of transients. Selenium also had a habit to load gap with ferrofluid – it also might slightly detransientize the driver. BTW, removing the ferrofluid is a big no-no as it completely changes the damping of the driver. Still, if the Selenium do NOT use ceramic magnet then it might be an interesting to try. Purely speculatively I think it might be a suitable driver to play Debussy’s “La Mer” performed by Philadelphia Orchestra, lead by Eugene Ormandy… :-)

BTW, here is another lead:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=200195741737

it is a pro version of 2440, it is not better driver but juts more hipped and more expensive. It will be very different then BMS drivers and foam... :-)

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
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   Target    Threads for related reading   Most recent post in related threads   Forum  Replies   Views   Started 
  »  New  Problems with horns: mid-range horns...  First or second order for 1" driver....  Horn-Loaded Speakers Forum     8  73055  07-21-2004
  »  New  Evaluation of tractrix curves based on visual surface r..  Re: The Delay of Time Delay...  Horn-Loaded Speakers Forum     17  119838  06-20-2006
  »  New  Earl Geddes: Horny Book..  Horns, Earl, bottomeaters Sound and confidence of ignor...  Horn-Loaded Speakers Forum     10  87656  07-19-2006
  »  New  Does horn surface porosity influence sound ?..  other possible materials that might be used....  Horn-Loaded Speakers Forum     11  60389  02-11-2007
  »  New  Adding one more non-spherical to Macondo...  Horn suggestions for 300Hz-1000Hz channel...  Horn-Loaded Speakers Forum     23  161564  12-15-2010
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