Horns - Necessary to complete the Audiophile Journey?

[mhardy6647]

Actually the A7 / A7-500 measure just about as well as any modern speaker if executed well, for instance if active crossovers are used and some voicing is used especially on the HF driver.

As far as polar response, I think that is basically a useless specification unless there are going to be critical listeners well off-axis. As far as I'm concerned, the high directivity (and yes 'beaming') of these VOTT speakers is a virtue, not a liability. Good holographic imaging comes from the recording. Any sound coming from the walls of the room is distortion of the inherent spatial qualities of the recording. High directivity preserves as much of the recording's imaging qualities as possible.

I am not about to disagree with any of the above -- although when it comes to listening, I am a big fan of the (completely unaffordable, at my socioeconomic level) big ol' tar-filled multicell horns (e.g., 1505) coupled to a 288 family member.

Gary Kaufman's A5s -- augmented with a split 210 LF horn loaded with 515Bs acting as subwoofers.

As Rolls-Royce famously used to say of their engines' power specification:
"Adequate."

 

[MakeMineVinyl]

I am not about to disagree with any of the above -- although when it comes to listening, I am a big fan of the (completely unaffordable, at my socioeconomic level) big ol' tar-filled multicell horns (e.g., 1505) coupled to a 288 family member.

View attachment 160167
Gary Kaufman's A5s -- augmented with a split 210 LF horn loaded with 515Bs acting as subwoofers.

As Rolls-Royce famously used to say of their engines' power specification:
"Adequate."

A lot of people like those, and who am I to say they're wrong. From my own experience, the multi-cell horns / 288 drivers have problems, at least for home applications. The multi-cell horns were designed for movie theaters, and their purpose was to distribute sound in a wide swath into difficult areas like balconies. In a home, because of their rather wide dispersion, they would nullify the one advantage the VOTT horns have; that of very tight and specific directivity. The room would be a much larger contributor to the overall sound reaching the listener, and imaging inherent in the recording would suffer.

The 288 and all other such 'large format' drivers have the problem of more mass to the diaphragm due to it's 4" size. As such, high frequency response suffers, and falls off dramatically at around 9kHz at best. This wasn't a problem when these speakers were standard equipment in movie theaters because the optical prints (and even magnetic ones) didn't have appreciable HF extension in that area.

The use of a 'super tweeter' horn can fill in the HF in home use, but then the problem of time alignment between the two horns becomes a problem. The elegance of the A7 / A7-500 and most all of the VOTTs is that there is absolute physical time alignment possible because the LF and HF horn's voice coils can be aligned vertically. That time alignment is very important to preserving imaging in the recording, and adding yet another horn can compromise this benefit.

So overall, I think that the stock A7 / A7-500 combination of 811/511 style horns is optimum for home listening. The multi-cells are good, but just not for the home if imaging is important. Granted the multi-cells look impressive as hell.

 

[mhardy6647]

Too bad the 511B (and to a lesser extent the 811B) don't sound all that great...

EDIT: OK, I should mitigate that a little bit.
1) I did live, quite happily, with a pair of 811B and 806 family members for quite a while in the guise of a pair of 846A Valencias.
1a) Heck, I've still got a pair of Santiagos (which include some contouring as well as padding on the HF driver).
2) Both of the aforementioned Altec horns are far more palatable than the abominations being used by Col. Klipsch in the same era.
3) Either of the aforementioned Altec horns will behave, and sound, much better if crossed over well above their nominal cutoff/lower limit frequency.

1)
P1020753 by Mark Hardy, on Flickr
1a)
DSC_0870 (2) by Mark Hardy, on Flickr
2)
dampedcornyhornies by Mark Hardy, on Flickr

 

[MakeMineVinyl]

Too bad the 511B (and to a lesser extent the 811B) don't sound all that great...

Actually they do! If that wasn't the case, I wouldn't be still using the 511. The one thing that is mandatory however with these horns is that thick damping material (I used Aquaplas) must be applied to the whole exterior of the horn to stop resonances. Bondo automotive putty also makes an excellent damping material. About 3/8" to 1/2" over the horn flare works well.

 

[Vuki]

Altec 288k on 400hz jmlc horn with xover - on axis

 

[MakeMineVinyl]

Altec 288k on 400hz jmlc horn with xover - on axis
View attachment 160178

That's awfully uneven though, and would be very difficult to EQ out. The 'k' version undoubtedly uses the 'Tangerine' style phase plug, which I found to be very harsh sounding in all the drivers, and sounded like the response suggests. I'd stick with what you have in your original picture.

 

[mhardy6647]

Actually they do! If that wasn't the case, I wouldn't be still using the 511. The one thing that is mandatory however with these horns is that thick damping material (I used Aquaplas) must be applied to the whole exterior of the horn to stop resonances. Bondo automotive putty also makes an excellent damping material. About 3/8" to 1/2" over the horn flare works well.

sorry, I did back off a little on my comment; see the edited post. Yes, damping (actually mounting to a stiff baffle) does help -- but they're still ringy SOBs, especially left to their own devices.

I don't sell much. I did sell my 511Bs for what I paid for them... $75.
DSC_7275 (2) by Mark Hardy, on Flickr

The purchaser was, and remains, quite happy with them, in full disclosure.

 

[MakeMineVinyl]

sorry, I did back off a little on my comment; see the edited post. Yes, damping (actually mounting to a stiff baffle) does help -- but they're still ringy SOBs, especially left to their own devices.

I don't sell much. I did sell my 511Bs for what I paid for them... $75.

If sufficiently damped, they are as 'dead' as a rock, even the 511.

When I was an engineer at Altec at around 1980, the factory started spraying the exterior of these horns with Aquaplas because they knew the resonance problem.

 

[MakeMineVinyl]

sorry, I did back off a little on my comment; see the edited post. Yes, damping (actually mounting to a stiff baffle) does help -- but they're still ringy SOBs, especially left to their own devices.

I don't sell much. I did sell my 511Bs for what I paid for them... $75.
DSC_7275 (2) by Mark Hardy, on Flickr

The purchaser was, and remains, quite happy with them, in full disclosure.

Tell him to buy a 1 gallon can of Bondo. He'll be even happier.

 

[Vuki]

That's awfully uneven though, and would be very difficult to EQ out. The 'k' version undoubtedly uses the 'Tangerine' style phase plug, which I found to be very harsh sounding in all the drivers, and sounded like the response suggests. I'd stick with what you have in your original picture.

Not really. It deviates +/-2 dB from the straight line 800-9khz. At 13khz there's dia resonance which every aluminium dia 288 has. It goes away at 10°, just as the (intentional) slope up goes flat. I' m not sure one can get better FR with 288+any horn. I would have to see it to believe it.

 

[tuga]

Not really. It deviates +/-2 dB from the straight line 800-9khz. At 13khz there's dia resonance which every aluminium dia 288 has. It goes away at 10°, just as the (intentional) slope up goes flat. I' m not sure one can get better FR with 288+any horn. I would have to see it to believe it.

Have you tried a circular Tractrix or a JMLC?
And adding a tweeter above 8-9kHz?
It looks like it would work best in a 3- or 4-way configuration.

LeCleac'h measured the Altec 288 with two different horns at the ETF in 2010. His comments below:

Electrovoice 6040 horn (old version) + Altec 288-16G driver
Extended frequency response but with a positive slope from 230Hz to 15kHz.Smooth frequency response curve. Better to use that horn between 900Hz and 8kHz. Low distortion. Very low H3 over 400Hz. Note the 24dB rise of the level of the H2 component from 700Hz to 10kHz.
The group delay curve rises above 10 centimeters (= 0.3ms) below 600Hz.
Low level of reflected energy from mouth to throat.
Few diffractions between 1500Hz and 4kHz around t = 0.7ms and 1.4ms. HOMs above 8kHz.

JBL 2353 biradial horn + Altec Lansing 288-8K driver
Smooth frequency response between 600Hz and 8kHz. Low distortion. No H3 above 1000Hz but rapid rise below 900Hz.

The group delay curve rises above 10 centimeters (= 0.3ms) below 900Hz. Better to use that horn between 900Hz and 8kHz.
Reasonable amount of reflected energy from mouth to throat. Some diffractions. Noticeable breaking modes or HOMs above 8kHz.

 

[Vuki]

Have you tried a circular Tractrix or a JMLC?
And adding a tweeter above 8-9kHz?
It looks like it would work best in a 3- or 4-way configuration.

LeCleac'h measured the Altec 288 with two different horns at the ETF in 2010. His comments below:

Electrovoice 6040 horn (old version) + Altec 288-16G driver
Extended frequency response but with a positive slope from 230Hz to 15kHz.Smooth frequency response curve. Better to use that horn between 900Hz and 8kHz. Low distortion. Very low H3 over 400Hz. Note the 24dB rise of the level of the H2 component from 700Hz to 10kHz.
The group delay curve rises above 10 centimeters (= 0.3ms) below 600Hz.
Low level of reflected energy from mouth to throat.
Few diffractions between 1500Hz and 4kHz around t = 0.7ms and 1.4ms. HOMs above 8kHz.

JBL 2353 biradial horn + Altec Lansing 288-8K driver
Smooth frequency response between 600Hz and 8kHz. Low distortion. No H3 above 1000Hz but rapid rise below 900Hz.

The group delay curve rises above 10 centimeters (= 0.3ms) below 900Hz. Better to use that horn between 900Hz and 8kHz.
Reasonable amount of reflected energy from mouth to throat. Some diffractions. Noticeable breaking modes or HOMs above 8kHz.

Here it is. As one can see -even with oversmoothing (probably 1/3oct) it's not so linear as 288k on JMLC horn. There is same 13khz peak (smoothed here). The measurement of 288k/JMLC I posted is with no smoothing.

 

[Vuki]

Have you tried a circular Tractrix or a JMLC?
And adding a tweeter above 8-9kHz?
It looks like it would work best in a 3- or 4-way configuration.

I have 902 with round tractrix, but have not try it with 288. Tried super tweeter but didn't find it useful - 288 really goes to 15k and I don't feel that anything is missing. I like it in a 2way a lot.
Large 2way
Small 2way

 

[mhardy6647]

You know... I am both amused and heartened to find a hornie underground on this site.

DSC_7253 (2) by Mark Hardy, on Flickr

DSC_0457 (3) by Mark Hardy, on Flickr

 

[Longshan]

Haven't heard a horn that sounds great

These ones (Alexander 1103) sound amazing. Feels a bit weird playing them, but the tone is awesome.

 

[Tom Danley]

Not really. It deviates +/-2 dB from the straight line 800-9khz. At 13khz there's dia resonance which every aluminium dia 288 has. It goes away at 10°, just as the (intentional) slope up goes flat. I' m not sure one can get better FR with 288+any horn. I would have to see it to believe it.

A BMS 4550 on a 511 is a very good performer and extends the hf an octave, a new crossover, a change in ports and a 2226 woofer can extend the low end an octave too and at least keeps something Lansing haha

 

[Vuki]

A BMS 4550 on a 511 is a very good performer and extends the hf an octave, a new crossover, a change in ports and a 2226 woofer can extend the low end an octave too and at least keeps something Lansing haha

Fraltecstein

 

[Sal1950]

Bondo automotive putty also makes an excellent damping material

Bondo, an unusual product to use for dampening? It does become very hard after fully cured but I imagine a nice thick application would have positive results if from nothing else than it's pure mass.
I wrapped my old Klipsch LaScala's with something that I can no longer remember.
Quite often today when I see those TV commercials for that FlexSeal product I think about how it might just be the perfect substance to dampen something like the outside of an ole school horn. Comes in a very thick liquid form and could ultimately be applied about as thick as you wanted. Dries to a very pliable rubber like substance.

Thank goodness that's something we don't have to give much thought to with modern horn speakers.
In any case I'm not about to start tearing apart my JBL HDI-3600's, it might void my 5 year warranty. LOL

 

[tuga]

Bondo, an unusual product to use for dampening? It does become very hard after fully cured but I imagine a nice thick application would have positive results if from nothing else than it's pure mass.
I wrapped my old Klipsch LaScala's with something that I can no longer remember.
Quite often today when I see those TV commercials for that FlexSeal product I think about how it might just be the perfect substance to dampen something like the outside of an ole school horn. Comes in a very thick liquid form and could ultimately be applied about as thick as you wanted. Dries to a very pliable rubber like substance.

Thank goodness that's something we don't have to give much thought to with modern horn speakers.
In any case I'm not about to start tearing apart my JBL HDI-3600's, it might void my 5 year warranty. LOL

Not that your JBL are horns but which modern horn speakers are you taling about, Klpsches? I suspect that they're still being built "the old way"...

 

[Sal1950]

Not that your JBL are horns but which modern horn speakers are you taling about, Klpsches? I suspect that they're still being built "the old way"...

OH SORRY, Do I have to call the JBL's "wave guides" to be PC?
Yep I Guess.
At Klipsch there is no "old way" , There's only Paul W. K. way.