Beyond the Ariel

[oltos]

If we have two constant directivity wave guides and one with significantly higher directivity than the other, the wave guide with the higher directivity will give a measurement that shows a significant clear impulse response. The increase in indirect sound only increases comb-filtering, group delay and decay.

. iirc they produced a very dynamic sound and a deep sound stage at the sweet spot (they are there). If you can live with this quite narrow listening window, then it is fine for you. It is easy to design a narrow and constant horn, but you will not find it anymore in the market because the demand has changed towards much wider coverage.

I guess my main concern with the AH425 vs any or all of these

https://www.audioheritage.org/vbulletin/showthread.php?31481-Are-Iwata-horns-that-good

https://exclusive-audio.jp/en/produ...UlrNo9mZj1W2blrSpPdTxbT7vU3bt6DRwHuTxFXMQnQ27
https://exclusive-audio.jp/en/produ...kO2Qsk_XOsTAMx0VyaaNGPc79bGp20OSJEoFIf4egjr3A

https://josephcrowe.com/products/3d-cad-plans-for-es-290-biradial-horn-horn-no-1670
https://cdn.shopify.com/s/files/1/0...BMS_4591-8_off-axis3_480x480.png?v=1649504045

https://josephcrowe.com/products/3d-cad-files-horn-no-1994-es450-biradial-for-jbl-2446-2-throat
https://cdn.shopify.com/s/files/1/0...ot_2023-10-14_170306_480x480.png?v=1697317415

is that at least for critical stereo/mono music listening (as opposed to movie/dialogue soundtracks?), I would expect that I would want both a wide and deep sound stage.

 

[weltersys]

Why can't I find any directivity plots for the AH425 in this GedLee https://cdn.shopify.com/s/files/1/0...BMS_4591-8_off-axis3_480x480.png?v=1649504045 or in that (?) format for the JBL horns from your last post?

Probably because nobody has actually accurately measured the polar response of the AH425.
Never received a response when I asked about them over 10 years ago:

Post in thread 'Beyond the Ariel'

2013-11-23 11:01 pm

Comparison of AH425 and CD waveguide at 1 kHz.

Lynn,

Since you did not answer the question I posed:

"What is the -6 dB beamwidth of the horn you are using in the "Beyond the Ariel" prototype at 500, 2000, 4000, 10,000 Hz?"

And then posted simulations, rather than measurements, am I correct in assuming you have not measured the actual polar response of the horn (or woofer) you are using in the "Beyond the Ariel" prototype?

Art

• weltersys

Certainly not holding my breath since then.

I guess my main concern with the AH425 vs any or all of these is that at least for critical stereo/mono music listening (as opposed to movie/dialogue soundtracks?), I would expect that I would want both a wide and deep sound stage.

Why don't you simply listen to your AH425's and confirm or deny your expectations of what type of sound stage you perceive with the music you enjoy?

 

[Robh3606]

Not when you move off axis.... when you move past the sweet spot.

Hello

Don't you have to move off axis to get out of the sweet spot? 10-15 degrees is a very narrow window.

Clarity increases with directivity. The higher the DI, the less indirect sound that is created. Indirect sound can be argued to be a form of distortion. This increasing clarity is not subjective and can be measured. If we have two constant directivity wave guides and one with significantly higher directivity than the other, the wave guide with the higher directivity will give a measurement that shows a significant clear impulse response.

So you are defining the increase in clarity by a reduction reflections. In what kind of acoustic environment? In a typical sized room we would listen in with typical furnishings or worst case.

When I tried Heils I found that reducing the backwave did indeed sharpen imaging. That is an extreme condition WRT reflections

I have compared CD vs Exponential that does indeed narrow up to 10-15 degrees last couple octaves but didn't notice an increase in clarity.

Why would you see that in the impulse response which is gated before the reflections can pollute the measurement? Like a CSD as an example.

Rob 🙂

 

[marco_gea]

I think that the original Iwata profile would fit to your needs / expectations:
https://www.audioheritage.org/vbulletin/showthread.php?31481-Are-Iwata-horns-that-good

It is looking very nice and seems to have good acoustic loading. Personally, I don't like the jmlc Iwata variant.

Another option but maybe much more expensive are the Yamamoto horns without fins SS-500 or better SS-300.

I use the Yamamoto SS-300, and I can confirm that, for me at least, they are the end game in all of this.

 

[marco_gea]

"A system which has a rising on-axis DI cannot be successfully equalized, because the on-axis response will tend to rise at high frequencies."
Might this mean for example that you can equalize the Radian745Be/TH4001 combo for relatively flat off-axis response but not the same driver in the AH425 horn?

The TH-4001 isn't fully constant directivity either (only approx. constant on the horizontal plane).
But, context is important. That JBL quote comes from optimising horns for theaters and live PA, where coverage of large swathes of audience with the same frequency response is the most important goal, while some coloration due to diffraction is an acceptable compromise.
For critical listening at home, or in a mixing studio, the priorities are different, and those same constant directivity horns that JBL was advocating for in that very same document would NOT be preferable at all, vs. either the TH-4001 or the AH425.

 

[Robh3606]

For critical listening at home, or in a mixing studio, the priorities are different, and those same constant directivity horns that JBL was advocating for in that very same document would NOT be preferable at all, vs. either the TH-4001 or the AH425.

Well the 4430/35 used diffraction horn and were JBL's best large format monitor sealers and longest lived in their catalog. I would say there are two sides to that and you may not find them acceptable. That doesn't make it universal and many people still like the 2344. It's not perfect but neither is any other horn/waveguide.

This is an interesting read.

https://www.audioheritage.org/vbulletin/showthread.php?4408-JBL-Technical-Notes-Volume-1-Number-15

Rob 🙂

 

[camplo]

In the spirit of the origin of this thread, we’re not breaking any new ground here folks……new clothes for old ladies is all I can take away from the past 4-5 years this thing has lingered on. Sounds great to some……but just smells like mothballs and cedar to me. These huge systems kinda remind me of vintage seaman’s trunks…..too much nostalgia being repurposed here for sale in the new age audio thrift store. And mostly from old dudes whose outer ear waveguide is collapsing under its own weight, desperately trying to recapture their aural acuity.

Fellas…..get a really comfy chair, a great pair of Audeze headphones and embrace your seniority. Close your eyes, Add in a little aroma therapy and I guarantee that all the sights and sounds of a Friday night at The Blue Note will come rushing in like waves.

Yeeeeaaaah..... No 😂

Physics on earth remains. Large sizes are a require to create high efficiency and high directivity.

Don't you have to move off axis to get out of the sweet spot? 10-15 degrees is a very narrow window.

Yes but when I see people describe these type Horns and the head in vice comments immediately think ok anything past 0 degrees, dead on axis, and the HF will significantly. Instead the sweet spot doesn't seem to whither without a good amount of leaning from one side to the other, I think, who rocking side to this hard while listening. I haven't moved off axis one time while typing this post and I'm not even listening to anything right now. at 1 meter a one person experience for those type horns, but further back it does widen. I would always judge by -3db 20khz when looking at any polars I've been able to find or simulate. If I were to use 7000khz sweet spot calculation is much wider. One thing that did come true which was said by JMLC himself, iirc, HF doesn't wither until you cannot see the throat of the horn, but of course, wall angle equates to directivity commonly.

I have compared CD vs Exponential that does indeed narrow up to 10-15 degrees last couple octaves but didn't notice an increase in clarity.

You have done what I wish to do. The best I could do is source measurements of an Gedlee Abbey and the comb filtering was much higher, at a lower spl and closer distance than my measurements. Both rooms had hard surfaces, and the Abbey room had some acoustic treatment. my take away though a very crude comparison, was that the wider wall angles simply caused more comb filtering.

The abbey at 30" and my horn at 36"? though possibly 54" we'll say 36" to be safe

You said you compared? Where are your measurements???? Ears lie measurements don't

 

[camplo]

Why would you see that in the impulse response which is gated before the reflections can pollute the measurement? Like a CSD as an example.

First sorry for the miss typings in my reply above. I had only been awake for about five minutes at that point. Also did not check the window setting on those measurements, to make sure that they were identical. Normally, I set the right window to 500 ms.That is plenty enough time to allow reflective data... I think.

 

[swak]

Personally, I don't like the jmlc Iwata variant.

What did you dislike from it? What was your listening distance and distance from side walls? What horn(s) did you prefer in that same setting?

 

[camplo]

I guess my main concern with the AH425 vs any or all of these

is that at least for critical stereo/mono music listening (as opposed to movie/dialogue soundtracks?), I would expect that I would want both a wide and deep sound stage.

Regarding your geddes quote, just know that hes in agreeance with how I described narrow vs wide dispersion. You are there or they are here is slang so of course one might use them inversely but still mean the samething, that is; higher DI = more direct sound dominate listening, lower DI = inceasingly indirect sound contribution. The only source of direct sound is your loudspeakers. The only source of indirect sound are from the reflections and excited room modes.

 

[Robh3606]

First sorry for the miss typings in my reply above. I had only been awake for about five minutes at that point. Also did not check the window setting on those measurements, to make sure that they were identical. Normally, I set the right window to 500 ms.That is plenty enough time to allow reflective data... I think.

I am not talking about a raw measurement. A gated one like 5 msec for CSD or period limited for Wavelet. If you are using a raw 500ms you are going to have all type of reflections in the measurement. Are you including the room response?

Is that a Stereo pair?

A single with reflections included?

What are you using? Rev? I use CLIO 7.11 and CLIO Pocket 3.

What smoothing are you using? That saw tooth is typical of any measurement with high resolution say 1/24 as an example. Why do you say it's comb filtering which is basically benign in many cases.

How are you quantifying what you posted is indeed comb filtering and determining how audible it is?

You said you compared? Where are your measurements???? Ears lie measurements don't

I have gated and ungated single system measurements.

Rob 🙂

 

[marco_gea]

Well the 4430/35 used diffraction horn and were JBL's best large format monitor sealers and longest lived in their catalog. I would say there are two sides to that and you may not find them acceptable. That doesn't make it universal and many people still like the 2344. It's not perfect but neither is any other horn/waveguide.

This is an interesting read.

https://www.audioheritage.org/vbulletin/showthread.php?4408-JBL-Technical-Notes-Volume-1-Number-15

Rob 🙂

I wouldn't for a minute consider a 1" JBL titanium compression driver on a small "butt-cheek" diffraction constant-directivity horn, such as those in the 4430 & 4435 monitors, even remotely in the same league as a 2" TAD beryllium driver on the TH-4001 horn.

They are worlds apart in terms of sound quality (if properly implemented and filtered, of course). And they were contemporaries (both 80s technology).

 

[mayhem13]

Yeeeeaaaah..... No 😂

Physics on earth remains. Large sizes are a require to create high efficiency and high directivity.

I dunno.......an open back pair of planar headphones are pretty darn small, extremely efficient and offer the absolute finest directivity.....plus you don't have to worry about those sagging deformed waveguides hanging off the side of your head. i know you like to argue a point to frustration, but clearly you've missed the mark here.

 

[docali]

What did you dislike from it? What was your listening distance and distance from side walls? What horn(s) did you prefer in that same setting?

I don't like the shape and the look of this horn. Besides this, I have simulated the jmlc iwata and it is published on my site. There is a beaming character of that horn, and the polar have a knee. So, also technically not my cup of tea

 

[Robh3606]

I wouldn't for a minute consider a 1" JBL titanium compression driver on a small "butt-cheek" diffraction constant-directivity horn, such as those in the 4430 & 4435 monitors, even remotely in the same league as a 2" TAD beryllium driver on the TH-4001 horn.

You are entitled to your opinion but that's not the point. Your original post said they were not suitable for the use they were designed for. Considering they were sold for 20 years and used in mastering and monitoring even after they were out of the catalog I would have to say many do not share your opinion.

I am not saying the TAD's can't outperform them just that your opinion is not universal.

Rob 🙂

 

[camplo]

at least for critical stereo/mono music listening (as opposed to movie/dialogue soundtracks?), I would expect that I would want both a wide and deep sound stage

Overtime I've come to the conclusion that when people say a wide and deep soundstage, combined with the fact that I know that soundstage is just another word for, imaging. All you're saying is that imaging, which is just another word for accuracy, is very high/good. This, in my opinion, can be seen in the measurements.

You'll never hear people say the imaging was deep but narrow... or the imaging was wide but shallow. People like the sound of their own voice and using adjectives as about it.

 

[camplo]

I have gated and ungated single system measurements.

Do you mind sharing the impulses of each? We can pull those up in rew

 

[camplo]

This is one of the reasons that I actually prefer the old single frequency polar graphs, you can see what is happening at individual frequencies and these details are not lost in the singular polar plots as we are seeing in these last few posts. Yes it is more difficult to see overall what is happening but the resolution of the details is not lost. There is nothing wrong with seeing an overall detailed map as just shown, but it does not tell the entire story.

What is the issue really? Isn't it just people using low resolution data, that is, averaged/smoothed data to make their results look better than they really are?

 

[camplo]

A system which has a rising on-axis DI cannot be successfully equalized, because the on-axis response will tend to rise at high frequencies."

Maybe stop polluting yourself with info other than this board and you wouldnt be in a constant state of confusion.

A system with a rising DI can be equslized on axis. EQ isn't used to address anything off axis, period...

 

[swak]

I don't like the shape and the look of this horn. Besides this, I have simulated the jmlc iwata and it is published on my site. There is a beaming character of that horn, and the polar have a knee.

I did not consider you were basing your judgement on looks or simulations.