Search for the Gary Dahl build, which is up and running.
As everyone can tell, I'm in no hurry to build the successor to the Ariels. I still really like them, and after the last Rocky Mountain Audio Fest when Gary was visiting for a few days, he gave some insightful comments on the sound of the Ariels vs his new speakers. They do sound alike; the new speakers (as expected) have much better bass, better upper bass, and lower mids, while the Ariels still sound a bit more open. But that's not on a level playing field: the Karna is a more advanced amplifier than the Amity, and I have a bigger listening space that isn't as well-damped as Gary's listening room.
I'm not a fan of constant-directivity speakers with a 90-degree spread; I like a more open, more spacious sound, similar to the Ariels right now. That's why I'm reading parallel threads about the GPA-902 and 802-Alnico with great interest, because an additional 1" driver like that with an AH550 pointed up about 45 degrees might be an interesting way to create a more ambient sound than the Radian-745/AH425 by itself.
The dispersion of the AH425 at 10 kHz is getting pretty narrow, maybe 20~30 degrees wide, and although nominally flat on-axis, the room energy is getting pretty deficient compared to the direct sound. Although direct-sound dominates the spectral impression, room sound counts too, and if the room is getting too "dry", you'll hear it. The prospect of a Fostex or even more exotic supertweeter is appealing, but to be honest, most of the add-on supertweeters I've heard didn't add that much to the overall sound. A little, sure, but just a little.
The "bullet" style supertweeters (like the Fostex or Gotos) are only a little wider in dispersion than the AH425 at 10 kHz ... maybe 30 degrees instead of 20 degrees. Not a big difference in terms of room illumination in the 10~20 kHz range.
Although the Altec/GPA 802 and 902 drivers are kind of old-school with tangential creased-aluminum surrounds, they are a known-good match for the 416 driver, and might be just the ticket for a bit of extra sparkle above 7 kHz.
To that effect, a 7 kHz 2nd-order Bessel highpass filter, the driver and horn aimed at the first ceiling reflection, and the driver/horn time-aligned with the Radian745/AH425. The ceiling image is time-delayed, of course, but the off-axis sound from the small-format driver is time-aligned with the sound from the large-format driver.
Just a thought. Maybe something Gary or Pierre can experiment with, if they're curious.
As everyone can tell, I'm in no hurry to build the successor to the Ariels. I still really like them, and after the last Rocky Mountain Audio Fest when Gary was visiting for a few days, he gave some insightful comments on the sound of the Ariels vs his new speakers. They do sound alike; the new speakers (as expected) have much better bass, better upper bass, and lower mids, while the Ariels still sound a bit more open. But that's not on a level playing field: the Karna is a more advanced amplifier than the Amity, and I have a bigger listening space that isn't as well-damped as Gary's listening room.
I'm not a fan of constant-directivity speakers with a 90-degree spread; I like a more open, more spacious sound, similar to the Ariels right now. That's why I'm reading parallel threads about the GPA-902 and 802-Alnico with great interest, because an additional 1" driver like that with an AH550 pointed up about 45 degrees might be an interesting way to create a more ambient sound than the Radian-745/AH425 by itself.
The dispersion of the AH425 at 10 kHz is getting pretty narrow, maybe 20~30 degrees wide, and although nominally flat on-axis, the room energy is getting pretty deficient compared to the direct sound. Although direct-sound dominates the spectral impression, room sound counts too, and if the room is getting too "dry", you'll hear it. The prospect of a Fostex or even more exotic supertweeter is appealing, but to be honest, most of the add-on supertweeters I've heard didn't add that much to the overall sound. A little, sure, but just a little.
The "bullet" style supertweeters (like the Fostex or Gotos) are only a little wider in dispersion than the AH425 at 10 kHz ... maybe 30 degrees instead of 20 degrees. Not a big difference in terms of room illumination in the 10~20 kHz range.
Although the Altec/GPA 802 and 902 drivers are kind of old-school with tangential creased-aluminum surrounds, they are a known-good match for the 416 driver, and might be just the ticket for a bit of extra sparkle above 7 kHz.
To that effect, a 7 kHz 2nd-order Bessel highpass filter, the driver and horn aimed at the first ceiling reflection, and the driver/horn time-aligned with the Radian745/AH425. The ceiling image is time-delayed, of course, but the off-axis sound from the small-format driver is time-aligned with the sound from the large-format driver.
Just a thought. Maybe something Gary or Pierre can experiment with, if they're curious.
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Lynn,
Again a great set of posts by you. I am more in agreement with you on the wide dispersion rather than the E. Geddes very direct sound field concept. In my previous horn designs as I used in my avatar I went for the widest dispersion pattern I could achieve, more of a 90 degree dispersion pattern. How I did that was with very short and fast flaring horns, not a conic type horn with a very narrow dispersion path. You could walk across the room and be so far off axis with the opposite speaker and still clearly hear that side of the sound, there was no sharp cutoff zone where you could move and lose the opposite side. It does take more room treatment to keep side reflections down but that is more of what I have been after in my design concepts. As you say we all come to certain conclusions about what sound we like. I have worked in the opposite direction when doing Pro Audio PA speakers but I do think that is an entirely different situation, ignoring that would just lead to feedback problems in a live environment, different designs for different requirements. My latest consumer speakers are again a very different approach and concept, I have to think differently trying to make a small speaker sound like a large speaker and enclosure design is so very different also. It is a quest that some of us follow, others can argue about mythological perfection, I don't know how to get there. I don't expect to ever recreate an orchestral sound field in a small room without major electronic manipulation of the sound field and using many more than a single pair of speakers.
Again a great set of posts by you. I am more in agreement with you on the wide dispersion rather than the E. Geddes very direct sound field concept. In my previous horn designs as I used in my avatar I went for the widest dispersion pattern I could achieve, more of a 90 degree dispersion pattern. How I did that was with very short and fast flaring horns, not a conic type horn with a very narrow dispersion path. You could walk across the room and be so far off axis with the opposite speaker and still clearly hear that side of the sound, there was no sharp cutoff zone where you could move and lose the opposite side. It does take more room treatment to keep side reflections down but that is more of what I have been after in my design concepts. As you say we all come to certain conclusions about what sound we like. I have worked in the opposite direction when doing Pro Audio PA speakers but I do think that is an entirely different situation, ignoring that would just lead to feedback problems in a live environment, different designs for different requirements. My latest consumer speakers are again a very different approach and concept, I have to think differently trying to make a small speaker sound like a large speaker and enclosure design is so very different also. It is a quest that some of us follow, others can argue about mythological perfection, I don't know how to get there. I don't expect to ever recreate an orchestral sound field in a small room without major electronic manipulation of the sound field and using many more than a single pair of speakers.
What bothers me about conicals and near-conicals (with smoothed throat transitions) is the sharp edge of the dispersion pattern. As you walk around the speaker, the MF and HF suddenly "blink off" and all you hear is the rumble from the near-omnidirectional bass driver. This sounds very unnatural to me.
One of the hallmarks of a LeCleac'h horn is a very soft edge to the pattern; the soft edge is maintained at all frequencies, including the cutoff transition region. The overall pattern varies with frequency (it is not constant-dispersion) but there are no sharp edges. It behaves like a 3~4" direct-radiator mounted on a low-diffraction enclosure.
This, I suspect, is part of the reason for almost no horn sound at all. As you walk around the enclosure, it just gets duller sounding, like a direct-radiator. Completely unsuitable for PA and movie-theater sound, but it was never designed for those applications.
Impulse response and on-axis response are also very good; again, like a 3~4" soft-dome (if such a thing existed), but with greater headroom and lower distortion.
Since the AH425 mimics a 3~4" soft dome in many ways, I have little problem using a supertweeter ... this what you'd do if you were designing a speaker around a large dome midrange. A soft (or beryllium) dome covering 700 Hz to 7 kHz would be pretty special, and the AH425 has no problem with that range.
One of the hallmarks of a LeCleac'h horn is a very soft edge to the pattern; the soft edge is maintained at all frequencies, including the cutoff transition region. The overall pattern varies with frequency (it is not constant-dispersion) but there are no sharp edges. It behaves like a 3~4" direct-radiator mounted on a low-diffraction enclosure.
This, I suspect, is part of the reason for almost no horn sound at all. As you walk around the enclosure, it just gets duller sounding, like a direct-radiator. Completely unsuitable for PA and movie-theater sound, but it was never designed for those applications.
Impulse response and on-axis response are also very good; again, like a 3~4" soft-dome (if such a thing existed), but with greater headroom and lower distortion.
Since the AH425 mimics a 3~4" soft dome in many ways, I have little problem using a supertweeter ... this what you'd do if you were designing a speaker around a large dome midrange. A soft (or beryllium) dome covering 700 Hz to 7 kHz would be pretty special, and the AH425 has no problem with that range.
Not a bad suggestion, with the wide pattern going back-to-front (illuminating the back wall and sweeping up to the ceiling reflection), and the narrow pattern left-to-right.
This would be the same radiation pattern used in the latest Audio Kinesis speakers, and I can say from the A/B comparison I heard at the last RMAF show that it works well. (Duke handed me the controls for the array of back+up tweeters, and I'm pleased to say it has no negative effects on imaging, while improving the ambient impression quite noticeably.)
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Aren't you contradicting yourself here?
As I've have been advised, it would be a lot less risky of your time, effort and money to "go to a store and buy what you like". They may even let you borrow the speakers. That way you'll hear them in your room and with all of your electronics. Or at least you ought to bring that Pass XA30.5 amp of yours to the shop (Watch your back; two-man lift, that one).
Otherwise, if you must DIY it, try partnering with someone (hopefully within driving distance) who's got plenty of theoretical knowledge supporting a very particular speaker design that how he/she explains will achieve high performance in several critical areas. If those explanations really makes sense to you, offer to share the expenses for building it-after getting ball park prices on part and/or labor.
This way if one of you ends up liking the speaker more than the other, the one partner can afford to buy out the other. Likewise, if both of you like it then when, say, he pays you for your outlay for the parts-plus a percentage for shouldering the initial risk-you might catch some price breaks when you go to buy the same parts again.
And if neither of you like the sound of the speakers? Unlikely, thanks to prior precautions; in any case, each of you would have only lost half of what you'd otherwise would have spent. As they say, 2 out of 3 ain't bad (?) Am I making sense?
Just my 2 cents.
Hi Lynn,
Thank you for your comprehensive response.
As I wrote few times, my only purpose in posting here was to share my experience, I didn't seek any advice, since, AFAIK, faithful recreation of the sound of symphonic orchestra playing in a music hall with superb acoustics is unattainable, at any cost.
I shared it in this thread because of I thought that some people participating here could relate to my experience and frustration.
Apparently it didn't happen.
As for the DIY route, some parts of my setup are self-assembled, more than true DIY.
All my power cords are assembled from Neotech cables and Oyade plugs.
The isolation transformers are ordered to my specs from a local workshop, with line filters, power cords and power sockets assembled by me.
The preamp is based on IVC made by Tribute, followed by a buffer a la John Curl.
If and when I'll resume listening to music at home, I plan to build a phono stage and make some experiments with interconnects and speaker cables.
As for speakers.
I thought of listening to horn-based DIY speakers and, should I like them, copy the design. However, when in my living room the front wall is 2.64 meter away from my ears, horn-based speakers are probably inapplicable.
Thank you for your comprehensive response.
As I wrote few times, my only purpose in posting here was to share my experience, I didn't seek any advice, since, AFAIK, faithful recreation of the sound of symphonic orchestra playing in a music hall with superb acoustics is unattainable, at any cost.
I shared it in this thread because of I thought that some people participating here could relate to my experience and frustration.
Apparently it didn't happen.
As for the DIY route, some parts of my setup are self-assembled, more than true DIY.
All my power cords are assembled from Neotech cables and Oyade plugs.
The isolation transformers are ordered to my specs from a local workshop, with line filters, power cords and power sockets assembled by me.
The preamp is based on IVC made by Tribute, followed by a buffer a la John Curl.
If and when I'll resume listening to music at home, I plan to build a phono stage and make some experiments with interconnects and speaker cables.
As for speakers.
I thought of listening to horn-based DIY speakers and, should I like them, copy the design. However, when in my living room the front wall is 2.64 meter away from my ears, horn-based speakers are probably inapplicable.
I see no contradiction, the two quotes are complementing one another.
So far I haven't heard any speakers that are more to my liking than my present ones.
On top of that, replacing the speakers probably wouldn't eliminate my frustration, since, AFAIK, faithful recreation of the sound of symphonic orchestra playing in a music hall with superb acoustics is unattainable, at any cost.
AFAIK, there is no such person in my country.
There is one person in my country with horn-based DIY speakers, however, when in my living room the front wall is 2.64 meter away from my ears, horn-based speakers are probably inapplicable.
Again, AFAIK, faithful recreation of the sound of symphonic orchestra playing in a music hall with superb acoustics is unattainable, at any cost. So I don't see that my frustration can be eliminated, neither by purchasing anything not by going the DIY route.
Since I portrayed the source of my frustration quite a few times in this thread, probably too many times – yet people don't get it – I see no point in repeating myself anymore. It isn't likely that further repetitions will change the situation.
Therefore this is my last response in this thread to any suggestions about improving my present sound setup.
Should there be any suggestion that I'll find applicable I'll act upon it – but I wouldn't continue the discussion here.
Thank you all for your good will and willingness to assist and contribute.
There's life outside the villiage
Tom Danley and an unlimited budget has a track record of producing things that people faithfully believe impossible.
Tom Danley and an unlimited budget has a track record of producing things that people faithfully believe impossible.
What is more important, enjoyment is not a function of accuracy, nor it is a proprietary right of expensive stuffs.
My neighbor like to play piano. But recorded piano sounded much better in my home
If your wife's barbeque doesn't taste good, it is probably not because your tounge is used to the tender loin at Four Seasons, but most probably because your wife cannot cook The Fostex FT 90 H which I am using were measured as part of a review by Jean Hiraga for La Nouvelle Revue du Son in the early 80's. They measured at 30° (compared to on axis): -1dB at 10 kHz and -5dB at 15kHz.
Comments on the measurements (translated) from the review:
"If one compares the measurements to other high quality tweeters, one notices that the FT 90 H is much more linear than the competitors.
We can say that the FT 90 H is one of the tweeters with the least distortion even at high level"
If I look at the measurements of the T900 (HobbyHifi 1/2005), the same can not be said: less linear, much higher distortion.
Comments on the sound by Jean Hiraga and colleagues:
"great transparency, very sweet, remarkable separation between notes ...
On classical music this is the best tweeter we have ever heard.
The delicateness and the beauty of the upper harmonics can totally modify a high quality high efficiency speaker system that with other tweeters will appear more aggressive".
In the NRDS review the FT 90 H replaced the T925 which they normally used in their l'Audiophile Onken style system.
The above is also my experience, but the interesting point to make is that there are huge differences between these tweeters even from the same manufacturer. So if you might have heard some, it does not tell the whole story of what is possible.
I use the Altec 808-8B with the 909-16A membranes. As far as I know the only difference between an 802 and 808 is the membrane. I was able to compare the 802, 808, 909 and Radian membranes, and preferred the 909-16A membrane for the upper midrange - lower treble duties. In the past I have also used these on a smaller horn equalized in the upper frequencies without supertweeter. The very high Q 19kHz resonance was very slightly detectable.
Thank you, Peter! All good information to have, especially about the substantial differences in performance between the different Fostex supertweeters.
I'm still attracted to the idea of directivity correction with an additional tweeter with just a bit of "super" in it. The AH550, and possibly one of the small AutoTech horns, look like good choices for the small-format Altec/GPA tweeters. The sonics (and EQ) of an ambience retrieval tweeter are somewhat different than the main, on-axis MF/HF driver, and Duke LeJeune of Audio Kinesis pointed out that the benefits are still there if the level is -6 dB below the main tweeter. So there's lots to play around with.
I'm still attracted to the idea of directivity correction with an additional tweeter with just a bit of "super" in it. The AH550, and possibly one of the small AutoTech horns, look like good choices for the small-format Altec/GPA tweeters. The sonics (and EQ) of an ambience retrieval tweeter are somewhat different than the main, on-axis MF/HF driver, and Duke LeJeune of Audio Kinesis pointed out that the benefits are still there if the level is -6 dB below the main tweeter. So there's lots to play around with.
Hi, sorry for the two cents question : If this sort of driver could be in the Lynn's tastes : an Heill Ess AMT v1 near the AH550 ? Just to enlight the room with transcient and little détails.
It is said to sound very well above 5k to 7k Hz. But at these frequencies, I don't know if it's possible center to center with the AH550 ? Not talking about the time alignement in relation to the rear body of the horn (in case of passive filter - no DSP time treatment).
But as a rear open driver maybe it's not so important (cardioid or foam casing in the rear of it to lower the front wall signature ?)
Were AMT given up because unpossible for this project ? (by taste or technical issues in relation to the other chosed drivers)
(I often read for what it worths on some french forums than FT96H is as bad than FT90H was "very" good... ; no real good bullet tweeter from Fostex today !)
It is said to sound very well above 5k to 7k Hz. But at these frequencies, I don't know if it's possible center to center with the AH550 ? Not talking about the time alignement in relation to the rear body of the horn (in case of passive filter - no DSP time treatment).
But as a rear open driver maybe it's not so important (cardioid or foam casing in the rear of it to lower the front wall signature ?)
Were AMT given up because unpossible for this project ? (by taste or technical issues in relation to the other chosed drivers)
(I often read for what it worths on some french forums than FT96H is as bad than FT90H was "very" good... ; no real good bullet tweeter from Fostex today !)
Or sideways, or 45 degrees.
I was never happy with the tweeter, but my ears were a lot younger then. I usually turned it off when I used his Altecs. It did add something, but it was something a little to fake for my taste. No one else seemed to mind it.
Exactly Pano. I never liked that concept either; it always introduced some kind of unnatural image smear.Or sideways, or 45 degrees.
Not sure my ears are that sensitive to smear, as many are. For me the gripe was tonality.
Tweeters do help the warmth of strings, but otherwise they just sound glued on and unnatural to me. I don't hear those shimmery tweeter sounds in nature. Natural sounds just blend, I'm not conscious of the top end at all. Not easy to get right.
Getting the balance of warmth vs natural isn't easy. At least not for me.
Tweeters do help the warmth of strings, but otherwise they just sound glued on and unnatural to me. I don't hear those shimmery tweeter sounds in nature. Natural sounds just blend, I'm not conscious of the top end at all. Not easy to get right.
Getting the balance of warmth vs natural isn't easy. At least not for me.