Chris
I usuaully see this as less effective. There is not much that you could ask or say that I have not heard before and answered. It just seems to me that time is saved by allowing everyone to hear the questions and answers. Keep the conversation respectful and I'll participate.
That's all very well, but I repeat my point - what does modulation distortion have to do with imaging ? Precious little. Diffraction, on and off axis frequency response, polar response curves and so on do. Whether or not modulation distortion is important for other aspects of the performance and by how much is not relevant to imaging characteristics.
On the contrary, it's the predominate audio industry opinion that achieving very low distortion is important, and a lot of continuing effort is expended in that direction, but this opinion is held contrary to all the studies that show an extremely poor correlation between measured distortion and perception of quality, dating back as far as the works of Toole.
The engineering part of the audio world keeps working on further optimising parameters like distortion that the research side of the industry have already shown are of relatively low importance in perceived quality.
You've obviously read Earl's papers on the audibility of distortion and group delay, this is what I'm talking about.
So you say, but first you have to sort out and isolate all the different variables in a controlled way.
Just because the wave-guide sounds better (which I definitely agree, I've been a fan of waveguides for a long time now) and the measured distortion is typically lower does not show causation when there are so many other differences in the performance that introduce confounding variables.
The point of my original post was to draw attention to these other virtues of waveguides that are often overlooked and to provoke a bit of thought and discussion into whether it is in fact things like diffraction reduction that are one of the key attributes that improve sound quality rather than differences like lower distortion that are taken for granted as being the explaining differences.
Your "lower distortion is why waveguides sound better" falls on its face when you compare a good quality dome tweeter with a good quality similar sized waveguide loaded ribbon. The ribbon sounds clearly better, smoother, cleaner, more realistic, images better etc, yet it has quite significantly higher measured distortion than the best dome tweeters.
Why does it sound better if distortion measures worse ? People like Zaph would have us believe that people prefer the sound of distortion if they prefer the sound of a ribbon over a dome, but that's nonsense.
The logical answer is that although the distortion of the ribbon is a bit higher it is still low enough and that it measures better in some other more important way. So what is this other attribute it possesses ?
That's the question isn't it, and I don't know the answer, although I suspect that freedom from breakup resonances and very low baffle diffraction due to the waveguide are probably key points, both of which contribute to narrowband smoothness in frequency response on and off axis, although I think there's also more to it than just the frequency response differences.
My point is the easy obvious answer is not necessarily the correct one, and we can't assume causation from correlation...
Last edited:
Answer
Gentle Cue
The Genesis of the gentle cue can be traced here http://www.diyaudio.com/forums/multi-way/213123-why-2nd-order-best-not.html
After going through labour, the off spring was born here http://www.diyaudio.com/forums/multi-way/214896-gentle-cue.html
Gentle Cue
The Genesis of the gentle cue can be traced here http://www.diyaudio.com/forums/multi-way/213123-why-2nd-order-best-not.html
After going through labour, the off spring was born here http://www.diyaudio.com/forums/multi-way/214896-gentle-cue.html
Last edited:
Do you have a link to that material? Do the tests that you reference, "significantly higher measured distortion" include AM and FM distortion tests.
My guess: the horn-loaded (oops..."waveguide-loaded") ribbon probably has quite a bit less FM distortion than your dome tweeter. I've yet to see standard test results on drivers or driver/horns include data on AM or FM distortion, even though though the test procedures exist for taking them (...see the Klippel article, above).
Chris
I hope that you are also being respectful in your reply.
No, these questions don't need to be on the forum, but they are respectful, albeit a bit probing on your referenced reports, and on topic.
However, it will have to wait for a little while - it is Saturday night in the U.S....
Chris
If by AM and FM distortion tests you mean two tone testing with widely separated tones then no, I don't have anything to hand, however I highly doubt that FM modulation is a significant issue with a tweeter because for the phase modulation of the high tone to be sufficient the low tone has to be low enough in frequency to produce a lot of excursion relative to the high tones wavelength, and that just isn't going to happen with a 3Khz+ crossover frequency.
AM distortion is in the same boat - significant excursion would be required. The main sources of distortion in a tweeter with a high pass filter are going to be plain old non-linearity which will show up in harmonic and (closely spaced) two tone testing.
You can find some examples of both measurements here:
Zaph|Audio
(Be warned, Zaph is very anti-ribbon
)Ever considered that perhaps the reason why you haven't seen the data is that it just isn't all that important once a certain minimum threshold of performance is reached ? Just because we have the technology to measure all kinds of cool things in minute detail doesn't necessarily make the data useful, nor does it guarantee that it translates directly into audible differences.
If you've never seen published AM/FM distortion data on drivers how can you be so sure that it is the explanation for the differences you hear ?
Last edited:
Doppler distortion in loudspeakers
Quoting:
"The results were intriguing. Distortion of the flute was gross at 10mm peak diaphragm displacement and not in the least bit euphonic. On the contrary, Doppler made the sound as harsh as you might expect of a distortion mechanism that introduces intermodulation products. At 3.16mm peak displacement (below Fryer's suggested detectability threshold) the distortion level was obviously lower but still clearly audible; and even at 1mm it could still be heard affecting the flute's timbre and adding 'edge.'
Everyone who uses a two-way speaker (me included) can take heart from the fact that most music signals are less revealing of Doppler distortion than this special brew. But these findings undermine the view, widely accepted in the last two decades, that Doppler distortion in loudspeakers is not something we should trouble about. Having done the listening, I side with Moir and Klipsch more than with Fryer, Allison, and Villchur on this issue—something that may come as no surprise to anyone who has heard the effects of low-level jitter and sees where the Fryer criterion appears in fig.2.
It has often been claimed that, with a two-way speaker, there are audible benefits to using a crossover frequency below the typical 3kHz, the usual explanation being that this removes the crossover from the ear's area of greatest sensitivity. But I wonder. Perhaps this not-uncommon experience actually has much more to do with the D word. A three-way solution is potentially even better. Three-way speakers bring new design challenges, of course, in particular the need to achieve another perceptually seamless handover between drivers. But from the Doppler perspective, having a crossover for the bass driver at 400Hz or 500Hz is, unquestionably, better."
The notion that FM (or AM) distortion isn't audible doesn't pass the "gut test" - sorry.Everyone who uses a two-way speaker (me included) can take heart from the fact that most music signals are less revealing of Doppler distortion than this special brew. But these findings undermine the view, widely accepted in the last two decades, that Doppler distortion in loudspeakers is not something we should trouble about. Having done the listening, I side with Moir and Klipsch more than with Fryer, Allison, and Villchur on this issue—something that may come as no surprise to anyone who has heard the effects of low-level jitter and sees where the Fryer criterion appears in fig.2.
It has often been claimed that, with a two-way speaker, there are audible benefits to using a crossover frequency below the typical 3kHz, the usual explanation being that this removes the crossover from the ear's area of greatest sensitivity. But I wonder. Perhaps this not-uncommon experience actually has much more to do with the D word. A three-way solution is potentially even better. Three-way speakers bring new design challenges, of course, in particular the need to achieve another perceptually seamless handover between drivers. But from the Doppler perspective, having a crossover for the bass driver at 400Hz or 500Hz is, unquestionably, better."
I'm beginning to see a pattern. If you, for the moment, take the notion that modulation distortion IS audible, and at very low percentage levels, even for "pure tones" like the flute, then the effect of going 3-way or 4-way for direct radiating speakers is to limit modulation distortion.
I've done this same technique with tapped horn subs (17-40 Hz nominal passband) in order to limit distortion. However, if you consider the use of inheritly-low modulation distortion devices (horn-loaded, that is), then two-way speakers are possible while still holding down FM distortion at high frequencies. I've found that having crossovers above ~500 Hz are problematic and introduce their own significant issues.
One more topic to throw in: cabinet diffraction...if your midrange-to-high frequency horn is sufficiently sized, it will not lose pattern control at low frequencies due to limited mouth size. This results in limiting cabinet diffraction issues (I've personally heard this demonstrated in the Klipsch chamber in Hope). However, if "small speakers, small horns" is so important to you, you will be dealing with cabinet diffraction issues, and they don't sound very good to my ears.
Just my $0.02.
Chris
Last edited:
Here is another link from the same author that I believe is saying what I'm thinking, and also affirms (at least partially) what GedLee has said elsewhere:
Euphonic Distortion: Naughty but Nice?
Chris
Euphonic Distortion: Naughty but Nice?
Chris
is there any news to this? is there any explanation now why waveguided tweeters sounds better?
i have just discovered waveguided tweeters, i had an old pair of monacor dt300 and wg300 (the guides fitted very poorly to the tweeters by the way) on the shelf that i putted into my system the other day. i hade earlier rejected these as nonsens, too narrow beaming for my taste. but now, in my latest room, they sound just superb, best so far! i think i hear a lot more details and the music or sound field has more body and directness to it, everything sounds bigger and more real, more physical, it is almost like more air is vibrating, more energy in the sound field.
if it only where just as easy to judge sounds and soundfields as it is to judge a picture for correctness or artistics
i have just discovered waveguided tweeters, i had an old pair of monacor dt300 and wg300 (the guides fitted very poorly to the tweeters by the way) on the shelf that i putted into my system the other day. i hade earlier rejected these as nonsens, too narrow beaming for my taste. but now, in my latest room, they sound just superb, best so far! i think i hear a lot more details and the music or sound field has more body and directness to it, everything sounds bigger and more real, more physical, it is almost like more air is vibrating, more energy in the sound field.
if it only where just as easy to judge sounds and soundfields as it is to judge a picture for correctness or artistics
cool, i bet they sound excellent
i have a pair of 27tff on my shelf not in use and have had the same thought to buy wg148r after seen heissmanns results, Test Seas Noferro-900 Visaton Waveguide WG-148R
please let me know how yours turns out
cool, i bet they sound excellent
i have a pair of 27tff on my shelf not in use and have had the same thought to buy wg148r after seen heissmanns results, Test Seas Noferro-900 Visaton Waveguide WG-148R
please let me know how yours turns out
Did either of you get around to trying the Seas in the WG148?
Results?
After reading this, I'd like to know if you have any guesses why the Salon 2 beat the M2 in the AVS Forum shootout.
Speaker Shootout - two of the most accurate and well reviewed speakers ever made | Page 18 | AVS Forum
I haven't read expert opinion on the outcome. It's something that still confuses me.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.