While large enough group-delay distortion could inded make a downward swoop out of a short wideband signal (like turning a click into something like "peeeuuuu" *) I have a hard time to believe that speakers have that extreme group-delay distortion. But I will try it out with that song. I could even leave the speakers out and use a DSP to generate group delay until it is perceived easily on headphones.
Edit: I forgot to mention that natural instruments and our hearing do also have some intrinsic group-delay distortion. This may probably also cause a base drum being perceived as swoopier on a really wideband system without group-delay distortion than on a LF restricted one ( "defrauding" the lower parts of the spectrum) with group-delay.
Regards
Charles
* one natural occurence of this effect are the so-called whistlers. Whistler (radio) - Wikipedia.
Last edited:
Agreed there is scant evidence.
Imo, it is very rare to read of a test that properly isolates group delay audibility (or relative phase shift audibility, being the same thing.)
What evidence that does exist, leads to that it is increasingly more audible the lower the frequency, and perhaps the higher the SPL. Conclusions I share.
Bjorn just posted a relevant paper in the Hornresp thread, owing to group delay discussion there too.https://www.diyaudio.com/forums/subwoofers/119854-hornresp-1203.html#post6625738
Here's a quote from Section 3.3 of the linked paper, where the paper talks of adding perceptual evaluations to its objective research methodology.
"The same conclusion was reached when
evaluating excess-phase systems, where the magnitude was fixed but increasing low-frequency
phase shifts were simulated. The findings from this latter experiment were notable, as it was
observed that phase distortion of the order introduced by loudspeakers at low frequencies is
definitely audible, even to the majority of non-expert, untrained listeners when using music for
audition. "
My own experiments with phase flattening/group delay elimination ....
....as low in frequency as possible, listened to outdoors in mono with a single powerful sub,....... make me strongly agree.
It's low-end time domain audibility and how it foundationally impacts the entire musical experience imo. And it needs a single non-reflected source to be easily heard and fully appreciated, ime.
Indoors it's of course harder to hear, especially with stereo and/or multiple subs.
I've found once my ears are trained outdoors, i know what to listen for indoors.....(and almost always end up crying having to come back inside
)
My system is not symmetrical in the room currentl...one side I have 40ms at 40hz on the other 15ms...the lower side is also just about corner loaded....I can remember looking at the left woofer (not in the corner) while noticing how something different was going on there vs what I was hearing in my headphones. If that don't solidify the idea that the room dominates at bass levels nothing does lol...
What got me looking was a session of thought concerning bass quality and the idea that an 808 sends the whole signal at the same time....so why could I here the transient before melodic boom.....put on my headphones and the difference between the two was indistinguishable....went back to the loudspeaker and I could hear a noticeable gap between the transient and the lower melodic note.....
To be fair sometimes 808's tend to be a very fast signal sweep from high to low anyway....its just that this there was a difference in that time from system a to system b..headphones are obviously not lacking in performance in that area....
I can notice a 10ms delay on my keyboard input....definitely a 20ms.....my dsp probably as 1.5ms to that already...
What got me looking was a session of thought concerning bass quality and the idea that an 808 sends the whole signal at the same time....so why could I here the transient before melodic boom.....put on my headphones and the difference between the two was indistinguishable....went back to the loudspeaker and I could hear a noticeable gap between the transient and the lower melodic note.....
To be fair sometimes 808's tend to be a very fast signal sweep from high to low anyway....its just that this there was a difference in that time from system a to system b..headphones are obviously not lacking in performance in that area....
I can notice a 10ms delay on my keyboard input....definitely a 20ms.....my dsp probably as 1.5ms to that already...
Interesting concept that should work, as long as you cross the 10s low, which is definitely possible with the RCF 4" drivers. The ND940 is slightly cheaper than the 950 and a tiny bit cleaner overall.
RCF is the only big PA manufacturer that offers 2 way systems with crossover points as low as the best large format studio monitors (Kinoshita, Meyer, Strauss etc.).
I suppose you intend to use subs?
The Ciare PR614 looks like the 18sounds horns I was speaking of that everyone seems to like..... I like the roundish horns more so than the rcf...I'm not an expert horn person either.
Do not alter or misquote posts. This made clear in rule #12.
Camplo,
40ms delay is slapback echo length, if your sub is trailing by that much, you definitely should be delaying the mains to match.
The noisy high frequency transient attack of a kick drum (real or 808 generated) leads the "melodic boom". In the example below, the time between the initial transient and the first of the smaller amplitude "boom" is about 15ms, with a 60Hz fundamental dropping to 30 Hz at the trailing end.
As far as keyboard delay, 20ms will mess with your timing, put you a 64th note behind at 180BPM ;^).
Attachments
Thank you Ron and Camplo.
Yes, I will use a subs below 120-140hz. I have 2 JBL 2241 and 2 AE TD18H for it.
After years of fighting with JBL 2435BE I gave up and choose the way the Legis did with his "a'la Synergy" 4x12" and horn in the center, but with 10" JBL 2251J. They seems to have same cones as Legis Fane's, but with aquaplas applied. They have details, "air" and the "tone" in it, but they can't go lower than 120-140hz.
Yes, I will use a subs below 120-140hz. I have 2 JBL 2241 and 2 AE TD18H for it.
After years of fighting with JBL 2435BE I gave up and choose the way the Legis did with his "a'la Synergy" 4x12" and horn in the center, but with 10" JBL 2251J. They seems to have same cones as Legis Fane's, but with aquaplas applied. They have details, "air" and the "tone" in it, but they can't go lower than 120-140hz.
AXI2050 is interesting, forum search turned up very little, mostly bashing from people who haven't any experience with the actual CD itself. Did you do the build or is it still in the planning stage?
I was thinking 300hz seems like a good fit for @Joseph Crow Audio's Sabourin Horn Plan #1293
I have no idea how well suited Sabourin/AX2050 would be for near-field listing, which actually would be closer to my needs for HiFi home audio use in a smallish room if even possible to house something of these dimensions in a small room given spacing distances needed between speakers and surrounding walls.
I am at like 85% I have the boxes pretty much assembled except for bracing...something I haven't talked about yet....I took a trip over to visit Bill Fitzmaurice...I don't think anyone has the bracing game mastered in the way he does...
I have the wood for the bracing...the tools...and now that I can describe the happenings of group delay in a more confident way my OCD told be to move forward lol!!!...I have some veneer arriving tomorrow I believe....still no work until the middle of may...I must of made too much money last year =? Either that or covid finally affected my field...either way.
Nearfield is dependant on KA of the XO of the lower driver...and dispersion at the top of the horns register
A KA=2 or lower is ideal I believe...And I personally decided that 7.5+/- degrees at 16khz was my top side limit...though that is very tight for the average person unless sitting in one spot is ok with you. I am experimenting I guess you could say with the desire of using the largest horn possible, using that beamwidth, as a size limitation, since horn size and dispersion go hand in hand...Looking at the Sabourin at first glance, the dispersion up top is likely to be slightly smaller but near the numbers I gave concerning my limitations. I generally associate the anticipated dispersion with the tuning...when experimenting with Horn resp, the above tolerance landed me at 350hz...his horn is elliptical or rather, a rectangle in nature, and he has the tall dimension on the vertical to give the horizontal the best chances...I can only model round horns in Hornresp but generally speaking based on the ideas above, we are at least in the ball park. I haven't considered the idea of running my horns which are elliptical, in the same orientation because I am trying to keep center to center as close as possible. Long story short...I would use something like that nearfield...you are looking at the so called "head in vice" situation which I feel is exaggerated but to each his own...would you like it nearfield...depends. I have some ideas of directivity and energy that lead me down this path...The lot of us would improve upon the concept of the MTM with a horn in the middle, using a large format compression driver and use a constant directivity waveguide in the middle. I have not experimented with a 4" diaphragm, 2" exit driver...but you can model this is HornResp and get a clue of how low you can get with it at domestic volumes...I can run my axi without a XO and no horn and cover a good amount of territory...I haven't played with them in a while, and I am not sure how loud they could play...never hit xlim and being that I am going to use a horn no need to find it in that state. I think based off the response you'll see below, you could run the axi down to 500hz with a waveguide, which is a just under a KA=2 for a 15"...smaller mids...even betta...I also only know a little about waveguides and how they change the response of a driver vs that driver with no horn/waveguide...
Attachments
Last edited:
Group delay from a different light.
https://eprints.soton.ac.uk/426110/1/RS2018_HarrisEtAl_Final.pdf
https://eprints.soton.ac.uk/426110/1/RS2018_HarrisEtAl_Final.pdf
@camplo, I'm tagging along, interested in your updates on the AXI2050 project.
Can't really add much other than I like that the driver can cover a broad bandwidth and doesn't require a mid-high crossover.
Also, I don't know enough not to fall for marketing, "Audiophile systems" and "HiFi quality" does it for me. I have zero interest in Pro Audio sound systems for home HiFi and lack the knowledge and means to experiment with Pro drivers for HiFi use:
The innovative Axi2050 delivers unrivaled intelligibility and perceived audio performance making it suitable for high efficiency audiophile systems or high output professional 2-way designs.
and
Audax Professional Line 13" Woofer - PR330M0
This 13" woofer offers hi-fi quality along with professional characteristics, such as high efficiency (98dB); large magnet with a vented pole piece for high heat dissipation; and a heatsink designed Zamak chassis. The flat copper copper wire voice coil is wound onto a fiberglass reinforced Kapton former for exceptional power handling (150W). Ideally suited for strong bass response down to 40Hz using a C4 alignment.
Can't really add much other than I like that the driver can cover a broad bandwidth and doesn't require a mid-high crossover.
Also, I don't know enough not to fall for marketing, "Audiophile systems" and "HiFi quality" does it for me. I have zero interest in Pro Audio sound systems for home HiFi and lack the knowledge and means to experiment with Pro drivers for HiFi use:
The innovative Axi2050 delivers unrivaled intelligibility and perceived audio performance making it suitable for high efficiency audiophile systems or high output professional 2-way designs.
and
Audax Professional Line 13" Woofer - PR330M0
This 13" woofer offers hi-fi quality along with professional characteristics, such as high efficiency (98dB); large magnet with a vented pole piece for high heat dissipation; and a heatsink designed Zamak chassis. The flat copper copper wire voice coil is wound onto a fiberglass reinforced Kapton former for exceptional power handling (150W). Ideally suited for strong bass response down to 40Hz using a C4 alignment.
2435HPL is really nice from 850hz and up, but I can't get it sound right no matter what crossover or WG I used.
The high quality pro audio drivers blow Hifi drivers away...you could start there lol....
The saying is "Theres no replacement for displacement"....Larger diaphragms result in higher efficiency and thus lower distortion...."Pro Audio" is centered around this because they are trying to feed large areas with low distortion...When you use the quality PA stuff at home the distortion gets even lower at domestic levels....way lower than the small woofers of typical "hifi" could ever achieve....
If you read this thread, you'll know more than a few things...
One easy way is to search this thread for post by myself....I've asked so many got damn questions its crazy....
The people here have been so generous to lend their time and expertise its impressive....if only the rest of the world could be as nice as the people have been to me here. Many years of wisdom is inside this thread....and I purposely question every little thing I could think worthy of knowing not only for myself but so that the DIY community could have access to the same info. My OCD keeps track of what I want to know...hence the late and persisting discussion of Group Delay lol.....
The saying is "Theres no replacement for displacement"....Larger diaphragms result in higher efficiency and thus lower distortion...."Pro Audio" is centered around this because they are trying to feed large areas with low distortion...When you use the quality PA stuff at home the distortion gets even lower at domestic levels....way lower than the small woofers of typical "hifi" could ever achieve....
If you read this thread, you'll know more than a few things...
One easy way is to search this thread for post by myself....I've asked so many got damn questions its crazy....
The people here have been so generous to lend their time and expertise its impressive....if only the rest of the world could be as nice as the people have been to me here. Many years of wisdom is inside this thread....and I purposely question every little thing I could think worthy of knowing not only for myself but so that the DIY community could have access to the same info. My OCD keeps track of what I want to know...hence the late and persisting discussion of Group Delay lol.....