Upcoming Tom Danley Hifi speakers

[Tom Danley]

You chose a 500 ms time window in REW (the lower of the two, not the gating, which should equal the exclusion of reflections in measurements, indoors around 4 to 5 ms mybe) that suits room equalization. But you seemingly want to talk about upper midrange performance, where the room modes are of no concern. For this, you want to use CSD-mode, a window of 5 ms at most and a 30 dB span from peak signal. You may set rise time to 0.15 ms. This should produce a proper plot in the first place.

Hi
I posted the raw data in that same post, have at it and show me what feature your concerned with.
Tom

 

[Tom Danley]

Hi all, new member here who has long been following Mr Danley's killer designs and helpful, generous posts.

Hi Tom, i hope it's not inappropriate to have snipped the SH-50 waterfall from your dropbox and post it here...if so, please say and i will try to have it removed. I just thought this would make for easier discussion.
View attachment 135795
To me, the decay looks so dang clean especially beyond about 800Hz.
And i'm wondering if any of that decay cleanliness might be attributed to a reduction in airspace between the 5" mid cones and the horn with something like a volume reducing phase plug ..... and strengthening the acoustic lowpass. ??
And if that is being done for the mids, is it for the 12"s as well?

Hi
It would mostly be the directivity or gradual widening of the pattern that begins around 500-600 Hz on down If i recall, at 500Hz, that speaker is still -10dB at 90 degrees off axis so most of the sound is in the pattern. The acoustic low pass is actually part of all horns piston driven regardless if you design around it or not, you cannot have Zero space between the radiator and phase plug and the throat has air mass.

The difference here is unlike most cone / horn drivers, this acoustic low pass is designed in and only effects frequencies well above the electrical crossover and it is not driven like the vent resonance on a bass speaker, this operates below that resonance with the sound passing through the port unimpeded...
The reason is all of the non-linear things, extra sounds the speaker adds for free, get louder, faster than the input signals sound. Hence the old Phrase, "Headroom is your friend". The are not like direct radiating hifi speakers, a pair of SH-50's are often used for an audience of up to perhaps 300, with subwoofers 600 or more people so they idle in a living room.
Best,
Tom

 

[fluid]

Not much wiggle room there. Wide dispersion is preferred, and imaging is not sacrificed. That’s the opposite of what some of the recent commentary in this thread has been pushing.

Read in isolation that quote would seem to be definitive, however the 3rd Edition of Floyd Toole's book covers more information and commentary around this topic and there is a relevant comment from Toole himself here

https://www.avsforum.com/threads/ho...-what-the-science-shows.3038828/post-57504496

"This is not a new topic for me. 38 years ago I set up a listening room which had heavy velour drapes along the fronts of the side walls. When pulled out, the side wall reflections were absorbed, giving pinpoint, tight, imaging. When they were pushed back, they allowed for a more open, spacious soundstage. One tended to favor rock and pop, the other more spatially oriented classical recordings. Such an option only works well if one has well designed loudspeakers to begin with".

There has also been other research that could be interpreted as reaching different conclusions which was also done properly by competent researchers.

https://users.aalto.fi/~ktlokki/Publs/JASMAN_vol_146_iss_5_3562_1.pdf

"For example, although assessors reported attributes relating to perceived width and the perceived envelopment independently during the elicitation, those have been identified as components of one perceptual construct when AHC was performed on the assessors ranking data. This is a known challenge in evaluations of realistically-complex soundfields, and several studies have shown that the perceived width and envelopment are attributes that listeners show difficulty in separating".

"Finally, the preference profile (Sec. III E) combined the sensory, physical, and hedonic observations. This analysis supports previous findings, that assessors systematically preferred the sound fields with lower RT. In our study, the most preferred acoustical conditions presented fields that evoked the sense of being less reverberant and less wide and enveloping. The sources were perceived as closer to the listener, exhibiting high levels of proximity. It is also important to note that the current results suggested that a negative preference is apparent for acoustical conditions with RT higher than 0.4 s, the proposed mean value in the IEC recommendation."

The previous findings mentioned are these
https://www.aes.org/e-lib/browse.cfm?elib=17241
Preferences of Critical Listening Environments Among Sound Engineers
"A study of preferred listening environments among fifteen sound engineers illustrates the universal principle that “one size does not fit everyone.” By using the measured impulse responses of nine studio control rooms that were then encoded using the Spatial Decomposition Method, each space was simulated in an anechoic chamber with a 30-channel reproduction system. Preferences depended on the occupation of the sound engineer and on the nature of the song. While mixing engineers preferred acoustically dry environments with high clarity, mastering engineers preferred more reverberant environments with less clarity. Reverberation and clarity appear to be the dominant dimensions for preference. Extensive interviews with the subjects provided more nuanced explanations of how the sound engineers experience a listening space".

So as was quoted before "read on and draw your own conclusions. It may be that “one size does not fit all".

 

[changer]

Hi
I posted the raw data in that same post, have at it and show me what feature your concerned with.
Tom

I wasn't criticizing Tom, I just commented that gnarly used the wrong parameters in REW.

 

[gnarly]

Hi
It would mostly be the directivity or gradual widening of the pattern that begins around 500-600 Hz on down If i recall, at 500Hz, that speaker is still -10dB at 90 degrees off axis so most of the sound is in the pattern. The acoustic low pass is actually part of all horns piston driven regardless if you design around it or not, you cannot have Zero space between the radiator and phase plug and the throat has air mass.

The difference here is unlike most cone / horn drivers, this acoustic low pass is designed in and only effects frequencies well above the electrical crossover and it is not driven like the vent resonance on a bass speaker, this operates below that resonance with the sound passing through the port unimpeded...
The reason is all of the non-linear things, extra sounds the speaker adds for free, get louder, faster than the input signals sound. Hence the old Phrase, "Headroom is your friend". The are not like direct radiating hifi speakers, a pair of SH-50's are often used for an audience of up to perhaps 300, with subwoofers 600 or more people so they idle in a living room.
Best,
Tom

Hi, that all makes sense to me, as I've been studying and building DIY synergies rather intensely for the last 2-3 years. I'm on version #9 now, with no end of learning in sight, sigh... haha. (i met you at the last Infocomm at Orlando, asking you questions about using a coax CD crossed low, straight to 12"s or 10"s...and using FIR processing.....and so many thanks again for the kind help you gave).

The SH-50 waterfall took me a little by surprise, looking like it decayed faster above 800Hz than what i've seen with my builds. Since i haven't bothered to reduce airspace between the cones and horn since about version #4, i thought i should ask.
But i really don't look at waterfalls very often and am not fluent with them. Virtually all of my testing is outdoors as best as can be done, sticking with good ole mag and phase

Yep, "Headroom is indeed our friend !!!"........I've used my DIY Synergies for some pretty large neighborhood parties...

But enough of my talk....may i ask a Hyperion question...

Is the sub section vented? Looks like it might be from the line drawing....like there is a bottom port, and the design of the base and feet are to help accommodate the port???
(I love the opposing sub drivers...only kind of sub i want any more,..... one that won't toss a beer haha)

Best, Mark

 

[voodooless]

But i really don't look at waterfalls very often and am not fluent with them.

Is the sub section vented? Looks like it might be from the line drawing....like there is a bottom port, and the design of the base and feet are to help accommodate the port???

The bottom exit goes though though the middle almost to the top and makes for quite a long relex port. Tuning is probably quite low. The slanted top side might act as a kind of difusor for standing waves and might act as an internal flare as well?

 

[ctrl]

It's probably not the same cabinet as in that .png picture but i found a couple other old SH-50 ARTA file and put them in a drop box folder in the link below.

Tom, thanks for the measurements. The first reflections were hard to see, but I think the selected gate shows the measurements without room reflections. Thus, the frequency response down to 200-300Hz is to be considered realistic, but already strongly smoothed.
SH-50@1m - FR

This means that possible resonances below 600Hz cannot be seen in the CSD and BD diagrams.

But the range up to 3kHz the decay looks amazingly good for the design and size of the horn - that surprised me, based on my experiments with diffraction slots, as you have already explained, that's where the horn really makes the difference it seems.

Below 500Hz there is a resonance in the CSD, but this could also be a room resonance.

What surprised me a bit are the decay problems in the high frequencies. There are a few places that need a couple of oscillation periods until they are damped by at least 20dB.

If one look at the burst decay (BD), there is slow decay ("stored energy") around 3.5kHz, 5.5kHz and around 10kHz.
Part of this could perhaps be due to reflections at the diffraction slots and the rest is caused by the compression driver?

SH-50@1m - Culmulative Spectral Decay (CSD), as sonogram and as waterfall. I don't like the waterfall diagrams because you can't clearly identify the frequencies and the length of the decay. But since many know these diagrams...

SH-50@1m - Burst Decay (BD), as sonogram and as waterfall. This is the better way of showing the decay behavior, since each frequency is shown according to its period length, allowing direct comparison of the decay behavior at different frequencies.


Unfortunately, I have no comparative measurements on a comparably sized horn. The largest horn I can offer measurements for is the XT1464 at a distance of 1m with a dome tweeter - not quite fair, but perhaps useful as a reference for fast decay for people who are less familiar with the diagrams.
FR CSD BD
It must be said, however, that when using compression drivers in the 10-20kHz range, the decay behavior is usually not optimal, since the driver diaphragm almost always shows breakup behavior below 20kHz.

 

[Tom Danley]

Tom, thanks for the measurements. The first reflections were hard to see, but I think the selected gate shows the measurements without room reflections. Thus, the frequency response down to 200-300Hz is to be considered realistic, but already strongly smoothed.
SH-50@1m - FR
View attachment 135928
This means that possible resonances below 600Hz cannot be seen in the CSD and BD diagrams.

But the range up to 3kHz the decay looks amazingly good for the design and size of the horn - that surprised me, based on my experiments with diffraction slots, as you have already explained, that's where the horn really makes the difference it seems.

Below 500Hz there is a resonance in the CSD, but this could also be a room resonance.

What surprised me a bit are the decay problems in the high frequencies. There are a few places that need a couple of oscillation periods until they are damped by at least 20dB.

If one look at the burst decay (BD), there is slow decay ("stored energy") around 3.5kHz, 5.5kHz and around 10kHz.
Part of this could perhaps be due to reflections at the diffraction slots and the rest is caused by the compression driver?

SH-50@1m - Culmulative Spectral Decay (CSD), as sonogram and as waterfall. I don't like the waterfall diagrams because you can't clearly identify the frequencies and the length of the decay. But since many know these diagrams...
View attachment 135929 View attachment 135931
SH-50@1m - Burst Decay (BD), as sonogram and as waterfall. This is the better way of showing the decay behavior, since each frequency is shown according to its period length, allowing direct comparison of the decay behavior at different frequencies.
View attachment 135930 View attachment 135932

Unfortunately, I have no comparative measurements on a comparably sized horn. The largest horn I can offer measurements for is the XT1464 at a distance of 1m with a dome tweeter - not quite fair, but perhaps useful as a reference for fast decay for people who are less familiar with the diagrams.
FRView attachment 135982 CSDView attachment 135983 BDView attachment 135984
It must be said, however, that when using compression drivers in the 10-20kHz range, the decay behavior is usually not optimal, since the driver diaphragm almost always shows breakup behavior below 20kHz.

Hi
That looks right to me.

In the Burst decay, when you see an angle going down to the right, that is usually a reflection.

A reflection that is X periods at F1, is usually at 2X periods where 2XF1 is, hence if strong enough makes a slope.

The red glob at the top, not sure what that is, i don't hear anything but it's real high and a 16 year old driver / speaker now.

It's been so long since i did these, I don't have clean measurement for these like needed to work out a crossover etc, these are in a busy living room.

Some of the late stuff would be from the exposed ledge of the 23 inch tall cabinet it sits on with part of the top of it exposed and it sits with a subwoofer next to and slightly in front of it.

Things at the front of a horn are not good for measurements unless one was fooling around like i was then.
What's fun is to compare a measurements of a larger Synergy horn vs cones and domes, in a living room, taken with the speakers at the same locations with mic at the listening position. That's where you can see the effect of directivity in a measurement.

Best,

Tom

 

[Tom Danley]

View attachment 135979
The bottom exit goes though though the middle almost to the top and makes for quite a long relex port. Tuning is probably quite low. The slanted top side might act as a kind of difusor for standing waves and might act as an internal flare as well?

Your a good guesser and correct on both counts
Tom

 

[puppet]

Say Tom, have you given any thought to swapping out the CD with an AMT or a ribbon driver for a hifi application?

 

[voodooless]

Say Tom, have you given any thought to swapping out the CD with an AMT or a ribbon driver for a hifi application?

I doubt those would have the correct wavefront to properly work in the horn. Some people over at DIY audio made some multi entry horns with an AMT though, so it is possible. Also a coaxial unit is used, which would make it even harder to use a AMT or ribbon.

 

[gnarly]

View attachment 135979
The bottom exit goes though though the middle almost to the top and makes for quite a long relex port. Tuning is probably quite low. The slanted top side might act as a kind of difusor for standing waves and might act as an internal flare as well?

Ah yes, thx. I didn't see the shadow duct running through up to the top. Nice discernment, as confirmed.

 

[hardisj]

I took the day off of work to go on a field trip to Danley Sound Labs. I was treated to a long demo of a prototype of Tom’s new Hyperion speaker as well as a couple others. Words cannot do the Hyperions justice. They are incredible! I’ll follow up with some specifics later when I get some time. I made a 10 hour round trip drive today (I really hate Atlanta traffic) and am beat so I am going to bed.

Was great to meet @Tom Danley and the really great folks working there. I can’t thank them enough for allowing me to visit them for a few hours today and get a tour of their facilities.



 

[richard12511]

I took the day off of work to go on a field trip to Danley Sound Labs. I was treated to a long demo of a prototype of Tom’s new Hyperion speaker as well as a couple others. Words cannot do the Hyperions justice. They are incredible! I’ll follow up with some specifics later when I get some time. I made a 10 hour round trip drive today (I really hate Atlanta traffic) and am beat so I am going to bed.

Was great to meet @Tom Danley and the really great folks working there. I can’t thank them enough for allowing me to visit them for a few hours today and get a tour of their facilities.

View attachment 136255View attachment 136256View attachment 136257View attachment 136258View attachment 136259View attachment 136260View attachment 136261


Wow! That's an amazing looking horn! Glad you took Tom up on his offer.

 

[Purité Audio]

Looking forward to hearing your thoughts.
Keith

 

[AudioJester]

Legendary!

 

[TimVG]

Sweet @hardisj !

The one on the left looks like a home version using their paraline technology.

 

[Newman]

Read in isolation that quote would seem to be definitive, however the 3rd Edition of Floyd Toole's book covers more information and commentary around this topic and there is a relevant comment from Toole himself here

https://www.avsforum.com/threads/ho...-what-the-science-shows.3038828/post-57504496

"This is not a new topic for me. 38 years ago I set up a listening room which had heavy velour drapes along the fronts of the side walls. When pulled out, the side wall reflections were absorbed, giving pinpoint, tight, imaging. When they were pushed back, they allowed for a more open, spacious soundstage. One tended to favor rock and pop, the other more spatially oriented classical recordings. Such an option only works well if one has well designed loudspeakers to begin with".

?? He was pointing out that you can only do that with wide-dispersion loudspeakers, i.e. "...the advantage of loudspeakers designed to meet the criteria described in my book, and recognizable in comprehensive anechoic data like a Spinorama, is that the customer can choose." His post was another example of the gains provided by wide dispersion. You seem to have found another interpretation.

There has also been other research that could be interpreted as reaching different conclusions which was also done properly by competent researchers.

https://users.aalto.fi/~ktlokki/Publs/JASMAN_vol_146_iss_5_3562_1.pdf

"For example, although assessors reported attributes relating to perceived width and the perceived envelopment independently during the elicitation, those have been identified as components of one perceptual construct when AHC was performed on the assessors ranking data. This is a known challenge in evaluations of realistically-complex soundfields, and several studies have shown that the perceived width and envelopment are attributes that listeners show difficulty in separating".

"Finally, the preference profile (Sec. III E) combined the sensory, physical, and hedonic observations. This analysis supports previous findings, that assessors systematically preferred the sound fields with lower RT. In our study, the most preferred acoustical conditions presented fields that evoked the sense of being less reverberant and less wide and enveloping. The sources were perceived as closer to the listener, exhibiting high levels of proximity. It is also important to note that the current results suggested that a negative preference is apparent for acoustical conditions with RT higher than 0.4 s, the proposed mean value in the IEC recommendation."

Interesting study, thanks for the link, but they said it is not about loudspeaker dispersion, which they did not vary.

Toole points out (3rd edition) that the many and varied (and not all that successful overall) attempts, over the years, at adding sound processors to stereo material for home playback, have been driven by chronic dissatisfaction with the lack of envelopment that stereo speakers can provide in the home.

Narrow dispersion speakers only make the situation worse, and also make the 'phantom centre image colouration effect' stronger, by restricting early side reflections that can help fill in and mitigate the effect. One study with a hint of contradiction to this point, only begs for closer analysis of the study and care not to misinterpret or over-generalise, rather than bringing the generic issue that Toole describes into question.

For discrete multichannel playback, however, we can have a different discussion and come to different conclusions re preferred speaker characteristics.

The previous findings mentioned are these
https://www.aes.org/e-lib/browse.cfm?elib=17241
Preferences of Critical Listening Environments Among Sound Engineers
"A study of preferred listening environments among fifteen sound engineers illustrates the universal principle that “one size does not fit everyone.” By using the measured impulse responses of nine studio control rooms that were then encoded using the Spatial Decomposition Method, each space was simulated in an anechoic chamber with a 30-channel reproduction system. Preferences depended on the occupation of the sound engineer and on the nature of the song. While mixing engineers preferred acoustically dry environments with high clarity, mastering engineers preferred more reverberant environments with less clarity. Reverberation and clarity appear to be the dominant dimensions for preference. Extensive interviews with the subjects provided more nuanced explanations of how the sound engineers experience a listening space".

?? That statement was in reference to room treatments, not loudspeaker dispersion.

So as was quoted before "read on and draw your own conclusions. It may be that “one size does not fit all".(Toole)

What Toole was saying there was (paraphrased), despite all the experimental evidence I am about to walk you through, you can still draw your own conclusions (i.e. ignore or reinterpret it), instead of accepting my best interpretation of it. He was a bit testy, because certain people offering certain acoustic products had misrepresented his position on early reflections after the publication of his first book.

cheers

 

[tomtoo]

I took the day off of work to go on a field trip to Danley Sound Labs. I was treated to a long demo of a prototype of Tom’s new Hyperion speaker as well as a couple others. Words cannot do the Hyperions justice. They are incredible! I’ll follow up with some specifics later when I get some time. I made a 10 hour round trip drive today (I really hate Atlanta traffic) and am beat so I am going to bed.

Was great to meet @Tom Danley and the really great folks working there. I can’t thank them enough for allowing me to visit them for a few hours today and get a tour of their facilities.

View attachment 136255View attachment 136256View attachment 136257View attachment 136258View attachment 136259View attachment 136260View attachment 136261


Hey soldier, wake up, report urgently awaited.

 

[fluid]

His post was another example of the gains provided by wide dispersion. You seem to have found another interpretation.

I don't think this is the right place to have this discussion in depth but there are parts of it that are relevant as Tom's speaker's are all narrower in dispersion.

I only see the comment as stating that different amounts of early reflections result in different perceptions and that those tend to suit certain program material and preferences differently. I don't see how there is a gain from wide dispersion if you then go and absorb the reflections, but I can see that if you wanted to be able to change the presentation through variable room treatment that you would need wide directivity speakers to give you the option.

The definitive quote you posted is not in the 3rd Edition of the book, written as it was in the 1st / 2nd editions. The research is still there and after reading all of it I do not come to the conclusion that wide directivity is always better or more preferred in every situation. What I have found through my own experimentation with directivity and room treatment is that there are indeed trade offs to be had between more or less early reflections and whether they come from lateral directions or not. I find the same as Floyd Toole and Earl Geddes that the program material and personal preference do play a part in which option suits better.

In my view you are taking a very strong stance and using phrases like ignore it or reinterpret it suggests that your view is the only possible way of understanding what was written correctly. For me and many others one size does not fit all. There is no one single solution that works perfectly for all situations, programmes and preferences.