What does a "great room" mean?

[jkeny]

John, it's relevant in the sense that perhaps a significant number of people are disturbed by room reflections much more than everyone else, and therefore they need a "great room" for listening; just having the system work well is never going to do it for the hearing of these people. I note comments by people at times that they listen to classical performances in halls and performance venues, and they are disturbed by the acoustics of the space and/or their listening position - it's unsatisfactory, even though it's live.

And if the hearing of these people who need to have the room work for them varies between individuals, then there be no one size fits all "great room" ...

I've been in a couple of heavily treated rooms, for audio listening, and they're not for me - far too dead, a somewhat disturbing space to be in ..

Ah, I see, Frank - yes, I agree & from Rodney's post the main issue is in the area of low bass which I'm not too concerned about - I find I get along fine without worrying about this. In fact one of the areas where bass is greatly improved is in the electronics - when people hear my digital devices the usual first comment is "where did that bass come from". Obviously this is down to psychoacoustics as there's no difference in the bass frequency - IMO, some clarity is being introduced in auditory perception & the signal is being changed in some way that better suits ASA principles?

However, I do find the whole DML speaker technology interesting & will be following up on it, when I get a chance. The offerings in the domestic area are BMR (balanced mode resonators) speakers which come in very cheap at €14 for 4.5" driver from Radionics

 

[fas42]

In fact one of the areas where bass is greatly improved is in the electronics - when people hear my digital devices the usual first comment is "where did that bass come from". Obviously this is down to psychoacoustics as there's no difference in the bass frequency - IMO, some clarity is being introduced in auditory perception & the signal is being changed in some way that better suits ASA principles?

Yes, this is very much the case ... even though my playback is over speakers that nominally have poor bass response, the subjective impression is of deep, powerful, intense bass; there is absolutely no need to actually reproduce the fundamentals of the lowest notes for the replay to be convincing in the bass area - as an example, full bore pipe organ workouts have all the gusto one could wish for - vibrating window panes not required ... , .

 

[jkeny]

Yes, this is very much the case ... even though my playback is over speakers that nominally have poor bass response, the subjective impression is of deep, powerful, intense bass; there is absolutely no need to actually reproduce the fundamentals of the lowest notes for the replay to be convincing in the bass area - as an example, full bore pipe organ workouts have all the gusto one could wish for - vibrating window panes not required ... , .

Yes, trying hard not to mix up the two threads I started but I have to say this - "believability" may require rattling window panes for some people

 

[fas42]

Regarding DML speakers, I have to say that the demos on YouTube are not doing it for me - they sound like normal, muddy PA speakers to me - would you have an example which shows them working in a better fashion?

 

[Rodney Gold]

I give up .... dont worry about your room , rather have someone tinker with your electronics..

 

[jkeny]

Regarding DML speakers, I have to say that the demos on YouTube are not doing it for me - they sound like normal, muddy PA speakers to me - would you have an example which shows them working in a better fashion?

I agree, Frank I haven't found a convincing youtube demo yet - the theory looks convincing but maybe it doesn't translate into the real world?

 

[jkeny]

I give up .... dont worry about your room , rather have someone tinker with your electronics..

I don't have "someone" address the electronics - I do it myself.

 

[JackD201]

Yes but I'm not really that hung-up on low bass - most of the music is above this frequency

Sounds to me like it's just an indulgence - a place where one can show off how extravagant & rich one is & audio is just the vehicle for this - a bit like having a room built to stage your trophies?

Sorry if this sounds harsh - it's not directed at you personally, just the concept of a "Great Room" sounds a bit like the Wizard in Oz

Squeezing every last bit out of a room's potential is no more Wizard of Oz-ish than doing the same for electronics. Just sayin'.

 

[Robh3606]

... even though my playback is over speakers that nominally have poor bass response, the subjective impression is of deep, powerful, intense bass; there is absolutely no need to actually reproduce the fundamentals of the lowest notes for the replay to be convincing in the bass area - as an example, full bore pipe organ workouts have all the gusto one could wish for - vibrating window panes not required ... , .

Hello Frank

No difference without the first octave. No need for below 40Hz bass?? Well if that's the case we are as far apart as you could possibly be in this hobby. It doesn't sound right without it. If I want that I can stream through my Echo.

Rob

 

[jkeny]

Squeezing every last bit out of a room's potential is no more Wizard of Oz-ish than doing the same for electronics. Just sayin'.

Sure, Jack but if you notice I split Rodney's post into two sections - the first being about low bass treatment - I just didn't find this of great importance to me but everyone is entitled to address their room in whatever way they wish.

It was the rest of the post that I thought reminded me of the Wizard out of Wiz of Oz - a bit smoke & mirrors

 

[Mike Lavigne]

Squeezing every last bit out of a room's potential is no more Wizard of Oz-ish than doing the same for electronics. Just sayin'.

+1.

solving the room is more about relentlessness than anything. for me it was about getting a reference in my head and then seeing how what I did got me closer or farther from it. once I got on the scent of where I was going it was just staying on it and seeing what was in the way of getting there.

ultimate gear optimization certainly can involve an open check book, the room not so much. but......there can be logistical obstacles that are daunting. I decided to move from one home to another......but that turned out to be only a step in the direction in the long run.

 

[microstrip]

IMHO, the most important aspect of a room has no possible treatment - volume. When discussing particular cases it would be nice for readers if the dimensions of the room. Type of building is also of great importance - some rooms are intrinsically treated for bass.

I have moved my system along four listening rooms with very different dimensions and building techniques - the houses differ in age more than one century. The best of them never needed any treatment and sounded much better than all others.

My interest in room treatements was triggered by the excellent article of Keith Yates "A matter of diffusion" http://keithyates.com/a-matter-of-diffusion/ in the Stereophile magazine - IMHO it deserves to become a sticky in any audio forum. Much later I spent long hours in the Cello room in Lisbon, that was fully treated in a similar way using RPG material and ASC tube traps, with plenty of diffusion and absorption, including bass traps. Fortunately, several years after the shop closed I was able to buy most of the treatment that was taken from the room.

Although I have limited experience, I got the feeling that when entering the treatment we should use professional materials of high quality - there is a wide gap in performance between the expensive RPG and ASC materials and the most other cheaper treatments that I have tried.

 

[JackD201]

Hi Micro

Volume is indeed a huge factor. That said, lest everybody start aspiring for ever larger rooms, I should say be careful what one wishes for. When one commits to a pretty large space one better be aware that a whole new level of commitment is going to be required. While a larger volume solves quite a number of problems, what it will take to pressurize that room with minimal strain on the loudspeakers and amplification might be surprising.

 

[c1ferrari]

Great question. I would love to tour a number of professional mastering houses to educate myself!

 

[jkeny]

Regarding DML speakers, I have to say that the demos on YouTube are not doing it for me - they sound like normal, muddy PA speakers to me - would you have an example which shows them working in a better fashion?

Frank, just came across this DIY DML speaker which sounds pretty good considering the source is a phone, I believe https://youtu.be/ONOxc1p0XBI skip to 3:50

 

[fas42]

Frank, just came across this DIY DML speaker which sounds pretty good considering the source is a phone, I believe https://youtu.be/ONOxc1p0XBI skip to 3:50

Yes, I agree John - that's certainly now in the game ...

 

[fas42]

Hello Frank

No difference without the first octave. No need for below 40Hz bass?? Well if that's the case we are as far apart as you could possibly be in this hobby. It doesn't sound right without it. If I want that I can stream through my Echo.

Rob

Rob, I've heard systems that go all the way down there, equalised to boot using DEQX - and I'm not hearing magic ... I tried the organ CD I use for this sort of thing, and some ZZ Top - nope, it's wasn't happening - sound was far too "small", the impact was missing. The notes may be there, but if it doesn't connect in the musical sense then it's pointless, all the effort has not conjured up a realistic illusion.

 

[jkeny]

We can all follow the idea of a compression wave being produced by a speaker cone moving in pistonic motion at a particular frequency which we then perceive as a pure tone.
We can easily understand how these waves hitting a reflective surface will bounce back & cause interference with the incident wave
We can all easily understand how this can produce peaks where the reflected wave's peak amplitude coincides with the peak amplitude of the incident wave & troughs when troughs converge. These peaks & troughs give ride to the comb filtering.
And we know from psychoacoustics that if reflections arrive at the ear within a certain time (depending on frequency) we perceive it as part of the original sound. If it arrives after this time we perceive it as a reflection which can either be perceived as a beneficial widening of the soundstage & envelopment in the sound or can be perceived as a muddying of the sound.

In my brief reading & research into these Distributed Mode Loudspeakers, I'm trying to make the logical connection between the how these resonances on the panel create the tones that we hear

Here's a video of the resonances on a plate - I believe this is called a Chaldini resonances [video]https://youtu.be/wvJAgrUBF4w[/video]
The patterns seen at the various frequencies are beautiful & formed when the sand moves away from the resonating nodes on the plate & gathers in the non-resonating areas.
So can anybody make this connection between these resonances formed on a DML panel & the sound we hear? What is the mechanism whereby we hear a pure tone from a collection of resonating sections on a panel? It's not producing a correlated compression wave - it's said to produce a decorrelated series of smaller waves from these resonating sections of the panel which is perceived as a pure tone. So how is this series of smaller decorrelated waves transformed into the auditory signals that we perceive as a pure tone?

This is what the NXT paper says - which isn't helpful "Think of it as an array of very small drivers, all radiating different, uncorrelated signals that nonetheless sum to produce the desired output." How do decorrelated signals sum to produce a correlated signal? Where does this happen - outer ear, inner ear, auditory processing?

This might seem unconnected to the ideas of the "Great room" but I think that understanding how DMLs work may give us better insight into room interactions & needs/concepts behind room treatments

 

[stehno]

In the "what's most important for 'believability'" thread, there's a kind of gentle & mannerly impasse where a number of members that state the room is the just as important an element in believability (depending on the speaker) as the source & electronics.

I've not had much experience with different room treatments as mostly the rooms I've listened to reproduction in were what I considered of a reasonable quality, acoustically.

Recently I've discovered DML speakers - distributed mode loudspeakers popularised by NXT speakers. I must admit that I never paid much attention to these as they were marketed more as PC speakers & "lifestyle" speakers rather than hiFi. Maybe it's because this speaker technology has evolved somewhat to address the shortcomings of DML & BMR (Balanced Mode Radiators) have developed from them?

But anyway, the point of this technology is that instead of the optimal goal of traditional speaker technology which was a point source radiator for all audible frequencies, DML has a different dispersive way of radiating sound. Traditional speakers use a pistonic driver attached to a cone to generate longitudinal sound waves (correlated between speakers) wheres DML use a panel on which resonances are created at the various frequencies - transverse sound waves.

Unfortunately, I don't have AES membership & this site (Tectonic) have many AES papers on DML & room interaction but this public paper is a good summary of the main ideas - summarised here:

In live performances:
· The sound sources are multidirectional, radiating sound in all directions, most of it away from individual listeners in the audience.
· Perceptions of timbre, space, and envelopment created by reflections within the room are essential parts of the performance.

In sound reproduction:
· Most loudspeakers have significant directivity and are aimed at listeners. Nevertheless, if the playback system is truly up-to-snuff, this directivity generally need not be considered a negative by any means. For that matter, the soundstage itself can be considered to have a significant directivity and it too is aimed at listeners planted in the audience."

· Ideally, perceptions of timbre, direction, distance, space, and envelopment should be conveyed by multichannel audio systems delivering specific kinds of sounds to loudspeakers in specific locations. Whoever said that multi-channel is a requirement is to me an excellent indicator they know very little what they speaketh.

· Ideally, what listeners should hear should be independent of the room around them. To a great extent, I agree. In practice it is the required degree of independence that is under investigation. Hardly. Since few if any do any real investigation into such matters. The fact that the author thinks multi-channel is a required ingredient to any solution tells me that if there was any such "investigation", what are the real credentials of the investigator?


This makes sense to me & would seem to suggest that room treatment for this technology is both far less & essentially different to that used for traditional, directive speakers.

What do people make of this in the light of the idea that one can treat a room to achieve a "great" sounding room? Not much. Especially if the one making such a claim is convinced multi-channel is a requirement for any potential solution.

I have two questions (at the moment):

Q1. how is this room treatment designed to achieve the "great" room as it appears that there isn't a consensus about this? Assuming the room is of reasonable quality to start, if the playback system is up-to-snuff (you can count them on one hand maybe), the room treatment should have little effect because what should be an overwhelming amount of music info filling the room (by a well-thought-out playback system) should easily overtake or overshadow a given room's reasonable deficiencies.

Q2. Is this lack of consensus because it's not a "great room" that's being designed - it's actually dependent on the speakers being used in that room. No, it's not dependent on the speakers being used in that room. Well, nothing like the weight some-to-many like to give speakers in general.

A general lack of consensus regarding this topic (and soooooo many other topics) should be an excellent indicator that high-end audio, at least from a performance perspective, remains very much in its infancy. Regrettably it's not. But I digress.

 

[jkeny]

A general lack of consensus regarding this topic (and soooooo many other topics) should be an excellent indicator that high-end audio, at least from a performance perspective, remains very much in its infancy. Regrettably it's not. But I digress.

Thanks Stehno - very good points which I mostly agree with & as you can see from this thread I'm working my way into trying to better understand this whole room interaction area
I don't read the multi-channel comment in the same way that you do - what he is stating is again that what is heard IDEALLY SHOULD be independent of room interactions.

I'm particularly interested in what you said here & it's what I'm trying to tease out in this thread"Assuming the room is of reasonable quality to start, if the playback system is up-to-snuff (you can count them on one hand maybe), the room treatment should have little effect because what should be an overwhelming amount of music info filling the room (by a well-thought-out playback system) should easily overtake or overshadow a given room's reasonable deficiencies."
This exactly concurs with my experience & it's what I said in the "believability" thread & what I'm trying to delve into further in this thread - the idea that when a room is of a reasonable quality, it becomes a moot variable in achieving "believability", that what is of more import are improvements in the electronics.

My last post above yours was an attempt to question how DML work because understanding this may well give us a far better understanding of the role of room interactions & their place in our listening