The quest for my hyper speaker - Very Large room dilemma

[mcdn]

He is not incorrect but it seems your understanding of the concept is not clear. Do please use the room mode calculator linked on that post and see at what size room you will see a room mode at 8Hz (clue 21m). Then think if a room of that size will be considered a “room” in the sense of a domestic space. Even the OP’s room is not that large


I think the discussion is relevant to the person’s question. He wants big bass and he has a large room.

As I read it the point of Rene's analysis is that all rooms have a mode at 0Hz, which gives room gain regardless of the frequency of the first resonant mode. This will be the case for any room where the reflected wave is not significantly attenuated (though what significant means is likely to be complex. the analysis applies perfectly only to fully sealed rectangular rooms, but the effect in a real room will still be there if lessened according to leakage)

yes the idea of a 0Hz mode is not intuitive, but he has done the hard maths and it corresponds to most peoples' lived experience.

Note the effect does not appear for ported subs below the sub's resonance, as the driver displacement simply pushes air out of the port. The room gain to DC is a feature of sealed or infinite baffle subs only. Might this be part of the reason why some people prefer that alignment?

From https://audiosciencereview.com/forum/index.php?threads/analytical-analysis-room-gain.23211/: "We have a flat in room response for a sub with finite bandwidth. Why is that? Well, we have actually forgotten one thing; the indices (nx,ny,nz) do not start at (1,0,0), (0,1,0), or (0,0,1); they start at (0,0,0)! We have a mode at 0 Hz that pressurizes the room the same in all positions, so no gradients, and it satisfies the wave equation as discussed already. Room gain is simply the effect of having an eigenmode at DC!"

 

[Deleted member 48726]

This is an incredibly helpful and educational post. And I will definitely be looking into this. The problem is obviously aesthetics. This is a nice room and most of the pro sound speakers will stick out like a sore thumb. As much as I am truly value-oriented, The cost savings will simply not be worth it unfortunately.

Hmm. Thinking out of the box here but what if you bought some really nice pro speakers and used some of the saved money to get them veneered or professional painted?

Or even have some speakers built.
I would take contact to a speaker builder and have him sketch some proposals. They should of course be equipped with.pro drivers.

 

[RayDunzl]

Wide (little JBL) vs Narrow (MartinLogan electrostats) dispersion in my much smaller room...

I attribute the "hash" in the unsmoothed response to reflections.

It shows in the impulse response, too. Spikes are reflections.

I find the panels to be superior for critical listening at the sweet spot.


The current "big boy":

Martin Logan Neolith

Martin Logan Neolith, Martin Logan Neolith review, Martin Logan Neolith specs, Martin Logan Neolith test,

www.subwoofermania.com

 

[fredoamigo]

However your post made me think that if there is some new state of the art research that shows a significant audible negative from the floor and ceiling reflections

There is a German study from the 80's concerning the impact or negative effect of floor reflections that I should find.
The conclusion was that the effect emanating from the floor is not as negative as some say and in any case not significant unlike the ceiling.
If there is one or more studies that confirm a significant negative impact for what concerns the floor I am a taker and I apologize in advance for my ignorance.
The scientific hypothesis on the subject is that for tens of thousands of years the auditory system of humans is adapted to the reflection of the ground because when we are outside we have essentially reflections of the floor.

 

[Keith_W]

You're in Whistler! I have been there a couple of times. When I was a medical student, a family friend had a deluxe chalet on the ski slopes. The top floor had a huge picture window with a spa big enough for 8 people in it. It was great sitting in the hot bubbly water, watching it snow outside. Sadly it's very difficult for me to get to Whistler given that I live in Australia

 

[Ilkless]

FYI Joseph Crowe mentioned above is based in Ontario.

Speaker No.1680

In this blog post I feature speaker No.1680 which is a 2-way utilizing a SEAS 10" woofer and 1" compression driver. Features I custom designed and built speaker No.1680 after a build commission by a customer who was a turn-key build that offered reasonable sensitivity, deep bass, and...

josephcrowe.com

No dog in this race, just thought large horns optimised for smoothness and dispersion and machined in wood fit the acoustic and aesthetic needs of the listening room.

 

[thewas]

There is a German study from the 80's concerning the impact or negative effect of floor reflections that I should find.
The conclusion was that the effect emanating from the floor is not as negative as some say and in any case not significant unlike the ceiling.
If there is one or more studies that confirm a significant negative impact for what concerns the floor I am a taker and I apologize in advance for my ignorance.
The scientific hypothesis on the subject is that for tens of thousands of years the auditory system of humans is adapted to the reflection of the ground because when we are outside we have essentially reflections of the floor.

There seem to be more research sources on this:

An Enticing Marketing Story, Theory Without Measurement?

At the risk of being accused of boosting sales on my recent book, all of this is covered in some detail, with measurements and references. BTW the book is not a "profit center" for me - it is a technical book. The short story is that steady-state in-room measurements reveal nothing reliable...

www.audiosciencereview.com

Blind Listening Test 2: Neumann KH 80 vs JBL 305p MkII vs Edifier R1280T vs RCF Arya Pro5

My take as I've done many times, speakers that exaggerate the pattern on/off-axis may sound harsh while speakers with inverted pattern sound smoother. How can a speaker exaggerate the pattern on-axis?

www.audiosciencereview.com

 

[aliqaz]

There seem to be more research sources on this:

An Enticing Marketing Story, Theory Without Measurement?

At the risk of being accused of boosting sales on my recent book, all of this is covered in some detail, with measurements and references. BTW the book is not a "profit center" for me - it is a technical book. The short story is that steady-state in-room measurements reveal nothing reliable...

www.audiosciencereview.com

Blind Listening Test 2: Neumann KH 80 vs JBL 305p MkII vs Edifier R1280T vs RCF Arya Pro5

My take as I've done many times, speakers that exaggerate the pattern on/off-axis may sound harsh while speakers with inverted pattern sound smoother. How can a speaker exaggerate the pattern on-axis?

www.audiosciencereview.com

Considering this data, and Dr Tooles info, it seems that vertical and reflections are not that detrimental. However Bjorn did mention being part of an extensive study where apparently this was of the utmost significance. I wonder if anything was published from that

 

[Purité Audio]

Vertical, floor and ceiling are I believe the most harmful, horizontal can add ‘spaciousness’ but vertical can only be detrimental.
Keith

 

[FrankW]

Again again you are calling for blind tests in debates.

Correct, because I already exposed your lack of perceptual/psycoacoustics knowledge and making unsubstantiated claims about reflections typical of those who sell studio treatment products https://www.audiosciencereview.com/...-only-on-front-wall.43295/page-3#post-1535717

But there's no need for this when the measuring difference is already backed up by blind tests! This is something you don't seem to understand

You can't cite a single blind test of speakers with reduced floor bounce being preferred, something you don't seem to understand. You were already informed of what Toole summarized of the research
https://www.audiosciencereview.com/...ased-speaker-designs.6441/page-57#post-402552

You really should acquaint yourself with psycoacoustics. Reflections from floor and ceiling are audible. I'm sharing information which is already backed by proof.

Laughable.
That meaningless cherry picked quote has zero context. a complete red herring since no one contends a single. floor reflection isn't audible. You are very clearly claiming speakers that have "less" measurable floor reflections are preferred to those with "more" floor reflections, with zero evidence/proof to support.
Ali can safely disregard your claims, since he clearly stated he's basing his speaker decisions on blind listening test results.

As a physician I am familiar with the concept of blinded control trials. During the beginning of my hobby I conducted my own single blinded and double blinded trials, which, due to the fact that I was not able to hit statistical significance, led me inexorably down the path of objectivism.

 

[FrankW]

Considering this data, and Dr Tooles info, it seems that vertical and reflections are not that detrimental. However Bjorn did mention being part of an extensive study where apparently this was of the utmost significance. I wonder if anything was published from that

Sorry, you posted while I was typing. His cherry picked quote is of a test where it was determined that a floor reflection is "audible". As usual, he cites zero blind listening tests of loudspeakers and whether less/more is preferred. Beware of recommendations of those who sell studio treatments as home fashions. Every visible reflection/measurement becomes an audible problem to be "treated".

 

[FrankW]

Vertical, floor and ceiling are I believe the most harmful, horizontal can add ‘spaciousness’ but vertical can only be detrimental.
Keith

Not based on any evidence https://www.audiosciencereview.com/...y-without-measurement.7127/page-3#post-162871

 

[Inner Space]

Not based on any evidence https://www.audiosciencereview.com/...y-without-measurement.7127/page-3#post-162871

C'mon, Frank. To be accurate, Toole offers just one non-blind study that he says "seems" to show something or other. The rest of what he offers is untested anecdata, and he himself concludes "Chasing this issue to ground will require some real research." (Pun presumably intended.) His evolution-related theory is absurd, given that our hearing has been evolving for 7m years, and we've lived with reflective floors for a few hundred at most.

I have been in rooms where lateral reflections have been managed, and floor and ceiling bounce sticks out like a sore thumb. When they're also managed, the room improves drastically. I understand that dealing with the floor is very difficult, but we should be very aware that it's bad policy to say, "It's very difficult to deal with, so let's just say it doesn't matter." In fact that's a huge weakness in this hobby - low-hanging fruit is endlessly discussed, and high-hanging fruit is ignored, because it's too hard.

 

[Sokel]

In fact that's a huge weakness in this hobby - low-hanging fruit is endlessly discussed, and high-hanging fruit is ignored, because it's too hard.

If reality is not convenient too bad for reality

 

[FrankW]

I have been in rooms

Anecdotal. So still zero evidence anyone prefers speakers with reduced measurable floor/ceiling etc reflections. When you can cite some, please do, thanks.

where lateral reflections have been managed, and floor and ceiling bounce sticks out like a sore thumb.

The fact that lateral reflections were "managed" says it all. IOW, not a room based on actual listening test preferences, even for so called (deafened) Studio folks. Last check, Ali's room is not a "studio". The evidence is very clear for what listeners prefer in stereo.

 

[Bjorn]

I have been in rooms where lateral reflections have been managed, and floor and ceiling bounce sticks out like a sore thumb. When they're also managed, the room improves drastically. I understand that dealing with the floor is very difficult, but we should be very aware that it's bad policy to say, "It's very difficult to deal with, so let's just say it doesn't matter." In fact that's a huge weakness in this hobby - low-hanging fruit is endlessly discussed, and high-hanging fruit is ignored, because it's too hard.

I'm sorry, but we can't trust that because you have't conducted a ABX blind test. The fact that early arriving specular reflections can be altered with 20 dB doesn't of course prove anything. Or the fact that you can have deviation of the frequency response with several dBs over a wide area here besides several narrower areas with several dBs. Not backed up any studies at all. Several dBs over wide frequency area can of course be totally inaudible and doesn't change the tonality at all. Yeah, right.

Let's turn this around. When did Harman conduct and publish a blind test with a speaker that avoids foor reflections and minimizes ceiling reflections vs one the doesn't (like Revel or other typical speakers) and proved it to be totally inaudible?
And why is it that we are suppose to only trust certain psycoacoustic researchers and neglect the others? Doesn't for example Søren Bech's or SydAudCon's studies count at all?

We shouldn't forget here that Harman also has commercial interests and they also have a certain room and test method which give limited answers in many aspects. For example: They have never tested late arrival quality diffusion in regards to spaciousness and how this could effect the so called preferable lateral contribution. Most who actually have, have found that they prefer this over side wall reflections. Still, many draw conclusions and calling it science that we prefer side wall reflections based on extremely limited testing and only with a certain type of treatment. Any small room acoustican with knowledge and experience with different types of treatment know this would be very narrow minded and foolishness. After all, you can achieve spaciousness in multiple ways in a room and without using active side wall contribution.

BTW: We need differentiate between specular vertical reflections and the ground floor bounce which is SBIR related. The latter is partly below the Schroder frequency and specular reflections are only above.

 

[FrankW]

Let's turn this around. When did Harman conduct and publish a blind test with a speaker that avoids foor reflections and minimizes ceiling reflections vs one the doesn't (like Revel or other typical speakers) and proved it to be totally inaudible?

Argument from ignorance
Please cite the blind listening tests of reduced vertical reflections speakers being preferred in stereo/living rooms. Thanks.

 

[Bjorn]

Vertical, floor and ceiling are I believe the most harmful, horizontal can add ‘spaciousness’ but vertical can only be detrimental.
Keith

In most cases they are. But it will depend on areas like:
- How the speaker measures vertically
- Ceiling height
- Widht of room and horizontal beamwidt of speakers
- If the room has been treated or not and how it decays or for some would call how "reverberant" it is

The audibility of reflections are also highly dependend on angle and how the level is compared to other reflections. I.e. we can't necessairly hear a single reflection when it's being masked by many other reflections with higher or similar level. At that point we are only hearing them combined, which skews imaging, pin-pointing, localication, etc. But if where to attenuate many, we would hear a single one clearly and especially from certain angles.

All this is well known psycoacoustics and it's why it will often depend. Masking effects are real and why one needs to be careful to draw general conclusions.

 

[Inner Space]

... even for so called (deafened) Studio folks.

Yes, I agree that we studio folk are all deaf morons. (But you seem to have built a whole hobby around our product ... go figure.) In the meantime, this deaf moron would comment:

The evidence is very clear for what listeners prefer in stereo.

"Prefer" is such a weak concept. I have attended various tests with various questions. The strongest question is, "Which of these sounds like real life?" The "prefer" metric is weak because participants - by their own admission - tend to answer based on, "This is what I'm used to, but more of it." Which doesn't offer hard data other than in terms of market appeal. Certainly it's not a question about fidelity.

The intellectual gyrations caused by reluctance to answer hard questions is amazing. The fact is, if we're interested in fidelity - i.e. hearing only what's in the recording, with nothing taken away and nothing added, then all reflections are destructive. But practical researchers know most people won't go as far as eliminating reflections, so they explain away the huge disadvantages of domestic listening as "Envelopment!" "Spaciousness!" and so on. Total cop-out.

 

[steve59]

Meridian DSP 8000se

The M logo on the lower portion of the cabinet and original serial number show these are the latest iteration of the dsp8k that I upgraded with the Special Edition kit in 2019 leaving a bit over a year left on the warranty.I'll include the 218 dac/zone controller and upgrade speakerlink cables at...

www.usaudiomart.com