The quest for my hyper speaker - Very Large room dilemma

[mcdn]

Your original post is below. I was replying to those numbers. In order to achieve what you said you need 10" peak to peak excursion from 4x 18" drivers. As the wavelength of 8Hz is 42m, no domestic size room will be have much (if any) room gain either.

Self evidently 120dB of free field bass at 8Hz requires stupid excursion, nobody would or should argue that. You‘re confusing free field and in room SPL. And they’re not my claims, they’re quotes from Matthew Poes and James Larson of Audioholics, widely recognised as the preeminent source of proper measurements of bass. You’re also ignoring scientific analysis of room gain done by another member here, and everyone’s common experience, which is that there is a lot of room gain at low frequencies.

 

[FrankW]

What I understand is that the room is not inherently bad acoustically, in fact large rooms have numerous acoustic advantages as well. It's just very difficult to fill with bass because it's so big, and I sit too far away so I require really high spl's without distortion or compression.

Your track record indicates you like wider dispersion speakers (Focal>Revel) in that room, unless I missed your post in this large thread indicating otherwise. Seems to me that you need a similar wider dispersion speaker, with deeper bass and more output. That means either larger, active, or both.
My two cents.

 

[sarumbear]

Self evidently 120dB of free field bass at 8Hz requires stupid excursion, nobody would or should argue that. You‘re confusing free field and in room SPL. And they’re not my claims, they’re quotes from Matthew Poes and James Larson of Audioholics, widely recognised as the preeminent source of proper measurements of bass. You’re also ignoring scientific analysis of room gain done by another member here, and everyone’s common experience, which is that there is a lot of room gain at low frequencies.

I was simply responding to what you posted. I don’t know, or care who those people are. I go by science and the numbers were wrong.

I’m not confusing free field with in room. Allow me to remind you the physics of room gain. You seem to ignore that the wavelength of 8Hz is 42m. To have any room mode to occur you need a room where the walls are at least 21m apart so that half of the wave will reflect and add to the sound created by the driver. Otherwise, there will be no reflections hence no room gain.

 

[aliqaz]

Your track record indicates you like wider dispersion speakers (Focal>Revel) in that room, unless I missed your post in this large thread indicating otherwise. Seems to me that you need a similar wider dispersion speaker, with deeper bass and more output. That means either larger, active, or both.

My two cents.

Thank you Frank. I do like wider dispersion speakers. But I have multiple systems that are already wide dispersion. As I have learned from this thread from the experts and as was my own inkling, in a room like this narrow dispersion would be much preferred as the room would dominate far too much otherwise. As a result I want to go narrow dispersion in this room to get far more direct sound and minimize sidewall interaction. Also the room is a bit reverberant and I want to reduce that as well, so again the logic for narrow dispersion.

 

[dedobot]

You may not know where Vancouver, British Columbia is (where I live) as I stated on my post but it is the opposite of a remote area without complicated audio services. It's a major city with every kind of complicated audio service you can imagine. The room in question is in my chalet in the mountains of Whistler, BC (1.5 hours from.vancouver) which again is the opposite of remote as we have multiple installers who do large complicated houses. So again the problem is not finding the people to do this, there are plenty of them, is whether they follow professional objective philosophy and are up to date on the latest developments and don't just shove a bunch of marked up stuff on to me as the middlemen.

Anyway. Until now you lived with F208 at this place . Everything from Jbl Everest, large Genelec/Neumann/ATC options to mine MEG suggestions will take your breath with a mandatory digital room direction . Just don't spend more than 50k USD. My very humble opinion of course.

 

[audiofooled]

I don't know if this fits the bill but could it be sufficient performance wise?

Backes & Müller GmbH | Saarbrücken | BM Line 50

Mit seinen Linienstrahlern setzt die BM Line 50 Maßstäbe im Lautsprechersegment und ist im vertikalen Aufbau geprägt. Hier klicken!

0-backesmller--zhb-de.translate.goog

 

[mcdn]

I was simply responding to what you posted. I don’t know, or care who those people are. I go by science and the numbers were wrong.

I’m not confusing free field with in room. Allow me to remind you the physics of room gain. You seem to ignore that the wavelength of 8Hz is 42m. To have any room mode to occur you need a room where the walls are at least 21m apart so that half of the wave will reflect and add to the sound created by the driver. Otherwise, there will be no reflections hence no room gain.

So you think René is incorrect?
Thread 'Analytical Analysis - Room Gain'
https://audiosciencereview.com/forum/index.php?threads/analytical-analysis-room-gain.23211/

Obviously no bass in cars either, being so small. Let’s stop polluting the nice man’s thread eh?

 

[kipman725]

18m long room is more the size of a cinema, a traditional Hi-Fi speaker is insufficient for such a space. For something off the shelf I would be looking at a system like the Meyer Bluehorn, Danley, Alcons, ETC. with an additional sub bass system.

 

[sarumbear]

So you think René is incorrect?
Thread 'Analytical Analysis - Room Gain'
https://audiosciencereview.com/forum/index.php?threads/analytical-analysis-room-gain.23211/

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

Let’s stop polluting the nice man’s thread eh?

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

 

[Bjorn]

Wow, that must sound really bad. Can you link the designs (yours?) that have beaten the Revel Salon2 in a controlled blind listening test, preferably with positions constant and reasonably quick switching time. Thanks.

Not necessarily bad, but it indicates something can be better. Everything is relative.
We don't need a blind test here. Why? Because we know that other speaker design will measure considerable more even when placed in a room. And that's only considering the frequency response.

Let's look at a comparison between Revel Salon and a CBT prototype measured at 2m distance and 1m height.

The raising treble with the CBT is imply due to lack of EQ on axis. A newer Revel speaker will not make much of a difference here. This is simply the cause of boundary interference. Less ceiling height would have made a bigger difference BTW.

Feel free to run a blind test if you don't think such differences in the response (overlooking the treble) is audible. In the time domain, the difference is also huge due to vertical reflections. And are there any researchers with blind tests that have shown us that early arriving vertical specular energy is not audible at all? That's a rhetorical question and the answer is clearly no.

 

[gnarly]

+1

If you don't allow for the extra headroom you will have the compressed sound that so many associate with LOUD music. With a system that has ~10dB of dynamic headroom you can play music at realistic levels without it sounding LOUD.

This has been a principal requirement for me, after having heard LOUD music that stays linear with low distortion, even for the dynamic headroom needed.
It's so amazing to me, how higher SPL just keeps sounding better, and how high the dang SPL meter reads, when a system truly maintains linear response throughout the spectrum.
I say dang SPL meter, because it's often a wake up alarm to limit the listening duration !

The acid test imo, in determining a systems max linear SPL capability, is simply at what measured average SPL level does it starting sounding loud. That simple.
Don't even have to measure it with the new AES75 Max SPL standard (adopted from M-Noise)......ears work just as well haha

Most domestic hi-fi speakers come up short in this area even in much more modest rooms. I would look at the more refined horn based systems, if these SPLs are important to you.

FWIW: The Wisdom and Steinway Lyngdorf systems I mentioned previously are also quite capable of achieving these SPLs in your room, but both are large and expensive.

Wan't to say I enjoy your comments, and the upper echelon commercial home-audio models posts.
I rarely look at home audio, being entirely into DIY and mainly exploring proaudio for technological advances.

One thing I'd add about the Wisdom and Steinway models....both will require their subs, as part of their system...
(And I do wonder if the Steinway can pull off the large space. The only sub offering I saw was a sealed dual 12"....could take quite a few of them stacked together)

Imo, NO system wanting to make 90+ dB @ 20ft in a large room, that extends down to at least 30Hz, and with linear dynamic headroom,.... ...
will be able to do so without sub(s), or the their equivalents output somehow imbedded into the main speaker.

It takes driver displacement ime, or efficiency gains from horn loading, to go both deep and loud. No getting around it, I think.

Setting aside horns for a second, on the conventional cone side I am leaning towards the perlisten s towers towers due to their high sensitivity, the MTM configuration to reduce vertical reflections and the lowest distortion figures that I believe exist for a cone speaker (meaning the maximum amount of headroom before compression). What gives me pause, is the necessity of subwoofers, and the wider than horn horizontal directivity.

Since moving on from my big Meyer's I posted about earlier, all my speaker focus has been on DIY, particularly on larger unity/synergy builds.
Here's an example of one without secondary flares. (for use with sub)


One handy rule of thumb I've learned is Don Keele's classic pattern control formula.
Where lowest frequency of pattern control = 1,000,000 / (mouth size in inches x horn pattern angle in degrees.
So the blue guy above has a 90 degree horizontal, 60 degree vertical pattern. And is 33" wide z 22" tall.
By the formula, horizontal control holds to about 300Hz . 1,000,000 / (90x33)= 309
And vertical holds to about 750 Hz 1,000,000 / (60x22) = 758

Ok, why bring this up? It's for horns, but I've found it holds up well for waveguides too.

You can apply it to your JBLs and see pattern control is letting go both H&V around 1000Hz.
I've found the ROT very helpful in evaluating any speaker that incorporates a waveguide or horn.

If patten control is important to you, just like there's "no replacement for displacement for direct radiating subs",
my experience is there's no replacement for size when it comes to pattern control.

Hope that all made sense..

 

[Bjorn]

@aliqaz
A word of advice would be to either have the opportunity to test the speakers in your living room before purchasing or have an open buy. There's nothing that beats testing in own environments.

 

[Mr. Widget]

One thing I'd add about the Wisdom and Steinway models....both will require their subs, as part of their system...
(And I do wonder if the Steinway can pull off the large space. The only sub offering I saw was a sealed dual 12"....could take quite a few of them stacked together)

Yes, both the Wisdom and Steinway systems require matching subs. In the case of the Steinway systems they do not consider them subs, but rather woofers... in particular they are called "boundary woofers". They crossover higher than is typical of subs and must be up against a wall or in the wall. And yes, you do use quite a stack of them. For the LS systems you typically use 6 per side.

For full disclosure we are dealers for both of these lines as well as several others discussed in this thread. My comments are reflecting actual experience. Most of our projects involve working with high net worth clients and NDAs so I can't get into details, but I will add to this discussion that we have installed the in-wall version of the Steinway LS speakers in an enormous room that is three stories tall with an open cage elevator off to the side. The speakers are hidden behind walls covered with custom decorative grillwork. The far wall is floor to ceiling glass for the spectacular view.

When desired, the system fills the room at concert levels. They absolutely handle huge spaces with amazing grace.

 

[Mr. Widget]

@aliqaz
A word of advice would be to either have the opportunity to test the speakers in your living room before purchasing or have an open buy. There's nothing that beats testing in own environments.

Agreed, but in cases like the subject of this thread, it is not typically possible.

I suppose if the OP decided to go with a high end pro audio solution, he could rent a system from one of the pro-sound companies and give that a whirl before committing.

 

[Bjorn]

Thank you Frank. I do like wider dispersion speakers. But I have multiple systems that are already wide dispersion. As I have learned from this thread from the experts and as was my own inkling, in a room like this narrow dispersion would be much preferred as the room would dominate far too much otherwise. As a result I want to go narrow dispersion in this room to get far more direct sound and minimize sidewall interaction. Also the room is a bit reverberant and I want to reduce that as well, so again the logic for narrow dispersion.

Take note that 's important to do something with you rear wall in order to minimize flutter-echo or "reverberation" even with a speaker with a narrow beamwidth. Doing something on the front wall would also help but the rear wall is the most important area.

 

[FrankW]

I hope you aware that Revel has collapsing horizontal directivity (not constant), vertical lobing and superposition between drivers, floor bounce, no time alignment between drivers, cabinet diffraction issues, and higher modulation distortion compared to what achievable. If such a speaker is A+, I wonder that grade we should give better designs

We don't need a blind test here. Feel free to run a blind test

"We" do and the burden of proof lays 100% with you, the claimant. 2 ears and a brain are not an in room microphone.
Btw, that isn't a Salon2 and we knew you had no blind listening tests in any case. Question was rhetorical.

 

[FrankW]

I want to go narrow dispersion in this room to get far more direct sound and minimize sidewall interaction. Also the room is a bit reverberant and I want to reduce that as well, so again the logic for narrow dispersion.

Understood, so indeed, either horns or other form of directional speakers like the Beolab 90 et al. Good luck sir.

 

[Bjorn]

"We" do and the burden of proof lays 100% with you, the claimant. 2 ears and a brain are not an in room microphone.
Btw, that isn't a Salon2 and we knew you had no blind listening tests in any case. Question was rhetorical.

Again again you are calling for blind tests in debates. 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, perhaps because you haven't read many studies or you don't understand how the speaker interacts with the boundaries. You really should acquaint yourself with psycoacoustics. Reflections from floor and ceiling are audible. I'm sharing information which is already backed by proof.

I’ve done a lot of testing on the effects of reflections in rooms, and there was a big, big project in Denmark about twelve years ago, with a lot of companies involved in investigating effects of reflections in rooms. I had the pleasure of being a test person, where we could actually simulate the audible effect of the floor reflection, sidewall reflection, ceiling reflection, and so on independently. The single most disturbing reflection in the room is the floor reflection. That is what makes the speaker sound like a radio and not like the actual event. ... The floor reflection absolutely must be handled. It was a joint project of Danmarks Tekniske Universitet, Bang & Olufsen and KEF led by Prof. Soren Bech.

 

[GXAlan]

That definitely is easier said than done. I live in Vancouver, British Columbia, most high-end installers typically just like to push among the small suite of products and brands that they sell. And these are super high-end retailers. Most have little to no idea about the latest advances in DSP and acoustics, and Voodoo runs amok. When I was setting up my whole house for audio video, I got frankly unbelievable quotes for mediocre products and mediocre implementations. I ended up partnering with a flexible installer who followed my instructions (which was fun as I am a hobbyist) and we were able to create a state-of-the-art sound and audio video solution for the whole house.

Vancouver is close enough to @amirm. I assume you need to go with a vendor in your territory for buying the stuff but maybe it’s worth hiring Madrona as a consultant. Would be a great article for this site!

 

[aliqaz]

Again again you are calling for blind tests in debates. 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, perhaps because you haven't read many studies or you don't understand how the speaker interacts with the boundaries. You really should acquaint yourself with psycoacoustics. Reflections from floor and ceiling are audible. I'm sharing information which is already backed by proof.

That is a very interesting post. I was initially interested in limiting horizontal reflections. 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, then the attempt to be made to limit those. Especially as my ceiling is so high the reflection will be arriving very late. Then an MTM cone speaker or a constant directivity horn have to be the key to minimize all those reflections. However the horn should also limit horizontal dispersion.