Pros and Cons of Sealed Listening Rooms

[kach22i]

Now admittedly this is not exactly going to please most non-audiophile partners. However, the results were fantastic. That old speaker form the 90's and a pair of subwoofers were amazing. Just something to think about.

I would think they might be a bit bass shy, but love the illustration and wonder how electrostatic or open baffle speakers would behave under similar circumstance.

 

[sbnx]

I would think they might be a bit bass shy,

You can't see them in the pictures but there are two subwoofers in the system. One to the left and one to the right of the main speakers. The bass was tight and articulate and definitely not "shy". The nice thing about this setup was that I could find the best possible seating position and speaker position to provide nice bass along with the other suff. I posted a pic of the REW data form 20Hz to 500Hz smoothed to 1/24 octave as a reference.

 

[Exlibris]

The best room i ve heard to date , (im repeating myself lol i ve told it before) .
Was at a dealer who is now out of business in nijmegen
I ll always remember when they were setting up an avalon ascendent on a all levinson system and let it play for a couple hours before the client came , (half a day on the juice.)
I could come in and listen by myself while they knew i didnt have the money then .
It was a trapezium shaped room well isolated but with not that much treatment certainly not overdampned .
When that thick double glass door shut you could feel the music everywhere , it was like the whole room was filled with energy .
No sound would come in totally private relaxed listening
I m gonna measure that room at some time , its now part of a furniture shop.
Might come in handy when i will do some thing myself.
The speakers werent even big, its just a 2.5 system 2 7 inch woofers.
I ve heard the same speakers playing just average in other rooms .
Thats when i knew the room is ......

Ps it was only the door that was glas it had no windows of some sort , plus it could be covered with a curtain.

Was the trapezium shaped room narrow at the speaker end and wider at the listener end? I'm imagining the speakers were along the shortest wall(?) Did the ceiling slope as well? I've often thought that a sort of "bandshell-shaped" room would sound good. Perhaps this trapezium shaped room sort of emulated that without the true parabolic shape.

 

[andromedaaudio]

Hai,
I ve listened to both , speakers placed on either side
But the real magic happened indeed when the speakers where placed against the shortest wall.
Kind of a amphitheater idea .
No the ceiling didnt slope .
I would love to experiment with that though.

Plus for that sound you need power behind it .
Pressure behind the music , good solid state will do it , convergent tubes do it too

 

[Exlibris]

Hai,
I ve listened to both , speakers placed on either side
But the real magic happened indeed when the speakers where placed against the shortest wall.
Kind of a amphitheater idea .
No the ceiling didnt slope .
I would love to experiment with that though.

Plus for that sound you need power behind it .
Pressure behind the music , good solid state will do it , convergent tubes do it too

I would have thought that the amp would be helped by the amphitheater flare. The room would kind of act like a horn.

 

[andromedaaudio]

No , an amp shouldnt need the room shape to reach the desirable spls imo.
Thats 2 different things , the room needs to be energized properly .
An amp needs to have absolute control over the LS units , otherwise its all distortion
A Set which is just able to reach the desired Spl s wont do .
Yoiu need a bit of headroom for good musical energy

 

[Exlibris]

No , an amp shouldnt need the room shape to reach the desirable spls imo.
Thats 2 different things , the room needs to be energized properly .
An amp needs to have absolute control over the LS units .
A Set which is just able to reach the desired Spl s wont do .
Yoiu need a bit of headroom for good musical energy

What are "LS units"?
I'm going to be using a 30 watt amp on 94 db speakers.

 

[andromedaaudio]

Loudspeaker units .
It could work if the specs the manufacturer provides are real and the impedance curve doesnt dip too low.
What also helps is the amps powrsupply , i like an oversized one for instant dynamics.
A 30 Watt could be enough sure , just try if possible , before the actual purchase

 

[PeterA]

So it is funny how we get locked into thinking a certain way. You know you always walk into a room and the stereo is setup on the far wall with the listening seat somewhere near the door. Well my epiphany moment was to turn this upside down. I took a bunch of my "spare" gear and setup a system in my living room. But instead of setting it up against the wall (by this I mean with 3+ feet between the speaker and the wall) like I did before I set it up with the seat out into the room several feet from the wall and the speakers with their backs to the opening to the room. See pic. The idea is that I got left to right symmetry and the speakers have a mile of space behind them.

Now admittedly this is not exactly going to please most non-audiophile partners. However, the results were fantastic. That old speaker form the 90's and a pair of subwoofers were amazing. Just something to think about.

Extremely interesting position. Did you also try switching the speakers so that the tweeters were on the inside? Did it sound as though the soundstage was back in the hallway or dining room? Can you describe the sound for us?

 

[Duke LeJeune]

But the real magic happened indeed when the speakers where placed against the shortest wall.
Kind of a amphitheater idea.

I've seen this sort of geometry used in recording studio builds. Having the non-parallel side walls further apart at the back of the room than at the front of the room tends to direct the first sidewall reflections behind the main listening area. In other words this is an effective technique for minimizing early sidewall reflections WITHOUT absorbing them, so that energy survives to become later-arriving reflections after another bounce or two.

Imo this avoidance of early sidewall reflections effectively "disrupts" the small-room-signature which would normally tend to super-impose itself atop all of the recordings. So you hear "less of the room", but because the room is using geometry instead of absorption to accomplish this, the reverberant field is still strong enough for you to hear "more of the recording venue". Indeed this is one of the reasons WHY recording studios often use this type of room geometry: So that the engineers can clearly hear the recording venue cues on the recording, instead of having those venue cues (whether real or synthetic) masked by the acoustic signature of the much smaller room they are mixing or mastering in.

 

[Exlibris]

I've seen this sort of geometry used in recording studio builds. Having the non-parallel side walls further apart at the back of the room than at the front of the room tends to direct the first sidewall reflections behind the main listening area. In other words this is an effective technique for minimizing early sidewall reflections WITHOUT absorbing them, so that energy survives to become later-arriving reflections after another bounce or two.

Imo this avoidance of early sidewall reflections effectively "disrupts" the small-room-signature which would normally tend to super-impose itself atop all of the recordings. So you hear "less of the room", but because the room is using geometry instead of absorption to accomplish this, the reverberant field is still strong enough for you to hear "more of the recording venue". Indeed this is one of the reasons WHY recording studios often use this type of room geometry: So that the engineers can clearly hear the recording venue cues on the recording, instead of having those venue cues (whether real or synthetic) masked by the acoustic signature of the much smaller room they are mixing or mastering in.

This is slightly off-topic, but what about rooms with low ceilings. Ive always assumed a 9' ceiling would sound better than 8' and 8' better than 7'. I ask because most of the older homes in my area have basements with low ceilings.

 

[Duke LeJeune]

This is slightly off-topic, but what about rooms with low ceilings. Ive always assumed a 9' ceiling would sound better than 8' and 8' better than 7'. I ask because most of the older homes in my area have basements with low ceilings.

I'm inclined to agree with you.

 

[kach22i]

This is slightly off-topic, but what about rooms with low ceilings. Ive always assumed a 9' ceiling would sound better than 8' and 8' better than 7'. I ask because most of the older homes in my area have basements with low ceilings.

All the room sizing calculations I have seen start with ceiling height.

This means a smaller room the lower the ceiling goes.

And the smaller you go, the more problematic the modes/nodes become.

There is a certain size that is considered too small for proper bass, and it's near that 7' ceiling marker.

 

[spiritofmusic]

I run an 18'x48' room, eaves descending 30° R and L from midline apex ht of 9' to side walls 4' high.

Just looking at those dimensions, I really feared the worst and potential waste of £50k. My reservations were totally contradicted the moment speech was found to be hugely intelligible, and music played effortlessly saturating such a large space.

Quite how a ceiling ht varying from 9' max to 4' min could result in this still perplexes me.

 

[andromedaaudio]

Duke , thats exactly the way i would be heading .
You have to be very carefull with adding absorption for not taking to much life out of the sound .
I am also thinking what an angled back and front wall would do ,.
No parallel walls but with a centerline in the middle , then for example 30- 40 degrees angles to the side, a completely curved/ angled space
I think you could make a drawing with speakerpositions / listening spot and see how all the reflections will bounce in advance

 

[Exlibris]

I run an 18'x48' room, eaves descending 30° R and L from midline apex ht of 9' to side walls 4' high.

Just looking at those dimensions, I really feared the worst and potential waste of £50k. My reservations were totally contradicted the moment speech was found to be hugely intelligible, and music played effortlessly saturating such a large space.

Quite how a ceiling ht varying from 9' max to 4' min could result in this still perplexes me.

I'm wondering if we can assume that if voices sound good in a room that it will be a good room for audio, and vice versa.

 

[spiritofmusic]

I believe it's no coincidence. So, once the room was built, carpet laid, hifi set up higgedly piggedly non optimally, and my anxiety levels were right up, I could SO easily hear conversation up there. I had way more confidence at that point it was gonna work out. And my strong guess is that other than symmetrical layout and eliminating concrete and glass I was cursed w before, my descending eaves have proved massively beneficial.

 

[Mike Lavigne]

I'm wondering if we can assume that if voices sound good in a room that it will be a good room for audio, and vice versa.

even though i take it for granted, visitors do comment that talking voices in my room are particularly normal sounding. you can talk very quietly and it's easily heard and articulated. in my house it's very open with lots of windows and high ceilings and the voice sounds are different, the space somewhat swallows up parts of the voice sounds, and other aspects of voices are boomy.

 

[spiritofmusic]

Mike, if I had bought the chapel here on my own, I'd likely have installed my system in the main signature space. But that would have meant energising a 35x30x20 volume, just over the floor area I have in the loft, but nearly 4x the volume, and 2x what I had in my old apartment. And throw in lots of nooks and crannies, staircase, lobbies, all hard surfaces.

I'd have saved on the loft conversion outlay, and likely would have gone to high efficiency horns.

Whether I could have achieved The General's outcome of energising a similar size space on 1.46W is another matter Lol.

 

[Exlibris]

in my house it's very open with lots of windows and high ceilings and the voice sounds are different, the space somewhat swallows up parts of the voice sounds

I've noticed that in some rooms where I work. And the worst room for trying to hold a meeting is, shockingly, pretty close to a golden ratio. It has a wooden floor, not many windows, and drywall all around so its pretty average in that regard. You just can't hear people speak unless you are really close to them.