How to make small room sound bigger


Is It possible to make a relatively small room sound larger ? I have a 14 x 11ft with 8 ft ceiling. The room is completely empty, with vinyl floors with cement floor under.  Looking into vicoustic sound treatments. 

What would be the best approach with absorption vs diffusion and placement to attain a bigger sound space if at all possible ? 

I wrote to vicoustics, but did not hear back. 

speakers : SF Elipsa, Diapason adamantes, Focal utopia micro

amps: mastersound 845, mcintosh mc452, NAD M10

 

ei001h

@clearthinker 

Excellent point. The objective is to improve SQ AND avoid near field listening. I enjoy classical music, large scale symphonic works and such. I would like to feel the scale as much as possible to simulate a concert hall. While I know it's highly unlikely to perfect, I am looking for a way to maximize this, if at all possible in 11x14 room. 

I plan on using SF Elipsa SE  and/or Focal Micro utopia, using SET Mastersound. I've experimented with this and the amp drives my speakers without any difficultly. 

@mahgister - I am aware of Helmholtz resonators, I have read of their effectiveness but to be honest, I’d have a very steep learning curve on those. They certainly seem to be a lot more work than what I’ve done so far. Congratulations on your patience, because learning how to do it, before even implementation - wow.

Anyone in here thinking I am overstating, just look at the math:
https://www.sciencedirect.com/topics/engineering/helmholtz-resonator

Q˜=p˜m/Zint

or, since p˜m=p˜b1−Q˜Za,rad,

(7.53b)Q˜=p˜b1/(Zint+Za,rad)

where p˜b1 is the complex amplitude of the blocked pressure, Zint is the acoustic impedance of the resonator presented at the mouth, which comprises the sum of the impedances of the air in the neck and in the cavity, and Za,rad is the acoustic radiation impedance of the mouth. For a circular mouth of radius a it is given to a close approximation by the radiation impedance of a rigid circular piston with ka ≪ 1.

(7.54)Za,rad=(ρ0c/πa2)[(ka)2/2+j(8/3π)ka]

which shows that the reactive (nearfield) component dominates where ka ≪ 1.

The mean sound power absorbed by the resonator is given by

(7.55)Wabs=12|Q˜|2Re{Zint}=[12|p˜b1|2/|Zint+Za,rad|2]Re{Zint}

This attains a maximum value at the resonance frequency when |Zint + Za,rad| = |Rint + Ra,rad|. This maximum may be maximized by equalizing the internal resistance and radiation resistance of the resonator, to give

(7.56)Wabs=12|p˜b1|2/4Ra,rad=[πa2/4ρ0c(ka)2]|p˜b1|2

Helmholtz diffusers are also powerful not only the very well known resonators which also diffuse some frequencies anyway...

It is a tube with a filtering end mouth with no neck and an open end... I used tube of different diameter and length...

By the way dont be afraid by the mathematical DESCRIPTION with equations...

Your ears/brain COMPUTE everything without using any numbers...

Just EXPERIMENT.... And LISTEN.....Most people are afraid of mathematic...learn the physical meaning of these devices , throw the equations on the garbage bin and experiment and listen with your own ears... Simple... It is FUN.... and it work... Especially if you use many devices that compensate each other... I created my device and tuned them by ears not by resolving a set of equations.... 😁😊

Is it perfect?

No...

Is it astounding in S.Q. improvement?

 

Yes, i laugh at the idea of any costly gear upgrade...

I listen music not sound now...

 

@mahgister - I am aware of Helmholtz resonators, I have read of their effectiveness but to be honest, I’d have a very steep learning curve on those. They certainly seem to be a lot more work than what I’ve done so far. Congratulations on your patience, because learning how to do it, before even implementation - wow.

While I know it's highly unlikely to perfect, I am looking for a way to maximize this, if at all possible in 11x14 room. 

This may sound nuts (oh heck, I've just chambered a bullet, someone's going to flame me over this no doubt).

I listen to orchestral music quite a lot, and I really love movie score. Try using your long wall as the front wall, try diffusion entirely on the front (long wall) with deep use of absorption in the front corners for lower frequencies. Absorption if possible on the top and bottom edges of your now long front wall.

Absorption on the back wall, however, if you're going to play with diffusion do not use quadratic (it's not going to give you benefit at all, certainly not here, it takes distance to develop an effect, which you do not have). You can get binary amplitude diffusion to work at extreme short distances, with absorption. If you do trial BAD with the holes, use 1/2" holes it helps with lower frequencies.



Set your speakers off the front wall, through trial and error and keep them in from the left and right boundaries ( I would start with 7 foot apart), this is why I am suggesting using the room the wrong way round. You could also try using absorption on first reflection points on the sides as well to open up for the larger sound you're trying to portray. The sides of the room, those reflections are a dead give away sonically on room size.

Your seating position would be not far off the back wall, giving you an equilateral triangle with your speakers, if you do the ceiling possibly try mixed absorption & diffusion.
If you have someone who can help you, a handy mirror to visually see the first off axis reflection points of both speakers (not just the closest one) on the side walls should be diffused or absorption treated.

It's absolutely a compromise, it's one that's worked for me and others, trying to get what you asked for.
 

@rixthetrick 

The maths is noted, but unfortunately only an approximation of the true equation so ,fortunately for me, not much help.

 

The problem with using a small room in 'landscape' orientation is that on the short dimension there isn't space behind the speakers and behind the listening position.  So if the speakers are moved forward to give them air from the front wall, as you say, the listener hears bad reflections from the rear wall just behind him.  It isn't easy to damp those.  It may well be better to accept some side wall reflections adjacent to the speakers.

Yes you have it - it's all a compromise.