Room acoustics

Hi,

Can anyone help with this one?;

I read something on the net recently to the the effect that room acoustics play a large part in the performance of hi fi; It reminded me that my lounge leaves a lot to be desired; the room is a mild "L" shape with the speakers sited in the leg of the L. This means that the left speaker is next to an alcove and the right one is really too close to a wall to be ideal.

My question is whether sound deadening materials (I'm open to ideas) can be used to at least aleviate effects of resonance, diffusion etc?

I wonder if anyone has experience of this and could help or perhapts coud suggest a web site?



thanks,


David

 

David,

Try Adams site, nice and easy layout and good basic grounding too.

http://www.killahertz-acoustics.co.uk/

 

Not entirely certain what you mean mild L.....?

But you would be better possibly firing down the longer leg.

Its not a good idea to have the speakers in alcoves or near corners[obtuse] ie a fire place. If you can bring both speakers into the main body of the room this should help.

But as stated I'm not certain as to the room shape to be able to comment further.

 

Yes, I know, it would be better to fire down the lenth but this would mean major room re organisation - i'm not quiet sure what else to do with the piano at the moment.

By mild I mean that the leg onle extends about a foot or so - trouble is it still bxes in the speakers a little.

Wioll try to post you a rough plan if thats ok - im not quite sure how to get it onto zg!





cheers!


D.

 

Hi David,

What are your main complaints about the system's sound?

What you feel needs improving, will suggest different solutions.

For bass that is either very boomy and overblown or very lacking (but would not normally be with that speaker) you need some bass traps. Good ones are the likes of RPG Modex and my own Confidence units.

For upper bass and lower midrange being a bit ‘ommmm’ sounding try either the Auralex LENRD or cheap but not so effective copies from eBay.

If you are unhappy with the mid and high detail, confusion, harshness etc.. will need either absorption or diffusion. Diffusion is more expensive but generally gives a more natural sound. Something like the RPG Skyline, QRD or again my own Ambience are good. For absorption you can get pretty cheap foam egg crate stuff or fabric covered ridged fibreglass but it is easy to over-deaden the room and the sound that is not absorbed will still reflect about the room as before.

Hope this helps

BTW, this might prove some interesting reading, our brochure - http://www.audiosmile.co.uk/Brochore.pdf (I know, I spelt Brochure wrong >.<)

 

Thanks for the info Tenson.

This enquiry is not prompted by any specific complaint; more I looked at tha arrangement (not for the first time) critically; I'm always on the lookout for more resolution, sound stage etc.



thanks again for the suggestions,


David

 

If your room is L shaped and long, I would reccomend firing across width ways as below..
the x being the speaker and you being the 0.


............................
..............x........x....
.............................
...................0........
............
............
............
............

 

Your speakers and listening chair should be in the same leg of the "L" for a start.

 

If only my lounge were large enough to allow!

The leg only really invoves about 1-2 feet, just nuisance value.

The room lenght is about 17 feet, width at widest point about 14, at narrowest about 12 feet.



thanks for the idea though.





David

 

............................x.....
..................................
sofa.....................tv.....
..................................
............................x.....
.................................
.......................
.......................
.......................
.......................
.......................
.......................



rough current arrangement

 

doesnt look ideal david.

IMO of course.

 

I agree with you.

 

David I'd take a guess from your room layout that what you would benefit from most is some bass traps.

I'd suggest either buying some RPG Modex, waiting a few months to try mine on sale or return from a shop, or get some eBay cheap foam things and upgrade later if it works for you.

 

Thankyou Tenson.

Excuse my ignorance - I must admit I'd never heared of them! How do you use these?

Perhapts it tells me on your web site? I haven't looked properly yet.

 

You put them in the corner of your room behind the speakers. They absorb bass and stop it reflecting which reduces build-ups and also cancellations so basically takes bass away where there is too much and adds it where there is not enough. It also reduces the time it takes for the bass to decay after the original sound. This gives much, much less boomyness, so you have tighter bass.

 

Interesting stuff- Thanks

The RPG Modex ones are not cheap at $679.00.

Is there any name for the cheap ones on ebay or do you just type 'bass trap'?

 

Just try bass trap. They are NOT the same thing as mine or the RPG ones though. They work on different principals and are, quite frankly, inferior for anything below roughly 100Hz. They can certainly give you a small idea of what to expect though.

 

Would this mean that speakers can be placed closer to the wall, for instance , in smaller living rooms?

 

It does, especially if you have some way to lower the bass output of the speaker a little. With my active PMC's I could put them as close to the corners as I liked and they would never get slow or boomy bass, I just got more of it! So I would put them in the corners and use digital EQ to lower the bass accordingly. I could also have used the built-in bass tilt control on the speaker. You could build a simple very gentle high-pass filter for the system or get a Behringer DEQ like I have.

In fact I would strongly suggest the best solution for you is to get some decent amount of good bass traps like 4 of my Confidence units or 8 of the Modex (they are half the size) to go in the corners behind the speakers and then use the DEQ to adjust the bass output to be nice and smooth. This way you have the best of both worlds and I can assure you it works very well indeed.

Do you use a turntable or mainly CD?

 

I'm afraid I've succumbed to the convenience of cd.

This all sounds expensive Tenson!

Also, no offence, but isnt a digtial EQ a little against audiofile hi fi theory? ie minimum interference with the signal path for best results?

The base traps sound interesting.