Need help setting up my Room (Placement of acoustic panels / bass traps etc)

[Ethan Winer]

Originally Posted by Lewis.

I bought some of these 'Offeccet' Acoustic panels and just need a bit of help / advice as to where I should place them

Usually the best advice comes from the manufacturer. But this short article explain the basics, and includes links to more detailed explanations:

Acoustic Basics

--Ethan

________________
The Acoustic Treatment Experts

[Lewis.]

Thanks Ethan. I've read a lot of your stuff in the past and found it to be very helpful.

One more question on my bass traps - they are foam/rock wool filled. Should I drill some round 25mm holes in the sides so they absorb sound side on too? It's an idea i've been toying with. They are better if they are behind the listener from their design (or so I think) so having some holes in the side the acoustic energy could enter that way too right - what do you think?

[Dange]

I looked those panels up OFFECCT

They operate in the 150-500Hz range (although the site offers no more tech data other than that) so are not for use at first reflection points. You need to figure out which boundary surfaces of your room are causing the modal effects and place the panels on them.

I'm guessing the panels are some sort of broadband Helmholtz panel. Drilling holes in the side will impair their performance.

You may need a few more than the 4 panels though. Sell your speaker cable risers and spend the money on something that will have an effect the sound

EDIT: those speaker cable risers are in your line of sight from the listening position so probably will affect your perception (as you can see them). They are doing nothing physically but if you think they improve the sound, their only effect is psychological. Having said that they do keep things neat and tidy, you can vacuum/dust under the cables easily I suppose! Just hope you didn't pay a silly amount of money for them.....

[Lewis.]

Thanks for the reply Dange. Ok so they should ideally be placed behind me then I guess so the speakers are firing directly towards them. I get a lot of bass on the left side wall towards the rear, does it matter if the panels are side on - will they still absorb bass like this? I will post more pics later to illustrate my room as its not ideal on the rear wall for placement of panels due to a door and notice board! So what do you recommend for first reflection points? Diffussion instead? I was considering some rpg skyline panels. There's a lot of echo when I clap my hands despite the heavy rug, and there's now a fabric armchair to the left too. I'll put up more pics later so you guys can get the jhist!

[Lewis.]

Forgot to say: yea I know the cable elevators do nothing at all but o got them purely because they look neat and stop the cables getting covered in dust and stuff - hoovering around that area is way easier now! They weren't expensive either.

[Glenn Kuras]

Originally Posted by Lewis.

Forgot to say: yea I know the cable elevators do nothing at all but o got them purely because they look neat and stop the cables getting covered in dust and stuff - hoovering around that area is way easier now! They weren't expensive either.

It is amazing how many posts I have read where the person SWORE the sound was better.

[Ethan Winer]

Originally Posted by Lewis.

Should I drill some round 25mm holes in the sides so they absorb sound side on too?

Sure, it can only help.

--Ethan

________________
The Acoustic Treatment Experts

[Jens Eklund]

Originally Posted by Lewis.

Should I drill some round 25mm holes in the sides so they absorb sound side on too?

If the device relies on membrane/helmholtz principle: absolutely not, since that would reduce the performance drastically.

[SAC]

But if the source and amplifier are set above the speakers, the downward orientation of the cables placed upon properly elevated and calibrated cable stands would allow gravity to help the little electrons more efficiently traverse the distance, thus increasing the efficiency of the speakers.

...Not to mention that it would help the cables avoid drafts and colds.

You see, there was a benefit of spending far too many years studying fissiks!

[Jens Eklund]

Originally Posted by SAC

But if the source and amplifier are set above the speakers, the downward orientation of the cables would allow gravity to help the little electrons more efficiently traverse the distance, thus increasing the efficiency of the speakers.

You see, there was a benefit of spending far too many years studying fissiks!

[Lewis.]

Back on topic. What are we thinking for the side Walls instead? Diffussion?

[Jens Eklund]

Originally Posted by Lewis.

Back on topic. What are we thinking for the side Walls instead? Diffussion?

Before you start to treat against something, it’s usually a good thing to know what we are trying to fix.

[Lewis.]

Ah sorry - I thought I had mentioned it but obviously not! My mistake!

Well theres a pretty bad bass null at the listening position, which vansihes when I either stand up, or put my head close to the floor and lean forward a little while seated. Mid and treble are ok, although there's some high pitched echo present when you clap so that needs to be addressed also.

Any help is much appreciated! thanks

[Jens Eklund]

Originally Posted by Lewis.

Ah sorry - I thought I had mentioned it but obviously not! My mistake!

Well theres a pretty bad bass null at the listening position, which vansihes when I either stand up, or put my head close to the floor and lean forward a little while seated. Mid and treble are ok, although there's some high pitched echo present when you clap so that needs to be addressed also.

Any help is much appreciated! thanks

The nulls are related to modal issues and perhaps some SBIR. The "flutter" can be addressed with diffusers and/or absorbers. You should make some measurements to be able to verify what the exact problems are and try to understand the behavior of these in order to successfully treat them. This applies especially to the modal response of your room. There are tons of threads in the forum that deals with these questions.

Sincerely Jens Eklund