DIY Room treatments

[gjc121]

Hi,
I have a second system in the attic and the room is an odd shape. L shaped room with a 4x4 m square adjoining a 4.5x3m oblong with part sloped ceilings and a little alcove etc.
There is some carpet/rugs on floor in front of system.

Looking to improve sound stage and stop reflections from the long sidewall and alcove, also to experiment with bass trap or similar in corners and behind speakers etc.
Some sort of covered panels would be good-cost effective please :)

[Ammonite Audio]

In a relatively small space you probably won’t want any additional acoustic absorption once some soft furnishings are in place. Bass traps that are truly effective are monstrously big things, so have a good think about whether you actually need them, and whether you are prepared to live with their bulk and intrusion. Common types of acoustic panels cannot absorb bass frequencies unless made very deep, so do be aware that panels are usually only effective at upper-mid to high frequencies, where inappropriate implementation has the worst effect on the overall room acoustic.

That aside, people almost always assume that they need acoustic absorption, when in reality they actually need acoustic diffusion to break up reflections so that they are randomised and become relatively benign. In the old days, theatres used fancy ornamentation to achieve good diffusion, and things like bookcases, record storage etc can provide good diffusion without costing anything.

Moving on, my advice is to never place absorption panels at first reflection points, because that is frequency selective and musically destructive. Use diffuser panels instead at first reflection points, or none at all. I know that Toole et al do recommend suppressing first reflections but in a small room it never works, and neither does placing absorption behind the listening position where (again) diffusion is usually a better bet. Don’t be tempted to measure the room and attempt to interpret the results in any meaningful way, unless you have access to a professional program like Odeon.

Your situation is almost certainly much simpler than you think, so tread carefully. If you think absorption might be helpful in any position, use rugs, drapes, quilts, piles of cushions etc to experiment, then you’ll have a clearer idea of what actually works, and what you like.

Since it’s an attic room, do consider isolating the speakers from the floor. When done properly, that stops structurally transmitted sound, which others in the house might appreciate, but it also means that you hear the speakers, and not the speakers plus the room structure singing along. Remove that last aspect and you might just find that nothing else needs to be done.

[AJSki2fly]

I would find some heavy secondhand velvet curtains that you can experiment hanging from floor to ceilings along he walls, possibly breaking up your L shape. I think you will be surprised at the change they can have. There is some free software REW for Mac or Windows, all you need is a USB mic, don’t worry about spending money on an expensiveness one a simple one in a usb camera/mic will do,,the you can experiment with different speaker, listening position and soft furnishings and measure the difference. But most important is to use your ears, and when your happy with how it sounds, sit down and forget it and enjoy the music.

[Mikeandvan]

Since it’s an attic room, do consider isolating the speakers from the floor. When done properly, that stops structurally transmitted sound, which others in the house might appreciate, but it also means that you hear the speakers, and not the speakers plus the room structure singing along. Remove that last aspect and you might just find that nothing else needs to be done.

Without going off thread too much, how would you suggest isolating speakers from the floor? spikes, rubber pads or another way? With the floor being suspended. I have mine on spikes, but these rest on metal discs that themselves are on faux marble slabs, which rest straight onto the carpet.

[Macca]

In a relatively small space you probably won’t want any additional acoustic absorption once some soft furnishings are in place. Bass traps that are truly effective are monstrously big things, so have a good think about whether you actually need them, and whether you are prepared to live with their bulk and intrusion. Common types of acoustic panels cannot absorb bass frequencies unless made very deep, so do be aware that panels are usually only effective at upper-mid to high frequencies, where inappropriate implementation has the worst effect on the overall room acoustic.

That aside, people almost always assume that they need acoustic absorption, when in reality they actually need acoustic diffusion to break up reflections so that they are randomised and become relatively benign. In the old days, theatres used fancy ornamentation to achieve good diffusion, and things like bookcases, record storage etc can provide good diffusion without costing anything.

Moving on, my advice is to never place absorption panels at first reflection points, because that is frequency selective and musically destructive. Use diffuser panels instead at first reflection points, or none at all. I know that Toole et al do recommend suppressing first reflections but in a small room it never works, and neither does placing absorption behind the listening position where (again) diffusion is usually a better bet. Don’t be tempted to measure the room and attempt to interpret the results in any meaningful way, unless you have access to a professional program like Odeon.

Your situation is almost certainly much simpler than you think, so tread carefully. If you think absorption might be helpful in any position, use rugs, drapes, quilts, piles of cushions etc to experiment, then you’ll have a clearer idea of what actually works, and what you like.

Since it’s an attic room, do consider isolating the speakers from the floor. When done properly, that stops structurally transmitted sound, which others in the house might appreciate, but it also means that you hear the speakers, and not the speakers plus the room structure singing along. Remove that last aspect and you might just find that nothing else needs to be done.

Great advice that.

I can add that I lived in an attic room for a while. It was fine with no treatment. A bookshelf and a bed, that was it. It was quite a large space, carpeted. I was using small speakers at the time, Mission 731LE on spiked stands. I found them best firing out from under the sloping bit of the roof, rather than the other way. Which makes sense if you think about the reflections from the slopes. If you are planning on deploying a similar speaker then I don't think you will need to do much if at all. If it is some sort of wideband monster that will probably be different.

[Ammonite Audio]

Without going off thread too much, how would you suggest isolating speakers from the floor? spikes, rubber pads or another way? With the floor being suspended. I have mine on spikes, but these rest on metal discs that themselves are on faux marble slabs, which rest straight onto the carpet.

Spikes couple the speaker to the floor so there is no isolation at all and placing a heavy slab between spikes and floor will only alter the character of the sound transmission, not prevent it, but every little helps. Isolation, in varying degrees, can be achieved by:


Spring systems which when carefully specified can provide total isolation (Townshend Seismic products are the Gold Standard but you can go DIY at modest cost). The challenging bit of designing a spring system is to get the correct spring rate, with optimum damping, and (most importantly) having something that's stable in use.

Elastomer systems where good isolation can be achieved at mid-high frequencies, but compared to a sprung system low frequency isolation is often poor. Gaia do some good ones.

Foam pads like the Auralex products used in studios are the cheapest and most convenient way to achieve some isolation and decoupling, but in truth not much.



Moving from a 'hard coupled' mindset to one that accepts speakers can be quite softly supported is quite liberating in terms of sound reproduction, but much more liberating for anyone living in a house or flat where transmitted sound to other rooms and/or neighbours is a problem (that's pretty much all properties, and even those supposedly constructed in accordance with Building Regulations Part E).

[alphaGT]

Some very good information in this thread! I’ve been thinking of sound treatments myself, so I’m “Absorbing”, some of this advice.

A radical idea, but to isolate speakers, you can hang them. I recall long ago a woman I knew had some small speakers hanging in fishing nets from the ceiling. At first I thought it was just a nautical themed decoration, but upon hearing them, they gave a fantastic 3D quality to the sound. And, were out of the way. I realize this may be over the top for many, but it’s food for thought.

Russell

[Ammonite Audio]

Some very good information in this thread! I’ve been thinking of sound treatments myself, so I’m “Absorbing”, some of this advice.

A radical idea, but to isolate speakers, you can hang them. I recall long ago a woman I knew had some small speakers hanging in fishing nets from the ceiling. At first I thought it was just a nautical themed decoration, but upon hearing them, they gave a fantastic 3D quality to the sound. And, were out of the way. I realize this may be over the top for many, but it’s food for thought.

Russell

Mark Baker of Origin Live shares that thought, but I have no idea whether the result sounds any good!

https://www.originlive.com/wp-content/uploads/2017/loudspeakers/astute-twin-angled-in-1000-400x418.jpg

[karma67]

i got very good results when i just put a b&q paving slab between my stands and carpet,it did wonders for the bass,i dont know though if the height change played more of a roll in that or not.

[gjc121]

Hi,
Currently Marantz Imperial 6 speakers and on marble stands with blue tac 'marbles/balls' between stands and cabinets.
marble stands are on thin rubber stiff backed pads, all standing on laminate flooring.
Speakers and stands are heavy....
Thanks

[Macca]

The Imperial 6 does have some deep bass but it is way down in level. Try them and see. If you are getting some bass boom then the cheapest, simplest way to fix it is with digital EQ. You could build bass traps but they need to be big (like the corner posts of a boxing ring) and dense. The little panels you see on the walls in some rooms will only absorb and scatter much higher frequency reflections and will do nothing to correct any bass modes. Unless the room is very bright and reflective it's my opinion that you don't need them. Killing those reflections completely can make the room too dead and actually reduce the size of the soundstage.


Or third alternative is building/buying resonators to cancel the modes but again a lot more hassle than using EQ. Although getting the EQ right isn't just plug and play either.

[alphaGT]

My speakers have 3) 12” woofers in each. So I’ve got real bass problems! But just keeping them away from the corners, and a few feet from the back wall does a LOT to tame it. Getting the woofer farther off the floor can help too.

Russell

[Mikeandvan]

Spikes couple the speaker to the floor so there is no isolation at all and placing a heavy slab between spikes and floor will only alter the character of the sound transmission, not prevent it, but every little helps. Isolation, in varying degrees, can be achieved by:


Spring systems which when carefully specified can provide total isolation (Townshend Seismic products are the Gold Standard but you can go DIY at modest cost). The challenging bit of designing a spring system is to get the correct spring rate, with optimum damping, and (most importantly) having something that's stable in use.

Elastomer systems where good isolation can be achieved at mid-high frequencies, but compared to a sprung system low frequency isolation is often poor. Gaia do some good ones.

Foam pads like the Auralex products used in studios are the cheapest and most convenient way to achieve some isolation and decoupling, but in truth not much.



Moving from a 'hard coupled' mindset to one that accepts speakers can be quite softly supported is quite liberating in terms of sound reproduction, but much more liberating for anyone living in a house or flat where transmitted sound to other rooms and/or neighbours is a problem (that's pretty much all properties, and even those supposedly constructed in accordance with Building Regulations Part E).

What are the options if you've got a carpeted sprung floor? I thought the faux marble slab would provide a nice flat hard surface for the speakers to sit on - whether they are spiked or on some form of squidgy plastic supports.

Here's my current speaker set up. https://live.staticflickr.com/65535/47616920491_3de5671842.jpg (https://flic.kr/p/2fxKavM)IMG_20190411_215126077_HDR (https://flic.kr/p/2fxKavM) by Mike Van (https://www.flickr.com/photos/145505522@N02/), on Flickr

As you can see my components stand is also rigidly fixed to the floor by its spikes, and that's a heavy stand, is this ideal?https://live.staticflickr.com/65535/48018390368_0163553c99.jpg (https://flic.kr/p/2gadNwd)IMG_20190607_123743162_HDR (https://flic.kr/p/2gadNwd) by Mike Van (https://www.flickr.com/photos/145505522@N02/), on Flickr

[Ammonite Audio]

My recommendation for speaker isolation is simply to stop sound transmission from the speaker, into the structure of the room and house. The same does not apply to a rack, which generally needs to provide a stable and aesthetically pleasing support for equipment, so I would not criticise your equipment stand which is perfectly functional. Speaker isolation using compliant springs or elastomer supports is generally a good thing, except when slim tower speakers are used, in which case stability becomes possibly rather more important. For that reason, other than experimenting with something like rubbery layers underneath the marble slabs to add some further decoupling between those and the carpet, I don't think there's much that you can do, practicably.

[AJSki2fly]

Try some of these under the speakers https://www.ebay.co.uk/itm/4-x-Sorbothane-30mm-Diameter-Isolation-Feet-Spheres-4-x-Self-Adhesive-Pads/293118018248?hash=item443f3202c8:g:r3oAAOSwsY1c~5g q buy the right size for the weight of each one.

Sit in your listening position and get someone to move a mirror (about 1’ by 1’) along the side wall, parallel to the wall, at your head height. When you can see the speaker in the mirror the speaker next to the wall this is the first reflection point, try hanging a curtain or something absorbing like a wall rug at that point. In the corners behind or next to your listening position you can experiment with cardboard boxes in a tower at odd angles to the walls an each other, this will stop low end bass reflections, a curtain drape across the corner can help. Often overlooked are ceiling reflections, a triangular sail type material suspended below the ceilings no will stop a lot.

If you do all the above you will probably be quite surprised by the difference, but it may all sound a bit dead, so subtle changes in the size of the above and position of the reflection absorbers until you get what you want.

As for most of us it will be a matter of compromise and tweaking until it sounds good for you.