Experiences of homemade room treatments.

[twelvebears]

Right chaps.

Now the weather is finally warming up, I'm determined to crack-on with a long over due task in the Man-Cave.

Room is great but due to the proportions and reflective surfaces, is rather 'lively' and needs some calming down.

My plan is to make floor to celing 'Super Chunk' bass trapshttp://www.hometheatershack.com/forums/home-audio-acoustics/7758-corner-traps-finally-finished.html for the corners, with some panels for the walls.

I just wondered if anyone had made anything similar and if so, how they had got on?

[YNWaN]

I've got four homemade panels and they work very well. I'm about to make a couple of bass panels, but they are likely to have plywood outside skins (2mm probably),

[twelvebears]

I've got four homemade panels and they work very well. I'm about to make a couple of bass panels, but they are likely to have plywood outside skins (2mm probably),

Hi Mark.

I was going to use 75mm RW3 rockwool sheets with a wood frame and fabric cover for the walls.

Corner traps will be as per the link. Just dead space in the den, so no problem with the space they take up.

Gotta be worth a shot for the little it will cost eh? :eyebrows:

[bobbasrah]

Hi Steve, the chunks as corner traps you linked to certainly are neat with respect to finish. If there is room to do it, room treatment will prove very worthwhile, and can be done as cheap as you like. I am a perhaps overly paranoid over having reflective surfaces replaced by wooden frames facing into the room, no matter how small the area, so went a slightly different variation on the same idea.

Attenuation and reflection at the various frequencies of these materials are fairly readily available, and there are a number of specialist suppliers who claim to offer improved performance albeit at considerably greater cost than building products. Irrespective, <=100Hz performance remains very poor, but at such wavelengths any attenuation is very difficult, even using resonator panels.
In practice, I found treatment to enable the amp volume to be raised considerably before exciting room modes, but it is the front sound stage which really benefits when treatment kills rear reflections, and front treatment cleans that up a little further. In my own case, it was the rear, rear corners, and front corners in that order which provided the most significant and progressive improvements.

FYI, I ended up with assemblies which required minimum permanent fixings as follows-
Each corner has a single wood pole wedged between ceiling and floor, with two legs off this into the corner to maintain distance.
Triangular batts are randomly shoved into a bin bag (fibres) and wedged in the top and bottom of each corner above and below each stand-off.
Light timber frames were glue/screwed up to a max of 600/100mm and garden fleece stapled on one face. 100mm thick semi rigid glass wool batts were placed on the frame, some with the alloy/net backing left on at the rear, and fixed in place with a dab with a glue gun and fleece stapled again to the frame. I used two fabrics, one a fine net material you could breathe through for use at ear level, the other a less permeable furniture fabric, again stapled neatly to the frames, for all other areas.
Panels are held on the pole using plastic pipe clips screwed to the frame.

In theory, the alloy membrane left on the glass wool acts as a partial diaphragm, reacting to frequencies only after passing through the batt. Whether it makes any difference is difficult to assess, but it did no harm.The batts are sometimes cheaper this way and they tend to be less "fluffy".

[MartinT]

Hi Steve

I can't speak for home-made room treatment, but my TubeTraps and PicturePanels certainly do an excellent job of deadening my room's flutter echo and reducing bass modes. Good luck with your project!

[YNWaN]

Hi Mark.

I was going to use 75mm RW3 rockwool sheets with a wood frame and fabric cover for the walls.

Gotta be worth a shot for the little it will cost eh? :eyebrows:

That's pretty much how my four current panels are - but with perforated hardboard on the back and felt feet to stand them proud of the wall.

Easy to make and work very well (custom sizes too :))

[twelvebears]

Thanks Chaps, all very encouraging, especially in light of how little I have to lose in giving it a go.

Bob.

Thanks for the description of the arrangement you've used. Don't suppose there's any chance you could post a few pics at some point? I'd find it useful and I'm sure other here would be interested.

I was going to do the front AND rear corners (front would be a bit smaller due to the glass wall) and there's already shelving unit behind me which I'll be using to hid a load of rockwool slabs cut into squares.

Will also be making some mobile panels tha I can move to stand behind the speakers when I use.

Martin.

Flutter echo and room nodes. Yep, think I've got both of those, assuming flutter echo is the very fast, almost ricochet echo that follows a sharp hand-clap?

[MartinT]

Flutter echo and room nodes. Yep, think I've got both of those, assuming flutter echo is the very fast, almost ricochet echo that follows a sharp hand-clap?

That's it, Steve. Nasty and causes smearing of transients and fine detail.

As for any bare walls you may end up with, try copying the PicturePanels idea with more of that insulation in a wooden frame covered with fabric to make 'large pictures' to hang on the walls. One behind your head works wonders.

[bobbasrah]

Absolutely Martin, so long as the panel is acoustically transparent, whatever hits it is absorbed (short of long wavelengths). Paint it, print, crochet, the options are wide open.....
I know lads who stacked entire glass wool rolls in the corners and threw drapes over them to very good effect also.
The beauty of back wall treatment is you are not constantly looking at it, and it is the first reflection point from the speakers, so ideal for absorption and/or diffusion.

We tend to sit in the back of a U shaped seating arrangement, so the wall is pretty close behind us. This wall is lined at ear level with 1000/600 panels between a narrow shelf and a deep pine shelf at the top carrying the brica-ornaments. Very effective. If I lean back close to the panel you can feel the bass pressure in your ears. Quite a strange and interesting effect as the volume gets increased.

Steve, sorry mate, I have never managed to get a photo through the usual suspects yet for some reason.
I will try it again tomorrow failing which I can email them.

[twelvebears]

That's it, Steve. Nasty and causes smearing of transients and fine detail.

As for any bare walls you may end up with, try copying the PicturePanels idea with more of that insulation in a wooden frame covered with fabric to make 'large pictures' to hang on the walls. One behind your head works wonders.

Yes that was my plan - work out roughly how many and where and them tart them up by covering with fabric prints afterwards.

Also need to get some more ruggage on floor (hard ceramic tiles but one big rug in the middle of the room) and some shallow acoustic tiles for the 1st reflection point on the ceiling too.

[Sonority]

Steve,
I do have some fair experience of DIY trapping and what is involved in 'getting it right'.
I kept a log of the whole thing here :-
http://forums.musicplayer.com/ubbthreads.php/topics/1984380/Wall_boundary_trapping#Post1984380
You may care to have a look. It is very picture intensive, and for you probably starts to get good around page 2 - 3.
There is an absolute ton of info on that site / forum, but that is it's main reason for being there..
While it is easy to do, lots of very important bits of info are not immediately obvious, like how to keep a bass trap 'live' for high frequencies, just how important first reflection points are, and how the corner traps behind you need to be totally absorbing - not live.
If I can answer any questions I will try.
I can say one thing as absolute though. Getting the room right with acoustic panels really does work and makes a huge improvement to what your kit can do.
Hope you have fun.
Stephen.

[MartinT]

I've tried my TubeTraps different ways round and I get the best sound in my room with all four of them set to absorbing. It's worth experimenting.

[Sonority]

Hello Martin,
I would agree that it is worth experimenting.
Tube traps are very different beasts though to fixed panel traps.
I have a friend who uses tube traps pretty much everywhere in the room - not sure I could lose that much space :-)
Front fixed corner bass traps to the best of my knowledge help if being reflective of high frq. This is obviously not writ in stone - and very easy to do either way.

[twelvebears]

Steve,
I do have some fair experience of DIY trapping and what is involved in 'getting it right'.

Bloody hell Steve! 'Some fair experience' has got to be the understatement of the decade! :eek:

Your blog has been hugely helpful, but if it's OK, would you mind me pestering you with a few questions if I can't work it out after a thorough read?

The two that spring immediately to mind are:

1. Any particular views about what density of rockwool slab to use? 45-100Kg/M3 easily available and for the amount I will need, the price difference is not a factor, just want to use whatever will work best.

2. Guessing the paper facing makes the panels reflective to HF? If so, are there any other ways to do this?

I'm planning triangular, floor to ceiling corner traps both front and rear, panels on both side walls, and over my listening position.

Anyway, very, very helpful.

Thanks

[Sonority]

Steve,
No problem at all with answering your questions.
It was fun running with that diary and I made friends all round the globe during the process. We all kind of helped each other.

Firstly I found Sheffield Insulations to be incredibly helpful and very useful. I doubt you will find FRK faced rockwool over here - at least I couldn't at the time.
Thats why I used 'lining paper' glued to the face to act as a high Frequency reflecor. Aluminium foil, brown 'kraft' paper or thin plastic sheet will all give very much the same required result.

Knauf us 'RS' numbers to indicate weight, so RS80 is 80Kg M cube.
I used predominantely RS80 and RS60 in thickness of 100mm or 75mm (100mm is better). RS100 is very heavy and probably not worth the (much) extra over RS80.

RS80 is great to work with, in pretty much any thickness over 2" (sorry - old school)
RS60 is as low as I would personally go as below that the rigidity becomes a problem in the panel, ie - they become rather floppy.

I had some RS30 - hopeless! so that was condemmed to stuffing.

for your corners I would, if poss, run with 80 or 100. Much easier to work with and wont cause you problems over time.
The more wall space covered the better - ie if you can have them widthways across the corner rather than height = better. Also filling behind can help, even with just fluffy fibreglass. Not a huge difference but worth the effort (according to those who know - ie Ethan)

If you can, aim to have a Reflection Free Zone where you sit (RFZ).
First reflection point traps give you imaging that can be crazy good.

Just dont aim to kill the room dead - a nice 'live' environment is still required.
As you proceed you will quickly get what that means.

Good luck - keep us informed how you do.

Steve.

PS - Carpet adhesive was much cheaper at Jewsons / Sheffield insulations than most other places.

[twelvebears]

Cheers Steve, very useful again.

Yes I was looking at 80 - 100 Kg/m3 stuff, so good to have confirmation.

My plan is to get sufficient boards to go everywhere I think will need doing (certainly to cut all the triangles for the floor to ceiling corner traps), stack the corners and then experiment with the panels that go elsewhere and only make the frames and coverings once I'm sure on location.

Really looking forward to it and will definately post plenty of pics and updates.

All the best

Steve

[Welder]

:popcorn:

I really wish I could do more where I live.

[Sonority]

Steve,
Did I understand your meaning correctly where you say 'cut out triangles' that you intend to take a rectangle piece of rockwool, say three or four inches thick lop off two sides then stick them one on top of each other from floor to ceiling?
If yes - that is really cool :youtheman:. Probably ott, but just about enough as my friend says. & I am not the one to go saying something is ott, I fully realise that :)
All the off cuts can easily be used in a frame as other traps.

I may have read that wrong, I realise that!

[bobbasrah]

What an extraordinary project Stephen, stunning work, superbly recorded and anotated for posterity and reference.
It would have been interesting to quantify how much the modes were attenuated by the treatment, but as it was a custom build room rather than a retrofit, that would have been impossible.
Makes the average home treatment effort seem rather insignificant, even though sonically that is rarely the case.
Impressive stuff.....

[twelvebears]

What an extraordinary project Stephen, stunning work, superbly recorded and anotated for posterity and reference.
It would have been interesting to quantify how much the modes were attenuated by the treatment, but as it was a custom build room rather than a retrofit, that would have been impossible.
Makes the average home treatment effort seem rather insignificant, even though sonically that is rarely the case.
Impressive stuff.....

If I can track down or borrow some sort of measuring kit, I'll be happy to take before and after readings.

[twelvebears]

Steve,
Did I understand your meaning correctly where you say 'cut out triangles' that you intend to take a rectangle piece of rockwool, say three or four inches thick lop off two sides then stick them one on top of each other from floor to ceiling?
If yes - that is really cool :youtheman:. Probably ott, but just about enough as my friend says. & I am not the one to go saying something is ott, I fully realise that :)
All the off cuts can easily be used in a frame as other traps.

I may have read that wrong, I realise that!

No, that's exactly right Steve.

Basically I'll be getting 4 triangles from a 4'x2' for the rear corner traps - i.e the long side and the face of the trap being 33" wide - and stack floor to ceiling. The rear corners are just dead space so really no loss whatsoever.

The front corner traps will be smaller because of the amount of wall available on the return before the front glass wall of the room - they will come from getting 8 triangles from each sheet, with these having a 24" hypotenuse.

Need to decide on who to order the boards from because although 60kg/m3 and 100kg/m3 are easily available, 80kg/m3 isn't at all. It would help if I'd used the board before and a feel (literally) for how firm the 60kg/m3 stuff is. If it's solid enough to support a triangular stack, then I'd use that, otherwise I'll either track down the 80kg stuff or make to with 100kg.

Any comments on the 'squishability' of the 60kg boards would be helpful.

:)

[bobbasrah]

Steve, if you can measure it beforehand it may prove interesting later, not least from your own point of view.
It never occurred to me to measure before mucking into it here. Wish I had, just out of academic interest. To my ears there is a substantial increase in the amp volume to achieve the same sound levels compared to the bare room, as so much reflection is damped particularly at the rear. Volume has to go a lot higher before room modes become noticeable now for certain.
Another noticeable benefit, our room is open plan, but the the sound seems remarkably contained, and nowhere near as loud elsewhere, although 2am blowouts are still a no-no. Quite satisfied. Better than any equipment upgrade I ever did....

Unless there is a huge difference in cost for the batts, I would recommend going for the higher density, and the thickest you can get if you are cutting and stacking them. A 8ft wall is a lot of trangles. Chances of them stacking even 21 slats 100mm thick without being held in place are still pretty slim though.
Being slightly away from the wall with the batts does no harm as the pressure build-up is away from the wall surface from memory....

[Sonority]

Steve,
Let's see if we can save you some money here.
I know that the triangle method *looks* simple, but honestly - you are using an awful lot of very expensive product that you certainly do not need to. If you got 4" or 3" thick batts, and stood them lengthways on end (two should or will then reach the ceiling being 2.4m (batts are 1200x600mm) ) the air gap makes very little difference. You can very easily fill it with *much* cheaper standard fluffy fibreglass roll. You will find that this gives you 98% of the effect that using full fill as your intent. With the amount of panels you intend to use that 2% is honestly hardly worth chasing - IMO. the extra saved can be put to very good use elsewhere :), remember there are *12* corners in a room (usual four sided) and they all benefit from treatment. The amount of work will be identical in the long run - and probably easier than the triangle method.
Bob is correct in what he says - at the wall junction the speed = zero so nothing to 'trap' there - hence gap = good.
However - if you do wish to run with your suggestion, my thoughts are with Bob, I would personally have at least two 3/4" thick ply triangles equally spaced used as support in each column.

I personally think that over time RS60 will begin to compress at the base. 80 will be better, 100 should be fine - but would need confirming with the manufacturer.

As for availability - this is what I would be looking for :-
http://www.sheffins.co.uk/manufacturers/url_frames.asp?MyURL=http://www.knaufinsulation.co.uk
<Edit, for some reason the actual page will not show - you need to navigate to it from the L/H column. Products : Rock mineral wool slabs : Universal slab> Hmm it helps if you know what your looking for!! They make way to many products.
Unit 4
Victoria Road Retail Park
Crown Road
South Ruislip
HA4 0AF

TEL: 020 8839 4321
FAX: 020 8839 4301

I think that is the closest branch. Give them a call, have a chat, see what they can do for you. I bet they would deliver, they have a huge fleet of trucks!

Let me know how you get on with them, my branch could not be more helpful.
If you have a company, or know someone who does - some trade discount may come your way ;)

I also agree with Bob, measurements are fun and could prove useful later on. It also gives a visualisation as to what you are actually hearing.
I could not do this as I did not have any kit (still dont, but a friend does :eyebrows: ) I just knew that I would not be making anything worse.

Yes, the volume knob needs to go higher the more that you do - but, and it's a big but, 90db in my corrected room *sounds* subjectively louder than in an untreated room. Maybe due to the fact that you are hearing the speakers alone and very few nasty time smearing reflections :scratch:

Without re-reading my whole diary I am certain I made notes along those lines somewhere <happy memories>

If you want to hear just what will happen (at the very least) just buy 4 packs of standard loft insulation. Dont even unroll them - in fact definitely dont unroll them, just leave them sealed in the polythene - I am not the best fan of that stuff :steam: just stack two packs in the rear or front corners - you have rudimentary corner traps - working at about 40% of what you will achieve. If you like what it does just put some proper batts right in front of it and forget its there. Instant trap.

Hope that helps - remember, what you want is the most important thing, what I have suggested is just that - a suggestion. No harm in doing what you want. My corner traps work just fine but conform to no norms other than looking ok to me.

Cheers.
Steve

[bobbasrah]

......OR.... If you are mainly going to use batts rather than rolls, stick two bales on their end in the back corners and jam them in/lean something against them temporarily.
That will give you an idea of what to expect in the lower frequencies. The plastic wrap will still reflect shorter wavelengths, but the acoustically porous batts that will ultimately face outward will kill corner reflections, and the corner fill will still attenuate lower frequency build up. If the fill is plastic wrapped it makes no difference as the reflective frequencies would be absorbed in the front panel before hitting it.

You would need 7 bales to do as you envisage. I would be tempted to suggest make all the panels the same and break up the visual impact a bit as only the top and bottom thirds of the wall are where the pressure is greatest.

Foil faced were the battss I got here, as oddly the wool was heavier and more compact, and unlike 4 by 2 metricated british they were 1000/600mm. I ended up with a short fill panel for the bottom, and a recessed box/shelf/display under the top panel (above listening height) which gave some WAF.....

Played around with the foil face both ways round for the main panels, but ultimately left them with this facing the rear. I think Ethan's advice/opinion was that although the membrane does nothing directly in that position, it may partially attenuate low frequencies in a cross corner arrangement.

You will certainly appreciate the difference it all makes, and you may be surprised how it affects out of room intrusion also....

[Sonority]

Hello Bob,
I only made the suggestion of trying the rolls as they are exceedingly cheap to buy when compared to the compressed rock wool batts - but your suggestion is equally valid.
The reason we have adopted 1200 x 600 in the UK is standardised heights of rooms (usually 2.4m - roughly 8 feet in old money) and this works with block and brick sizes also, so for the construction industry it makes life easy.
With regard to foil faced. While this *is* available it is usually a factory option and an awful lot needs to be ordered for them to do so. I never did find any actually as a stock item. In the end that probably worked for the better as I could make anything I needed with the spray glue and paper / card facing.
The amount of batts per pack also varies here dependant on the thickness ordered - so Steve needs to aware of that.

Cheers.

[bobbasrah]

All understood Stephen. If the rolls are cheaper and can be used as fill, nothing wrong with that at all, it was simply that Steve seemed to be focussed solely on batts, and your suggested experiment could still be done that way with a couple of bales instead.
I know lads who have used stacked rolls in the corner and thrown drapes over them to dramatic effect. I'm a firm believer in the low-cost high benefits of simple broadband traps.

It has been many years since I was raidng Jewsons and Keyline for building projects back home, but I rather assumed the same imperial equivalents prevailed. Well out of touch on this and uk pricing these days though.

Foil backed batt was/is more common in Romania than plain and peanuts price-wise, no idea why, but metric standard is 1000/600. As I said, the standard 100mm batts for some reason seemed lighter and less rigid than the foil backed at the merchants, hence that was what I got. They only have 50mm and 100mm here also, so it's a bale of 8 or a bale of 4 respectively....
From memory it was about 80 Ron a bale which would be less than 15 quid.

[twelvebears]

Thanks chaps, your collective input and experience is very much appreciated.

What I may well do, is order sufficient batts to do the front face of the corner traps, perhaps to a depth of 8" (i.e. a double layer of 100mm batts) with a void behind, listen and the fill with bound insulation rolls (pinching your idea Stephen) and see how it goes.

That way if I do decide to do the fill with chopped up slabs, I'll only have wasted a few rolls of insulation.

[twelvebears]

Have also noticed that Sheffiled Insulations have a branch in Barking, East London, which is basically on my drive home from work (Canary Wharf) and I just happen to have a car with a massive boot, so even in batches, I can save myself delivery costs.

Collecting the first load tomorrow!

[bobbasrah]

Have also noticed that Sheffiled Insulations have a branch in Barking, East London, which is basically on my drive home from work (Canary Wharf) and I just happen to have a car with a massive boot, so even in batches, I can save myself delivery costs.

Collecting the first load tomorrow!

All sounds like a sensible plan Steve, but would suggest you get a pack of garden fleece or similar (B&Q?) to wrap or cover the exposed batts. Very cheap but acoustically transparent. Those floating fibres get everywhere and are downright irritating, before even attempting to cut them....:rolleyes:
Enjoy your first foray....:cool:

[Sonority]

Excellent news Steve, looks like an interesting weekend ahead.

WRT Bobs suggestion ref covering the batts. If you do decide to do that the stuff is also available from garden ctrs as weed suppressant (make sure you get the woven fibreglass stuff some is very soft, some fairly stiff - both work ok)
I would doubt it will be needed for the Knauf stuff as they have a new method of production which stops fibres from coming off as the old yellow / green stuff used to. The new stuff also has better acoustic values (so they say) than before, you may have noticed it changed half way through my build!
It is pretty irritating stuff as Bob says - cool showers after help!

The white facing I put on mine is polyester wadding available from most material stores (Dunelm?) at reasonable prices. It allows for very open weave fabric to be used without being able to see the colour of the batts behind. It is totally acoustically transparent.

Very much looking forward to seeing this take shape.

Cheers.

[bobbasrah]

WRT Bobs suggestion ref covering the batts. If you do decide to do that the stuff is also available from garden ctrs as weed suppressant (make sure you get the woven fibreglass stuff some is very soft, some fairly stiff - both work ok)


Yep ;) that's the same stuff Stephen, known as garden fleece for some reason - available in white, brown, or black, of german manufacture and pretty cheap from memory (Think it was about 2 quid for a 5m by 1.5m pack over here... YMMV)
It feels like an acrylic, but you can blow through it easily, it cuts with sharp scissors readily, and can be stapled through with your average office stapler onto pine. It takes quite a bit of tension before it rips, so is ideal for smoothing the panel onto a back frame with envelope corners before finishing with chosen fabric.:D

[twelvebears]

would suggest you get a pack of garden fleece or similar (B&Q?) to wrap or cover the exposed batts. Very cheap but acoustically transparent. Those floating fibres get everywhere and are downright irritating, before even attempting to cut them....:rolleyes:
Enjoy your first foray....:cool:

I know just the stuff. Susy has loads in her greenhouse, but I'll buy my own I think! :lol:

[bobbasrah]

I know just the stuff. Susy has loads in her greenhouse, but I'll buy my own I think! :lol:

Well it should circumvent arguments as to why you have tomato plants growing out of the wall corners......:eyebrows:

[twelvebears]

Weather has slightly buggered plans for playing around with the insulation that is currently filling my car.

Arse!

[bobbasrah]

Weather has slightly buggered plans for playing around with the insulation that is currently filling my car.

Arse!

:scratch: English summer weather already?:eyebrows:

If it is plastic wrapped batts as it should be Steve, bring it is from the car and stand it in the corner.... If it is exposed roll or batts, bin bags are cheap enough....:cool:

[realysm42]

Do you have to measure to work out what is needed in your rooms? I'm aware it'll be different for everyone due to the unique combination of gear and rooms, but I wouldn't know where to start with this (although I'm very intruiged).

As far as I'm aware my gear sounds fine, even at high volume but you don't know what you don't know, right?

[bobbasrah]

Do you have to measure to work out what is needed in your rooms? I'm aware it'll be different for everyone due to the unique combination of gear and rooms, but I wouldn't know where to start with this (although I'm very intruiged).

As far as I'm aware my gear sounds fine, even at high volume but you don't know what you don't know, right?

You can google and work out from room measurements what your room mode frequenclies might be, but that will not change anything though.... :rolleyes:

Grab all the duvets, blankets, or whatever comes to hand (unless someone is is on night-shift), and stick them in the back corners and see if it makes any difference to what you are hearing ?:scratch:
If it does, start thinking how to make it more permanenet without domestic dis-harmony....:cool:

[realysm42]

Is someone could see the things I do with my stereo, they'd think I'm ocd or a bit mental. I'll give that a shot though lol, thanks :)

[Sonority]

Steve,
That was a bit of bad luck with the weather - great when that happens isn't it! Getting the slabs wet won't harm them, but then can smell decidedly weird when drying out (got that t shirt!)

Martin - Ethan never stops saying ''you can never have too many bass traps'' and from what I have learnt I would tend to agree. I doubt that there is a room in existence that could not do with some help.
What you do need to be very wary of though is not 'killing' it stone dead. A lot of folk get completely the wrong idea with acoustic panels, assuming that the more you kill the room the better. Totally wrong, but very, very easy to get right.
I took it that I would not be making the room any worse, and just kept asking questions until I was satisfied I was going in the right direction.

[bobbasrah]

So.....
Do you have a pile of stuff in the house yet, or are you enjoying acoustically treated music on the move ?