Acoustic Wall Panels - what fabric to cover?

[djblack]

Hi Folks

Looking to upgrade my existing acoustic wall panels to some deeper ones with Wickes dense wadding.

Obviously I need to cover these panels (6 of them, a meter square each) with fabric.

Has anyone got advice as to suitable fabric to use, apart from standard loudspeaker grill fabric?

Thanks

D

[pemberto]

Djblack,

Have a gander over at Custom Audio Designs, http://www.customaudiodesigns.co.uk/screens/fabricmenu.htm

Lots of really good info for all aspects of Acoustic treatment.

Pemberto

[avanzato]

Loudspeaker grill cloth and the Professional acoustic fabrics will be fire rated or should be. Otherwise you can use any fabric that allows air through it, the easier you can blow through it the better.

Which Wickes product are you using?

[Gary Lightfoot]

30mm high density slabs?

[avanzato]

I was wondering as I tried the dense slab and then swopped for the cavity slab which was miles better. I also tried fluffy fibreglass and fibreglass slab from B&Q and they all seemed better than the dense slab I first got.
Then I was directed to Bob Golds (http://www.bobgolds.com) list of absorbtion coefficients page where the numbers probably explain it better then I can.

[djblack]

..slabs - I tried the high density ones too and found the 50mm "normal" density ones better... in my room...

I guess its not to say that would be better in every case though...

D

[djblack]

Out of interest... and I guess I am opening up myself to (more?) ridicule...

My original acoustic panels were made from 1m square 6mm mdf panels with a deep foam backed carpet glued on.

You would be gobsmacked as to how good these actually worked out.

I think the placement of the panels is often just as important as the build.

I used the old "get a pal with big arms to move round the room" trick to check the best place to mount the panels... again, it makes a huge difference.

D

[djblack]

pemberto - many thanks for the link - that is a great find.

That material feels a bit expensive but the choice and quality certainly seems to be there...

avanzato - Another great link - that guy has cenrtainly done his homework... wish I had found that a while ago!

D

[Gary Lightfoot]

I'm sure I've seen panels constructed with MDF and other 'accoustic' material that were meant to do exactly what you're home made panels did, except yours were much cheaper. :)

I think people are more likely to aks you how you made them than try to ridicule you!

Gary.

[pemberto]

About 6 months ago on the Discovery Home and Leisure channel (Sky) presenter John Revell had a 2 part show about building a home cinema. During the show he built several of these panels.

Construction of these panels consisted of a 2x2 frame with a 4mm mdf backing board. 50mm rockwool panels inserted and the covered with a muslin cloth to keep the rockwool from escaping and the covered in a finishing cloth. To attached to the walls he used double sided velcrow.

[djblack]

...that was quite a good, two episode program....

It was amusing watching him go round a couple of dealers (from memroy, it may have been one) and being astounded at the prices!!

My Tivo caught that series - god bless wishlists!!! I think I dumped it to DVD for future reference too... better go dig it out...

D

[pemberto]

djblack,

Have a look at these. Very impressed by what this guy has done.

http://stargateunofficial.com/SGU_tSearch.asp

http://www.avsforum.com/avs-vb/showthread.php?s=&threadid=487747


Paul

[Gary Lightfoot]

That's a great look, and probably didn't cost the earth either. I think the frames look is much better than a plain treated wall. Wish I'd thought of doing that. :)

Gary.

[djblack]

..yeh, these frames look very professional and I bet they work really well too..

I am not sure if I would have the patience to make so many of the damn things... after the first 6, the rest may not be of quite the same quality... he he!!!

I liked his room build photos - nice idea with the platform/stage up front - quite a nice easy feature to add...

D

[pemberto]

Here is another one, http://webpages.plantationcable.net/tomrhyne/Construction.html It would seem that the guys in the US like to use a lot of Guildford of Main fabrics for home cinema's.

http://www.guilfordofmaine.com the main fabric for Acoustical Treatments is Guildford of Main FR701 style 2100. 48 of colours to select from and from what I can work out it costs $20.00 per yeard from www.acousticalsolutions.com

[Gary Lightfoot]

GOM fabric has always been mentioned over at AVS ever since I started going there, and seems very popular. I don't think we have anything similar over here though.

I wonder what speaker grill cloth would be like? It's cheap and comes in some other colours as well as black, and being acousticaly transparent would mean the accoustic material underneath would be able to work to its full effect.

Gary.

[pemberto]

Gary,
You can get GOM fabric over here. Its distributed by Interface Fabric Group, which I think is the European arm of Guildford of Maine, http://www.interfacefabrics.com/index-uk.html
Contact Details: Interface Fabrics
Hopton Mills, Mirfield, West Yorkshire, WF14 8HE
UK Sales Tel:01924 490491, General Enquiries: +44 1924 490591

I managed to get sent a fabric sample sheet from Acoustical Solutions in the US for GOM fabric which looks very good as well as SoundSuede panel fabric, http://www.acousticalsolutions.com/products/panels/sound_suede.asp ,in 55 different shades and Acoustone acoustic grill cloth, again they look very good. I might go down the soundsuede route.
Paul

[Gary Lightfoot]

Thanks for the info Paul.

Gary.

[stevebez]

Howdy

I kind of like the look of heavy hanging curtains... quite dramatic ... ceiling to floor ... even a little extra long to cover any gaps on the floor... gets rid of the flat surface rebound and sound absorbtion is - well really good depending on how heavy / dense the material and interlining is. You need pretty thick and heavy interlining. I don't think its a substitute to wall panels but if I put my cinema together I think I will go his route. It can hide any wall panels pretty well too, but does take up a bit of space and interfere a little with ventilation if there are vents behind these curtains.

Also you can probably wind them out the way electrically if you have the appropiate rails ... could really look the part.

Don't think its a substiute to wall panles though but the combo could be benchmark.

Any Thots ?

Rgds Steve.

[dazca1]

Are these soundseude panels along the same lines as Auralex sound treatment?

[pemberto]

Dazca1,

Yep, they are along the same linees. Have a look at Acoustical Solutions website, http://www.acousticalsolutions.com for details of what they offer for Home Theater. For information on the SoundSeude panels have a look at http://www.acousticalsolutions.com/products/panels/sound_suede.asp

I am currently only interested in the fabric as I plan to make my own panels. I just cannot work out if I should use the SoundSuide or use the Guildford of Maine fabrics.

At the end of the day its all down to the wife. She has the final say on what this is going to look like. I just get to buy the toys.

Pemberto

[snapper]

Hi.

I have a very 'bright echoey' room. Am I better with high density slabs or normal ones?

curtains are not an option.

thanks in advance

W

[avanzato]

I have a very 'bright echoey' room. Am I better with high density slabs or normal ones?

Use the normal ones probably called 'Cavity slabs' in the DIY shop generally the thicker the better as then you cover a wider range of frequencies. One pack should be enough to start with and 2 packs will be plenty. Wickes have 85mm thick Rockwool or B&Q Warehouse have 75mm thick Knauf Fibreglass, the Knauf is better value but more itchy to handle IMHO.

[Gary Lightfoot]

Snapper,

Do you have carpet on the floor of your room? Plain wooden flooring can cause lots of echo, and wall treatments may or may not help if that's the case. Try laying a rug or similar downand see if that makes a difference (assuming wood flooring).

Gary.

[snapper]

Yes this is a living room with solid wooden floors, plaster walls.
a thick large wool rug has helped but not cured it.
I have already bought 5 high density slabs 30mm from Wickes but I dont want to waste time & effort if something else would work. My intention was to make 5 panels to stick on the walls around the room.

thx

W

[avanzato]

Put the slabs in the room and see how they alter the rooms acoustics. Subjectively I felt the softer slabs and even fluffy rolls sounded better but that's in my room so yours may just need the HD slab.

Just putting the absorber in the room will give you some idea of how it's going to work or not.

[Killahertz]

It is often preferable to use a high-density panel, one that sustains it's own shape whilst free-standing. Whilst of obvious benefit, you have to be aware that excess density will negate absorption at the target frequency range. It may very well be absorbent at bass frequencies (assuming sufficient material depth), but essentially reflective at the more important specular range. The same (within reason) follows for the covering.

Whilst neither needs to be audio-specific (or expensive), they do need absorbency and transparency to be effective. Medium density Rockwool (in a simple frame) is both cost and acoustically effective. And, whilst Cara fabric (from Custom Audio Designs) is acoustically ideal, it is expensive, but readily replaced with a natural hessian or muslin fabric (which can be dyed to suit).

If you want/need to use curtains instead, then use a heavyweight material. Better still if they are lined over a light filling of BAF/Dacron wadding. And used heavily ruched, rather than layed flat.

PS: Edited to add a link to a natural fabric supplier:

http://www.whaleys-bradford.ltd.uk/products.cfm

[stevebez]

Some persian rugs hung on the wall? - not cheap but bet missus may like the idea...!!! Not best insulator but they aint bad.

Rgds Steve.

[ROZ]

A mate of mine is an acoustic engineer (part of the design team for the acoustics at Bridgewater Hall (Halle Orchestra) gave me some advise on acoustic partitioning. He said you'd never completely isolate without > 4"-5" void.

As I had a only 2" to use he said the best I could do was a drywall affair with low density acoustic fill-roll covered with two thincknesses of high density acoustic wallboard (he also said there probably wasn't much between normal materials and these acoustic ones - just a bit of snakeoil, which is what he also says about high proce interconnects for AV applications :lesson: ). I only had space for 38mm fill and 12mm wallboard.

Trick is not to attach your studwall frame to the wall you're trying to isolate. We were soundproofing a party wall in preparation for our HC investments (amp arrives tomorrow :rotfl: ). This makes it a bit more tricky if you're trying to isolate all four walls (plus floor and ceiling :confused: ) This then ensures no vibration is transmitted through the frame to the wall behind, and allows it to flex and let the fill absorb the sound. The frame was then "sealed" with hign modulus acoustic mastic (more snakeoil?) before fixing the wallboard, taping, filling and painting.

All in all, with a chippy helping out (paid) it probably cost less than £300 for two 13' x 11' walls.

NB One thing to bear in mind is the amount of noise that gets transmitted under floorboards and wall cavities. Good idea to stuff partition fill roll or equivalent under in there.

Good luck

[Gary Lightfoot]

Hi Roz,

That is indeed a tried and tested method of sound isolation that works very well indeed. Two layers of 1/2inch plasterboard (UK term for wallboard) or one of 1/2 inch and another of 5/8 inch which are glued and screwed together make a stiff wall that won't flex too much. A wall that flexes too much can act as a bass trap and suck all the bass out of a room. 4x2" wood is prefered for stiffness again, as smaller will be more flexible. As you rightly say, if the new wall touches the existing wall, the sound vibrations will pass straight through the materials that make it and straight into the room next door. A 1" gap with 4" wood studding and 1" plasterboard infilled with 4" of rockwool is a cheap and very effective method of sound isolation. If possible, use a rubber strip between the bottom footer and top header to help improve isolation further (for bass vibrations, these isolaqtion methods work mostly for 125hz and above IIRC).

Using high modulus silicone rubber is to ensures a good seal and fills all air gaps, whilst remaing somewhat flexible without breaking the seal. Where air can go, so can sound (a 1" hole will allow 15dbs of sound through, and can negate the effect of fitting a new wall altogether), so you should do all edges, probably before and after fitting skirting.

My rear wall in my loft was only 2" thich with 30mm high density slabs and edges sealed with silicon rubber, but that works quite well, though 4 x 2 would have been better of course. Bass response in the loft is less due to the thinner flexible back and side walls I have. It's good compromise between having a good volume and not annoying the nerighbours. :)

Your recommendation of doing something with the floorboards is a good idea - it's probably the weak link after making the new wall.

STC values are used to show the effectivness of sound proofing, and the higher the number you can achieve the better. A 4x2 wall as described can achieve an STC of approx 41, which is 11 more than an average wall of around 30 IIRC. An STC of 50 is 4 times quiter than an STC of 30.

Gary.

[mattym]

you can get acoustic panels made to any size and covered in interface fabrics (or any other for that matter!) from

www.rpg-europe.co.uk

[ROZ]

Hey Gary,
Have you got a feel for which wall I'd be better off fixing my sats to;
a) The front wall common to our neighbour's with no cavity insulation
b) The "soundproofed" stud wall isolated from the party wall

[Gary Lightfoot]

Hi Roz,

I'm not sure what you mean by the front wall for your satellites, but if you have a pic of your layout, that might help.

I decided not to attach any speakers to any walls, so that would reduce the chance of transmitting any vibrations through them - I did this partly to reduce sounds going through the walls, and also because I wasn't sure how much vibration would shake my roof tiles of (my hc is a loft converision of sorts). :)

So my side and read surround speakers are all on stands, though I have started making some speakers similar to these:

http://www.wilsonaudio.com/products/watch_wallmount/main1.shtml

They fix to a wall plate using spikes so that they are more isolted from the wall. I thought I'd try an experiment using existing drivers and crossovers and to see if I could make it work, then I could have the rear surrounds on the wall but higher up and firing down at the seating area, rather than the bi-pole arrangement I currently have.

Gary.

[ROZ]

Now that's a design I haven't seen before (in the vertical position anyway?). Very inventive.

Sorry about the lack of clarity before Gary. Sorry no photos (must get that digital camera sometime... :( )

There are two walls (joining at one corner) that I can mount the sat on. One is an outside cavity (uninsulated) wall, common to our neighbour. The second is the "soundproofed" stud wall I installed against the common party wall between ourselves and our neighbour.

The question is, with speakers bolted tightly to them, will more sound be transmitted to our neighbours along the solid cavity wall, or through the acoustic wall board and rock wool filled stud wall. :confused:

[ROZ]

Just heard back from my Acoustic Engineer buddy who says to definately fix them to the acoustic stud wall as it's independent of the party walls... :thumbsup:

Let it be written, let it be done. Could I finally be able to roll out ROTT this weekend - I've been saving it since it arrived on 10th Dec :eek:

[Gary Lightfoot]

Glad you got it sorted - I can see that the studd wall would be less likely to transmit than the existing wall, so that seems like good advice. :)

Hope you get it all up and running by the w/e!

Gary.

[djblack]

Hi Chaps - a small update with the latest version of my wall panels!

I decided to make up 6 panels, each 0.8M by 1.2M.

I have made up frames with CLS (38mm *63mm from memory). I have made a rectangular frame and added a brace half way down the "long" side for extra ridgidity.

I have them sitting waiting for the glue to dry tonight, and hope to get them painted black matt tomorrow - so the white wood is not visibly through the fabric.

Wall fixings - well, after a long think, I have gone for Screwfix mirror plates.

http://www.screwfix.com/app/sfd/cat/pro.jsp;jsessionid=IKHSKO00ZO541CJO2C1SIIQ?id=1311 4&ts=51997

I intend using 4 of these per panel. I did look at other concealed brackets, but decided on these as they do look ok and will be a) easy to fit and b) strong and wong be knocked off the wall like some of the ones that would just "hang-on".

As for fabric.... after much deliberation, I have gone for Maplin's KS50. This is a black felt like speaker grill cloth. It is intended for the rear parcel shelf on the car, but looks and feels fine for this application. It is heavy enough to be durable, thick enough to hide the colour of the internal sound insulation (a major consideration that several folks have forgotten about!) and should be acoustically transparent enough to do the job. The second ideal here is the price as its only £1.99 a half meter (by 1.6m wide) if you buy more that 5 meters.... much less cost than some other fabrics I looked at.

As for the next step (beyond black paint) - planning on using a thin plastic DPC sheet as a backing to hold the insulation in - this will be stapled to the rear of the frame. The grill cloth will be simply stapled on too once its done.

I am still thinking what to do to ensure the insulation stays put - I dont want it wandering forwards and pushing the grill fabric. I am cosidering a quick spray of aerosol adhesive to hold it to the plastic backing sheet. To be honest, it may not need anything given the Wickes insulation is dense enough to hold steady.... which would be good.

So.. off for a beer now... and take my old panels off the walls in preparation!

DJ

[Gary Lightfoot]

Hi djblack,

Gonna take some pics so we can see the construction and fitment? :)

Gary.

[djblack]

Yup, took some pictures... and my better half laughed and commented as to how sad we all are.....

DJ

[Gary Lightfoot]

Women need to do that sometimes to make them feel better about themselves. :)

Gary.

[ROZ]

I can't tell you in an open forum what my missus thinks A and V stand for.... :eek:

She's got a dirty mind :smashin:

[cyphaflip]

Does muslin cloth really work? I just got done making some mid and high freq absorbers, covering them in muslin cloth so that the prickly fiberglass insulation doesn't fall out, and I try doing a clap test to see if I hear a difference...

Either I don't have dog ears, my garage's acoustic profile is complete crap, or i'm not listening right, but clapping against my dusty new panel and against a wall makes little (albiet some, but still very little) difference...

-_-;

[Gary Lightfoot]

If the muslin cloth isn't acoustically transparent, it may be just as reflective as the walls. If it's black I would use speaker grill cloth like that found at Maplins. It's AT so will allow the fiberglass to work. Did you position the absorbers at the first reflection points along the wall?

I used foam backed carpet along the lower half of my walls (uo to ear height) as well as completely covering the screen wall, and in conjunction with the floor carpet completely eliminated slap echo.

Gary

[mattym]

heavy cloth ill reduce high frequency absorption considerably but will give some LF performance. Muslin cloth should be AT

how many panels did you make and what is in the room?(in the way of carpets.)

[ROZ]

It's like bringing back from the dead. A two year old thread is resurrected.
Cool :cool: