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Audio/Video Hardware => Acoustics and Room treatment => Topic started by: JimGore on January 16, 2011, 08:13:31 PM

Title: Bass trap build (at last!)
Post by: JimGore on January 16, 2011, 08:13:31 PM
I have had these 2 huge rolls of think pink in my lounge for the best part of a year now.  What worries me is that I don't really notice them any longer.  Whenever someone comes over to visit for the first time they always look at the pink monsters strangely, but most of them are too kind to say anything.

So, at long last I have decided to make them look a bit better.  I didn't want to just cover the rolls in fabric, I want something nicer - add some wood into the equation.

Saturday morning I went off to the hardware store, and had them cut an entire 2.4m x 1.2m plywood sheet up into 1.2m x 6cm planks.  Also picked up 4m of chicken wire.

Next, I went off to the material shop, and picked up batting, compressed batting, some dodgy and cheap brown material (looks like it comes out of the 70s), and some nice textured black fabric of some kind.

Now, I want the bass traps to go up quite high, so I had 2 options:  Build it tall, or make 2 shorter traps which would stand on top of each other.  Went for the 2 shorter traps because it will be much easier to move around.

Let me tell you something - chicken wire is a terrible thing to work with.  This build is making me increasingly glad that I don't work on a chicken farm!

Some pics:

The frames complete for 4 bass traps:

(http://lh6.ggpht.com/_QihvKTtjaEc/TTMyasgofvI/AAAAAAAAANk/MSRl_MjFFe0/DSC01831.JPG)

Another angle:

(http://lh4.ggpht.com/_QihvKTtjaEc/TTMyakZqWbI/AAAAAAAAANo/3pQWECXqxEw/DSC01832.JPG)

Close-up:

(http://lh4.ggpht.com/_QihvKTtjaEc/TTMya5Wpk3I/AAAAAAAAANs/DUoYIfOrzC0/s576/DSC01833.JPG)

Chicken wire installed into the back, top and bottom:

(http://lh5.ggpht.com/_QihvKTtjaEc/TTMyaxZak7I/AAAAAAAAANw/GH-1Nz_pVK0/DSC01836.JPG)

Cheers for now.
Ian.
Title: Re: Bass trap build (at last!)
Post by: NoSnipeLimit on January 16, 2011, 08:37:44 PM
Luckily your not going to put chickens in there :/ or are you...
Title: Re: Bass trap build (at last!)
Post by: ByronH on January 16, 2011, 08:56:42 PM
I like the angles, they're going to look somewhat enigmatic like the monoliths in "2001: A Space Odyssey" 8)
Title: Re: Bass trap build (at last!)
Post by: WD on January 16, 2011, 08:56:55 PM
Stuff those with finches and you'll have enough tweeters.... aaarrgh!
Title: Re: Bass trap build (at last!)
Post by: johnc on January 16, 2011, 09:12:16 PM
I thought they looked quite nice as they were.
It will be interesting to see the transformation.

"Pink? Pink? Well, what’s wrong with pink?
Seems you’ve got a pink kink in your think.
Does it matter what color? Well, that gets nope.
Be it pink purple or heliotrope."
Title: Re: Bass trap build (at last!)
Post by: JimGore on January 16, 2011, 09:19:13 PM
John, I like pink as much as the next guy, but unfrotunately it doesn't suit my lounge colours very well.  ;D ;D ;D

Cheers,
Ian.
Title: Re: Bass trap build (at last!)
Post by: WD on January 16, 2011, 09:21:45 PM
I thought they looked quite nice as they were.
It will be interesting to see the transformation.

"Pink? Pink? Well, what’s wrong with pink?
Seems you’ve got a pink kink in your think.
Does it matter what color? Well, that gets nope.
Be it pink purple or heliotrope."

Eminem se moe.
Title: Re: Bass trap build (at last!)
Post by: alternativeroute on January 16, 2011, 09:59:56 PM
Plywood really makes a nice cost effective material to work with... Especially when:

Quote
had them cut an entire 2.4m x 1.2m plywood sheet up into 1.2m x 6cm planks.

Yes. You could probably do that at home yourself but why suffer the pain when builders or mica can do it for you easily.

I am sure your neighbours were curious watching you unpack the chicken wire from the car...
Title: Re: Bass trap build (at last!)
Post by: JimGore on January 16, 2011, 10:04:48 PM
Quote
I am sure your neighbours were curious watching you unpack the chicken wire from the car...
I had the same thought  ;D

Quote
I like the angles, they're going to look somewhat enigmatic like the monoliths in "2001: A Space Odyssey"
The shape of the frame is simply a function of esthetics rather than function.  As I was building it I was remined of the old days when I was in primary school.  We used to like building kites out of dowel rods, and we used to get a similar profile on them - worked better than straight frames.
Title: Re: Bass trap build (at last!)
Post by: cybasoul on January 17, 2011, 12:44:41 PM
Tell me some thing Ian, why???? why???? I want to know why is it that every thing you tough turns into gold? Why I ask again!!! Is it those gloves of yours or something Im over looking? Or is it the coffee/coke and ciggies combo?
Title: Re: Bass trap build (at last!)
Post by: JimGore on January 17, 2011, 12:59:45 PM
Thanks Vuyani, I appreciate your sentiment.

To clarify: everything I do doesn't work out well.  There is alot of trial and error background I am building on which I don't always share, but gives me valuable experience.  When I do get something to work out I obviously share it with everyone here.

Next thing is that I am patient when it comes to the concept and idea phase.  I spend enough time thinking and considering options before I start building - I try to figure everything out before I start so you have a plan to work from, even if it is only in my head.

BTW: When are you coming over to listen to the Litil speaker kit?

Regards,
Ian.

Title: Re: Bass trap build (at last!)
Post by: NoSnipeLimit on January 17, 2011, 01:13:19 PM
What frequencies are you aiming to better with the bass traps?
Title: Re: Bass trap build (at last!)
Post by: JimGore on January 17, 2011, 01:22:38 PM
Not really sure about that.

This type of damping is very wide range, so I am sure they will damp just about anything that comes their way, including someone running into them.

About a year ago I put the thinkpink rolls in my lounge and it improved the bass response instantly.  I never really cared to measure it - the sound was better so I was happy.

The only reason I am building the bass traps now is so that they look better than the think pink rolls in my lounge - no other reason.

Regards,
Ian.
Title: Re: Bass trap build (at last!)
Post by: Rotten Johnny on January 17, 2011, 03:00:02 PM
The only reason I am building the bass traps now is so that they look better than the think pink rolls in my lounge - no other reason.
Apologies if my dumb question triggered something  ;)
Title: Re: Bass trap build (at last!)
Post by: JimGore on January 17, 2011, 03:55:11 PM
Quote
Apologies if my dumb question triggered something
No such thing as a dumb question.  Like I said earlier - a man needs to get inspiration from somewhere   ;)

If you didn't mention it, it might have been another 10 years before I decided to build them.
Title: Re: Bass trap build (at last!)
Post by: Gerhard on January 17, 2011, 07:20:37 PM
Now this may very well be a stupid question! :-[

Were the think pink rolls still in their plastic bags? I'd imagine so in light of your valid concerns in the "Isotherm vs Think Pink" thread about damping material and the use of "open" fiberglass in bass reflex speakers. So the question now is - in my head at least - what made the difference? Is it that "something" (anything really) placed in the particular locations in the room - corners probably - would have made a difference? I.e. the offending sound waves were not absorbed/turned into heat but were scattered instead. And if so, what would the effect be of having both "something" in the corners and something with acoustic absorption properties.

I ask this for my own edification and probably others' as well since I like to know what I will have to do in my room.
Title: Re: Bass trap build (at last!)
Post by: JimGore on January 18, 2011, 07:02:13 AM
Hi Gerhard,

If you just place anything in the corner it doesn't absorb the bass - it just reflects it back in a different way.  The think pink is still in the plastic.  That being said, the bass doesn't care about the little bit of plastic - it goes right through it.  Midrange and treble frequencies do however mostly bounce off as they don't have the energy to pass through.

Regards,
Ian.
Title: Re: Bass trap build (at last!)
Post by: iondb on January 18, 2011, 08:09:48 AM
That looks good.  Also, a question about bass traps.  I have a very small room for listening. Would a material bag with pieces of think pink work in the corners, right behind the speakers (almost against it)?  Or maybe the opposite corners from the speakers?
Title: Re: Bass trap build (at last!)
Post by: DRNB on January 18, 2011, 09:13:42 AM
That looks good.  Also, a question about bass traps.  I have a very small room for listening. Would a material bag with pieces of think pink work in the corners, right behind the speakers (almost against it)?  Or maybe the opposite corners from the speakers?

Material bags with Think Pink I will work. And it will work in any corner, behind or opposite. I would personally put it in the corners behind the speakers.

Main thing is for bass absorption you need a fairly high density. So a easier product to work with is something like enegylite or rockwool, mainly because it doesn't need to be compressed. I've build a few basstraps using Think Pink, and would in future rather look at using one of the other mentioned products.

http://www.insulpro.co.za/energyliteIP.htm
Title: Re: Bass trap build (at last!)
Post by: ByronH on January 18, 2011, 09:44:16 AM
Would IsoTherm serve well as a safer alternative? Also, how susceptible do you think these traps would be to pests such as rodents and mildew, mould, etc?
Title: Re: Bass trap build (at last!)
Post by: DRNB on January 18, 2011, 10:16:19 AM
Would IsoTherm serve well as a safer alternative? Also, how susceptible do you think these traps would be to pests such as rodents and mildew, mould, etc?

Would work fine, but just as Think Pink the density is lower than that of EnergyLite, Rockwool and other Ridged Fibreglass products, which means you need to find a way to compress it, like with e frame Ian is building. Take a look at Ethan Winters web page.

http://www.realtraps.com/art_measure.htm

http://www.realtraps.com/art_measure.htm

http://www.radford.edu/~shelm/acoustics/bass-traps.html

http://www.ethanwiner.com/basstrap.html

There are so much reading in this regard, its just not true.
Title: Re: Bass trap build (at last!)
Post by: fdlsys on January 18, 2011, 11:04:02 AM
If I may;

@iondb: Creation of the audible standing wave ("bass booming") on lower frequencies is in function of the frequency and the length of the room and most effective use of bass traps usually requires experimenting.

Most efficient bass-trapping, especially in the larger rooms where multiple standing waves may occur, is usually done by either having different types (material density) of traps, or by building traps that combine materials of different densities, usually packing/rolling them into some form of "sandwich". Ian's favourite "dog blanket" would be one of the denser ones that would go closer to the middle of the sandwich.

In the recording studios, it is perfectly normal to find the acoustic resonators (google Helmholtz) that are the most efficient in fully stripping not only the bass boom, but also midrange, etc. (smaller rooms).

In case of Clubs and similar closed spaces where eardrums are pushed to the max, it is not unusual to find combinations of Helmholtz resonator based panelling, and passive bass traps that often contain material as dense as strips made of gypsum boards or chipboard, either inside the sandwich, or in the double-wall cavities hanging loosely (fake walls).

To come back to planet Earth; for our so-so typical listening room scenarios, what Ian is doing is perfectly good enough. Sandwiching some dog blanket in the middle and packing the fibre(ous) material around it in such a way that it's denser closer to the middle, and looser towards the outside would increase the frequency bandwidth of the trap.

Finally; I firmly believe that all artificial fibre material that is extruded from raw mineral or other inorganic materials should be avoided always, no debate. Problem is that inorganic fibre is brittle and it keeps breaking all the time, often turning into miniature particles that end up suspended in the air, and eventually in our lungs.

IsoTherm on the other hand is a Polyester fibre. It does not break off, and even if you intentionally turn it into "dust" and breathe it in - the fibre particles are not "sharp" and do not damage the lungs.

To give you an example of exactly how bad the materials like ThinkPink or traditional fibreglass are - responsible speaker manufacturers have stopped using these back in the early 80s even for the sealed (compressions) enclosures!
Why? Two reasons:
- If you open the speaker box (servicing) the fibre particles will escape into the outside air
- Particle dust created inside the sealed boxes WILL penetrate the porous spider/spring material of the speaker and end up in the coil-magnet gap.

Moral of the story: Use the organic soft fibre materials, forget about the rest.

@ByronH: All manufacturers of all types of these materials (incl. organic) claim that they are mildew/rot resistant, mainly because the primary intended use for these is thermal (and acoustical) insulation, so this resistance was a design objective.

Final word: Even though sheep's wool is the nature's ultimate and perfect fibre material for all purposes, it is NOT to be used for the open speaker boxes or bass traps. The reason is that it is extremely attractive to all sorts of pests (attracting even more pests) so one would have to treat it on regular intervals with insecticide.
For sealed boxes however (assuming that you treat it before sealing the box) it's a true miracle damping material. Non-uniform fibre, varying natural density, very flexible thus easy to pack into rolls/sheets of desired density. Typically, you would need 1/3 less sheep wool to achieve the same damping effect on midrange-high FQs compared to using the man-made fibres.

Mike
Title: Re: Bass trap build (at last!)
Post by: JimGore on January 18, 2011, 11:10:02 AM
Thank you Mike.  Very informative.

Ian.
Title: Re: Bass trap build (at last!)
Post by: fdlsys on January 18, 2011, 11:19:00 AM
A pleasure Sir!
Title: Re: Bass trap build (at last!)
Post by: DRNB on January 18, 2011, 01:22:13 PM
Creation of the audible standing wave ("bass booming") on lower frequencies is in function of the frequency and the length of the room and most effective use of bass traps usually requires experimenting.

Most efficient bass-trapping, especially in the larger rooms where multiple standing waves may occur, is usually done by either having different types (material density) of traps, or by building traps that combine materials of different densities, usually packing/rolling them into some form of "sandwich". Ian's favourite "dog blanket" would be one of the denser ones that would go closer to the middle of the sandwich.

Just to make myself more clear in case people might have got the wrong impression from my earlier posts. I didn't mean what Ian doing is not a good idea... it will work very well, but its a lot of work. I would strongly suggest to any one that want to take on a bass trap DIY job to try out this route: http://www.radford.edu/~shelm/acoustics/bass-traps.html
It will work well as a wide band absorber, and no real need to sandwich.
Title: Re: Bass trap build (at last!)
Post by: DRNB on January 18, 2011, 01:58:32 PM
Appologies Ian, I don't want to take over the thread, but this is a must read to anyone that want to do this.  ;D

http://www.ethanwiner.com/acoustics.html
Title: Re: Bass trap build (at last!)
Post by: JimGore on January 18, 2011, 02:09:35 PM
No problems!  We are all here to learn things - not just to look at pictures of builds.

Please feel free!

Cheers,
Ian.
Title: Re: Bass trap build (at last!)
Post by: fdlsys on January 18, 2011, 03:19:14 PM
Just to make myself more clear in case people might have got the wrong impression from my earlier posts. I didn't mean what Ian doing is not a good idea... it will work very well, but its a lot of work. I would strongly suggest to any one that want to take on a bass trap DIY job to try out this route: http://www.radford.edu/~shelm/acoustics/bass-traps.html
It will work well as a wide band absorber, and no real need to sandwich.
My literary effort that you are referring to has been started way before yours was posted  ;D It just took a while to finish; I am at the office after all... No reference to anything you posted, really.

The intention was to steer everybody away from using mineral fibre, more than anything else.
Title: Re: Bass trap build (at last!)
Post by: faultysa on January 19, 2011, 12:14:42 AM
Saw the effort going in here on the weekend, cant wait to see those rolls replaced.
Title: Re: Bass trap build (at last!)
Post by: JimGore on January 19, 2011, 07:29:13 AM
I removed one of the rolls last night to start cutting it up.  The lounge looks so strange and empty without that pink monster in the corner  ;D

Ian.
Title: Re: Bass trap build (at last!)
Post by: JimGore on January 23, 2011, 02:17:23 PM
Status update:

I finished these off to the point where I was usnig them last night.  Man, what a difference this is making to my system.  Literally everything is better, from the bass right through to the high frequencies.  I think the extra height is helping alot as well.  They also look a damn sight better than the pink rolls I used to have  ;D

Photos:

Lining the inside of the frames with batting, and over that goes a much denser version which they call "compressed batting".  Similar in thickness and texture to felt.  These are stapled in to hold them in place:
(http://lh6.ggpht.com/_QihvKTtjaEc/TTwZ6BLtKUI/AAAAAAAAAOI/J8XF2kjxTD4/DSC01844.JPG)

Next, I cut up a whole load of think pink into strips:
(http://lh4.ggpht.com/_QihvKTtjaEc/TTwZ6TeKHFI/AAAAAAAAAOM/5swxDgh3FkM/DSC01845.JPG)

Which I then cut into triangles, and put into the frames.  I tried to get as much of it in as possible, so it is quite dense and compressed:
(http://lh5.ggpht.com/_QihvKTtjaEc/TTwZ6ZzPdjI/AAAAAAAAAOQ/I21W_28Aj0U/DSC01848.JPG)

Next, added a couple of layers of all different things over the think-pink.  Had to include my dog blankets of course:
(http://lh6.ggpht.com/_QihvKTtjaEc/TTwZ6cY4EBI/AAAAAAAAAOU/eDnirQ6OrJs/DSC01849.JPG)

After which I applied the black fabric covers.  Here you can see how I fasten it down with staples:
(http://lh6.ggpht.com/_QihvKTtjaEc/TTwZ6VRU5rI/AAAAAAAAAOY/5BafzkT0He8/DSC01851.JPG)

And this is how I fold and finish the bottoms and corners:
(http://lh4.ggpht.com/_QihvKTtjaEc/TTwaENdbyPI/AAAAAAAAAOc/mLeLDCcqe64/DSC01852.JPG)

Two done, two to go:
(http://lh4.ggpht.com/_QihvKTtjaEc/TTwaEeauycI/AAAAAAAAAOg/_5vt0ZcPn5E/s576/DSC01859.JPG)

Next, I put some white oak through the thicknesser / planer and sawed them up to make these boomerangs:
(http://lh5.ggpht.com/_QihvKTtjaEc/TTwaEz-t6mI/AAAAAAAAAOk/I49KkxjXOSw/DSC01861.JPG)

Boomerangs sanded down:
(http://lh3.ggpht.com/_QihvKTtjaEc/TTwaE1z301I/AAAAAAAAAOo/ht2_5mfLmVQ/DSC01862.JPG)

Boomerangs fit nicely on the top and bottom of the bass trap:
(http://lh3.ggpht.com/_QihvKTtjaEc/TTwaE1Pj0PI/AAAAAAAAAOs/jvWWq57ahyY/s576/DSC01863.JPG)

The new look in my lounge:
(http://lh4.ggpht.com/_QihvKTtjaEc/TTwaJcs-RNI/AAAAAAAAAOw/9ec4nfd4V0g/s576/DSC01864.JPG)
Title: Re: Bass trap build (at last!)
Post by: JimGore on January 23, 2011, 02:23:28 PM
Finally, let's do a costing on this project.  This costing will be to build 4x bass traps as shown in the pictures above:

(1x) Sheet of shutter plywood @ R 220
(1x) Roll of think-pink (or isotherm, whichever you prefer)  - 100mm thickness @ R 220
(1x) 100ml wood glue @ R 20
(100x) brad nails (or screws) to make the frames @ R 10
(250x) staples @ R 35

3m chicken wire @ R 90

4m Batting from your local material shop @ R 100
4m Compressed batting (of felt) @ R 120
3m Black material for covering them up @ R 150

2.5m white oak for the trim bits @ R 200

Total comes to R 1165, so that just short of R 300 each.  Not too bad, and worth every cent!

Cheers,
Ian.
Title: Re: Bass trap build (at last!)
Post by: ByronH on January 23, 2011, 02:28:28 PM
The completed traps look great Ian 8) I bet you're going to get asked a couple of times whether they're additional loudspeakers :D I have to ask, how did you go about cutting up all that Think Pink? I get the itches just looking at the stuff!
Title: Re: Bass trap build (at last!)
Post by: ByronH on January 23, 2011, 02:30:28 PM
Total comes to R 1165, so that just short of R 300 each.  Not too bad, and worth every cent!

You've sold me on some traps ;) I just need to figure out how to secure a high enough WAF...
Title: Re: Bass trap build (at last!)
Post by: NoSnipeLimit on January 23, 2011, 02:39:36 PM
They sure do look good Ian.  Good work.
Title: Re: Bass trap build (at last!)
Post by: faultysa on January 23, 2011, 03:17:40 PM
Guys, i was at Ian's earlier today as he was finishing them off. I wont lie i have heard a number of different types of music on a couple different speakers. On the HE speakers currently setup the sound is totally different.

These Bass Traps really do work incredibly well, my thought is all that Think Pink and the design are responsible for an incredible silencing of the stray bass in the room.

Absolutely incredible for me to enjoy Tracy Chapman again. Well done Ian, simple idea turned into another master piece.
Title: Re: Bass trap build (at last!)
Post by: Rotten Johnny on January 23, 2011, 04:14:05 PM
Looks great and no doubt the setup sounds great too.  Don't laugh at my panels when you see them.  :-\
Title: Re: Bass trap build (at last!)
Post by: alternativeroute on January 23, 2011, 04:22:36 PM
That looks great Ian!!! Have you ever done measurements to see before/after effects?
Title: Re: Bass trap build (at last!)
Post by: johnc on January 23, 2011, 07:36:54 PM
Nice work.  :)
It would be really good to see a frequency response graph with and without the bass traps.  ::)
Title: Re: Bass trap build (at last!)
Post by: Shonver on January 23, 2011, 08:30:15 PM
Quite inspiring! I unfortunately can't use this format of bass trap in my home. May have to go for those rectangular wall-mounted absorbers (forget what they're called now).

It would be really good to see a frequency response graph with and without the bass traps.  ::)

Room EQ Wizard is very good for this; HOLMimpulse does not appear to have the low frequency resolution; never tried SoundEasy's RTA.
Title: Re: Bass trap build (at last!)
Post by: JimGore on January 24, 2011, 07:26:11 AM
Thanks for all the replies. 

I am highly impressed with the difference these made to my sound.  After installing them I actually tamed the midrange and tweeter in my HE speakers a bit, and I now have a much more balanced sound overall.

Quote
how did you go about cutting up all that Think Pink? I get the itches just looking at the stuff!
I wore a long sleeve shirt out of thick material.  Also some nice yellow dish-washing gloves which I pulled over the shirt.  Next, one of those mouth and nose covering dust masks.  I did the cutting using a long piece of 3mm MDF as a ruler, and an NT cutter (knife with long blade which breaks off in sections).

I used 2 blades to cut all the stuff with.  The glass blunts the cutting edge quite fast.

Quote
I just need to figure out how to secure a high enough WAF...
Easy - let her choose the fabric to cover them in  ;)

Quote
Don't laugh at my panels when you see them.
No worries - I can behave when I need to ;D

Quote
That looks great Ian!!! Have you ever done measurements to see before/after effects?
Nope, but I will do some for you.  Perhaps next weekend or so.

Cheers,
Ian.
Title: Re: Bass trap build (at last!)
Post by: Hennie on January 24, 2011, 09:20:13 AM
Easy - let her choose the fabric to cover them in  ;)

Ian, I think you have married well!
Title: Re: Bass trap build (at last!)
Post by: Stereophreak on January 24, 2011, 10:41:09 AM
Personally, I think the roll of Thinkpink was a little more aesthetically pleasing, but it's the sound that matters hey?

Seriously though, that looks great! From my 1 hour experience in a completely dead sound recording room (even the little desk and mic stand had felt on it :D ), and how that freaked me out (sounds like you are wearing an invisible pillow on your head or something), I really think this could make a big difference in the sound too. 
Title: Re: Bass trap build (at last!)
Post by: DRNB on January 24, 2011, 10:48:33 AM
Looking very good Ian. I can just imagine they should work beautifully if I look at the area coverred by the traps.

Title: Re: Bass trap build (at last!)
Post by: creyneke on January 24, 2011, 10:51:01 AM
Hey Ian

How much would you charge to make me a set of these?
Title: Re: Bass trap build (at last!)
Post by: DRNB on January 24, 2011, 10:56:52 AM
From my 1 hour experience in a completely dead sound recording room (even the little desk and mic stand had felt on it :D ), and how that freaked me out (sounds like you are wearing an invisible pillow on your head or something), .....................

Just as a matter of interrest, many people makes the mistake to think a recording room should be dead. If you look at propper recording studios that is however not the case. Bass should be trapped as far as possible, while the studio itself should have a certain amount of reflections in it still, however the modal ringing should be kept small. Reflections under 2ms (IIRC) should be eliminated by absorption, and the RT60 (time that it takes the sound to drop with 60 db) should be controlled  controlled. Sorry, I can not remember the ideal time durations, apart from a dead room is a BIG no-no. Some of the links I posted earlier in this thread explains it perfectly though.
Title: Re: Bass trap build (at last!)
Post by: JimGore on January 24, 2011, 11:21:54 AM
Hey Ian

How much would you charge to make me a set of these?
To be entirely honest with you, it isn't something I would like to do again any time soon - I found it highly tiresome and un-exiting to build.  That being said, if you really don't want to do them yourself I would be willing to build them for R 2.5k each.

Regards,
Ian.
Title: Re: Bass trap build (at last!)
Post by: Stereophreak on January 24, 2011, 11:44:37 AM
Just as a matter of interrest, many people makes the mistake to think a recording room should be dead. If you look at propper recording studios that is however not the case. Bass should be trapped as far as possible, while the studio itself should have a certain amount of reflections in it still, however the modal ringing should be kept small. Reflections under 2ms (IIRC) should be eliminated by absorption, and the RT60 (time that it takes the sound to drop with 60 db) should be controlled  controlled. Sorry, I can not remember the ideal time durations, apart from a dead room is a BIG no-no. Some of the links I posted earlier in this thread explains it perfectly though.


I could have been clearer, but it seemed off topic - this recording room was very specifically for voice over work only. My own voice sounded awesome! They feed it back to you on the headphones, and I'm sure they fiddle with it on the desk first, because I really did sound like Shadow Stevens or something. In any case, I've seen recording studio's set up in bathrooms (Depeche Mode iirc?), so I guess sometimes a dead room is exactly the opposite of what you want?

Another weird effect of the dead room is that you feel like you should be TALKING REALLY LOUDLY! because you get no feedback from the room, and it feels like your voice is just falling flat on the floor in front of you, until the other guy starts talking, and you realise you can hear him fine. :D

I was just saying I think deadening resonance and reflections selectively could make a HUGE difference based on that experience, and I definitely don't think a dead room would be a pleasant listening experience.