John Sayers' Recording Studio Design Forum Archive

Info on that is all over this forum; here's a recap: Basstraps need to be deep (more wool volume means lower absorption).
A cornertrap (a superchunk for example) can be a broadband. It'll absorps the whole frq range (low, mid, high etc).
By adding a pass-filter in front you can make it low-end absorption exclusively (a low-pass filter can be anything from a sheet of plastic to a wood front, slats or whatever)

So yeah, a basstrap might as well be a broadband absorber but one with very low-end absorption

Oh, interesting. I've read over any over again on other forums "you need to treat your room with bass traps", but it seems like most of these are using broadband traps for all the applications I thought you used bass traps for. So when would you use a plain bass trap over a broadband trap?

Simple, your room needs to be balanced. Too much broadband absorption will kill mids and highs in your room.
You see low-end is harder to trap. So broadband will absorb less low than high end frq. In that case your room is out of shape (acoustically).

By adding a filter in front and make the trap work only on low-end, you'll keep the balance. Generally speaking, if you dress up your room with corner and wall absorbers, you should use the corner only for low-end trapping. If you only have corner devices you might wanna leave it broadband. So, it's just a matter on how much trapping devices you have in your room.. sort of.

If you check out this recent build I did: http://www.johnlsayers.com/phpBB2/viewt ... 10&t=12321, you'll see what I mean. The corner traps have a plastic sheet in front to filter high frq. The wall panels don't. You'll also see the difference in depth. The corner traps have deeper wool than the wall panels (which are mid/high broadband)

benirose wrote:Oh, interesting. I've read over any over again on other forums "you need to treat your room with bass traps", but it seems like most of these are using broadband traps for all the applications I thought you used bass traps for. So when would you use a plain bass trap over a broadband trap?

I keep on saying that the term bass trap is incorrect. People wrap some insulation in a cloth bag and call it a bass trap It is not a bass trap - just an absorber.

A bass trap is like the section under a soffit mount where the bass gets in via the port and is "trapped" in there and absorbed by the hangers.

A bass trap is like the area above a timber ceiling where the bass frequencies are trapped and absorbed by the hangers.

Like this picture that shows the hangers before the ceiling was added.



Here's the ceiling added with the ports down the side to allow access to the ceiling trap



I'm sorry - but I just can't accept a sheet of insulation wrapped in cloth being called a Bass Trap. It's an absorber.

Thanks John, I really appreciate you clearing that up for me!

A pair of questions I hope haven't been answered nigh to death. Feel free to answer with a link if that's faster.

I'm building a number of broadband absorbers using both 4"(in corners) and 2" (other areas) Rockwool insulation.

They are all built on a 1X4 frame, which seems to be a common theme here.

Some people perforate the 1X4's to let the sound access the insulation through the sides, either cutting holes, like jbassino's design, or actually cutting out a portion of the frame with what appears to be a jigsaw like Jakeman.

1)How much difference does it make to do this? Is it worth the extra effort?(mine would be covered in fabric so the looks don't matter).

And I'm reading that there is benefit to mounting the panels away from the wall, but I've yet to find information to determine how far.

2) Is there a reasonably simple way(read:able to be executed by newbies and other mortals) to estimate how far from a wall a panel should be?

Thanks
Keith

Here's my corner panels, i did them after reading the dairies on this thread, hope you like them.

http://www.johnlsayers.com/phpBB2/viewt ... =3&t=14696

Nice post. Well done Ro. Thanks for sharing it. It was good and helpful.

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Ro wrote:As there's some good DIY how-to-make absorbing panels I thought it would be a good idea to have a sticky made out of that.

Here we go with some detailed constructions of acoustic absorbers:
Soulfood's broadband wall panels
studio_drums's broadband wall panels
BradJacob's broadband wall panels
decode his broadband wall panels and speaker stands
dbyboth's broadband wall- and corner panels
scottgirvan's broadband wall panels
Jwl his gogo's design
jbassino's broadband wall panels
GuitarGodgt made these broadband wall and corner panels
doublehelix his ceilingclouds
MMS his cloud
Luke's frameless broadband panels
Jakeman's broadband panels
Broadband panels and corner traps by Ro
Panels by Phazinhead
SimonOstheim his Broadband and corner panels
More broadband panels bij sunspot
*new* Shameless self promotion of low-end corner absorber build in action

Here are some other finished product, less detailed:
http://www.johnlsayers.com/phpBB2/viewtopic.php?t=9310
http://www.johnlsayers.com/phpBB2/viewtopic.php?t=8276
http://www.johnlsayers.com/phpBB2/viewtopic.php?t=7627
http://www.johnlsayers.com/phpBB2/viewtopic.php?t=6655

There's already this sticky, but it's locked for reply.
Then there's this sticky.

Maybe some MOD could take a look and decide if things could be merged.
Right.

Nice collection share by you within [STUPID SPAM LINK REMOVED BY MODERATOR: SPAMMER BANNED AND BLOCKED PERMANENTLY] I really was looking for such brief post from weeks. Thanks

This is very helpful! Appreciate you doing the research. Thanks for sharing!

especially considering the search function doesn't work

In what way does it not work? I just tried it, and it is working fine here. What were you searching for, and what results did you get?

- Stuart -

Wonderful job Ro!

Great Thread!