JBL room mode correction products

General discussions on songwriting, mixing, music business and other music related topics.
Paul Woodlock
Member
Posts: 720
Joined: Thu Dec 16, 2010 8:22 pm

Re: JBL room mode correction products

Post by Paul Woodlock »

twilightsong wrote:
Paul Woodlock wrote:
twilightsong wrote:What about the popular Auralex 2'x2' foam squares for taming the reflections? (leaving aside the problem of room modes/bass freq's)

My old house had a bunch of those squares on the walls using the mirror trick... plus the wedges up in the corners and diffusors on the opposite wall

Seemed to help greatly

I can't be bothered to attach a bunch of fabric on rockwool or 703!

2" thick foam won't absorb well below a few hundred Hz. Especially if it's flat to the wall. Problem is you can end up absorbing the highs and not the mids and unbalancing the room
Right -- but are you saying that you do actually WANT to deaden the highs, but need to be sure you're taming the mid's, also?

Are you saying then that rockwool/703 is a better solution to take care of both?
Acoustic form works well and can work as well as rockwool, but like rockwool you've got to use enough of it and in the right places.

2" thick rockwool place directly on the wall won't be great either.

And yes the idea is to absorb the reflection equally across all frequencies If you just absorb the highs andleave the mids stil reflecting and responding you can make the room worse.

At least use 4" thick foam or rockwool and mount it away from the wall so there's a 4" gap behind it, or at the least 2" gap. Absorption right next to the wall does nothing as there's no air moving there, so its' waste of material
Got a Brian - Morans

"It's better to be hated for who you are than loved for who you are not" -- Andre Gide

twilightsong
Senior Member
Posts: 1888
Joined: Wed Dec 15, 2010 6:08 pm
Contact:

Re: JBL room mode correction products

Post by twilightsong »

Is your "studio build blog" still up somewhere?
"There is no avant-garde; only some people a bit behind." -- Edgar Varese
-----------------------------------------------------------
Cubase 5.5.2/ Win 7 64-bit/ Quad 9550/ UAD-2/ Wavelab 4/ more sample libraries than I can remember

Mandobilly64
Junior Member
Posts: 51
Joined: Mon Dec 27, 2010 4:03 pm
Contact:

Re: JBL room mode correction products

Post by Mandobilly64 »

At least use 4" thick foam or rockwool and mount it away from the wall so there's a 4" gap behind it, or at the least 2" gap. Absorption right next to the wall does nothing as there's no air moving there, so its' waste of material

Unless killing some of the highs is what you are trying to do. I hung a panel of OC 703 I made in my living room that was 2" thick and 4' x 4' built in a frame that actually makes contact with the wall but leaves a little space behind the fibreglass and it increased the bass in the room by killing some of the highs and mids. This is what I was trying to do in that room though because it has a cathedral ceiling and tile floors.

Paul Woodlock
Member
Posts: 720
Joined: Thu Dec 16, 2010 8:22 pm

Re: JBL room mode correction products

Post by Paul Woodlock »

twilightsong wrote:Is your "studio build blog" still up somewhere?
It should be here

http://forum.studiotips.com/viewforum.php?f=1

, but coincidentally over the last week or so the forum has been unavailable.
Got a Brian - Morans

"It's better to be hated for who you are than loved for who you are not" -- Andre Gide

User avatar
NorthWood MediaWorks
Senior Member
Posts: 2339
Joined: Wed Dec 15, 2010 5:51 pm
Location: Canada
Contact:

Re: JBL room mode correction products

Post by NorthWood MediaWorks »

twilightsong wrote:I can't be bothered to attach a bunch of fabric on rockwool or 703!
I just noticed you changed your signature quote Doug,
"The human voice is BY FAR the most expressive instrument there is and is the primary vehicle of musical communication. To strain at "perfection" is really to dilute the essential humanity of the performer... as well as the essence of humanity itself." -- Doug Hazelrigg
so perhaps with what it states now, a portion of this spectral discussion may be moot? ;) :o :lol:
Robin
Visit Northwood Mediaworks!
| Cubase Pro 8.5.20 | Wavelab 8.0.3e | HSO | Padshop Pro | Win10pro 64 | i7 16Gb | UR44 | Angry Wife |
| OSX 10.12.6 | MacBookPro Retina 15 | Loads of Other Stuff |

Woodcrest Studio

Re: JBL room mode correction products

Post by Woodcrest Studio »

Doug, if you don't want to make your own check these out:

http://www.acousticsaudio.com/PROD/KIN-HARDSIDE-24.html

I use some Kinetics hard side panels and they are great.

MarkOne
Junior Member
Posts: 181
Joined: Thu Dec 16, 2010 10:48 am
Contact:

Re: JBL room mode correction products

Post by MarkOne »

Doug, I built myself 4 x 2ft x 4ft x 4inch absorbers which were simple batten frames holding in slabs of rockwool (which come in 4x2x4in slabs here in the UK) I then covered these with that white breathable fleece you see gardeners use to wrap tender plants in the winter, wrapping them like christmas presents and stapling the fleece to the battens. this made an effective barrier to any stray particles from the rockwool, Finally we found some attractive blue fabric (again breathable - got to let air through to make the absorption work)

I put 1 inch spacers on the backs to give a bit of an air gap to aid the LF response and some picture hanging wire, and then just screwed hooks into the walls to hang them on.

These were placed at mirror points either side of the mix position and another pair two feet back. Hanging these was like getting a new pair of monitors, my stereo imaging is much more stable and I have a much less noticeable change in LF response around the room.

I've now bought enough rockwool and coverings to make another pair, one for the rear wall and one for the ceiling above the mix position.

I should add that the whole project was about £50 worth of materials and a couple of Saturday morning's work

You see can one pair of thems here:
Image
check out my new CD "Fantasy Bridge' here

User avatar
Strophoid
Grand Senior Member
Posts: 4648
Joined: Sun Dec 26, 2010 2:56 pm
Location: The Netherlands
Contact:

Re: JBL room mode correction products

Post by Strophoid »

And a lavalamp :D
Software: Steinberg Cubase Pro 8 64-bit.
Hardware: Intel i5 6600, 16Gb DDR3, Win7 64-bit
Mackie Onyx 1620i - Steinberg Midex 8 - Steinberg CC121.

My humble contributions to what could be considered music.

Krist Hochburger
New Member
Posts: 15
Joined: Tue Feb 15, 2011 5:57 pm
Contact:

Re: JBL room mode correction products

Post by Krist Hochburger »

Thanks Paul! That's a pretty cool analogy ( light bulbs and mirrors).
I will give that a shot.

Best regards,

Krist Hochburger

Paul Woodlock
Member
Posts: 720
Joined: Thu Dec 16, 2010 8:22 pm

Re: JBL room mode correction products

Post by Paul Woodlock »

Cool :)

Remember it only works for about 150Hz up.

Bass is omnidirectional in small rooms and acts more like a pressure wave ( and it's here you need the bulk of your absorption in order to damp the standing waves, with the resultant flattening of the bass/lo-mid freq response across the room and just importantly tightening of the bass
Got a Brian - Morans

"It's better to be hated for who you are than loved for who you are not" -- Andre Gide

twilightsong
Senior Member
Posts: 1888
Joined: Wed Dec 15, 2010 6:08 pm
Contact:

Re: JBL room mode correction products

Post by twilightsong »

Paul Woodlock wrote:Cool :)

Remember it only works for about 150Hz up.

Bass is omnidirectional in small rooms and acts more like a pressure wave ( and it's here you need the bulk of your absorption in order to damp the standing waves, with the resultant flattening of the bass/lo-mid freq response across the room and just importantly tightening of the bass
Yeah, my primary concern in my room is bass at the mix position -- it's almost non-existent. Then, I'll play the same music on another system like my car and it sounds fine (it also sounds fine if I listen from another room)
"There is no avant-garde; only some people a bit behind." -- Edgar Varese
-----------------------------------------------------------
Cubase 5.5.2/ Win 7 64-bit/ Quad 9550/ UAD-2/ Wavelab 4/ more sample libraries than I can remember

Paul Woodlock
Member
Posts: 720
Joined: Thu Dec 16, 2010 8:22 pm

Re: JBL room mode correction products

Post by Paul Woodlock »

twilightsong wrote:
Paul Woodlock wrote:Cool :)

Remember it only works for about 150Hz up.

Bass is omnidirectional in small rooms and acts more like a pressure wave ( and it's here you need the bulk of your absorption in order to damp the standing waves, with the resultant flattening of the bass/lo-mid freq response across the room and just importantly tightening of the bass
Yeah, my primary concern in my room is bass at the mix position -- it's almost non-existent. Then, I'll play the same music on another system like my car and it sounds fine (it also sounds fine if I listen from another room)
You need a big volume of absorption to damp the standing wave(s) that is causing the dip in bass response at hte mix position. The bass will then return to your mix position.
Got a Brian - Morans

"It's better to be hated for who you are than loved for who you are not" -- Andre Gide

twilightsong
Senior Member
Posts: 1888
Joined: Wed Dec 15, 2010 6:08 pm
Contact:

Re: JBL room mode correction products

Post by twilightsong »

Paul Woodlock wrote: You need a big volume of absorption to damp the standing wave(s) that is causing the dip in bass response at hte mix position.
Right -- but this thread has been mostly about absorbing the higher freq reflections... any advice on products or DIY to correct bass problems?
"There is no avant-garde; only some people a bit behind." -- Edgar Varese
-----------------------------------------------------------
Cubase 5.5.2/ Win 7 64-bit/ Quad 9550/ UAD-2/ Wavelab 4/ more sample libraries than I can remember

Paul Woodlock
Member
Posts: 720
Joined: Thu Dec 16, 2010 8:22 pm

Re: JBL room mode correction products

Post by Paul Woodlock »

twilightsong wrote:
Paul Woodlock wrote: You need a big volume of absorption to damp the standing wave(s) that is causing the dip in bass response at hte mix position.
Right -- but this thread has been mostly about absorbing the higher freq reflections... any advice on products or DIY to correct bass problems?
Yup what I just said above.
Got a Brian - Morans

"It's better to be hated for who you are than loved for who you are not" -- Andre Gide

twilightsong
Senior Member
Posts: 1888
Joined: Wed Dec 15, 2010 6:08 pm
Contact:

Re: JBL room mode correction products

Post by twilightsong »

Paul Woodlock wrote:
twilightsong wrote:
Paul Woodlock wrote: You need a big volume of absorption to damp the standing wave(s) that is causing the dip in bass response at hte mix position.
Right -- but this thread has been mostly about absorbing the higher freq reflections... any advice on products or DIY to correct bass problems?
Yup what I just said above.
Which was
You need a big volume of absorption to damp the standing wave(s) that is causing the dip in bass response at hte mix position. The bass will then return to your mix position.
I'm not sure what this means, however... Do you mean " a lot of the 2x4 type absorption panels" or something different? I ask because I was dimly aware that to get good bass absorption you needed to have big, free-standing baffle-type dealies...?
"There is no avant-garde; only some people a bit behind." -- Edgar Varese
-----------------------------------------------------------
Cubase 5.5.2/ Win 7 64-bit/ Quad 9550/ UAD-2/ Wavelab 4/ more sample libraries than I can remember

Karl
Junior Member
Posts: 163
Joined: Sun Jan 23, 2011 8:32 am
Contact:

Re: JBL room mode correction products

Post by Karl »

The essential problem with all of the frequency correction stuff is that they can only attempt to correct at a very specific point in the room and they have to do so by using equalization curves (sometimes severe ones) which will often create their own problems (phasing issues at the EQ boundry points).

It's largely an issue of room shape, physical dimensions and the nature of the surfaces in the room.

My studio area is in the basement of my house. Bought it new and I did all the finish work myself (started off as just a big empty room with concrete floor and open cieling joist's). It was split into a mechanical room, a small office, a guest bedroom and a home theater area (which I've now taken over as the studio).

When I designed the home theater area, I used a room mode calculator to figure out what the resonant mode frequencies would be and where they would be located (this is a critical thing...simply saying that the room has a resonant mode at 64 hz is useless...you need to know WHERE in the room that mode occurs).

Here's a link to the home theater site where you can download the excell spreadsheet...

http://www.hometheatershack.com/forums/ ... erter.html

The nice thing about this spreadsheet is that you can enter the listening position, and it will calculate the resonant modes that will exist, at that position, as well as their intensity. This gives you some idea of what you need to work on.

Here's another link to a site that has a real wealth of solid, technically sound information about acoustics for music production rooms. The guy also provides lots of info on DIY methods of dealing with room acoustic problems. Some easy to build bass trap designs etc.... He also talks a bit about some of the concerns with certain makes of rockwool (vapors of some sort...I dont recall the specifics but I think I recall that he lists brands that do not have this problem "Roxul" being one of them).

To save you some time, here's another link for a good source for the mineral board and batt's that you can use to make acoustic treatment panels.

http://www.atsacoustics.com/page--Selec ... l--ac.html

A final point to keep in mind too, many folks get the idea that all they need to do is absorb bass and dampen reflections. The treat the heck out their room and end up with an anechoic chamber that just sounds completely dead. Making good use of refractive panels is important too. For example, if you're working in a converted bedroom, you probably have a wall not to far behind your mixing position. While you could put up damping panels (Auralex etc...), oftentimes, the best thing to put there is a book case full of books. The book spines, sticking out at various depths, can make a great refractive surface thats very random in it's sounds reflection characteristics. It looks good and it's functional too.

Hope this helps.

Karl
Studio system-i5 750, Intel X25 SSD, 3 Raid 0 arrays (2 for streaming sample players, 1 for projects), 16 gig ram, Win7 Pro 64 bit, RME Multiface and Digiface, Cubase 4.5 and C6, NI Komplete 7, Omnisphere, Trillian, EWQL Symphonic Gold/Colosuss, BFD 2, Jamstix, Waves mercury pack, lots of mic's....yada yada yada.... see my equipment list at...

Reference Point Recording Equipment List

Reference Point Recording

Paul Woodlock
Member
Posts: 720
Joined: Thu Dec 16, 2010 8:22 pm

Re: JBL room mode correction products

Post by Paul Woodlock »

The LEDE - live end - dead end and/or diffusion treatments work well, but work better in large or larger rooms. Unfortunately in small rooms ( i.e normal bedrooms or studies, etc ) is that dimensions aren't big enough to allow a far field to develop. And while of course no wants an anechoic chamber it's better to err on the side of absorption because in a normal domestic sized room what comes off the back wall will still be classed as 'Early Reflections' and scattered or not it will smear the sound.
Got a Brian - Morans

"It's better to be hated for who you are than loved for who you are not" -- Andre Gide

twilightsong
Senior Member
Posts: 1888
Joined: Wed Dec 15, 2010 6:08 pm
Contact:

Re: JBL room mode correction products

Post by twilightsong »

Karl wrote:Here's another link to a site that has a real wealth of solid, technically sound information about acoustics for music production rooms. The guy also provides lots of info on DIY methods of dealing with room acoustic problems. Some easy to build bass trap designs etc.... He also talks a bit about some of the concerns with certain makes of rockwool (vapors of some sort...I dont recall the specifics but I think I recall that he lists brands that do not have this problem "Roxul" being one of them).
Damnit

I KNEW I had read -- MORE THAN ONCE -- that rockwool had this issue.
"There is no avant-garde; only some people a bit behind." -- Edgar Varese
-----------------------------------------------------------
Cubase 5.5.2/ Win 7 64-bit/ Quad 9550/ UAD-2/ Wavelab 4/ more sample libraries than I can remember

Paul Woodlock
Member
Posts: 720
Joined: Thu Dec 16, 2010 8:22 pm

Re: JBL room mode correction products

Post by Paul Woodlock »

twilightsong wrote:
Karl wrote:Here's another link to a site that has a real wealth of solid, technically sound information about acoustics for music production rooms. The guy also provides lots of info on DIY methods of dealing with room acoustic problems. Some easy to build bass trap designs etc.... He also talks a bit about some of the concerns with certain makes of rockwool (vapors of some sort...I dont recall the specifics but I think I recall that he lists brands that do not have this problem "Roxul" being one of them).
Damnit

I KNEW I had read -- MORE THAN ONCE -- that rockwool had this issue.
No it doesn't. Rockwool/Glasswool is safe. Some people are allergic to it. But some people are allergic to peanuts. It certainly doesn't give off vapours. That's just rubbish.

That site is also silly

http://www.atsacoustics.com/page--Acous ... --faq.html
Both thicknesses work very well to reduce reverb, ringing, and unwanted reflections in your room. The 4-inch panels will do more to even out the bass in the room, but they are not true bass traps and they will not absorb much below 100Hz.
Contradictory nonsense. First he says "4-inch panels will do more to even out the bass in the room" and then says "they will not absorb much below 100Hz."

4" panels won't help the bass whatsoever.

it then says:

In general, where you place the panels in the room is not critical.
which is complete rubbish ..

And then constricts itself by going on about placing the panels in corners, but also in first reflection points. This site doesn't appear to know the difference between standing waves and reflections.
First, you get more absorption per square foot of panel when the panel is placed in or near a corner.
This is rubbish. The specification of the material is the same wherever you put it.
Got a Brian - Morans

"It's better to be hated for who you are than loved for who you are not" -- Andre Gide

Karl
Junior Member
Posts: 163
Joined: Sun Jan 23, 2011 8:32 am
Contact:

Re: JBL room mode correction products

Post by Karl »

I provided the ethanwiner.com link as a good technical source for acoustics, the ats link was simply to provide a source for many of the materials that the ethanwiner site mentions (try calling your local Lowes or Homedepot and ask them about rockwool (sometimes called mineral wool) or even owens corning 703 or 705 board...you'll likely get a blank stare). What worked for me was to Google "Roxul" (a particular manufacturer).

Not to be argumentative but re...
First, you get more absorption per square foot of panel when the panel is placed in or near a corner.

This is rubbish. The specification of the material is the same wherever you put it.
The statement you cite doesn't claim that the "specification" changes depending on where it's placed, it says that you get "more absorption per square foot of panel" when it's placed in or near a corner. We can debate what's meant by "near" but It would seem to me that if a given size bass trap is more effective when placed in a corner, this is the same as saying that you get more absorption from that same trap when you place it in a corner....thus more absorption per square ft of panel/bass trap.
Studio system-i5 750, Intel X25 SSD, 3 Raid 0 arrays (2 for streaming sample players, 1 for projects), 16 gig ram, Win7 Pro 64 bit, RME Multiface and Digiface, Cubase 4.5 and C6, NI Komplete 7, Omnisphere, Trillian, EWQL Symphonic Gold/Colosuss, BFD 2, Jamstix, Waves mercury pack, lots of mic's....yada yada yada.... see my equipment list at...

Reference Point Recording Equipment List

Reference Point Recording

Post Reply

Return to “Steinberg Lounge”

Who is online

Users browsing this forum: No registered users and 1 guest