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Post by vego99 on Aug 6, 2018 16:59:01 GMT
Hello everyone.
I'll be picking up some 2" OC 703 in the next few days to construct some acoustic panels for my room.
I need some help determinning if I should be constructing 2" material panels or stacking them for 4" material panels.
On that, Should I provide an airgap?
Also note: these will be for reflection points and clouds only. Ill be construction superchunk traps on the corners.
Thanks, Erik
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Post by Michael Lawrence on Aug 6, 2018 17:32:03 GMT
Hi Erik-
Welcome. 2" OC spaced 2" off the wall works well. That's what I've done for a studio I work for. I don't have the data in front of me but it tends to be almost as effective as the full 4". I'm sure one of the others will be along shortly and can link you to the info.
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Post by Hexspa on Aug 8, 2018 3:47:53 GMT
Ya, no doubt you can use 2" with 2" air BUT 4x4 is better. You can continue that logic up to 8" of rigid. Having used 2x2, then moving on to 4x4, I can tell you I wish I had 16x16. Put it this way: your stereo image goes below 80Hz. If you even want to hear half of that then you better have thick RFZ panels. Naturally, you'll keep most of your stereo information above 250Hz, or thereabouts, but the thicker your panels, and the more of them, the better off you'll be - without question, besides money and space.
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Post by vego99 on Aug 9, 2018 17:55:50 GMT
Ya, no doubt you can use 2" with 2" air BUT 4x4 is better. You can continue that logic up to 8" of rigid. Having used 2x2, then moving on to 4x4, I can tell you I wish I had 16x16. Put it this way: your stereo image goes below 80Hz. If you even want to hear half of that then you better have thick RFZ panels. Naturally, you'll keep most of your stereo information above 250Hz, or thereabouts, but the thicker your panels, and the more of them, the better off you'll be - without question, besides money and space. Hex, Thanks for the reply. So what you are saying with the RFZ ( Reflection Free Zone) Panels, it is better to have them 4" thick with a 4" gap, correct? I perhaps should have called this thread something else since i have additional questions. I'm going to add to this posts with questions and new pictures.
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Post by vego99 on Aug 9, 2018 18:32:51 GMT
So I think i need to add additional questions. This is a newly built dedicated room and i am finding some interesting things regarding its acoustics. While i have ready many things on line and because of all the different opinions i have been getting confused. Everyone here seem to have more accurate answers without alot BS, so i respect your feedback suggestions and tips! Lets get to the basics: Room Dimension Length 19.5 Ft Width 14 Ft Height 8'8" Now that the room is finished, i have noticed some things. Slap Echo is horrendous, sound is glaring and bass has been interesting. ( all of which are acoustic related..) When the room was empty the room seemed to have some bass to it, very boomy. When brought down my record shelf and records and placed on the rear wall this helped with the slap echo in the back of the room but it also removed all the boomyness but also eliminated ALL of the bass from the room. Where and how should i be treating this room? Should i not have the record shelf on the rear wall acting as a diffuser? My initial thought s were to build super chunk bass traps for the 4 corners of the room using roxsul (install kraft paper face) and then build OC703 acoustic panels for the (non kraft faced) for the reflection zones and Faced panels for wall bass traps. Attached are some new photos of the room, you will see that the speakers have significantly changed since the first photos. The photos also show more of the ceiling beams that are also contributing to the issues. IMG_2532 by vego99, on Flickr IMG_2536 by vego99, on Flickr IMG_2533 by vego99, on Flickr IMG_2531 by vego99, on Flickr Ive added a picture of the back of the horn, not sure how i should tackle this bass trap. Thinking i should build the trap Above the horn? IMG_2534 by vego99, on Flickr Thanks for all your help, Erik
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Post by vego99 on Aug 9, 2018 18:56:44 GMT
I should note: my Umik-1 mic came yesterday so i can start playing around with REW.
Perhaps this may also help us understand the current issues in the room?
When doing a sweep, i should place the mic at listening position correct?
Thanks,Erik
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Post by patate91 on Aug 9, 2018 22:17:44 GMT
I should note: my Umik-1 mic came yesterday so i can start playing around with REW. Perhaps this may also help us understand the current issues in the room? When doing a sweep, i should place the mic at listening position correct? Thanks,Erik Yes start with the mic at the listening position. You seems to have two chair so measure both.
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Post by vego99 on Aug 14, 2018 17:22:51 GMT
I was able to setup REW and take some base line measurements. There are three: 1. Measured at speakers to make sure the active cross over was set correctly. As you can see, it is pretty spot on with its settings. Very Flat. 2. Measurement @ listening position. This is 38% from back wall.. As you can see there are some deep nulls in there. 3. Measurement @ a listening position against the record shelf... Things have smoothed out some and you can Hear/Feel bass. Any suggestions of what i can do to smooth out the 38% seating position? Should i just move the seating position to back wall? Are the record shelves causing an issue? Thanks, Erik
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Deleted
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Post by Deleted on Aug 14, 2018 19:36:20 GMT
Are these 1/3 octave smoothed? Unsmoothed graphs would be better for low end, see the whole truth.
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Post by patate91 on Aug 14, 2018 19:38:00 GMT
I would simply sit where it sounds better (if it makes sense to sit there).
Now frequency response is one part of the equation, impulse, waterfall, RT60, etc. have very usefull informations.
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Post by vego99 on Aug 14, 2018 20:48:56 GMT
Are these 1/3 octave smoothed? Unsmoothed graphs would be better for low end, see the whole truth. Zero Smothing Attachments:
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Post by Hexspa on Aug 15, 2018 20:29:32 GMT
Vego, Ethan recently posted about how 38% from the rear wall is definitely inferior its inverse, 38% from the front wall. Relinquish the uphill battle and sit more forward. Secondly, a bookshelf is not a diffuser. Diffusers act in specific and controlled ways and putting up any irregular surface will not suffice.
Apparently you have no treatment in the room. If that's true then your measurements are just a baseline and nothing to get upset about. Scoot up, put in some treatment and then let's see where you're at.
Thanks and cheers.
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Deleted
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Post by Deleted on Aug 15, 2018 20:51:59 GMT
So if understood right, these are just measurements from yet untreated room? Then it ain't that bad. Just do really big superchunks for every corner. You should be able to get pretty good sounding room. All the treatment will make your room seem smaller, but its worth it.
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ths61
New Member
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Post by ths61 on Aug 15, 2018 22:28:06 GMT
Corner Horns and Corner/Super Chunk Traps are going to prevent a bit of a positional challenge. May have to split the difference and/or go to soffit trapping.
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Post by rock on Aug 15, 2018 22:30:25 GMT
So right, if these are the untreated measurements, you have a good baseline. From your room dims, here are the calculated modes: amcoustics.com/tools/amroc?l=19.5&w=14&h=8.66&ft=true&r60=0.6 If you can identify the source of a particular mode...like the one at 60hz, it might correlate to the ceiling to floor fundamental mode @65hz averaged with the front to back 2nd mode @~58Hz. In this case, back wall absorption plus ceiling cloud(s) may help with this particular mode and so on. But I'm getting ahead of myself, shoot for the corner bass traps first. Following the standard treatment suggestions should show improvements and you can incrementally measure your progress. Yes, since you have corner speakers, there's little room behind them but superchunks above will work. Hexspa is correct that stuff on shelves is not really a diffusor BUT it can help eliminate direct reflections and is probably better than a bare wall for that. (if the backs of the shelving units are acoustically transparent to low freqs, thick fiberglass or mineralwool behind the units will give you some additional degree of mode/ringing etc. control. Full absorption on the back wall is good so wideband absorbers above your shelves is good and spacing always improves efficacy. Corner bass traps in the upper wall/ceiling corners will also help tame room modes. Flutter echoes are tamed with wideband panels. When thicker and spaced from the wall, they will be effective at lower freqs enhancing room mode taming. All this is pretty much "boiler-plate" advice and would probably work in just about any room. Cheers, Rock
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