KVR Audio

3ee · Post by **3ee** » Fri Apr 08, 2016 1:26 am

imminent update 'bout to follow!

got the chunk traps in teh house (not mounted yet, but in the room), got to prepare before and after.... 'n' stuff tomorrow

added: although, it's a different kind of mineral wool that suppose to be easier on the air to the core (a new "eccose" technology) I kinda feel their presence in the room, + I vacuumed them prior + I have the micro-fiber textile wrap going on (which is totally breathable yet microfiber)

...or maybe it's just that I've worked in the medium all day and then sweeped up the dust with a broom (wearing a mask btw) .. I still feel a little "hot pepper dust" in the air.

3ee · Post by **3ee** » Fri Apr 08, 2016 2:05 am

where-ever they are placed... the seem to radiate a sort of "negative" energy like a black-hole, if that makes sense.... like they want to absorb something... I predict a pleasant surprise after test results!

Compyfox · Post by **Compyfox** » Fri Apr 08, 2016 7:40 am

Looking forward to your results.

Pictures are also always nice. But this isn't GearSlutz's Acoustics section.

3ee · Post by **3ee** » Sat Apr 09, 2016 7:59 pm

will be sure to post pictures!

quick, yet important question! ...

is it possible that massive acoustic treatment pieces like these corner chunks will shift the peaks/nulls in the room, then re-placement (even if a tiny amount like 5 - 10 cm) of the speakers + sweet-spot is needed? (cause that's kinda what I witnessed after a quick REW test)

Compyfox · Post by **Compyfox** » Sat Apr 09, 2016 9:44 pm

Can happen indeed due to different waves bulding themselves up. This is why you'd theoretically need tuned traps in the low frequency spectrum.

But yes, a small adjustment to your speaker placement should improve things.

camsr · Post by **camsr** » Sat Apr 09, 2016 10:10 pm

So if you had a flat response in a room with no absorbers, then added an absorber to only one wall, would you still expect it to be flat?

3ee · Post by **3ee** » Sat Apr 09, 2016 10:31 pm

camsr wrote:So if you had a flat response in a room with no absorbers, then added an absorber to only one wall, would you still expect it to be flat?

The thing is... the is no flat response in a room, EVER! (for a typical placement, I found that more or less to be a fact)
... so my guess is that you treat only one wall, you can have a different signature of frequency problems since they interact in more than one way as it seems.

here's and interesting site (about what wall and where to treat theoretically):
http://amroc.andymel.eu/?l=520&w=310&h=240&r60=0.6

just enter your room dimensions and hover on the partials (warning, lower volume!) watching the 3D red/blue pressure areas. ... from what I understand, treating in those areas will help attenuate the problem by a coefficient factor.

camsr · Post by **camsr** » Sat Apr 09, 2016 11:32 pm

Each surface of a room interacts with the others, differently, depending on geometry angles and damping. Superchunks are good for shrinking modal decay, but they don't do it all, there's simply interference somewhere else.

3ee · Post by **3ee** » Wed Apr 27, 2016 2:58 am

After heavy weeks of more studying, moving things around and testing again and again (used the Behringer ECM8000 mic to do the tests) ... I came to the conclusion that it's more or less the best I can do atm in this room... before getting ridiculous

The sweetspot @ 38% / 2 = 19% ...and the monitors are 19 / 2 = 9.5%
This seems to work best in my room + the front, downward aiming bass ports.

So, summary and here are some pics...

12 pieces (1 piece = 100x60x10cm LxWxH ) will fill up 4 traps (dimensions in the picture)

The mineral wool density is 30Kg/m3 (probably should have gotten the 40Kg/m3 one) ,
Gas flow resistance is about 5000-6000 K Pa.s/m2

The fabric used to wrap the traps is a "Coolpass" which is a very breathable synthetic micro-fiber, perfect for this use it seems.

https://drive.google.com/file/d/0B3pYSM ... sp=sharing
(download the pic for a better resolution!)

...

camsr · Post by **camsr** » Wed Apr 27, 2016 5:47 am

That's a hell of a mode at the bottom end there. You can tell that the insulation can't do much at that frequency without more depth. The good news is you can probably get some more improvement in the bass by building deep traps at the back of the room.

3ee · Post by **3ee** » Wed Apr 27, 2016 2:01 pm

^you mean that 32Hz mode? ... as bad as it looks, it never bothered me, in fact, I always saw it as helping to extend freq range a bit... + it's easier to correct more or less with subtractive eq as I will be preparing some corrective eq bands IR with the help of REW

The whole reason for this treatment upgrade was to control the 70 Hz area, which I did by at least 4-6db. ... + there were many other happy side-effects at different frequencies

Compyfox · Post by **Compyfox** » Wed Apr 27, 2016 2:18 pm

First and foremost, I wouldn't call this a "mode", camsr. But yes, there is something happening at 30Hz that "builds upon itself". However... this could be due to various things. And we're still talking about a living room converted into a workspace type of deal.

In order to fix this, 3ee really needs a specific tuned absorber at a crazy size (not possible) or build a room inside a room/dedicated space (also not possible. What's most important is the waterfall chart. And that shows that he handled his "ring out" times really, really well. So he should barely have any flutter echo in his room. And this is the most important thing that counts.

Now he can definitely/easily work with corrective EQ engines and get the best out the room he has.

There is not much more he can do at this point.

BTW: Nice corner chunks. Would be a bit too much on my end (and I do not have the space due to my room build). But it get's the job done it seems.

3ee · Post by **3ee** » Wed Apr 27, 2016 4:16 pm

^ well, 32-33Hz is the "main" room mode to the length of 520cm .. but it's coupled with the monitors' bass port tuning, that's why it shows up like that on the waterfall plot I guess... (added: just checked, the Egg150 is tuned to 51Hz , so yeah.... it's mostly a room resonance then

)

Compyfox wrote:BTW: Nice corner chunks. Would be a bit too much on my end (and I do not have the space due to my room build). But it get's the job done it seems.

Thanks!

, yes they help quite a bit!
... not as much as I wish

, but honestly, have no idea how much they suppose to do.... anyway, can't wait to get back to mixing!

camsr · Post by **camsr** » Thu Apr 28, 2016 12:11 am

3ee wrote:^you mean that 32Hz mode? ... as bad as it looks, it never bothered me, in fact, I always saw it as helping to extend freq range a bit... + it's easier to correct more or less with subtractive eq as I will be preparing some corrective eq bands IR with the help of REW

You can certainly take this approach, but more bass trapping will also help level out the bass above 32hz more.

3ee · Post by **3ee** » Thu Apr 28, 2016 1:33 am

^ may certainly be! ... but there is furniture and other stuff that is "in the way" ... trust me, I thought about many options to move and adapt things to a better sweetspot ... the result must do at least atm, probably I'll need another bigger room in the future to start over.

the smaller the room, the (ridiculously) more that nneds to be invested in acoustic treatment as I found out...

Basstrap: EQ Acoustics or HOFA ..or DIY?