[Big Red Machine]

Some ideas for your ceiling. Think big!

[JWL.GIK]

Looks great, OP!

As far as where to place the remaining bass traps, use this listening test:
http://gikacoustics.com/video-testing-corner-bass-trap-placement/

You already have a good amount of coverage area in terms of treatment, so your room will be more consistent from point to point. You might use an SPL meter (several free phone apps) to get a bit more data, since the differences will be harder to hear.

[poseidonsvoice]

Ceiling is an interesting idea and makes sense to me. I could even talk the wife into ditching that fan as we rarely use it. Are the cloud mounting brackets the way to go for this application?

http://www.gikacoustics.com/product/acoustic-panel-ceiling-cloud-mounting-brackets/

They recommend it for 244's in that link so...yes.

Best,
Anand

[Vedder323]

I dont know, pretty underwhelmed with the results here.

No Treatments at all. 10-300hz VS ALL treatments after playing around with lots of different locations.

Both Speakers - No Treatment


Both Speakers - Treatment


Waterfall - No Treatment


Waterfall - With Treatment

[JWL.GIK]

I dont know, pretty underwhelmed with the results here.

Really?  In the response graphs, the curve above 60Hz looks much flatter. And in the waterfall graphs, the decay times on the ringing notes are much shorter even down to 40Hz. Not bad for just a few traps. Under 60Hz is much harder to treat, you need a lot of thick traps.

[poseidonsvoice]

Really?  In the response graphs, the curve above 60Hz looks much flatter. And in the waterfall graphs, the decay times on the ringing notes are much shorter even down to 40Hz. Not bad for just a few traps. Under 60Hz is much harder to treat, you need a lot of thick traps.

I agree.

Look Ron, you want your response 40-200 Hz to look flat as a pancake right? Ignore above 200Hz because I can see that is rather close to your Schroeder frequency. Notice how 100-200 Hz got flatter with the treatments, that's good. Now you want to fix the area from 40-100 Hz? Have you moved your 2 subs around? Have you tried more than 2 subs? That's where the magic lies.

Your waterfalls look fine by the way.

Best,
Anand.

[Vedder323]

Its entirely possible im expecting too much but when I spoke with GIK, the trouble area I was focused on was below 60. The traps helped with everything above these frequencies which is great and all but didn't really address the issue I was hoping for. No subs are being used in these measurements. These open baffles are supposed to be dropping -3 around 60 and thats what I was shooting for. While I can appreciate what the treatments are doing above 60, its frustrating that the area I wanted to treat was essentially ignored in what was recommended.

[poseidonsvoice]

The room wreaks havoc with LF response of any main speaker, that much you have proven (and it doesn't really matter who told you what about how low these open baffle main speakers are supposed to go; they cannot prognosticate that parameter exactly, just give you a general idea since room modes are a given). So the fact that the F3 isn't 60Hz is something I wouldn't be concerned with. Your F3, with the graphs you have shown appears to be 38 Hz. I'm drawing a line mentally at 85 dB to show you what I believe is the middle. So for example, you are right at flat (0dB) at 70 Hz. You won't know what the 'middle' is unless you do some measurements extending above 300 Hz. Like up to 1khz.

Now play your subs, introducing one at a time. Play with position.  Play with the crossover frequency, phase, etc.. of the ONE sub, and see how that changes the response of your system (2 mains + 1 sub). When it's as flat as possible, then fiddle with the other sub. Do the same thing. It takes time as you can already see.

See here: https://mehlau.net/audio/multisub_geddes/

Look particularly at the part that is titled "Exemplary data"; See how the response flattens below 100 Hz. Geddes prefers moving the mic in an ellipse while somebody else accesses the computer to tell REW to measure. But that isn't necessary. If you have an extra person to help, great, use them. If not, set the mic at the listening position on a boom mic stand and go for it.

The links to the HifiZine article in this post should hopefully help: http://www.audiocircle.com/index.php?topic=149872.msg1603064#msg1603064

Best,
Anand.

[debjit.g]

Anand, for some reason the link to the Hifizine doesn't work anymore. Maybe the website is down ? Does it work for anyone else ?

[danvprod]

Looks much better to me as well. Your peaks aren't as high and the nulls aren't as deep. Adding treatments doesn't changes the "shape" of what you room naturally does to the sound from 20-200Hz -- that is driven by the modes given by the dimensions of your room. But what you've done has helped quite a bit. Multiple-subs are needed to treat 20-60Hz, I think. You have the advantage of being able to move your sub arrays independently with with your mains, so that gives you a lot of flexibility there.

I too, noticed that the hifizine articles no longer are available -- does anyone have pdf copies of those?

[poseidonsvoice]

Dan,

I think that John R, the proprietor of HifiZine and AC may be updating the site.

Best,
Anand.

[Vedder323]

Here we go, diffusers are installed as well.

Both speakers 30-20k 1/3rd smoothing and with the subs in the second graph 10-20k. Any ideas on 120-150hz?

[danvprod]

looks like you have to continue to experiment with moving around your mains. Both have a peak with a cf near 120Hz, which are adding together. You might also want to experiment with the phase, q and gain of each of of your sub arrays, to try and flatten out the 45 Hz and 75 Hz peaks. Don't be afraid to have the subs overlap with the mains a bit more.

How is the sound quality now? Bass shy? Enough for you? I'd assume from that peak from 100-200 Hz you have too much mid-bass right now and it is likely to sound a bit muddy.

I see you installed the P.I. audio diffusers as well. Let me know what you think of them.

Thanks for keeping us updated on your progress.

[charmerci]

Here we go, diffusers are installed as well.

Both speakers 30-20k 1/3rd smoothing and with the subs in the second graph 10-20k. Any ideas on 120-150hz?

Yeah, it looks like you have too many woofers. You could disconnect a few of them! 

[JWL.GIK]

The traps helped with everything above these frequencies which is great and all but didn't really address the issue I was hoping for. No subs are being used in these measurements. These open baffles are supposed to be dropping -3 around 60 and thats what I was shooting for. While I can appreciate what the treatments are doing above 60, its frustrating that the area I wanted to treat was essentially ignored in what was recommended.

I doubt anything was intentionally ignored in our recommendations. We always do the best we can within budget and space limitations. Treating under 60Hz requires a lot of traps, typically we recommend Soffit Bass Traps in all corners (including ceiling corners), and even more coverage area with thick traps (Monsters or Alpha 6As) on walls & ceilings as well. Not everyone has room or budget for this, however.

Take heart, even without doing all that and by adding just a few traps, your ringing under 60Hz looks a lot better. Ringing/decay is just as, maybe more, important as the final frequency response graphs.

And I agree, you can do a lot at the low room mode frequencies with good subwoofer placements. Apologies if I've already linked to it, but this recent article gives some details:
http://www.gikacoustics.com/room-setup-speaker-placement-201-part-two-subwoofers/

[poseidonsvoice]

Gave a call to Ron, I think we've got him psyched and he is going to work on a few things. Sometimes picking up the phone and engaging in a 2 way sequential conversation is the fastest way to help out a brother in need...

Best,
Anand.

[Vedder323]

Gave a call to Ron, I think we've got him psyched and he is going to work on a few things. Sometimes picking up the phone and engaging in a 2 way sequential conversation is the fastest way to help out a brother in need...

Best,
Anand.

Been pretty darn busy and ordered another 244 traps to place on the ceiling. My pal Anand inspired me to move the speakers around and look at the wall behind me for options so I got VERY creative. Either way, I feel like I am moving in the right direction for sure - ill post new measurements asap.

[JWL.GIK]

Excellent! Keep us posted!

[pompon]

You need to do digital room correction.

Without correction:


With correction (2 eq point almost) : Not exactly the same mesurement. The bump at 50 and 130 hz was present no matter the position of the speakers and if I put basstraps/panels or removed them. The hole at 115 hz is caused from my door.


EQ won't fix nulls and not affect much the RT60 but it's very easy to cut a bump ...

You make the right choice using basstraps + panels + diffusors. You just need EQ to flat the frequency response and fix phases.

[Hipper]

I too use EQ despite using a lot of bass traps and it does improve the sound.

I use a Behringer DEQ2496.

pompon - what EQ do you use?