AudioCircle
Industry Circles => GIK Acoustics => Topic started by: Vedder323 on 9 Jun 2017, 02:53 pm
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Hey folks - Ron from New Record Day here. I have been using the GIK 244 bass traps straddled in the corners of my room over the last few years and when I learned how to measure, I noticed they aren't really doing a darn thing. After contemplation and soaking up as much knowledge as possible on room acoustics, I decided that perhaps I was asking too much of those traps to handle the real issues in the room. Well - I just ordered 4 triptraps to stack in the corners along with a pair of free standing Gobos for treating the first reflections. I wanted to start this thread to get any other advice on my room along with providing feedback as things progress.
My room.
14.6 feet wide by 14 feet deep. On the left, there is an entrance way that leads to our front door. Behind the listening position just off to my left shoulder, there is an entry way to another room or office which is another 10 feet deep by 9 feet wide. To the right of the listening room is an open kitchen with a bar - partial wall that opens up around chest level.
Here are some photos.
Listening room with reference speakers and my little helper taking measurements.
(http://www.audiocircle.com/image.php?id=163573)
Shot showing open side to the right - kitchen area
(http://www.audiocircle.com/image.php?id=163574)
Show showing left side of listening room, hallway opening to entrance to home.
(http://www.audiocircle.com/image.php?id=163580)
Shot showing the listening couch with room behind it.
(http://www.audiocircle.com/image.php?id=163579)
Here are some recent room measurements with the open baffle tower speakers only, no subs.
(http://www.audiocircle.com/image.php?id=163577)
(http://www.audiocircle.com/image.php?id=163578)
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Ron,
Please post low frequency measurements from about 10Hz up to 300 Hz, without any smoothing whatsoever (no 1/3 octave stuff). Leave the waterfall out for now, let's just look at your frequency response/amplitude response. Also please make sure you post what each vertical division on your vertical scale represents...2 dB, 5 dB, 10 dB, whatever it is...or else it is hard to interpret your graph. Please mention which speakers you are measuring, your OB speakers or your OB speakers + OB subs. Getting really, really good at making baseline measurements with the mic at the listening position specifically for frequencies less than 300 Hz is terribly important as the dominant factor here is your room, which in your situation is somewhat squarish with egresses to the left and right of the listening position. I would strongly recommend Room EQ Wizard.
Thank you,
Anand.
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Ron,
Please post low frequency measurements from about 10Hz up to 300 Hz, without any smoothing whatsoever (no 1/3 octave stuff). Leave the waterfall out for now, let's just look at your frequency response/amplitude response. Also please make sure you post what each vertical division on your vertical scale represents...2 dB, 5 dB, 10 dB, whatever it is...or else it is hard to interpret your graph. Please mention which speakers you are mentioning, your OB speakers or your OB speakers + OB subs. Getting really, really good at making baseline measurements with the mic at the listening position specifically for frequencies less than 300 Hz is terribly important as the dominant factor here is your squarish room. I would strongly recommend Room EQ Wizard.
Thank you,
Anand.
Hey bro!
Will do - ill knock out some new REQ measurements tonight or tomorrow and post them!
Also - ill be using both the mains and subs for reference listening but wanted to address them separately so ill post both measurements individually as we progress.
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Agreed, REW allows you to provide much more useable test data.
Also, if you can, start with a room measurement of the empty room with no treatments, then re-measure with each stage of treatment you add. While I agree that the TriTraps will be an upgrade over the 244s, I'd be shocked if the 244s aren't helping. Bass trapping is as much about coverage area in the room as it is about individual trap effectiveness. Once you get the TriTraps in, you can repurpose the very versatile 244s in a different location so they can continue to help. :thumb:
As you experiment with the new treatments and moving things around, this article might help you identify what to listen for during your testing & installation:
http://www.gikacoustics.com/learning-to-listen-acoustics-the-listening-experience/
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Ron,
Please post low frequency measurements from about 10Hz up to 300 Hz, without any smoothing whatsoever (no 1/3 octave stuff). Leave the waterfall out for now, let's just look at your frequency response/amplitude response. Also please make sure you post what each vertical division on your vertical scale represents...2 dB, 5 dB, 10 dB, whatever it is...or else it is hard to interpret your graph. Please mention which speakers you are measuring, your OB speakers or your OB speakers + OB subs. Getting really, really good at making baseline measurements with the mic at the listening position specifically for frequencies less than 300 Hz is terribly important as the dominant factor here is your room, which in your situation is somewhat squarish with egresses to the left and right of the listening position. I would strongly recommend Room EQ Wizard.
Thank you,
Anand.
As instructed here we go.
(http://www.audiocircle.com/image.php?id=163648)
No bass traps installed on the walls. Speakers are in reference position, 6 feet into the room.
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I was wondering what happened to you. I see in the first picture what happened. :P
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Ron,
What is the green and red trace? Individual responses? Ok. Good.
Now take a measurement with the mains playing at the same time from 10-300 Hz.
Best,
Anand.
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Ron,
What is the green and red trace? Individual responses? Ok. Good.
Now take a measurement with the mains playing at the same time from 10-300 Hz.
Best,
Anand.
Yes sir!
Here you go,
(http://www.audiocircle.com/image.php?id=163655)
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Ron,
Coming right along. Good.
I want you to start moving your main speakers around, front to back, side to side, while also measuring them just the way you have. Try to see if you can make it look smoother. Do what you can to move them, but without compromising imaging or staging. If you can't move them much and the measurement above is what we have to work with, fine. No big deal. But a few inches here and there can make marked differences.
After you have done that, then place the Tritraps in the front corners or 244's (if you don't have the Tritraps) and post those measurements.
Don't despair, I'm not the least bit surprised by your peaks and valleys from 40 Hz to 150 hz as this is the modal region which will look like that in all rooms that are untreated or do not have multiple sub implementation. The area from 100-300hz will also be highly influenced by the distance of your mains to the side walls, front wall, ceiling and floor - it is called SBIR or the Allison effect. Read about it here: http://arqen.com/acoustics-101/speaker-placement-boundary-interference/
100-300 Hz is difficult to get right. It will require room treatment (those Tritraps, 244's, etc...), proper loudspeaker positioning (as mentioned above), sometimes EQ and rarely broadband subs or mid bass modules can help, but that is extraordinarily tricky to implement without risking localization.
Calculate all the room modes for your room here, use approximate dimensions since your room dimensions are a little quirky: http://amroc.andymel.eu
as it is educational and may not apply to your room since yours is not perfectly rectangular. Read this for more on that subject: http://www.acousticfrontiers.com/room-modes-101/
Best of luck,
Anand.
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Just an aside!
I notice your Tri-traps are sitting on something. It might be worth measuring to see if they perform better when on the floor, and also using a pair in each front corner - one on top of the other (you said you got four but I can only see two in the pics).
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Just an aside!
I notice your Tri-traps are sitting on something. It might be worth measuring to see if they perform better when on the floor, and also using a pair in each front corner - one on top of the other (you said you got four but I can only see two in the pics).
Read the OP's 1st paragraph again. Those treatments in the front corners are 244's. He's ordered Tritraps and Gobos from GIK. They will probably take a week to arrive.
Best,
Anand.
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We have similar-sized space and speakers. My room is 14'6 x 16' and speakers are Super Vs. I think the tri-traps will be a nice upgrade. The 2x12s really energize the room and my FR from 20-300 looks surprising similar to yours. I have four of the soffit bass traps currently and am still feeling like I am needing more. Looking forward to your continued experimentation and reporting on what works for your room.
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Na
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Good advice so far. Because your room is open in some spots, the bass response is a bit less predictable. This listening test will help you find areas of bass buildup -- those are great spots to put bass traps if you can. Pay attention to pretty much all corners, walls, and nooks & crannies of the room....
http://gikacoustics.com/video-testing-corner-bass-trap-placement/
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Traps arrived in safety. Time to figure out the best placement for the older 244 traps, open to ideas, suggestions and expertise. Ill be using the taller Gobos for 1st reflections.
(http://www.audiocircle.com/image.php?id=164284)
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How about the wall behind the listening position? A mixture of diffusion and absorption on the back wall is a good thing. You can use them on the front wall too, but a mixed absorber/diffusor on the front wall would be great given that you have open bafflish speakers.
244's are also good wherever two or more walls are meeting, i.e. corners; floor/front wall section; ceiling/front wall; and on the back wall similarly.
Fool around and let us know!
Love the red!
Best,
Anand.
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I would agree with either rear corners or centered behind you on the rear wall. Another option is for your ceiling reflection zone.
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As you guys can see in the previous pictures, the wall behind me is a little tricky as it opens into another room. Would you say setting the traps on the ground right behind the couch would still provide benefits or should I consider creating a fake wall for them to hang on? Ideas?
(http://www.audiocircle.com/image.php?id=164286)
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Draw a line from your speakers directly to the listening position. Look up at the ceiling, that is your ceiling reflection line. Treat it and be happy. Minimum of 3 inch thickness there.
Fake walls are cool, but play with it and tell us how your soundstage changes. Try to avoid upsetting the SWMBO! :wink:
Best,
Anand.
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Draw a line from your speakers directly to the listening position. Look up at the ceiling, that is your ceiling reflection line. Treat it and be happy. Minimum of 3 inch thickness there.
Fake walls are cool, but play with it and tell us how your soundstage changes. Try to avoid upsetting the SWMBO! :wink:
Best,
Anand.
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/
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(http://www.audiocircle.com/image.php?id=152431)
(http://www.audiocircle.com/image.php?id=152080)
Some ideas for your ceiling. Think big!
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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.
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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
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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
(http://www.audiocircle.com/image.php?id=164334)
Both Speakers - Treatment
(http://www.audiocircle.com/image.php?id=164335)
Waterfall - No Treatment
(http://www.audiocircle.com/image.php?id=164336)
Waterfall - With Treatment
(http://www.audiocircle.com/image.php?id=164338)
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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.
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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.
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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.
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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.
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Anand, for some reason the link to the Hifizine doesn't work anymore. Maybe the website is down ? Does it work for anyone else ?
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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?
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Dan,
I think that John R, the proprietor of HifiZine and AC may be updating the site.
Best,
Anand.
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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?
(http://www.audiocircle.com/image.php?id=164560)
(http://www.audiocircle.com/image.php?id=164561)
(http://www.audiocircle.com/image.php?id=164565)
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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.
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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?
(http://www.audiocircle.com/image.php?id=164565)
Yeah, it looks like you have too many woofers. You could disconnect a few of them! :lol:
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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/
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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... :thumb:
Best,
Anand.
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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... :thumb:
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.
(http://www.audiocircle.com/image.php?id=165472)
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Excellent! Keep us posted!
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You need to do digital room correction.
Without correction:
(http://nsm07.casimages.com/img/2017/07/03//17070305173922427415128827.jpg)
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.
(http://nsm07.casimages.com/img/2017/06/22//17062203394922427415105886.jpg)
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.
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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?
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I am using the software Acourate from AudioVero + J-River to run the convolution.
I was using before REW to do the mesurement and simply put the "PEQ" point directly in J-river parametric EQ.
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?