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Post by Hexspa on May 29, 2016 21:50:22 GMT
I realize the first treated measurement looks more typical but I've gained a larger stereo image.
The main problem were the peaks at 70 and 85Hz. By taming those (ceiling and wall absorption) I'll be able to pull up the lower frequencies.
-m
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Post by Ethan Winer on May 30, 2016 18:53:29 GMT
At 2 dB per division this is actually quite good.
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Post by Hexspa on May 31, 2016 2:27:31 GMT
At 2 dB per division this is actually quite good. This is interesting - may I ask what you're looking for in these graphs? I understand you've mentioned +-10dB deviation in response, particularly below the Schroeder frequency; this is my understanding, not your exact words. However, mentioning "2dB per division" is something I don't ever recall hearing. Does this mean you're also considering the slope of the variations? What about the deviations within each division? Just wondering how a professional like yourself is interpreting this information. I realize it's like a senior surgeon who, while having inferior eyesight to a new medical graduate, can see much more into an xray or the like. Not saying my eyesight is superior! Thanks, -m PS - I'd like to add the target given by the article I posted earlier - the Bass Integration Guide - about 20dB decay over 150ms below 300Hz or so to hear your thoughts on decay plots and waterfall graphs. Thanks again.
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Post by Hexspa on May 31, 2016 2:35:12 GMT
And I know I can get questiony quick but...
A big problem with my new layout were the peaks at 70 and 85Hz. By turning my sub up it raises, like a shelf, everything below 200Hz despite my high cut filter down at 80Hz (really it's as though the filtering functions on the sub do nothing despite them being engaged (Yamaha HS10W)).
But, looking back on the measured response sans treatment, the curve didn't change much from before I'd taken the treatment out. Really what changed was the Q of the peaks and the decay (most substantially). Then again the speakers were only 2' away... I really don't want to take all the treatment out again and check what the untreated response is from their current distance of 102". Regarding response, the treatment seemed to have helped most with the severe nulls at 92, 150 and 210Hz.
So I'm wondering if adding treatment to my ceiling is even going to even that peak out much. I hypothesize it'll help with the ringing that's left but ya, it doesn't seem like all this absorption is helping as much as I'd assumed in the response department.
Since I want to use the front area as a recording zone I can't justify placing panels 4' high and bisecting my floor-ceiling plane (1/4 wavelength of 70Hz).
Anyway, I can see you saying, "More treatment is always better." but I'm hoping you can guide me forward or share some thoughts on what I've presented. Especially because, and I apologize, that despite searching on Google I can't find reference to the 2dB/slope/division criterion that you mentioned.
Thank you,
-m
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Post by Hexspa on May 31, 2016 3:24:32 GMT
and a pic
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Post by Ethan Winer on May 31, 2016 17:07:03 GMT
All I mean by "2 dB per division" is that the graph looks worse than it is.
If your sub volume affects a shelf from 200 Hz and below I'd investigate that further.
Yes, adding bass traps on a ceiling helps, just as bass traps anywhere else help. I have a good friend with a serious home studio, and putting foot-thick bass traps on most of the ceiling solved his remaining bass problems.
--Ethan
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Post by Hexspa on Jun 1, 2016 0:26:21 GMT
All I mean by "2 dB per division" is that the graph looks worse than it is. If your sub volume affects a shelf from 200 Hz and below I'd investigate that further. Yes, adding bass traps on a ceiling helps, just as bass traps anywhere else help. I have a good friend with a serious home studio, and putting foot-thick bass traps on most of the ceiling solved his remaining bass problems. --Ethan Ok, thanks. -m
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Post by Hexspa on Jun 21, 2016 7:48:54 GMT
Hey everyone. I've been busy with a few things, namely: redoing my panels, building superchunks, travel, preparing to build more panels and developing a curriculum for my teaching business.
I've reupholstered and recombined my panels so that they're all 4" thick 8lb mineral wool (IIG 1280, roughly the equivalent to OC 703 with more high-frequency absorption) and in an unbleached muslin wrap - very nice, cool, professional and inconspicuous. Currently I have 20 such panels plus nine super chunks (all four corners floor-to-ceiling plus an extra).
We've yet to cover the super chunks - that should be done by the end of the week.
I've mentioned my travel in another thread - it was a good rest.
I will be treating my ceiling with 10-12" thick pink fluffy. I intend to build at least 22 panels. This should be done before July.
I just read Ethan's suggestion that adding panels is logarithmic in effectiveness. However adding 40 more panels is impossible so I'm expecting to see an improvement in ringing at 70Hz (ceiling axial) and 85Hz (front-to-back axial) once everything is installed. Then it's on to teaching.
Thanks everyone I just haven't been interested in contributing much. Pics soon.
Apache!
-m
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Post by Hexspa on Jul 1, 2016 1:50:01 GMT
A slightly delayed video on the initial superchunk construction, room layout and plans: youtu.be/9U_M26HGxGM
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Post by Ethan Winer on Jul 1, 2016 20:13:26 GMT
^^^ Very nice!
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Post by rock on Jul 1, 2016 23:48:33 GMT
Yes, very nice. My question: would paper or plastic film glued to the front of the superchunk improve LF performance (of course at the expense of less mid/high absorption) ?
Cheers, Rock
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Post by Hexspa on Jul 2, 2016 6:37:00 GMT
Hey, thanks guys.
I actually forgot to put the kraft paper I ripped off the batts on two of the chunks.
My initial plan was, because each 4' chunk is essentially divided in half, to put paper on the extreme ends leaving the center two open like so:
CEILING paper - no paper | no paper - paper FLOOR
so that where my ears typically aren't (on the floor and ceiling) I can get better bass (also the 3-point corners are in those places) and in the center, where my ears are, I can get the better m-hf absorption. I should probably decide on that before I put on any more fabric.
I should mention that there is paper in the chunks on the bottom, middle and top horizontally. That was mostly to keep the insulation from falling out but I put the middle one in there just in case it might help with the bass a little. Totally unverifiable but ya, I did that.
The next video will show all of the completed chunks without fabric and my old panels being broken down. The video following that should show the the chunks with fabric and paper and my old panels fully finished but probably not yet installed. I still have the ceiling to do...
Looks like I'm a "Senior Member" now. Forget hiding my age I guess.
Thanks,
-m
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Post by Hexspa on Jul 3, 2016 7:36:31 GMT
I've glued paper on as mentioned. It really seems to work both tightening up the low frequencies and making the room more ambient. I think when I redo the ninth panel - which is hiding in the lower right of the photo behind my monitor and mixcube - with double paper (since it'll be in some random ceiling corner probably) I'll have a good mix. Besides, I'll be doing the ceiling and judiciously using paper and non-paper panels so I'll get more benefit there. In this pic you can also see the new unbleached muslin wrap on my now 20 all-four-inch panels. -m
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Post by rock on Jul 3, 2016 15:12:27 GMT
I just want to mention I like your use of the metal corner bead. Great idea! Do you have details or a video of how you made your panels?
Cheers, Rock
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Post by Hexspa on Jul 4, 2016 0:34:12 GMT
I just want to mention I like your use of the metal corner bead. Great idea! Do you have details or a video of how you made your panels? Cheers, Rock Making those was hard. The reason why was the drill - I had to put pressure to drill without the benefit of a jig or brace. Ultimately I used gravity and a pointed garden stake - the kind they sell at home depot, just generic - which just so happened to have both a 45 degree angle and a 90 degree angle. Probably not the exact ones but very similar to: www.homedepot.com/p/Greenes-Fence-4-ft-Wood-Garden-Stake-25-Pack-RC84N25U/204721121?cm_mmc=Shopping%7cTHD%7cG%7c0%7cG-BASE-PLA-D28O-OutdoorGarden%7c&gclid=CNvz3OzH2M0CFYqPfgodhukIPw&gclsrc=aw.dsHowever I just bought a hole puncher this week which is made for wall corners - not sure if they mean drywall bead but it does work. It pokes 1/8th inch holes which will probably fit the pop rivets perfectly (I used rivets). I used a modified Steve P. Helm design for my original panels and, having experience with that, knew I had the tools, experience and skill to make the triangle shapes. www.radford.edu/shelm/acoustics/bass-traps.htmlAll you need is some metal shears (the kind with the rounded outer edge - mine have a yellow handle), a rivet gun, an 1/8th inch metal hole puncher and two rivets per point of contact. So imagine since the legs are essentially a piece of folded metal 1.25" on each side, each side gets two rivets for a total of four per joint. I made the two holes on a little diagonal which you can see in the intro sequence of my video www.youtube.com/watch?v=9U_M26HGxGM Of course a measuring tape as well and a marker. One detail about the triangles is that you'll have to cut angles to be sure the sides fit with the face. I definitely test fitted and labeled the parts that fit together. I just interlaced them similar to how you fold a box. I should definitely make a close-up look at the construction. All I can say for now is that I strongly advise against drilling unless you can make a custom brace. Even then I think using a hole punch is far more efficient saving you massive amounts of energy, time and frustration. Also, if you decide to use drywall bead for regular rectangular frames, I'd advise against using the "in-between" pieces and just connect the front and rear frame with zip ties like I have in case you ever want to disassemble them. If you make those connector pieces like he does you'll have a big problem later - that's essentially permanent/you'll have to destroy/trash the frame. With zip ties you just cut em off etc. Very easy. Plus you can use the ties to connect chains and hang the panels. Cheers, -m
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