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Post by Ethan Winer on Mar 18, 2016 17:38:56 GMT
Absorbers on stands in front of the kitchen will help block reflections at mid and high frequencies. If the panels are thick it will help at lower frequencies too. So sure, and that's a lot better than a solid wall.
--Ethan
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Post by Ethan Winer on Mar 18, 2016 17:37:00 GMT
Sure, though it's more difficult to attach foam with an air gap.
--Ethan
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Post by Ethan Winer on Mar 18, 2016 17:36:14 GMT
I haven't tested this exhaustively myself, but apparently as the material gets thicker you can use less dense materials and still get good absorption. The higher density 705 is best when it's only 3-4 inches thick or thinner.
--Ethan
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Post by Ethan Winer on Mar 17, 2016 17:55:34 GMT
In another thread, Riley (bigcat) showed a drawing of his room that's narrower at one end. Usually a room should get wider and / or taller in the rear, but in this case that's not the best solution. As it happens, someone else today asked me why it's better for a room to be larger in back than in front. So I figured it's worth a brief explanation: I can think of three reasons to have angles in an audio room: One reason for angles is to avoid flutter echo, that "boing" sound you get when sound reflects repeatedly between two parallel surfaces. This applies both in rooms where you record as well as rooms where music is played through loudspeakers. Another reason is to deflect early reflections toward the rear of the room as an alternative to absorbing them. This applies mainly to playback rooms, though I could see a situation where reflections could be intentionally aimed away from distant microphones in a studio's live room. To answer the main question, if a listening room gets small in the rear, reflected sound will have a sort of megaphone effect as it comes back to your ears. But if the rear wall is larger, the direct sound spreads out (gets weaker) as it travels toward the rear and has less energy per square foot when it reaches the wall. Then again, the reflected sound will narrow again and get stronger, so my last point might be wrong. I'll be interested in hearing opinions or ideas from others about this. --Ethan
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Post by Ethan Winer on Mar 17, 2016 17:41:10 GMT
Yeah, this is a tough room for sure. I'd set up the speakers in front of the wall on the left in your drawing, so the window is in front of you while you sit and listen. I realize the door is then also in front of you, but this orientation gives the best bass response because the rear is farther away. A room should get higher and wider in the rear, but that's less important than having more length front to back. You definitely do not need to build a new wall. Put that effort and expensive into more bass traps. As for the bass traps, rectangle rooms have 12 corners and all are viable. If you'd rather not have traps in all of the wall-floor corners, at least put them in the wall-wall and wall-ceiling corners where possible. It doesn't matter if a corner is exactly 90 degrees. You'll still benefit greatly from large thick bass traps. Bass traps don't have to be symmetrical left and right. If you need to treat one corner differently due to a door, you can still straddle the other corner as usual. --Ethan
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Post by Ethan Winer on Mar 17, 2016 17:30:18 GMT
If you used a QRD calculator then I have to assume the math is correct. I know of two good ones: QRDudeAcoustic CalculatorAs for tolerances, I honestly don't know for sure. I ASSume being off by 1/4 inch is not a good idea. I'd aim to keep things within 1/16th inch, which isn't really that difficult. --Ethan
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Post by Ethan Winer on Mar 17, 2016 17:27:56 GMT
Thanks to hexspa who has been contributing a lot of good advice all over this forum. I'll just add that if you have "a ton of foam" you can make it work better two ways:
* Double up the panels (face to face) to make them twice as thick which absorbs to one octave lower.
* Panels that are already 2 inches thick or more can be improved by mounting them backwards. That is, you put the sculpted side against the wall with the flat side toward the room. That puts more of the absorbing "mass" away from the wall where it absorbs better.
--Ethan
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Post by Ethan Winer on Mar 17, 2016 17:11:52 GMT
Yes!
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Post by Ethan Winer on Mar 17, 2016 17:11:11 GMT
I never tested this so I'm only guessing, but I imagine this is pretty close anyway. I'll estimate that filling the corner behind a 4-inch thick panel increases absorption by 15-25 percent. Obviously, if you use a thin panel, filling the corner increases absorption more because there was so little to start with. But filling the corner requires about twice as much material. So when cost is a factor, it's better to have twice as many corners treated with 4-inch panels than half as many filled solid. I proved that in my Density Report article that shows twelve 3-inch traps doing a better job than six 6-inch traps. --Ethan
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Post by Ethan Winer on Mar 16, 2016 17:54:04 GMT
At the top of my article Build a Better Bass Trap I explain that for most home-size rooms, rigid fiberglass bass traps are better: Even for larger rooms, fiberglass bass traps are almost always a better choice. --Ethan
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Post by Ethan Winer on Mar 16, 2016 17:50:09 GMT
I believe many FM synthesizers actually use Phase Modulation, which is very similar to FM. In all honesty, I'm not sure what the advantages and disadvantages are of each method. I Googled: fm vs pm modulation but most of the hits were technical with a lot of math. I'll guess PM and FM sound more or less the same, but PM is easier to implement? As for microphones, today you can get good ones for a lot less than we paid back in the 1970s and 1980s. If I were to buy a microphone today I'd choose a known-good brand such as audio technica and buy based mostly on price. You say you have my Audio Expert book. The section "Microphone Types and Methods" explains that omni-directional small diaphragm condenser models are the flattest, but large diaphragm condensers have more fullness (proximity effect) when you sing close up. If it helps, I recorded all 37 cello parts in my video A Cello Rondo using only an audio technica 4033. And for my Tele-Vision video I used only a DPA 4090 for everything. I don't know anything about K-metering other than that it exists. --Ethan
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Post by Ethan Winer on Mar 15, 2016 19:43:49 GMT
Your speakers are in a good place, so leave them there.
Putting thick absorbers at the side-wall reflection panels is a good start, but you need more than that for best results.
As for FRK, you can use spray glue to attach thick paper to 703, and that works well to increase bass absorption. The type of paper they use to make grocery bags is ideal.
Your room is a good size, and I'd add at least eight 2x4 foot corner bass traps in addition to the reflection panels. Even 20 bass traps would not be too many. Of course, you can add more over time if you don't want to spend that much all at once.
--Ethan
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Post by Ethan Winer on Mar 14, 2016 19:10:48 GMT
I just realize I answered only half of your question. In a home theater or hi-fi setup, a receiver splits the audio between the main two (or five) speakers and a subwoofer. You can use a receiver in a stereo-only studio setting too. But most subs include a crossover that accepts the full-range main input signal, then keeps the bass and sends the rest on to the left and right speakers. So you don't really need a receiver unless you plan to play 5.1 surround audio. Looking at this Focal sub at B&H it seems to do that, though I can't tell if the crossover frequency is variable: www.bhphotovideo.com/c/product/687636-REG/Focal_Professional_FOPRO_CMSSUB_CMS_SUB_300W_11.htmlThe standard crossover frequency is 80 Hz, though you can go as high as 100 Hz to relieve even more of the burden from the main speakers and move it to the sub. So that Focal sub probably uses one of those frequencies. But either way, the sub provides the crossover, so it still doesn't matter what brands you use. --Ethan
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Subs
Mar 14, 2016 18:31:12 GMT
Post by Ethan Winer on Mar 14, 2016 18:31:12 GMT
No, it's not true that you need to match the brand of the subwoofer to the brand of main speakers. I have Mackie 624 speakers in my home theater, and they're coupled with a killer SVS subwoofer with twin 12s that's -3 dB at 18 Hz. This combination is fabulous. But if I had different model main speakers I'd still be very satisfied with this sub. And if I had the same speakers with another highly capable sub, that would be fine too. If you care, here's a recent tour of my living room setup: Ethan's Living Room Home Theater Tour--Ethan
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Post by Ethan Winer on Mar 13, 2016 17:25:02 GMT
Thickness does matter, but one layer of standard wall material should be fine.
--Ethan
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