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Post by ultrasonic on May 25, 2019 13:47:57 GMT
I've now finished the free-standing panel that blocks the view of the garden (attached). I've deliberately left the wood on show on this one for now as I quite liked the look but the photo gives an idea of what at least for most I think would be an aesthetic compromise. The panel is (deliberately) easy to move out of the way if/when I want to though. I'm pleased with how this turned out actually, as it's the first bit of 'furniture' I've made since making a not particularly brilliant chair at school getting on for 25 years ago! Attachments:
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Post by Hexspa on May 26, 2019 6:56:51 GMT
Again I'm going to disagree about something: aesthetics. On the contrary, acoustic treatment makes the place more aesthetic. We tend to get hung up on a room's visual appeal but few realize how much of a qualitative improvement acoustic treatment creates. You can go so far as to hide the panels behind a false wall - probably wouldn't even cost that much. Aesthetics are a personal thing, but I know for absolute certain that if I currently had a female partner (I'm a single guy) the chances of trying what I am right now would be negligible! One first reflection point panel will sit bang in the middle of the patio doors going out to the garden for example. I've got another propped up in the corner now it's covered and it's looking pretty big/imposing to be honest, but I'll see how it goes.This is my point of contention right here - that you want to optimize the treatment and save money but not perform comparative testing. You've misunderstood me there. I will be doing a lot of testing to investigate the effects of the panels I make. What I'm not going to do is to start making and dismantling panels to test out sticking paper on the back of them or not. I have spent a considerable amount of time making measurements to optimise my current setup, including optimising the sub optimisation. On HiFi forums where I also post I suspect I'm very much thought of as a 'measurement guy'! The only thing is that these are your first six panels and that's why I advise you, or anyone in your position, to keep it along the well-trodden path, enjoy the results and forget the last 20% of the details. I'm actually making twelve panels: six for first reflection points and six as bass absorbers. Or at least that's what I have the materials for and what I was planning to. Now I've got a couple of them in my room I'm worried that 12 may be a bit much! The panel looks good, by the way. I think a semi-thick fabric with the hem folded behind would look awesome and you could cover the thin edges with some black mesh. It would truly come as a surprise to me if you built these, installed them, came to appreciate the difference they make only to get rid of them. Thanks. For initial testing I've gone for the cheapest acoustically transparent material I could find, which is some white voile (net curtain material). If I keep them long term I'll then invest in some decent looking fabric, and I'd be doing this as part of redecorating the whole room so I'd decide on colour(s) then. I'm certainly hoping at least some of them will stay long term given the effort involved, but I'm trying to keep an open mind. Roger that. My dear female companion has been living with 'insulation obstacles' for about 10 years now. Perhaps it's a limiting belief to think that good women don't like good sound or support their partner's passions. Look at Ethan's wife!
Welp, no fear or judgement of measurements here. My panels still don't have FRK but my super chunks do. I really feel that FRK makes a significant impact though I haven't A/B measured. Maybe what I'm suggesting is to not FRK all your panels and maybe apply it once you upgrade your fabric - I also upgraded my fabric after about 7 years.
In my opinion it is never too much but, of course, we all have our comfort zones and unique needs and wants. I'm glad you're making 12, are they 4", since I was thinking about this before I went to bed. If you were just making 6 then I'd say just do a RFZ and forget about the bass for now.
An open mind never hurts.
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Post by Hexspa on May 26, 2019 7:01:45 GMT
I've now finished the free-standing panel that blocks the view of the garden (attached). I've deliberately left the wood on show on this one for now as I quite liked the look but the photo gives an idea of what at least for most I think would be an aesthetic compromise. The panel is (deliberately) easy to move out of the way if/when I want to though. I'm pleased with how this turned out actually, as it's the first bit of 'furniture' I've made since making a not particularly brilliant chair at school getting on for 25 years ago! Looks great. The garden will be an excuse to go outside.
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Post by ultrasonic on May 26, 2019 7:03:59 GMT
For likely amusement, here's what I measure for my right speaker run full-range on its own, showing the dominant 36 Hz peak: Just before Easter I added a subwoofer which I have integrated with my main speakers using a miniDSP 2x4 HD. This provides a crossover between the sub and main speakers ( currently at 120 Hz), time delay adjustment to get good phase matching in the crossover region, and I also use it to provide parametric EQ to the subwoofer signal (the mains only have the HP crossover applied). With this I achieved the following: (Both graphs have 1/48th octave smoothing applied.) The full frequency range comparison looks like this (grey is main speaker alone and red is the main + sub combination):
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Post by ultrasonic on May 26, 2019 7:05:19 GMT
The left channel looks a bit different due to the layout asymmetry:
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Post by ultrasonic on May 26, 2019 7:13:35 GMT
Welp, no fear or judgement of measurements here. My panels still don't have FRK but my super chunks do. I really feel that FRK makes a significant impact though I haven't A/B measured. Maybe what I'm suggesting is to not FRK all your panels and maybe apply it once you upgrade your fabric - I also upgraded my fabric after about 7 years. In my opinion it is never too much but, of course, we all have our comfort zones and unique needs and wants. I'm glad you're making 12, are they 4", since I was thinking about this before I went to bed. If you were just making 6 then I'd say just do a RFZ and forget about the bass for now. [/quote] The FRK is already on the panels. I felt I wanted a reflective layer on the front the the bass-trap panels to avoid the room becoming too dead sounding, since the RFZ panels alone will cover a fair proportion of the exposed wall area in my small room. Plus of course it should help a little with low frequency absorption. (I know you'll be wanting to say I should measure experiment re. how live/dead the room sounds but this was my thinking.) The panels are all 4".
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Post by Hexspa on May 26, 2019 7:15:24 GMT
36Hz room modes don't matter as much as what's above 63Hz or so. My room has a 41Hz mode but it hardly matters. If you can meet the targets even from 120Hz and up you'll be doing well but above 63Hz is the ideal focus. I take your point that higher frequency peaks are more problematic but the 36 Hz peak definitely is detrimentally noticeable on music. I'll post some comedy graphs of my untreated room response later. To piggy back off what I said before: keep the panels, sell the extra couch and make more panels. Ha! The couch you want me to sell hasn't actually been bought yet, but it will be . There are two battered old chairs in that location at the moment though. My room layout is very much dominated by getting a good AV layout, but I do need some seats for friends too . My choice to buy my current house was actually influenced by being able to get a layout as 'good' as I have. You'd be surprised how hard finding even this was (in a three bedroom house). 36Hz is definitely noticeable? What kind of peak are we talking? What does the peak sound like? 36Hz is definitely toward the bottom and not easy for me to pick out at apartment volumes under the context of unrelated music.
Yes, good layouts are way too hard to find.
EDIT: We're posting at the same time. I wrote this before you put your graphs.
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Post by Hexspa on May 26, 2019 7:23:10 GMT
Ya that's a big peak but, as you know, EQ handles that fine. Also, the Q is pretty wide so that can contribute to the audibility i.e. higher frequencies are more noticeable. If you're hearing any sub resonance at this point it's probably what's happening just below 50Hz or especially that one around 90Hz - though I wouldn't call 90Hz 'sub'. Your SPL is good but your decay can use some tidying below 100Hz; I aim for 20dB of decay within 150ms above 63Hz.
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Post by ultrasonic on May 26, 2019 7:25:40 GMT
Ya that's a big peak but, as you know, EQ handles that fine. If you're hearing any sub resonance at this point it's probably what's happening just below 50Hz or especially that one around 90Hz. Your SPL is good but your decay can use some tidying below 100Hz; I aim for 20dB of decay within 150ms above 63Hz. It was with the main speakers alone that it was noticeable, not with the sub and EQ in use.
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Post by Hexspa on May 26, 2019 7:26:50 GMT
Ya that's a big peak but, as you know, EQ handles that fine. If you're hearing any sub resonance at this point it's probably what's happening just below 50Hz or especially that one around 90Hz. Your SPL is good but your decay can use some tidying below 100Hz; I aim for 20dB of decay within 150ms above 63Hz. It was with the main speakers alone that it was noticeable, not with the sub and EQ in use. How were you noticing at 36Hz resonance with speakers that cross over at 120Hz?
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Post by ultrasonic on May 26, 2019 7:28:01 GMT
It was with the main speakers alone that it was noticeable, not with the sub and EQ in use. How were you noticing at 36Hz resonance with speakers that cross over at 120Hz? When running the speakers full-range (with no subwoofer).
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Post by ultrasonic on May 26, 2019 7:29:25 GMT
Oh, and I know the decay time could do with improving, which is why I'm experimenting with bass-trap panels .
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Post by Hexspa on May 26, 2019 7:34:19 GMT
How were you noticing at 36Hz resonance with speakers that cross over at 120Hz? When running the speakers full-range (with no subwoofer). I missed the part about them being full-range. Got it.
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Post by vengavelo on Sept 28, 2022 18:03:16 GMT
I hope it's not bad form to revive this thread. If so, I'm happy to start a new one.
I am making a corner bass trap. I have Roxul 80, unfaced. Can I spray-glue 1-mil aluminum foil to room face and accomplish the same thing? I'm only doing one 48x24 panel.
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Post by Ethan Winer on Sept 28, 2022 18:08:53 GMT
It's always better to start a new thread for a new topic. But the short answer is yes, though most people use thin plastic instead of aluminum foil.
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