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Post by rock on Sept 12, 2016 13:10:03 GMT
Hi Trdat,
I think you may have missed my point. I did not want to specify a particular RT60. I believe that is subjective (to a point). I merely intended to point you in a direction by showing you a link to the PDF. It is not the "Bible", but one of many resources. My intention was to simply state that "liveness" is a factor that will be present to some degree until you have total anechoic absorption (which I am not suggesting either).
Again, I agree that bass corner traps (all 12 corners) and RFZ panels are the first to tackle and the RT60 will follow. I do think measurements will reveal the finer details but are not absolutely necessary. So I think you're on the right track!
Cheers, Rock
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Post by Hexspa on Sept 13, 2016 5:22:49 GMT
Yes.
Remember trdat - you can always take panels out! The hard part is buying the stuff and putting it in! I sincerely doubt you can go overboard - especially once you get used to them. Good work going with the 6" - they're going to be monsters.
Lastly, the only difference between "bass traps" and "RFZ" (when dealing with broadband absorption - which 8lb mineral wool is) is placement! Please don't say "unfortunately rear wall." You'll be so glad you did it. Besides, why not be grateful for this amazing opportunity to maximize your listening environment?
No need to rush understanding; one idea, one step at a time.
Congrats,
-m
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Post by rock on Sept 13, 2016 16:34:16 GMT
Lastly, the only difference between "bass traps" and "RFZ" (when dealing with broadband absorption - which 8lb mineral wool is) is placement! -m I think I know what you mean by saying "broadband absorption" but just to be clear for Trdat: Corner bass traps with a paper, plastic or foil attached facing the room ARE different in that regard as the RFZs will NOT have the facing material which improves bass absorption of the corners traps at the expense of mid and high absorption. And to be even clearer if not totally redundant: For the RFZs you primarily WANT absorption at hi and mid frequencies so don't put facing on them. Cheers, Rock
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Trdat
Junior Member
Posts: 78
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Post by Trdat on Sept 15, 2016 15:20:45 GMT
Two (hopefully quick) questions guys.
1. Front wall bass trapping. Apologize for being pedantic but I can fit two 100cm bass traps from about 60cm of the floor. This option I have a bass trap straddling the corner directly behind speaker but it will be tight and can only get in 4inches in. The second option is to put on 100cm trap just above where the speaker goes but I should get 6 inches as I will have more room for straddling this will be centered between floor and ceiling.
My question is, having a panel beside or close(not directly behind, the panel will be straddling corner but just falls just beside the speaker very close to it) the speaker have any advantage?
2. Side wall Reflections. I have 100cm traps in length and would like to know the optimum position to cover the reflection free zone in terms of height to speaker. Meaning what part of the 100cm panel should cover what part of the speaker.
Does the bottom of the panel match the bottom of the woofer height? Or is the panel exactly centered so that the woofer and tweeter is in the middle of panel when placing it on the wall? I see different variations on pictures and cant decide.
Regards
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Post by rock on Sept 15, 2016 21:23:15 GMT
1. A picture is worth a thousand words (hint). I'm not able to visualize the details of you set-up but if the panels straddle the corner you should be fine. Corner bass traps are for the room, not the speaker so I don't know what your problem with the speaker is. For best results, they should go floor to ceiling. Is that what you a doing or are you only using one 2'x4' in each corner? Use 2 2x4 panels in each corner, one above the other and fit them across the corner the best you can. If you can't go across (straddle) the corner (like if there's a door), you can use 2 in an "L" configuration but to go floor to ceiling like that, you need 4 panels.
2. If there a a huge distance (like 3 feet) between your speaker's woofer and tweeter, you should probably center on the tweeter. But if you have more typical monitors, using a point between the woofer and the tweeter should be fine. You did not mention the size (h x w) of your RFZ panel (back to the picture thing), but if you want insurance that your RFZ is treated properly, use a bigger panel (2 2x4 next to each other 4'x4' or if height is an issue 3 2x4 on their sides for 4'x6), that way you don't have to worry about inches one way or the other.
Cheers, Rock
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Post by Hexspa on Sept 16, 2016 4:19:04 GMT
Your speaker is designed to have an acoustic center. That may or may not be your tweeter but it probably is. Consult your manual. Your ears, and by extension your RFZ panels, should all be parallel to that point.
You said you were going to watch my videos! I think I covered all your questions about treatment placement.
Having absorption behind and beside the speakers is good as long as that absorption is thick - it helps minimize boundary interference in the lower frequencies.
-m
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Trdat
Junior Member
Posts: 78
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Post by Trdat on Nov 2, 2016 6:46:42 GMT
Dear Hexpa, Rock, Ethan and other participants. Hexpa I have basically followed all instructions and finished my DIY's. I have attached photo's as the room actually looks aesthetically pleasing. I've done well with one major mistake. The issue is I still have a lively room. I did not intentionally aim to get the room lively as per your recommendations no FRK on RFZ. But unfortunately, the fabric used is not as transparent as the fabric on my ATS panel that I have. In another post, Ethan mentioned the talk test to determine if it is reflecting highs. According to the test I believe some highs are reflecting, you can hear a difference but not much. If the FRK panel is reflecting highs at 85% while foam is 25% and my ATS panel around 30% I feel my DIY panels are about 50%. So I'm not sure if that is cause for concern, I need to narrow down if the liveliness is from RFZ or just overall? Probably a bit of both... My question is obviously what are your recommendations? Unfortunately, I really can't move panels around... 1. I'm thinking to add a throw rug on the floor to stop reflection from that point. 2. Perhaps some foam panels for side RFZ points and for where the two frames meet. 3. Obviously adding more panels to get more of a balance out of room. But I suppose I need to use better fabric to absorb more high in the room as the liveliness is due to the poorly chosen fabric. In a nutshell, I used 100kg/m3 mineral wool for panels. Corner bass traps have 703 FRK for the first two inch All over is 4 inches with ceiling panel with a good 20cm gap. The chocolate panels are ATS cotton panel they are on reflection points but unfortunately it meets the DIY(cream color) panel with the wood frame near the reflection point you'll see in picture. So don't really have that large RFZ zone as i originally intended. I have approximately 20 panels but in a previous post here it was mentioned that I should technically cover as much as I can.
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Post by Hexspa on Nov 2, 2016 10:20:32 GMT
Looks amazing.
I doubt you want to reupholster the panels.
The only way to know what you have is to measure (REQ etc).
You can either be happy with what you have or modify by changing fabric, adding more panels or both.
I wouldn't throw foam up in a room like that if for no other than aesthetic concerns.
You could use a rug but having one reflective surface between you and your speakers isn't bad.
Keep it simple - fabric, panels, placement.
Thanks,
-m
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Post by rock on Nov 2, 2016 11:52:03 GMT
Yeah, really looks great! But yeah, if the panels don't pass the "talk test" that is going to compromise the RFZ and contribute to the liveliness. But you did such a nice job on the finish, it would be a shame to do all that over again.
Putting down a rug is low hanging fruit so you should probably try that first. If you do that, use a felt carpet pad under it. Besides adding thickness for acoustics, it feels softer under foot.
Besides that, the one more place where you could knock down a bit more liveliness is above or "downstream" of your RFZ panels as there is probably some flutter between the parallel walls. If you do that, placing them on the side walls in line and/or above your listening might be the most effective. But again, looks great!
Cheers, Rock
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Trdat
Junior Member
Posts: 78
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Post by Trdat on Nov 2, 2016 13:48:27 GMT
Thank God the side panels are hooked on so I can take them off and potentially reupholster the panels, thanks for that idea Hexpa it was simple but I didn't think of that. And I can do when I make more DIY panels for bass trapping for the back of the room. I can use the nice cream color for bass trapping(potentially reflecting some high) and purchase the exact same chocolate color fabric from ATS to match the chocolate colored ATS panels at the front. But reupholstering the side panels and adding that cheap look of the Burlap fabric(ATS fabric) won't look as good and it might just aesthetically look just as average if I add foam panels at those points. I say this because I do have foam panels which look pretty good downstream where Rock mentioned(attached photos). So if foam panels will do the trick let me know? I can consider both!! But I understand reupholstering could not just help RFZ zone but help with overall liveliness as those panels are massive as you have seen. So I'm presuming be patient and reupholster much better option. I won't reupholster the ceiling panel. But in the meantime, I can do some testing, get a real understanding if the difference is worth the reupholster. Now need to knuckle down and study how to use Room Wizard. And one weird question does the wood where both frames meet at a RFZ point cause any issues or not much to worry about? I ask this so I can consider the foam option if it is an issue but if it's minimal I could reupholster and not worry about the wood frame. I am interested in getting throw rug, I need one anyway already reaching minus 6. Adding some thickness underneath the rug is easy but I might as well purchase something that will absorb the highs well, and there is a range of materials for rugs. What do you recommend for the rug material to compromise of? Would those cheap colorful 100% polyester rugs do the trick? Thanks guys. I also have attached another photo of my obstacle a door at front of room, I'm presuming that could affect liveliness as well. But not much I can do here so I will work on the above. Anyway appreciated again. I think a bit more work and it will be great. Attachments:
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Post by Hexspa on Nov 3, 2016 23:45:15 GMT
The ideal scenario is probably to have the dead center of the panel mirrored to your speakers' acoustic center. Barring that, depending on the width of the frame, I can't imagine it being a huge deal. But, if you have foam, why not temporarily affix it there and do a listening/measuring test? We know Ethan favors empiricism so shall we not follow his lead?
REW is easy. Easier than making panels!
-m
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Post by rock on Nov 4, 2016 13:43:42 GMT
I don't know how different materials for rugs measure but in general, thicker is better i.e. more absorption at (relatively) lower frequencies. Polyester should be fine. If you search, you can probably find a chart comparing rug/floor coverings for acoustic properties if you really want to dig in. Minus 6? You mean C right? Wow, that's 21 F! (thanks google) Where do you live? Norway?
Cheers, Rock
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Post by rock on Nov 4, 2016 13:52:01 GMT
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Trdat
Junior Member
Posts: 78
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Post by Trdat on Nov 17, 2016 17:17:19 GMT
Hey Rock,
I'm from Australia, hence my use of Celsius but am living in Armenia, 1000 meters above sea level hot summers crazy winters. Lol. And probable only person with acoustic treatment in the country.
Anyway thanks for the links, they are a great help found some other info as well, the only issue is trying to understand what is considered an open back on the rug or a unsealed back? But I suppose if the pile is high and thick I wont need to put a layer underneath to increase absorption.
Still working on everything else, trying to get into REW and I am looking into reupholstering side panels at the very least.
Kindest Regards
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Post by rock on Nov 18, 2016 3:15:19 GMT
Hi trdat,
Nice to hear from you and glad to see you're moving ahead. Also very glad you mentioned your previous efforts with room treatment; "experience is the best teacher, and the worst experiences teach the best lessons" (unknown) Here's why I think you should measure your room with REW (free...free is good!)
Liveliness in rooms is normal, more or less. That's what we are used to hearing in our daily life in small rooms. When we step outside, we hear other cues that if form us of our environment there too, so the idea of placing absorbers in a small room is "unnatural" and it can sound "weird" if we expect to hear a room that we are otherwise used to.
Before I go any farther, I don't think I remember what you are using your room for. Is it stereo or home theater listening? Is it monitoring for audio mixing? Is it for recording? For recording and (loud) rock band rehearsal, I find maximum absorption (deadness) very appealing; all instruments are easily acoustically located from any point in the room (because of lack of reflections) and as an added bonus, overall SPLs are reduced for the same reason...but this kind of treatment is very unnatural and some people don't like it. As far a the deadness of instruments is concerned, electronic reverb and delay is very easy to come by these days (Built into keyboards, mixers and gtr amps, pedals, outboard gear etc.) so there is no problem to adding "great" artificial acoustic space easily at will.
If you are either listening or mixing, maximum deadness may or may not be what you are expecting since most rooms are not maximumly absorbent which bring me back to RT60 measurements (LF peaks and dips are very important too). After you get used to using the measurement software (Please take the time to learn to use it, it's just a matter of set up and getting your head around some concepts) you can easily measure modal ringing and RT60 and other aspects of your room acoustics as you install your panels and you'll be able to correlate your measurement graphs with what you are hearing as you go along to either confirm or refute any treatment "moves" you make. (talk about run on sentences! yikes!)
Cheers, Rock
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