Building a new Drum Room

Discussion in 'Acoustics (Live Room, ISO Booths)' started by Jason Morris, Mar 19, 2018.

  • AT5047

    The New AT5047 Premier Studio Microphone Purity Transformed

  1. kmetal

    kmetal Kyle P. Gushue Well-Known Member

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    Just fyi it doesnt matter which leaf you add mass to, as long as their different. Not sure if the outer leaf is more acessable than the inner leaf.

    Nothing looks crazy on the graph. Good luck with the wall section build.
     
  2. Jason Morris

    Jason Morris Active Member

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    Thanks!

    Was just considering something... My current plan for the next set of silencers (inlet) is to mount each to the leaf they are servicing and coupling them together with thick neoprene rubber.
    Last time I was able to mount the silencer servicing the inner leaf to concrete. This time I think it will have to be attached to the studs of my inner wall and/or ceiling.
    I "think" thats ok, since it's technically supposed to be part of that leaf.. but considering the inside-out design, the silencer will be 3 1/2" from the inner leaf sheathing. I guess this is adding another leaf?
    I wonder if thats going to be problematic.

    I wonder if it would be better to just use a single silencer on the oustide leaf with a big beefy duct that penetrates both leaves. Of course they would be caulked to high heaven, and would not be in physical contact with the inner leaf.. but I dunno. One way I am using half as many silencers, and the other way I am introducing another leaf, even though it is pretty small comparatively.

    what you think?
     
  3. kmetal

    kmetal Kyle P. Gushue Well-Known Member

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    Im having a bit of a hard time visualizing this. If you couple things id be certain to use a qualified iso bracket. The risc clips from pac international have variations of clips and diagrams for mounting all sorts of stuff. Garage door openers, ducting ect.

    In the book theres a diagram of an "exhange chamber" where ducting penetrates both leaves. Id try to follow that as closesly as possible.

    I know rod mentioned at one point that the powerstation actually had a couple areas of 3 leafs cuz they couldn't get around it any other way. He said you live with what you have to.


    Still cant picture the 3rd leaf mentally. But it seems to me it would be better to avoid it if you can simply keep the air flow quiet without resorting to the third leaf.

    Is it possible to mount the stuff on the concrete wall near the garage entry area? Or ceiling with iso mounts?

    I appologize i dont have grear answers in the hvac area, im gonna have to pony up and learn that area much better.

    One thing that comes to mind is if your planning on more ducting or whatever for the new ac, maybe this is more reason to try not initially adding a third leaf right away.

    To be honest, im sure sure that a third leaf always reduces isolation, or if its just much worse than a two leaf of similar mass. Maybe it varies case by case.

    Just fyi- if im MIA the next couple days its cuz ive some stuff to handle over here. Ill check in often as possible.
     
  4. Jason Morris

    Jason Morris Active Member

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    For the silencer on the outer leaf I can do that. For the inner leaf, I cannot.
    I know on the Johnsayers website the typical way of doing silencers these days is to have one silencer for each penetration.. so one on the inner and one on the outer leaf.
    It IS possible to do a single silencer on the outer leaf, but apparently, you don't get as much isolation that way.
    I've been trying to do whatever I can to get the best isolation possible, so I have operated on the assumption that I will do two silencers.

    In any case, we didnt get that far last night. We built a new wall, and I got one layer of drywall on it.
    Just doing that did seem to help the low-frequency isolation.
    The 30hz buzz is about 2 db less than it was. Hopefully, things will be even better after I get another 2 layers of drywall up.
    I also ordered some ISO pads for my AC unit. right now it is sitting right on the concrete pad. If that improves things another 1-2db I should be in pretty good shape. (hopefully)

    We also got the wiggly wall framed. That's looking pretty good.
    Plans for this weekend are putting in some lighting and running another 1 or 2 electrical outlets along that wiggly wall.
    Then maybe experimenting with different types of insulation for bass trapping. :)

    I hope the stuff you have to handle isn't too unpleasant! Thanks again for your advice!
     
  5. kmetal

    kmetal Kyle P. Gushue Well-Known Member

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    If thats the accepted method by Sayers or Stewart, or people as reliable, i dont see any issue with it. Ive not looked into silencers and their application so im flying blind in that realm. Got more to learn.

    Im not sure if iso mount brackets are necessary or not for the silencers, but id check.

    Nice! 2db at such a low frequency is not shabby. It will be interesting to see how the other layers add to the isolation.

    Nice. I hope that solves it. I think the next step would be isolation products for the lines, or for the mounting hardware connected to the house.

    Starting to get closer to the fun parts. Id consider at least 2 outlets. Its way easier put them in now.

    No prob, this build has been enjoyable to watch. Fortunately im just clearing stuff out for the water meter installer, so nothing to crazy over here.
     
  6. Jason Morris

    Jason Morris Active Member

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    Busy weekend. Got the electric for the wiggly wall run, and put up some track lighting.
    Framed three corner traps, as well as much of the ceiling to wall corner traps.

    Im using the fluffy pink stuff in the traps. R-30. I'm not sure if I am packing them too full or not?
     

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  7. kmetal

    kmetal Kyle P. Gushue Well-Known Member

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    Looking good man. Im itchy just from the pics. I bet it sounds drastically different in there.

    The ideal is the insulation has no compression.

    It looks like you peeled the kraft paper off, is that what you did?
     
  8. Jason Morris

    Jason Morris Active Member

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    There is some compression. tough it get it in those weird shaped areas without compressing it some.

    I did peel off the Kraft paper,. yes.
     
  9. kmetal

    kmetal Kyle P. Gushue Well-Known Member

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    Yeah that's one of those differences between the lab/paper plans, and the real world. Nothing id worry about.
     
  10. Jason Morris

    Jason Morris Active Member

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    awesome!
    So, I'm thinking of fabric next.. Trying to decide if I want to just go to the fabric store and buy burlap or just get the Guilford of main stuff.

    Anyone have any idea how the quality of the Guilford of Main SONA stuff is? is it basically just fire-rated burlap?
     
  11. kmetal

    kmetal Kyle P. Gushue Well-Known Member

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    Im not sure if it was SONA but we used Guilford fabric at the wave cave. Yes its just fire treated burlap, but, it is a high quality burlap. The burlap from the fabric store is sorta stringy, and fuzzy, and generally cheap feeling and looking.

    I used a type called muslin for my home studio panels and was happy with it. I also was happy with cheap burlap behind the slat resonators.

    At Normandy (Tony the owner) just picked out some fabrics he liked at a local discount fabric shop. He made sure they were breathable.

    The one area worth mentioning is fire treatment. You can get fire treatment spray online, and you have to treat both sides of the fabric. Its cheaper to diy the spray than get pre treated fabric.

    The reason i mention fire treatment is because it can void your insurance policy if there is not properly treated fabric, and you ever have to make an insurance claim. Insurance companies salivate at these opportunities to not cover the cleint.
     
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  12. Jason Morris

    Jason Morris Active Member

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    maybe I will just get regular burlap (or some other breathable fabric) and spray it.
     
  13. Jason Morris

    Jason Morris Active Member

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    So, after doing 3 corner traps and about 40% of the ceiling-to-wall corner traps I decided to take a REW measurement to see (visually) what the trapping was doing.
    I don't really know what I am looking at, but it seems to be doing SOMETHING. :D

    I included the new REW graphs at 10-22k AND 10-500hz.. Not sure if the 10-500hz is really useful or not, but thought zooming in to see more detail at the lower end of things might be handy.

    I also included the overlay of the room before I did the corner traps.

    What you think?
     

    Attached Files:

  14. Jason Morris

    Jason Morris Active Member

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    Here are a couple of waterfalls I created.

    I don't really know exactly what I am looking at, but I think they are showing things cleaned up quite a bit in the low end, and also the decay times in the meds and highs have been shortened quite a bit.
    Which is to be expected with all that insulation I have on the walls.

    Pretty remarkable difference in the low end though.
     

    Attached Files:

  15. pcrecord

    pcrecord Quality recording seeker ! Well-Known Member

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    Yeah, that 80hz would have hurt your mixes.. Good for you !
     
  16. kmetal

    kmetal Kyle P. Gushue Well-Known Member

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    It looks like an improvement. The waterfalls show some lingering decays at 50hz and below, and the octave above it, 100hz.

    On the impulse charts the dip at 60hz is a concern since the kick drums center frequency is usually between 40-60hz.

    If you tune your resonators to 80hz you should get some improvement at 60hz and 100hz as well. This should smooth things out well for your kit. The lingering junk below 50hz would really be tough to attack due to space limitations of the room. Most stuff below 40hz gets cut out anyway with a hpf during tracking or mixing, so i wouldn't be overly concerned.

    Overall things look good to me. Its nice to not see any nasty peaks in the liw mids or odd rings in the upper spectrum. And the decay is pretty uniform throughout the useful range.

    Since this is a tracking room you can manipulate the sound with drum and mic location. If the 60hz is still a problem after you add slats (if your planning to) then you can always make a tuned panel trap to hit the 60hz band exclusively.

    Overall things seem to be shaping up nicely. One thing phil (greene) told me when using frequency sweeps, was to sweep from low to high to test the mids and highs, and high to low for testing the bass.

    Hows the isolation? Any better with the new wall and insulation?
     
  17. Jason Morris

    Jason Morris Active Member

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    Yeah, hopefully the stuff around 100 will be tamed some more when I finish with the bass trapping. I only have about half the ceiling-to-wall corner traps done, so there is still room for improvment.

    I was not real hopeful that I could do much to deal with stuff that low. I just dont have enough space in my room to build traps that would deal with those frequencies.

    not sure what you mean? When Im taking measurements I should go from both high to low and low-to-high? Average them after? or keep them separate?

    It is marginally better. When the AC is running I am getting around 44-46db in the drum room. When the AC is off, it's closer to 40 (C-weighted) or 32 A-weighted.
    But most importantly, the wife is thrilled with how quiet the drum kit is in there. What little she can hear of the kick drum is drowned out by the ceiling fan.


    On another note.. I experimented today. I know you said that fluffy insulation was better for corner traps.
    I had installed fluffy insulation in my corner and ceiling-to-wall traps. I pulled the insulation from the ceiling to wall traps, and put in mineral wool and did another measurement.

    I'm not completely sure, but it looks marginally better in the VERY low end (smoother) but the null at 60hz is a little worse.
    So I think you are right. Im . going to put the fluffy stuff back. I attached a graph showing the mineral wool vs the fluffy stuff.
    Fluffy is green, and mineral wool is blue.

    But the more interesting thing is the waterfall. Look at what it did to the frequencies at 112 hz!

    I cant say I know for sure what I am looking at, but it is fun trying to figure it out!
    :D
     

    Attached Files:

  18. kmetal

    kmetal Kyle P. Gushue Well-Known Member

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    Not being an expert on chart reading, it appears that the waterfall shows the fluffy better, and the impulse shows the the mineral wool better. As you stated. Maybe the better decay is due to less density of the insulation, allowing more sound to scoot around in there, or more paths for the sound to get lost in.

    Its interesting how close they are. I would estimate that the limp mineral wool measures in between rigid fiberglass and fluffy in this application.

    I wish someone would write a book on acoustic testing, its amazing how all the standard 'must reads' on studio building and design, dont cover this topic to any great degree, if even at all.

    Glad to hear your isolation has improved. 6db is very respectable at such low frequencies. It will be nice to play drums free of noise concerns im sure!!

    Keep them seperate. When testing lows, use a sweep that goes from high frequencies down to low. Do the opposite for testing highs.

    I didnt ask why, but i assume it gives the lows more time and energy to build up, as the sweep runs from high to low. I also didn't ask who told phil that either. Over the years hes had some greats thru normandy like George Augsburger. He used to pay a tech to tune his room annually and eventually the tech showed him the process. Phils not always right (despite whay he may think), but he is usually right. Either way it might be worth trying to see if the results vary based on the sweep.
     
  19. Jason Morris

    Jason Morris Active Member

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    I'm glad you saw the same thing I was seeing. Makes me feel like I am at least on the right track. Maybe two non-experts equals one apprentice?

    Yep. I'm still going to try to work on getting the AC quieter. I have a crap ton of duct insulation.. I bought a whole roll of it!
    Im going to using that to quiet things down a bit. And I have to open the wall where the AC lines are coming in in order to do some non-studio related repairs, so maybe when I do that I can dampen the vibration of the AC lines in the house.

    I will try that later tonight. planning to do some more building this weekend.
     
  20. kmetal

    kmetal Kyle P. Gushue Well-Known Member

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    So two non-experts walk into a bar one day...

    ;)

    Nice. Have you used the iso mount pads yet for the unit?
     
  • AT5047

    The New AT5047 Premier Studio Microphone Purity Transformed

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