Carpet or hardwood floor?

[migouel]

Dear Friend

I’m new here and I'm real happy to joint this real interesting group, I’m looking forward sharing my new studio design with you knowledgeable people.

Here is my first question,
I have start building my new studio in my basement the one that I have right now is way to small and needed room, I’m your one man studio but might be if space is adequate have some friend over for recording. I’m still in the design part of it even if I started I'm still open to any suggestion.
I will have rockwool insulation in 2 x 4 wood stud wall with resilient channels cover with ½ drywall, on the ceiling same insulation with a drop ceiling with sound proof tile.
My question is should I go with carpet or hardwood for flooring?

Thanks

Alain

[knightfly]

Alain, carpet has a pretty uneven absorption - it only absorbs highs, so we tend not to recommend it for much of anything in a studio. What you need is a room that absorbs all frequencies evenly, and not too much, or it ends up dead sounding. I usually recommend wood or concrete or vinyl floors, so other surfaces can be more evenly absorbed with various materials that work together to get even frequency response in the room without losing too much of the highs.

I'm not sure what you're calling "sound proof tile", because there isn't any such animal - people tend to call their products "sound proof" because it sells - the reality is, there are only varying degrees of sound ISOLATION.

If you're referring to the typical "acoustic tile" that's commonly used in drop ceilings, it's far from sound proof on its own. However, at least one "acoustics" company sells a ceiling panel for these grids that has the familiar "sound board" face, with a 5/8" or 3/4" gypsum board laminated to the back side to make a one piece insert.

I've not tried these, but it seems like it would be difficult to guarantee an air tight seal on every part of the ceiling grid, which is what it would take for this to be any kind of barrier... Steve

[migouel]

Thanks Steve for the reply and Yes the ceiling tile I’m referring to is the "sound board" face, with a 5/8" gypsum and laminated to the back side, I did used them in a “Clean Room” that I build for our testing lab at work and though this might do the trick for my studio.

So if I got your answer right I should go ahead with hardwood floor instead of carpet? I find this real interesting, I always though that carpet was better for sound controlling!

Alain

[knightfly]

Yeah, if you can get the tiles to seal well they should help isolation somewhat - not nearly as good as a multi-layer, properly built ceiling, but not bad. It would help to add several inches of rockwool insulation above the panels, if that's possible.

As to the carpet thing, I've found over the years that several things that seem like they should work well, don't work at all - and some things that you'd never think make any difference, will change the results a lot.

Here is an absoption chart for some different common materials - the range is from 0 to 1.0, 0 being perfect reflection and 1 being total absorption - note the figures for carpet (top item) are nearly zero at low frequencies, but fairly high at the higher ones. BTW, virtually ALL these charts only go from 125 hZ to 4 kHz - it's difficult to test beyond those values, so almost no one does...

http://www.saecollege.de/reference_mate ... 0Chart.htm

This should give you an idea of what the different materials act like... Steve

[tluke]

Steve, in answering Alain, you may have answered my query as well.

I'm getting from you then, that wood is preferrable over carpet as it is more reflective.

I'm assuming then that more reflective is 'better', as we can always dampen the sound later? Is that correct?

Okay, then let me ask you this:

i intend to put in a plywood floor in my 10 by 12' basement room, and was going to put either drywall or plywood on the walls (two of the four walls will be angled, to prevent parallel surfaces).

-Would you say plywood is preferrable to drywall for the walls?
Significantly???

-and my last question is this: i had thought of building on top of the existing floor, which i believe is slightly raised to start, off the cement with probably 2 by 4's, and plywood on top of that. What i had considered doing actually, was to essentially repeat this. That is, place two by fours laying down on their sides all around, and put a new course of plywood over that. I thought this hollow space of a few inches might give me some added depth and punch to the sound? Do you think?

I appreciate you reading this very much, and look forward to your reply. THank you Steve,

tristan luke

[knightfly]

"I'm assuming then that more reflective is 'better', as we can always dampen the sound later? Is that correct?" -

Yes, and no - wood has a more EVEN absorption, meaning that although it absorbs LESS, it has a more even response through the audible frequency band and so it COLORS the sound less.

"Would you say plywood is preferrable to drywall for the walls?
Significantly??? " -

Most people use drywall for walls, partly because it's about half the cost of plywood and partly because it gives much better STC due to the increased mass over plywood. However, basements have their own set of problems, such as moisture and mold, low headroom, solid concrete walls, etc - because of the solid concrete walls you will have more bass energy in the room - since this is an UNEVEN response, it will lie to you when you mix, causing "non-portable" mixes from your system. Basements also have their good things, such as (usually) less need for sound proofing (except for between upstairs and down) - which brings us to another possibility for your walls - Panel resonators.

One way around some of this extra bass would be to "furr out" your concrete walls with 2x4's, mounting rigid fiberglas insulation between them and away from the front edge by an inch or so, and mounting thinner plywood between some of the joists, thicker plywood between others, and drywall between otners. If this looks too wierd, you could put small cleats over the studs after each section was done, and stretch cloth over part of all of the wall .

1/8" plywood absorbs most at about 150 hZ when placed over a 3.5" deep cavity, 3/16" at about 125 hZ, 1/4" at about 110, 3/8" at about 90 hZ, and 1/2" at about 77 hZ - deepen the cavity, and the resonant frequency drops - 1/2" ply on a depth of 5.5" drops clear to 60 hZ.

If your isolation between upstairs and basement is in need of improvement, then the above idea probably isn't a good one - it would couple too much energy into the concrete, which would "flank" into the upstairs area and radiate into the upstairs rooms.

"i had thought of building on top of the existing floor, which i believe is slightly raised to start, off the cement with probably 2 by 4's, and plywood on top of that. What i had considered doing actually, was to essentially repeat this. That is, place two by fours laying down on their sides all around, and put a new course of plywood over that. I thought this hollow space of a few inches might give me some added depth and punch to the sound? Do you think?" -

I wouldn't recommend this - double air spaces are not good designs for studios for the most part. You would probably be better off just adding another heavy layer of plywood, or if you need maximum isolation from upstairs you could add a soft board (like Homosote) layer and then another layer of plywood and then whatever floor surface. That would lower flanking noise through the concrete floor and into the concrete walls, finally ending up radiating from your upstair walls.

Let me know if any of this doesn't make sense yet... Steve

[tluke]

No, i think i'm getting it Steve, and it's very helpful. Thank you.

Okay, let me throw at you quickly what i'm planning to do now, and please let me know what you think.

-(tear up rug and clean plywood beneath) Put down layer of plywood over existing plywood for the floor.

-On the walls, use drywall. On two of the four walls, angle the plywood from left to right as suggested here, to prevent parallel surfaces.

-the ceiling now has a 'false' ceiling with tiles, which i hate, so i will tear down the false panels and skeletal metal framework which supports it, and put up drywall on the ceiling just like the walls.

How does this sound?

-just one question about the ceiling, i am considering placing some insulation in, which would sit behind the new drywall. This might help to isolate the recording room from the upstairs?


Thanks again so much Steve,


tristan luke

[knightfly]

Tristan, sounds good for the most part - On your ceilings, the amount of cost/effort you put in should depend on need, not "just because" - if you're expecting to play drums down there while a light sleeper snores away upstairs, then you need SERIOUS methods to get there. If you're just trying to lessen the sound to a level that won't be objectionable while someone upstairs is watching TV, then that's an easier project.

If you're playing really loud, say around 108 dB, and upstairs has the TV on, then 60 dB reduction between the two points would be enough. If you're playing not quite so loud (say around 95 dB) and someone is trying to sleep directly above you, 60 dB should STILL be enough. If you want to play loud AND have someone sleeping above, more like 70 dB would be desirable. I'm not sure I could reliably get you close to that amount of isolation if I were standing in the room with you, much less long-distance with only your eyes/ears to guide me. For one thing, you might not think to mention something that would catch my eye/ear, that was a serious problem.

Here is a post of mine copied from another thread on another board, that covers the what/why/where - it should answer most of your questions and possibly raise a few more -

This is a post I wrote on another board, it's easier than re-writing it all -

The least amount of ceiling height loss can be had for relatively cheap.

If you want good isolation from above, I would fit two layers of 5/8" sheet rock between each joist, using plenty of non-hardening, non-shrinking, either silicone or butyl caulk. If you can afford it, go for either Owens Corning or USG's Acoustic-rated caulk.

Retain these two layers with cleats fastened to the joists, up against the lower layer of sheet rock in each joist cavity. Caulk here too.

Place at least r-ll, preferably r-19 insulation between the joists and fasten as normal (staples)

Mount RC-1 Resilient Channel perpendicular to the joists, using at least 1-1/2" screws. Put the RC every 12".

Put masking tape or other removable markers on walls, or wherever they can be seen once the first layer of sheet rock is on the RC - these are your locators for screws for the second layer of sheet rock (and the first, for that matter) Also, put these markers on the OTHER two walls where the joists are - this is where you DO NOT put any screws when you're fastening the sheet rock - otherwise, you'll run the risk of "shorting out" the Resilient Channel. Not good.

These same markers can be used for reference so that you stagger screw placement in successive layers, so they don't collide and mess up the surface, etc - if you put one layer's screws offset 4" from the joist markers, put the next layer's screws offset by 8", etc...

All in all, put at least two layers of sheet rock on the channel - a layer of Celotex or similar between layers of sheet rock would be good too.

Be sure and put alternate layers oriented at right angles, to minimise crack bleed - caulk everything as you go.

This method, before any "cloud hangings", will only lower your ceiling about 1-3/4" with two layers of 5/8 sheet rock, or about 2-1/4" if you add a sandwich layer of 1/2" Celotex between.

It should give you at least 60 dB of isolation from/to above rooms, depending on the floor covering, etc.

Basic rule: if it won't float, it ain't soundproof.

Keep in mind here, that sound really is like water in a way, only even MORE intrusive - water generally only flows DOWN hill. So, if ANY part of your construction, old or new, lacks in any way, you won't see as much isolation as you thought you would. Things like flanking noise through structural supports/walls/nails, etc, poor seals around doors/windows, improperly caulked joints, EVERYTHING has to be done right in order for the isolation to be there... Steve

[tluke]

Thanks a lot for all the stuff on the ceiling regarding isolation Steve.

INterestingly, the guy who'll be doing the construction is my cousin, and he lives here, upstairs! So, i'm sure he'll appreciate your in depth attention to the issue of isolation.

I have till now coordinated my practicing and recording with the schedule of this house...which has worked okay...but since you posted this stuff i am reminded that i want to be as inobtrusive as possible, and the ability even to record like marimba or a reasonably quiet drum track with brushes at 12:30 AM would be wonderful.

Steve, let me get a little more, if i may, to the issue that brought me to you.

RIght now, practicing and playing (and thus recording) in that room is exceedingly uninspirational. This is because everything is so fucking dead. I can't stand it. I have played in a lot of rooms in the past year... and though too live would be a problem for recording i assume, when i'm not getting anything back i can't stand it. I just don't enjoy it.

I am guessing maybe it's the cement, as you said?, because you said that cement tend to absorb the low frequencies. And that is it... i can hear the tinny highs but... my bass drum is a (new) 22 by 18" DW maple instrument, and it is big and beautiful. I know there's a problem with the room when i don't like the sound of my kick.

So, my question to you is, if it is possible, what can i do (reasonably...if it can be done with sheetrock and a plywood floor that'd be great) to address this issue.

Allow me to describe the current state of the room to help you help me, if i may.

-It is about 10 by 12.
-2 of the 4 walls have cement directly behind them.
-A thin rug covers the floor. Beneath that is plywood, but it's old and no doubt moldy or whatever.
-the walls are lined with (ugh) that old from the fifties fake wood panelling.
-there's a false ceiling with the soft (and i assume possibly also a low end thief?) tiles.

So, as i said before, i intended to get some plywood and cover the old plywood...and am hoping that will help.

Then to either take off the fake wood paneling or cover it with new sheet rock.

And sheetrock the ceiling, taking out the paneling (and possibly getting more extensive based on what you said).


Should all this help me get some room in my room? Or will the cement walls always eat up the low energy and make me unhappy?

(I should mention lastly that my control room is in the basement also, but has sheetrock on the walls and that has some room in it, which makes me think this is not hopeless).

Thanks again very much Steve. Appreciate you sharing your valuable time and expertise.

[knightfly]

Tristan, it's going to take a bit to sort out what you've got and what you need, and unfortunately I have to get up at 4:20 AM for work tomorrow - I'll try to sort this out and get back to you tomorrow evening, although it will definitely NOT be a "one-post" solution... Steve

[knightfly]

Tristan, I just re-read my earlier posts, and have come to the conclusion that you're putting words in my mouth - my reference to concrete, "because of the solid concrete walls you will have more bass energy in the room" - does NOT mean that, as you put it, "you said that cement tend to absorb the low frequencies. " -

I'm not sure how you arrived at your conclusion, but it's exactly BACKWARDS from what I meant. When I said "you will have more bass energy in the room", I meant that the concrete does NOT absorb bass like flexible, framed walls do, so there will be MORE bass in the room, not less.

However, MORE isn't always BETTER, and it also doesn't mean EVENLY distributed - with little or no acoustic treatment in the room, you will experience serious peaks and nulls in Sound Pressure Levels at various 3-dimensional points within the room, and at different frequencies the peaks and nulls will also change, both in location and intensity.

What this means, is that without quite a bit of acoustic treatment in the room it will be very sensitive to location, in all three axes, of both mics and instruments.

One thing that COULD be robbing you of bass is - "the walls are lined with (ugh) that old from the fifties fake wood panelling" - if this is mounted on studs so that it can vibrate, then you have two walls of panel absorbers already built into your room, probably at around 125 hZ if the panels are 3/16" thick and on 2x4 studs. 125 hZ is a lot of where the "thump" lives for kick drum, so if that's being over-trapped it would seem like a bass loss.

If you could take your kick drum outside and have your cousin play it while you move your head around through likely mic placement locations relative to the drum, you will then know for sure whether the drum itself sounds good because this will take the room out of the equation and give you pretty close to a free field response. If you can't find a position relative to the drum that makes the drum sound good, then there's a good chance that the drum DOESN'T sound good, in which case it would need to be tuned differently. Here is the place to go for more info than you ever wanted on tuning drums -

http://www.drumweb.com/profsound.shtml

If the drum DOES sound good outside (hopefully NOT between two buildings with parallel outside walls) then your room isn't doing you any favors. In that case, you could try moving the drum around the room in small increments and looking for a sweet spot. It sounds to me like you may have the drum (or mic, or both) located in a null, otherwise known as a node - you may find that just by moving things around you will find a better location.

Your room has several modal frequencies that are very close to the natural resonant frequency of a 22" kick drum, which is about 308 hZ - so, it's possible that you may have the drum in a double node, one caused by length of the room and two being caused by the width.

Remember, when recording anything, if that instrument doesn't sound good to your ear at some location in the room, it won't sound good on a mic either. Try moving things around and experimenting to see what happens... Steve

[tluke]

Steve,

Thank you sincerely for your response to my post, and i appreciate that you are busy, and that this is a generous thing for you to do. That is: share your expertise.


I will try to be more consise, and still make myself clear.

Regarding the instrument(s): i'm a professional musician, a multi instrumentalist with a good deal of experience as a performer, as well as an instructor. Though this particular bass drum is only a year and a half old, i have used it in a variety of contexts musically, and a variety of rooms/halls. It sounds wonderful, for me. I'm certain that i'm quite satisfied with the sound of this instrument, and am quite capable of addressing issues with regard to tuning, changing heads, and muffling/opening the drum.

And, thank you for your suggestion regarding placement of the instrument in the room, i had experienced with that a lot actually...the best place i've found in fact, was about four feet out from a corner, pointing straight into it...but it is still quite'dead' and unsatisfactory.

So, once again, and more concisely, i want to liven this room. And, if you are willing, i would like you to tell me if i can make this room more live and roomy and less dead sounding by doing the following:

-taking down the fake wood paneling from the walls and replacing that with sheet rock (and angling the 2 of the 4 drywalls as you suggested)
-removing the rug from the floor, and installing new plywood over the existing plywood (for aesthetic reasons for one, also for sound?)
-removing the tiles from the ceiling, and drywalling that as well, possibly utilizing some or all of the measures you suggest to reduce sound pressure levels upstairs.

-In addition, i would like your suggestion if i may have it regarding:

-how thick plywood would you suggest i use on the floor?


I'll leave it at that for now, since you're obviously a busy man. And, thank you once again,


tristan luke

[knightfly]

Tristan, first let me say that if I seemed to be "talking down" to you that wasn't my intention at all. I get people who don't know much of anything, not because they're dumb but because they are inexperienced, and if I make the mistake of assuming they already know something I end up just confusing them more.

In your situation, that's now obviously NOT the case - it appears that you've already done most, if not all, the things I would do in your case short of construction. Now that I have a better idea of your background, hopefully we can stick to what ISN'T old news to you. Again, no slight intended, just trying to be thorough.

Your acoustic situation has me kind of confused though - other than the carpet, I would have thought your room would have a decent sound to it.

Would it be possible for you to post some kind of drawing of your room, complete with locations of any furniture, speakers, where you normally put the drum kit, and anything else you think might have an acoustic effect? This should include any construction details you're aware of (or even surmise) -

In the meantime, I've copied all your posts in this thread (along with my answers) and, on the off chance that all 125 acres of the industrial complex I work at doesn't need instrumentation help at the same time, may get a chance sometime tonight to read through your comments and "weed out" what could be causing the deadness you speak of. (Normally I would have been off duty two nights ago, but vacation coverage is mandatory with a 24/7/365 operation)

I'm hoping, though, that your drawing will shed some light because things aren't making a lot of sense to me just now.

Again, sorry if I seemed to be patronizing in any way - it's really difficult without each person posting a "life resume", to know where to start and what offends... Steve