# Isolating a guitar speaker + mic at home?



## Greg Ellis (Oct 1, 2007)

Has anyone had any luck with a homebrew solution for isolating a guitar speaker cabinet + mic?

Most of the time I get to play is late at night and people are sleeping so I have to keep the noise WAY down.

If I had an effective way to isolate the speaker cab so there's very little sound escaping, I could stick a mic in front of it and run that to my mixer into headphones.

Anybody done this at home with blankets or something?


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## ezcomes (Jul 28, 2008)

i have been recording at home...with the drums coming thru the monitors, so i've needed to cut the guitar down to hear it...

i close mic with an e609...

i stick the cab in a corner with a blanket along the walls to cut bounceback...and then cover the open side and top with couch cushions...works well, cuts the sound down a fair bit and records well...

- - - Updated - - -

side thought...i remember reading Pete Thorn's posts a couple years ago...(i think it was Pete)...he used the closet full of clothes...and then added pillows...


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## Option1 (May 26, 2012)

Coincidentally enough, I came across this ewechube vid last night that may help. I haven't actually watched it, but it seems that it may be along the lines of what you're asking, Greg.

[video=youtube;xFxH9sVe3Ls]https://www.youtube.com/watch?v=xFxH9sVe3Ls[/video]

Neil


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## Greg Ellis (Oct 1, 2007)

Thanks option1, i just watched that one myself.

Pete Thorn has a couple of videos about his new studio too, with some good ideas.

Very interested to hear about experiences with methods like these - for example, how quiet does it actually get?


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## jtienhaara (Dec 4, 2013)

If you want quick-and-dirty (but not cheap), a bunch of rigid insulation from your local hardware store can be taped together with that red insulation tape, and just kind of build a massive DIY styrofoam cooler.
























Of course if it's a combo amp you're isolating, be careful -- insulation works on both sound and heat!

A step up would be to build a proper frame with wood or MDF like the video Option1 linked above, and line the box with the rigid insulation.

It's worth noting that isolation rooms (WhisperRoom etc) are often built from MDF. You'll never eliminate sound for the rest of the house, but a well designed iso box might basically eliminate the highs, and cut the bass down by 30-40 dB. A cranked amp will still be very loud throughout the house. A kick drum will still be audible outside, but it does piss off the neighbours a lot less!

I have my doubts about the insulation in that video, though. First of all, that foam stuff isn't as dense as rigid insulation, so it's going to absorb and reflect less of the bass frequencies, which are typically the biggest problem in sound isolation. Secondly, compressing insulation (for example by bending it) deteriorates its insulation properties. Although the curved foam probably reflects some highs, I kind of doubt it does much for angling the lows -- which are the biggest frequency problem for phasing. Personally I just wouldn't bother with the curved foam bit. The box is so small you're going to have tons of reflections. I think it would be best to make the box big enough that you can move the mic around to find the sweet spot.

Anyway whatever approach you take, the more mass, the better the isolation.

Good luck Greg,

Johann


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## fraser (Feb 24, 2007)

i did once build something like that-
it was big enough to hold several 5 watt amps and a few mics.
i used mdf and that pink stuff johan shows-
the results were not great.
yes, it cut volume by a large amount-
in that way it was a success.
but the recorded signal was not good.
even though i built it deliberately very big,
it honestly sounded like an amp inside a box lol.
the confinement does something to the speaker and mic-
as johan mentions above, the frequencies get all messed up.

mine had a pair of front doors, i removed them and it helped a bit,
but then of course the box no longer isolated sound.
i think just having a better insulated box with only a speaker built inside 
would be an improvement, some added eq would help as well,
but my initial results were so disappointing,
and the thing took up such a huge chunk of my tiny apartment
that i dismantled it, tossed all the parts, and bought a pod lol.


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## kellythebastard (May 3, 2006)

Jet city makes a very inexpensive isolation cab. At around 399$ very cost effective


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## ronmac (Sep 22, 2006)

It's hard to work against the forces of nature. Isolating sound requires two systems of interference to be effective, mass and restriction of airflow. The mass is necessary to absorb the energy and diffuse it within its structure. A sealed enclosure is necessary to insure the energy that is not absorbed does not escape.

Placing a mic in front of an amplifier is all about capturing the energy released by a device designed to move air. Impeding that movement will definitely have an effect on the formation the microphone receives. I have never seen an isolation device that could effectively do it's job without a dramatic impact on the sound. 

If you need to record in an environment where e re is sensitivity to sound levels the best approach is to use a) a modelling device, or b) record a dry signal simultaneous to monitoring a modelling device and reamp at a time or place where sound pressure levels aren't a concern.


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## Noise Supply (May 31, 2013)

kellythebastard said:


> Jet city makes a very inexpensive isolation cab. At around 399$ very cost effective


That is super cheap. They are not cheap to build, generally, let alone to buy.

Moving blankets are a cheap way to isolate, but it's not a perfect fix, and not good enough when sleeping neighbours are concerned (excellent at killing the higher frequencies, understandably ineffective with the lower frequencies). It's more suited for helping to reduce bleed in a studio environment.

You are definitely going to want to build/buy an isolation box big enough for your amp, or use some speaker/mic emulation after your amp to record at night near sleeping folk.


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## Greg Ellis (Oct 1, 2007)

Some great input guys, thanks.

The Jet City box is a bargain, for sure, but it's a single-wall design as far as I can tell, and I'm not sure how much volume that would actually cut. Maybe not enough for my situation; not without additional measures.

I already have a modelling solution which works just fine for late night practice, and I use it a lot. But... 

I have a new amp on the way, and I need to figure out how to dial it in, how it interacts with my pedal board, etc. Ideally I would do that at stage volume, but I don't really have that luxury.

I'm working up to a reunion jam in mid-April, and we'll be playing LOUD at that event, but in the interim time, I'm mostly limited to low volume late nights messing with the amp, trying to find the sweet spots, seeing how it reacts to my dirt pedals and clean boosts and wah, etc. Ultimately, if I can find a way to rehearse quietly on the same rig I'll be using loud, I'll be way ahead of the game.

I have the ability to run the amp into an attenuator, and take a line out from that and maybe feed it through a cab simulation, but that signal path hasn't given me good results in the past.

The idea floating around my head at the moment is to build a relatively small box (say maybe 12x12x24") with the baffle about midway and a smallish speaker (maybe a single 10") sealed inside and close-mic'ed with an sm57 or similar on a gooseneck. 

If too much sound escapes from that sealed box, I can probably quiet things down more by packing the whole box inside a cupboard or closet with pillows or blankets or whatever for extra insulation.

I certainly understand that the sealed box design will limit the speaker's ability from moving freely, creating a compression effect, but I'm not sure whether I should expect that effect to be severe and distracting, or close enough that i don't need to worry about it.

Any other thoughts, with these additional details in mind?


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## jtienhaara (Dec 4, 2013)

Yeah, some great points up above!

If you have a closet available, run a test in there. Shut the door and crank it, see what happens. The closet has drywall (great for insulation) and maybe also fibreglass insulation inside, and it's much bigger than a box. If it gets you all the way there, you don't have to spend time and money on the box. If it doesn't, then you can start building... Or start adding layers to your closet walls, ceiling and floor! A couple extra layers of drywall are supposed to reduce dB significantly. Drywall is much, much cheaper than insulation.


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## Bobby1note (Jan 6, 2014)

Years ago, when I worked for an airline, I used to drag around a small Yamaha electric guitar for practicing in my hotel-room during lay-overs. I had a headphone amp called the Rockman X-100, and used to wail away to my hearts' content, without disturbing the guests next door. That was 25 years ago, so surely, there's something similar and better on the market, which costs less than a good isolation box.


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## loudtubeamps (Feb 2, 2012)

a little late to the party here, but as an addition......if u decide to go with an iso box, I would suggest placing the box on 4 tennis balls (used as feet) to isolate low freqs. from transmitting through to the floor. I have used table leg or couch casters to cradle the balls positioned within the footprint corners of the iso box.


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## Milkman (Feb 2, 2006)

Or you could spend $200 on a used Vox Tonelab and record direct. Problem solved.


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## Greg Ellis (Oct 1, 2007)

I had to put this project aside for a while to focus on learning songs for our annual jam, but that's over now so I'll start thinking about this again.

I've already got a Line 6 thingie that i use for headphone practicing. It's ok but not really awesome. Working up to the jam I spent some time tuning the Blackface amp sim in the Line 6 to sound like a recording I had made of my live amp, and I got it pretty close. Ended up running my live pedal board through the Line 6 and that worked out ok too for learning songs and rehearsing in the wee hours of the morning while the rest of the house was sleeping.

I've got an Alex attenuator on the way, and we'll see how that does with the Deluxe. It's got line out that I can probably run through some sort of speaker sim, possibly totally silent. If that doesn't work out for me, I'll go back to the speaker isolation cab idea. I think I can probably hack together a prototype in the garage and see if it kills enough volume to be useful. Some combination of attenuation with speaker isolation would probably be the best solution, but the line out of the attenuator sounds like it would be simpler, quicker, and easier. Won't know how it sounds til I try it, i guess.


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