Building an iso cab: need advice on speaker, mic and materials

[Hades]

Greetings Everyone,

I'm in the planning stages of building an isolation cabinet for electric guitar, a la the Randall Isolation cabinet and I would like the sage, all-knowing advice of The Collective.

I purchased a Blackheart Killer Ant 1W amp for the express purpose of using it as a power amp so as to be able to get that saturated power tube sound without needing to melt my face off with ear drum popping volume. I had an iso cab in mind when I got it too; with it's low power output, I can not only crank it and get good tube distortion, but its low top volume makes it easy for me to quiet it down with a good iso cab.

And just so no one thinks I'm silly for wanting to soundproof an already quiet amp, the reason I want to run to an iso cab is because time based effects sound better after power tube distortion--something which is virtually impossible to do any other way since you obviously can't give your mixer 100W of your Marshall on 11. I'm not interested in power attenuators or other tricks in the signal path...I want the real deal.

Anyway, I have good woodworking skills and tools, so the building part is no problem at all. I intend to put either a Celestion Alnico Blue or a Greenback in it; I haven't decided which. I'm personally leaning towards the Blue, even with it's much higher price, since it's lighter than the Greenback and I'll be able to get it to move more and get some of that classic speaker distortion even with the 1W input...But I'm not married to that idea yet either. I play blues/classic rock mostly, so both speakers will sound "right" for what I do. If anyone has an opinion on which speaker, I'd like to hear it. Of course, I'm open to other ideas too.

Next, what would be good soundproofing materials for the box? I'd like to get as close to zero sound bleed as possible. Given that the output of the Killer Ant is only 1W, it shouldn't be too hard to come up with a solution, I wouldn't think. I'm reasonably certain regular ol' egg carton foam wont cut it and I'll need something better...Though just to specify, if there's a $500 product that will get me to 99% and a $100 product that will get me to 95%, I'll go with the cheaper stuff. I ain't got a money tree unfortunately, so close will be good enough.

Lastly, microphones...Since iso cabs are sealed boxes, I'm worried about increased SPLs inside, so mic selection is on my mind. I want it to sound good obviously and not like a turd wearing a wool blanket, but I need something that wont get destroyed inside there too. Would the tough-as-nails Shure SM57 do the trick, or could I get away with and be better off with something like the Rode NT1? Other ideas and suggestions for good mics? Again, like above, I don't need "The Best" mic in there, just something that will sound pretty good in iso cab conditions...So no $1,500 Neumann please.

I hope I've given enough background info to get the proper answers, but if there's any questions about what I'm doing, let me know and I'll get back to you.

Thanks in advance for your time and help, I appreciate it greatly.

 

[darrin_h2000]

I did the same project and I power it with a Tech 21 trademark 10.

I used 1" thick MDF and a celestion vintage 30...shure SM57 or senn MD421 depending on what I want...some fiberbrace lined along the inside and then covered with the foam...it sits outside of the tracking room where the computer and plate reverb is...so if some sound gets out it doesnt effect the drummer or bass (Bass direct in is done 99% of the time nowdays)...its good to track all 3 at the same time so they can have eye contact and groove like they allways do.

 

[Hades]

...and then covered with the foam.

Did you just use regular ol' accoustic foam?

How well can you hear the speaker inside?

 

[bozmillar]

As far as microphone choice goes, almost any dynamic mic should be able to handle far more than you can throw at it with this. Just yesterday I recorded some gunshots with a small electret condenser mic rated at 120dBspl and a cheap dynamic mic. The condenser couldn't come close to handling it, and the dynamic didn't flinch at all, and this was at 5 feet with some insanely loud guns. Your 57 should be able to handle it just fine.

 

[AMcB]

I did a similar project. Mine has 1 v30 in it. It is about 4' high and 2'x2' wide. Pretty big, extremely heavy. It is made from 2 layers or 3/4" mdf with some noise barrier stuff I got from HD in between layers, I don't remember exactly what it was, but it was like $8 for a 3/4" 4'x8' sheet. Then layered the lid with 2 layers of it, plus the top has 6 oth that, then 6' of acoustic foam. Sounds pretty good. Can't tell it's in a box. Cuts all the highs and kids from outside. But the bass/rumble is still there, but not too bad, definately alot quieter than it should be. And that is with a 50w tube amp on about 8 or 9. I ended up spending $300-$400 speaker included, but I low to think it works better than anything you can buy.

Another thing. I wouldn't put a condenser in there, like you said, I'm pretty sure the spl increases alot because it's completely closed. I put a c214 in there and took it out quick because it was distorting.

Also I basicaly built a box, built a box around it. And cut it open, that way it was an air tight fit, then use a hinge to open the 150lb (estimate) lid. But an sm57 works great in there.

I'll try to post pictures later. Or got to myspace.com/amcbstudios and I have a few older pics, before I put acoustic foam in there I think. Also all he guitars on ther were recoded with it.