isolation cab diy

[intermittent hummer]

HI
I want to build an external enclosure for a speaker (guitar) so that i can shut the lid and (massively) atttenuate the volume, while mic-ing inside the box. i am thinking i will just get a v. large suitcase, and line it all round with rockwool, and possibly put a bit of plywood inside the rockwool, depending on sound colouration. Does this this sound sensible, and what type of rockwool should i use? i really need maximum attenuation due to neighbours.
many thanks
jp

[tomas]

I would think that a suitcase is unsuitable for this. You would want high density to keep sound from escaping the box. Think about thick birch plywood or the like.

[shufflebeat]

I see quite a few old 'box' style flight cases which once had a mixing desk on top and about 8u room below for amps, FX, etc. Since the advent of powered desks and speakers these have since fallen out of fashion. The timber is not thick but could be supplemented and the butterfly catches would make a good seal.

Idiot alert - This is just my immediate thought which may seem foolish on reflection.

[Studio Support Gnome]

you need to build 2 boxes, one that fits inside the other, the outer should be lined with rock wool, and the inner box sat on springs with clear space between it and the rockwool;....

the inner box should be lined with acoustic foam or fabric wrapped rockwool, and the speaker cabinet fitted inside of that.

the outer box will want to be at least 1 inch thick MDF , preferably 2 layers of it bonded around mass loaded vinyl.

the inner box probably 3/4 inch MDF.

the lid will want compression latches such as butterfly latches used on flight cases, and will need a seal of EPDM/neoprene around it.... this applies to both inner and outer boxes.

it will take 2 or 3 strong blokes to move it ,

it will work.

no the suitcase idea will not work .

[ef37a]

+1 to SSG but it might be cheaper to move!

One alternative is a Power Soak. Yes, an attenuated speaker does not sound like a 100W stack in full cry but then neither will a cab in a box.

Then, you don't have to run a speaker to within a gnat's undercarrige to get a good tone. Sound levels in the 90dBSPL region can give a nice sound and that level should be containable in a normal house and nuisance kept to a minimum if you pick your room and time of day.

But some people do not object to the noise itself. I have found instances where the guitar's SPL was on a par with the neighbour's local noise and quite low, (~70dBSPL) at that..No, some just don't want Rock&Roll "people" next door!

DI and software might be the only solution!

Dave.

[Jack Ruston]

My experience of that is that for clean sounds it works really well running at room volume. You can definitely record a nice sound without destroying the building. For higher gain sounds it's harder. A much bigger component of the sound comes from the behaviour of the speaker when it's pushed. It's for this reason that convolution speaker impulses sound tonally correct but 'flat' and strange.

J

[Mixedup]

You can't just stick a speaker that behaves nicely in an open room in an enclosure like that without it significantly changing the sound. No matter how good the isolation, you're essentially putting the thing in a very small room, and if frequencies are not coming out, they're staying inside that box, very close to the mic. In short, if you were to do a cheapo DIY job, then you might find that you'd get better results from a power soak and decent speaker impulses (or Nebula patches).

That caveat explained... I know that the man who designed the Hermit Cab tried various different configurations and speaker sizes/shapes before arriving at the 10" Eminence and the design/size of the enclosure, the mic clamp mounting and so on. The Hermit Cab is no longer sold, but it would be worth looking at the design principles. As said designer visits these parts from time to time, perhaps he'll be along to explain more at some point...

[Jack Ruston]

Someone needs to make a really good cabinet/mic/room simulation. I hear the Nebula patches are good, and I'm looking forward to trying those but I don't think they're on Mountain Lion yet are they? Their site says not supported. Is anyone successfully running them on later versions of mac OS?

J

[ef37a]

You can't just stick a speaker that behaves nicely in an open room in an enclosure like that without it significantly changing the sound. No matter how good the isolation, you're essentially putting the thing in a very small room, and if frequencies are not coming out, they're staying inside that box, very close to the mic. In short, if you were to do a cheapo DIY job, then you might find that you'd get better results from a power soak and decent speaker impulses (or Nebula patches).

That caveat explained... I know that the man who designed the <a href="/sos/jun03/articles/hermitcab.asp" target="_blank">Hermit Cab</a> tried various different configurations and speaker sizes/shapes before arriving at the 10" Eminence and the design/size of the enclosure, the mic clamp mounting and so on. The Hermit Cab is no longer sold, but it would be worth looking at the design principles. As said designer visits these parts from time to time, perhaps he'll be along to explain more at some point...

Hi Mix,
I don't know if the "Axe" cab is still made? That was a similar situation in that a lot of time and effort went into making the thing work and sound good.
Some things we cannot do! It is only fairly recently that a really good tape simulator has come about, albeit at considerable cost. I would aver that the "quiet" duplication of a snorting rock stack is no less trivial a task?

Dave.

[Mixedup]

Someone needs to make a really good cabinet/mic/room simulation. I hear the Nebula patches are good, and I'm looking forward to trying those but I don't think they're on Mountain Lion yet are they? Their site says not supported. IoIs anyone successfully running them on later versions of mac OS?

J

Nebula is capable of great things, Jack, it really is. But the quality of libraries is variable, and the best libraries (eg Tim Wisecup's 33609 highest quality version... not a speaker but a similarly complex thing to capture) take up a huge amount of processing - there was a versipn I couldn't even losd on my i7 quad 3.6GHz with 12GB RAM - so you kinda have to treat that like an offline process. It's also frustrsting that Acustica themselves seem so flakey, especially on the sampling side of things (which is currently PC only, I believe).

Thing is, to sell lots, most guitar plugs need to be low latency for performance. Hence IK focusing so hard on the iOS stuff instead of forever improving on Amplitude. I'd love to see someone crack this nut properly, though! Kinda surprised Fabrice/Slate or US haven't trained their sights on this yet.

[Jack Ruston]

Well UA have done their Engl amp recently haven't they. Not used it, but for latency reasons it's really going to appeal to Apollo users most of all. I used the Scuffham amp thing today and while the speakers were the usual fayre, the amp models were really great. Obviously there's the Kemper thing, but it's still expensive.

I think you're right...processing power is still the bottleneck despite the monster machines we now have. It's a question of it not being possible, it's more a question of it not being economically viable.

J