Isolation Box for a Guitar Cabinet Advice

[GreatOz]

Good day,

I am going to build a DIY isolation box for my guitar cabinets and would like some advice from people who have built them. The purpose is to isolate the sound coming from the cabinet so no other sounds go into the mic and to cut the volume coming from the cabinet.

What were your design choices and why? (examples include what type of acoustic insulation you used, how big it is, what you used it for, and etc.)

My box is going into a church backroom that is directly behind the stage (the wall for the church is insulated wood) and the door to it is only 2 ft (~61 cm) wide.
I do not ever plan on using anything bigger than a 1 x 12 cabinet, but was debating on making it big enough for a 2 x 12 in case someone else wanted to use it for that or I changed my mind in the future.

If I went with the 2 x 12 design, I would have to finish assembling the box inside that room because otherwise, it would be too wide for the door as most 2 x 12" cabs are over 2 feet wide.

I was thinking of making the length of the box 3 feet (~91 cm) long to allow the speaker some air to "breathe", but is this really necessary so that the sound is not too boxy?

As far as I know, just putting a cabinet in the box will make it sound at least a little boxy. Speaking of which, if you know of a way to make it not sound boxy or if it is not an issue at all, please let me know.

I am only planning on using one mic, either an SM57 or an e906, but was thinking about putting two XLR jacks in the side to allow for two mics.

I do not care about air ventilation because I am not putting a combo in there, only the cabinet; from what I was reading, air/cooling ventilation is only necessary for combo amps. The amp head will be separate and on stage with me.

Currently, my plans are to build a 23 in (~58 cm) wide by 36 in (~91 cm) long/thick (the cab will sit towards one of the sides facing the other), and 23 in (~58 cm) tall. The boards will be 3/4 inch (~2cm) thick MDF.
The foam I am planning on using is either Auralex or something like this. Plan so far is to screw the boards together, seal it with something like silicon and glue the panels on the sides. I will cut at least a few holes for all the cables. I was going to use a lid with a seal on it that uses a latch to close shut.

Do y'all have any further suggestions?

[ibanezrocks]

Re: Isolation Box for a Guitar Cabinet Advice

I haven't built one but I read up on them because I was considering it.

Having two layers seems critical if you want really good isolation. Build a box covered with acoustic foam on all sides, build another box with acoustic foam on all sides and put it inside the first, putting extra foam underneath each.

A bigger space will help it not sound boxy but how you insulate that space matters too.

Sent from my BlackBerry using Tapatalk

[SlyFoxx]

Re: Isolation Box for a Guitar Cabinet Advice

If you're good with working wood and already have the necessary tools just build a loaded iso cab. I wouldn't fool with a box and auxiliary cabinets. It will take serious marine grade plywood which ain't cheap, wires, jacks, insulation a high wattage speaker etc. Or..........

Save the hassle. 650 bucks, you add a speaker and mic.

I've had one for years and it works a treat.

http://www.demeteramps.com/index.php?route=product/product&product_id=69

[ehdwuld]

Re: Isolation Box for a Guitar Cabinet Advice

https://www.musiciansfriend.com/amplifiers-effects/jet-city-amplification-jetstream-iso-u-guitar-speaker-cabinet

Like this?

[GreatOz]

Re: Isolation Box for a Guitar Cabinet Advice

The isolation does not have to be perfect as I am using a low wattage amplifier (Blackstar HT5R Mkii likely on the 0.5W setting; haven't tested yet) and will keep the amp at conversation levels for volume. Combined with the box, the bleed I do not think would be an issue because of this reason. If I was running an AC30 at max on the other hand...... lol

I'm fairly good with my hands. The reason I wanted to build it was for the customization, the experience, and because it was cheaper. However, if what I want will come fairly close in price to a prebuilt one, I will likely just get the prebuilt one. I need an actual cost for this though. My gut tells me that, if I am trying to save money, then I am basically wasting my time and that I could get something pretty comparable for either the same price or not that much more.

I saw the Jet City thing, but haven't read any decent reviews on it. Might make a good platform though. Something like the Randall might be decent as well.

If building on myself will not really compensate for the boxy sound, I would heavily consider a prebuilt one that I would add my own speaker and modify as needed.

[MGW]

Re: Isolation Box for a Guitar Cabinet Advice

I have not tried one yet but from what I have been hearing and reading there is nothing else available anywhere that is as good as this cabinet by Rivera
Some of the people who have told me about it are highly respected in my circle of musicians.

[Mincer]

Re: Isolation Box for a Guitar Cabinet Advice

It is a cool idea...take some pics as you are building, as I love to see these kinds of things in-process.

[TwilightOdyssey]

Re: Isolation Box for a Guitar Cabinet Advice

I have the Randall 1x12 iso cab. A couple of things you might find helpful:
- the microphone and amplifier jacks are also isolated and located at the rear bottom of the cabinet far from the lid. A simple hole will cause air to escape and defeat the purpose of the cabinet
- the iso cab is actually two chambers, a longer lower one and a smaller upper one. The loudspeaker is mounted into the baffle between them and is ported
- I lined the inside of the lower chamber with 2" Auralex foam; it really tightened the response of the loudspeaker immo, but YMMV
- Even fully sealed, the iso cab only cuts 29dB from the sound. My 2W amps can easily get above 90dB SPL in an open room; I wrap the iso cab in moving blankets and put it on an Auralex GRAMMA to make it truly isolated
- Experimenting with microphones recommended; you may find that a mic you wouldn't normally use for guitar works really well in the iso cab

Here's what my iso cab sounds like in a mix:

[Ascension]

Re: Isolation Box for a Guitar Cabinet Advice

As a Church player I have run my cabinet off stage at several places. Because I run tube amps with my delay verb and any other time bacsed effects in the loop I need my head on stage close I will run a speaker cable and a cab alone off stage. That makes it a LOT easier because you don't have to worry about airflow to your amp and if you run a loop like I do you have a short cable run. The long speaker cable looses are minimal but trying to run long cables at signal levels is going to be a real issue to an amp way off stage. This is from experience over years of doing this. Right now I'm running my old 50 Carvin X50 B Hot Rod Mod head at Church beside me on stage with a Egnater Tweaker 1/12 in the back room miced.
Sounds like this through the FOH no effects here just amp guitar me. Guitar is my Mahogany neck and body Quit top Ebony board 96 Carvin DC 400 with the factory active module running a Hybrid Bridge and a Sentient neck fantastic tonal combo!

[Ascension]

Re: Isolation Box for a Guitar Cabinet Advice

Same service a little more controlled and dynamic song running delay and Verb in the loop crunch channel on the old Carvin using touch and guitar volume to clean up no drive pedal the Hybrid and Sentient Split on the DC 400.
Have a Celestion Heritage in the cab and a SM 57 about 3 inches off the grill on the cab off stage in the back room to the right of the stage.

[Ascension]

Re: Isolation Box for a Guitar Cabinet Advice

Another clip this time the old KOA 127 Alt 8 bridge Sentinet neck raw guitar real amp tones and no effects. This is IMO the best way to set up an iso situation with a cab off stage or in a on stage iso box miced and a head or combo on stage close to the player!! Real tube amp tones without the stage volume in the FOH!

[GreatOz]

Re: Isolation Box for a Guitar Cabinet Advice

Experimenting with microphones recommended; you may find that a mic you wouldn't normally use for guitar works really well in the iso cab

Which microphones did you end up using that you normally would not have for a guitar?
From my research, I learned a lot of people actually preferred something like an e906 over the traditional SM57 for specifically the Randall cab.

My guess is something that attenuates bass due to the nature of the box.

By the way, those clips sound great.

I am also now leaning more towards the Randall because I doubt I could build one for much cheaper and it would be a lot faster. I can always mod as necessary.
A 28 db cut would be fantastic. I can combine it with a reactive attenuator, just have it loud enough so the speaker is breathing. I don't need to run a 50 watt amp at full.

[Ascension]

Re: Isolation Box for a Guitar Cabinet Advice

Which microphones did you end up using that you normally would not have for a guitar?
From my research, I learned a lot of people actually preferred something like an e906 over the traditional SM57 for specifically the Randall cab.

My guess is something that attenuates bass due to the nature of the box.

By the way, that clip sounds great.

Thanks on the complement on tone. In my case the cab is in a back room and open to the room so I just have a SM 57 on a desk top stand sitting in front of the cone at about 3 or so inches off the grill cloth.
I personally like my tones better with my little Mesa Subway Rocket 1/10 combo. I run a Beta 57 on it when I play out at a much lower stage volume. The sound guy at our Church wanted all amps off stage so i went to a head and cab but he has me cranking so hard on the cab in the back I now get so much bleed through the wall where I'm standing that my stage levels are much higher than when I ran the combo on stage. It make no sense but that's what keeps the piece between me and the sound guy.
This is the Mesa at my old Church with the Beta 57 and stage level here is a whisper! No effects here amp is running a WGS ET 10.

https://www.youtube.com/watch?v=CuRn3A3PpNg

[TwilightOdyssey]

Re: Isolation Box for a Guitar Cabinet Advice

Which microphones did you end up using that you normally would not have for a guitar?
From my research, I learned a lot of people actually preferred something like an e906 over the traditional SM57 for specifically the Randall cab.

That’s probably due more to ppl who don’t know what they are doing than the mic in question .
I usually start with the little sister to your mic, a Sennheiser e609. My other oft-used mics for the iso cab are a Cascade Fat Head II and SM57. I use an SSL channel strip with a dbx compressor in the insert. I will swap mics for different parts, so it really depends on the texture I am looking for.

My guess is something that attenuates bass due to the nature of the box.

There may be some sort of cancellation going on but I doubt it, the mic is very close to the speaker. I use a Weber AlNiCo or Emminence Swamp Thang or Wizard depending on the part, and that has a much bigger affect on tone than the mic used.

By the way, that clip sounds great.

Thanks! I usually have something I am working on posted in Tips and Clips.

I am also now leaning more towards the Randall because I doubt I could build one for much cheaper and it would be a lot faster. I can always mod as necessary.
A 28 db cut would be fantastic. I can combine it with a reactive attenuator, just have it loud enough so the speaker is breathing. I don't need to run a 50 watt amp at full.

Glad I could be of service. I would look into the Auralex and moving blanket attenuation before using an amp attenuator, I am not a fan of how they alter my tone. Once again, YMMV.