Open-backed speaker cabs...

a_gherkin

bonjour! I have a jcm900 head and 4x12 cab and have read in various places that taking the back off your speaker cab can give you a superior tone? Is this true or is in only effective if you are micing up your speakers?
Im toying with the idea just so i can find the sweetest possible tone i can achieve and am up for trying most things... next stop is probably a PowerBrake.
Anyway, anyone got any suggestions here?
Cheers
Gherk

MissYouAllDay

I think its an opinion. Like I don't think ones considered generally better than the other.

For instance mesa makes alot of its cabinets closed back or 3/4 closed back on purpose to generate a certain sound.

Pacomc79

Closed backs give you more focused directed tighter sound.

Open backs are the opposite.

Neither is better or worse. It's all depending on what tone you're after.

On a JCM 900 with likely a 4x12 cabinet. I say nay, but go ahead and do it, just be careful in doing so so that you can replace it if you like the tone better with the back closed.

What it will allow is sound to spill out the back of the cabinet filling the room giving you a more open less directed sound. It's up to you what sounds better.

mccreadyisgod

The biggest difference between open- and closed-back cabinets is that open-back cabs tend to sound brighter, closed-back cabs sound more bassy. Closed-back cabs do tend to sound more controlled, too.

My ideal set-up, if I ever have the chance to build it, would be a closed-back 2x10" cabinet paired with an open-backed 1x12". Get the punch of the 10"s and the presence of the 12".

Mesa used to make 4x12" cabs that had the bottom two speakers closed and the top two speakers open. Those cabs are amazing...

PearlJamaholic

i never heard of this. i might have to try this sometime. i didnt think it would make a difference.

LemonYellowSun

I was curious on the difference in sound also, so I built a 2x12 cab about a year ago that has one side closed back and one side semi-open (good size opening on back panel). The two sides are totally isolated from each other via a 1/2" thick piece of plywood and some caulking (i went a little overboard). I then installed the same Cellestion speakers in both sides, wired seperately.

The difference between the two was definately noticeable. The open back was, as stated before, more open sounding. I personally prefer this sound as it has a "richer" tone. The closed back side definately had more bass emphasis and made the amp sound a little "honkier" (if that makes sense). I found that when I really cranked the amp and pushed the closed back side that it finally started to come to life. I guess it was just an issue of the air inside not allowing the speaker to move as freely (as is the case). Anyhow, I absolutely love the combo of the open back and closed back in one cab. The best of both worlds.

mccreadyisgod

I have a few 10" speakers lying around, I've often thought about building some cabinets for them... I've recently thought about doing the same thing as LemonYellowSun, a 2x10" cab, sealing one up tight and leaving the other side open or with a 1/2 back. But I'd wire it with one input for both speakers, not separate inputs.

Some day I will get my 2x10" sealed cab, too... I just need to find someone to make a sealed-back 2x10" cabinet for guitar. Then a Mesa 1x12" with a Celestion Vintage 30 and a 1/2 back...

Or an open-back 2x12" cab to go with my sealed 4x10" cabinets.