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Old 07-17-2007, 08:11 PM   #1
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4x12 Cab- closed vs. open pros/cons?

Hey Fellas/Gals,

Ok, My son and I are going to build a cab for his Peavey XXL 100 watt head. We were wondering about the pluses and minuses of closed and open cabinets. We would LOVE to get some opinions!
Thanks!
Ben
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Old 07-18-2007, 09:13 AM   #2
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I don't know if you've found it already, but there's a pretty lengthy and technical thread here about Celestions in open vs. closed 2x12 cabinets. The same principles apply, so you might want to take a look at it. HTH.
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Old 07-18-2007, 10:41 AM   #3
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What sort of music does he play? If it's hard rock or metal, he'll probably prefer the big bass chunk you get from a closed back. An open back has a lighter, airier sound.
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Old 07-18-2007, 01:25 PM   #4
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Well, all my cabs are ported!
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Old 07-18-2007, 02:38 PM   #5
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You use ported cabs for guitar, Max? What do you think of the tone from them? I'd imagine the bass would be even bigger than a closed back, but somewhat deeper and less boomy.

My Hiwatt reissue 2x12" has a small slot port at the back, but impedance plots say it's doing absolutely nothing.
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Old 07-19-2007, 03:44 AM   #6
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Quote:
Originally Posted by Steve Conner View Post
You use ported cabs for guitar, Max? What do you think of the tone from them? I'd imagine the bass would be even bigger than a closed back, but somewhat deeper and less boomy.

My Hiwatt reissue 2x12" has a small slot port at the back, but impedance plots say it's doing absolutely nothing.
I've been using nothing but ported cabs for guitar and bass since about 1978. As you might remember, I'm a big fan of T-S ported 4th-order Butterworth alignments with EVM speakers.

That is, I've been using nothing but T-S alignments until I recently bought that Avatar 2x12 cab with Greenbacks as an experiment -- you might remember this back when we were discussing sealed back boominess in that "Avatar 2x12 is too Boomy" thread. My initial opinion on the Avatar cab is still that that sort of 2x12 closed back alignment sounds bad, and that buying the cab was an impulsive mistake. I knew better, but boredom got the better of me and I wanted to try something just to try something. It was a classic case of GAS.

My personal take on T-S arrangements for guitar cabs is that they work pretty well. A proper alignment doesn't seem to suffer as much from that annoying resonant peak that you get with a sealed marshall-style cabinet that has no insulation inside. My dislike of the closed-back 2x12 Avatar/Celestion cab is so intense that I've shoved it into a closet where its been hiding for a few months. Since I bought it, I've never even used it.

To be fair, the boominess could probably be tamed by filling the box with polyfill batting. I bought a HUGE dog bed that was on sale just for the batting material, but I haven't gotten around to stuffing the cab yet. Another thing that I've considered doing is to map the frequency response of the cabinet, just so that I could design an inductive notch filter to get rid of that damned resonant peak. That approach may be geeky, but it might be the best way to tackle the problem.
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Old 07-19-2007, 11:22 AM   #7
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Talking

Quote:
Originally Posted by Steve Conner View Post
You use ported cabs for guitar, Max? What do you think of the tone from them? I'd imagine the bass would be even bigger than a closed back, but somewhat deeper and less boomy.

My Hiwatt reissue 2x12" has a small slot port at the back, but impedance plots say it's doing absolutely nothing.
Hi Steve.

I thought everybody else was doing the same on our side of the pond

Well, 4X12 wise i've had only hiwatt and sound city cabs, which are either back for the hiwatt i've had or front ported with two 60~70 mm holes. They're nothing like bass reflex (tuned cabs) as far as i know. The holes are there just to let the cones move a bit better not having to compress the air inside a closed cab. The bass response is nice, usualy huge and tight, thought the hiwatt imho was too midrangey, but that might have to do with the electronics too. And i've made myself a 2X12 with a monacor and a fane in it (what i had laying around ) which sounds superb with my L100 head, which is back ported something like 38 X 3cm. It sounds nice and not too boomy, thought i have hard time to tame the bass with the bandmaster on top of it. But that's also due to the P90 in my actual guitar. Remember that i'm a shit player and my coments are to be taken with a certain care. (do you say a grain of salt?) I have also made a bass cab for a friend which has a properly tuned port, and that thing shakes earth with only 2X10 celestions and a trace head.

Bye.

Max.
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