Hiwatt 4x12 with back panel vent?

xxxplorer

Well-known member
At my local guitar center, there is an old Hiwatt cab. Way too much for me, but it's awesome to see in person! I notice it has the back panel with about a 1" 'vent' along the bottom.

What would this do tonally to a cab? Is there an advantage to a rear vent over a front vent? I'm thinking of getting a piece of plywood and making a second back for one of my cabs to see what difference it makes, but want to hear from you guys too.
 
Re: Hiwatt 4x12 with back panel vent?

My Kustom cabs have a divider in the middle so they're basically 2 2x12's in the same cab, then they have vents behind each speaker. I can't really say with any certainty what the vents add, and the cabs are already way bigger than most 4x12's, but they sound ****ing huuuuuge. I used to have a half-back Mesa and it was the same way.

I know on a typical open back you lose tightness for chugging and stuff, that's not the case with any of these cabs.
 
Re: Hiwatt 4x12 with back panel vent?

Hmmmm... I may just go grab my saw and experiment hehehe. Worse case I scrap the back and make a pedal board.
 
Re: Hiwatt 4x12 with back panel vent?

Well, I went ans cut a slot in my back panel! Just traced the narrow edge of a 2x4 and cut it with a jig saw. At higher volumes the cab does appear to be less choked. No percievable loss in tigtness and no boomy sub lows. I think it's a solid lil' mod.
 
Re: Hiwatt 4x12 with back panel vent?

I have an old Hiwatt cab and I can tell you they are heavy as sin! Even heavier than my Rivera 4x12.

I think a significant amount of wood would have be cut out before the tone was affected.

My guess is that it is used to flatten the frequency response and perhaps make the cab a little louder?

Has that been your observatio?
 
Re: Hiwatt 4x12 with back panel vent?

Hard to say... I do want to say I hear a slight less boxyness and it doesn't sound as congested... That and Palm mutes don't fizz out like they can on some cabs... I like my palm mutes to resemble thunking a good water melon lol.

Before I did it, I did experiment with removing just the side handles and it did a similar thing. Another cool bonus is when I mic the vent I get a cool lowend sound I can mix in with my regular mic.

It's not a huge thundering low, just a thick usable one... I've tried in the past micing up ports on my earcandy and it was just way too much to mic... This is nice!

It's not ported, just vented... No measuring or calculating. Well, unless a 2x4 counts lol
 
Re: Hiwatt 4x12 with back panel vent?

Lol, that is kinda funny... You were actually one of the reasons I have been thinking about it all... Your tunes and gear journy are always fun!
 
Re: Hiwatt 4x12 with back panel vent?

Just played my faded gibson SG which I have tuned to B Standard with P90s into the cab... And it's much more noticable with the lower tuned stuff. The cab really does seem to breath better and I think I get a little more nuance. Speakers are EVM-12L on top and Swamp Thangs on the bottom. Beastly cab. Pretty satisfied with my lil' mod. I have a second 4x12 and I may even do the same thing... Only on the front baffle lol.
 
Re: Hiwatt 4x12 with back panel vent?

Holy moly, that cab must be capable of insane SPLs! My Rivera is loaded with a Wizard/Swamp Thang combo, but I've not tried it with any of my +30w amps yet, believe it or not. Hmmm ... I feel an experiment coming on! :)
 
Back
Top