Closed back vs. open back cab

[WhiteStrat]

I've got a 100 watt 2 x 12 combo with a "sorta" closed back. The back is certainly covered with a panel, but the top 4 or 5 inches of that panel is vented steel mesh--so lets call it mostly closed back.

Now I've heard of folks finding their closed back amps to sound much better after the back is removed--but if that's the case, why did the mfr. put it there anyway?

Anyone make this mod and have opinions?

Thanks
Strat

[ocnor]

It makes more of a difference with smaller lower wattage amps. Since the amp cab is smaller having an open back lets the out of phase signal from the back of the speaker disperse into the room. Some people think that gives it a fuller sound. IMO open back cabs sound less focused and lack low end. With a 100 watt amp you get plenty of sound from the front of the speakers. Having a semi-open back gives it a less boxy sound as the amp cab is not normally as large as a regular 2x12 closed back speaker cab. It really all comes down to personal preference but as you pointed out "Why did the mfr put it there"? As cheap as most mfr's are they are not going to add unnecessary parts to an amp driving up the cost just to make it sound worse.

[dementedchord]

not sure you could count on a big diff between a semi and a full open back... it's not like it's atuned port (bass reflex) going to too much port...

[soundchaser59]

Originally Posted by ocnor

IMO open back cabs sound less focused and lack low end.

My findings exactly. I thought I liked the open back for a long time, but it was really just that sensation of seeming louder that I liked. When I really started to pay attention to the quality of the tone, I switched back to closed back cabs, and I'm glad.

[antichef]

I've got a Vox AD15VT that is a 1x8 combo with a sealed back. Strangely, it had way too much bass for me. For some reason, simply removing the back piece made sound it sound less bassy and better to me.