#1
Almost all the guitar cabinets and combos I've seen have no backs to them, over the speakers.
All bass cabs seem to and of course all stereo, dj, monitor speakers do.

So why don't guitar cabinets/
#2
some don't, they are called "open back" this can help disperse sound better.

A "closed back" cabs has a back and is completely sealed. This tends to give a better bass response and the sound is more focused in front of the speaker.

Ported cabs have a port on the front baffle or the back baffle. these have characteristics of both the open back and closed back cabs.

All 3 types are very common
2002 PRS CE22
2013 G&L ASAT Deluxe
2009 Epiphone G-400 (SH-4)
Marshall JCM2000 DSL100
Krank 1980 Jr 20watt
Krank Rev 4x12 (eminence V12)
GFS Greenie/Digitech Bad Monkey
Morley Bad Horsie 2
MXR Smart Gate
#3
My Randall RM100 combo is closed back with a small vent on the back. That's pretty uncommon way to build a combo because getting the heat from the tubes out is difficult. Randall get over that by fitting a fan. The bass response of that thing is incredible for a 2x12 and I'm cetain that's mainly due to the closed back cab (plus it's friggin huge).
I was using a JCM900 combo (open backed) on top of a 1960 (closed back) and I needed the 4x12 to get some decent bass out of the thing. With the Randall I won't need it. All it needs is lifting off the ground so I can hear it properly and get decent feedback,
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#4
Usually closed back cabs are extension cabs as tube combo need the ventilation to cool the tubes
punk isn't dead, it's always smelled that way.

"A perfection of means, and confusion of aims, seems to be our main problem."
-ae
#5
Quote by Cathbard
My Randall RM100 combo is closed back with a small vent on the back. That's pretty uncommon way to build a combo because getting the heat from the tubes out is difficult. Randall get over that by fitting a fan. The bass response of that thing is incredible for a 2x12 and I'm cetain that's mainly due to the closed back cab (plus it's friggin huge).
I was using a JCM900 combo (open backed) on top of a 1960 (closed back) and I needed the 4x12 to get some decent bass out of the thing. With the Randall I won't need it. All it needs is lifting off the ground so I can hear it properly and get decent feedback,


Wow, did not know that! Interesting. My Carvin Legacy and 5150 combo are closed back combos, but the speaker section is separate from the head in both amps, so tubes are not enclosed.
Peavey 5150
Mesa Mark IV
Mesa Single Rectifier (Series 1)
Fender Custom Shop Tonemaster
Roland Microcube

-Whitebox OS 1x12
-Port City OS 1x12

Digidesign Eleven RackAxe Fx Ultra
#6
Yeah, the RM100 has the tubes inside the speaker box like a normal combo and relies on the rear vent to expel the heat. When I first saw it I said, "how does that work? Is there a fan inside it?"
"Why, yes, yes there is."
It looks like a pc fan and it doesn't seem to induce any noise into the amp. I'm pretty damn impressed with the amp in so many ways.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#7
Badass you got an RM Cath.
Quote by DeathByDestroyr
See, it's important that people clarify when they say "metal", because I pretty much always assume they are a Cannibal Corpse fanboi.
#8
Quote by Cathbard
Yeah, the RM100 has the tubes inside the speaker box like a normal combo and relies on the rear vent to expel the heat. When I first saw it I said, "how does that work? Is there a fan inside it?"
"Why, yes, yes there is."
It looks like a pc fan and it doesn't seem to induce any noise into the amp. I'm pretty damn impressed with the amp in so many ways.


The Mark IV also has a PC fan as well, I always like the idea, since the mark IV's tube arrangement is pretty cramped.
Peavey 5150
Mesa Mark IV
Mesa Single Rectifier (Series 1)
Fender Custom Shop Tonemaster
Roland Microcube

-Whitebox OS 1x12
-Port City OS 1x12

Digidesign Eleven RackAxe Fx Ultra
#9
My CCV had a 12V PC fan as well. Only one I saw like that though. Most don't from the pics I've seen.
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(512) Audio Engineering - Custom Pedal Builds, Mods and Repairs
#10
Quote by Reincaster
The Mark IV also has a PC fan as well, I always like the idea, since the mark IV's tube arrangement is pretty cramped.


Mark V has a fan as well.

RM50 has a fan.


Marshall DSL401 should have had a fan..
Quote by DeathByDestroyr
See, it's important that people clarify when they say "metal", because I pretty much always assume they are a Cannibal Corpse fanboi.
#11
My renegade is another amp with a fan. It's not loud enough to be a problem imo for me. Surprised more amps don't have them tbh.
RIP Gooze

cats
#12
Quote by R45VT
Marshall DSL401 shouldn't have cheaped out on underrated rectifiers.
FTFY
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band