1 head - 4 cabs?

jtm-series player · 11-06-2008, 07:40 PM

my PA-system features a poweramp, 2 fullrange-cabs (passiv),
and 2 woofers (passiv).

for small gigs I connect the 2 fr-cabs to the poweramp -
for bigger ones I use the output-jack of the fr-cabs(!)
to introduce the woofers to the system.

question:

can you do the same with guitar gear?
lets say you have a head and 4 16Ω cabs -
16Ω + 16Ω = 32Ω
32Ω / 2 = 16Ω overall impedance!

is it possible to wire 4*12 cabs like that?

I know Steve Morse uses 6 (!) cabs along with just
one of his signature amps, but he's got an extremely
complicated and expensive Bradshaw-switching-thing...

jtm-series player · 11-08-2008, 11:16 AM

oh come on!

no guitar-tecs or wall-of-sound-freaks in here?

JohnH · 11-08-2008, 02:02 PM

I think its OK, wire up the whole set of cabs in a series/parallel arrangement as per the individual speakers in a normal cab.
Hence, 4 x 16 Ohm speakers in series/parallel makes a 16Ohm cab, 4 x 16 Ohm cabs similarly wired makes a 16 Ohm 'wall'

John

jtm-series player · 11-09-2008, 02:35 AM

thx! sounds logic!

but where to put the output-jack, and can you still
use the cabs in "stand-alone mode"?

JohnH · 11-09-2008, 02:46 AM

Maybe you could have a special connector box with 5 jack sockets in it, four for the cabs with the appropriate wiring and one to go to the amp. Then just hook everything up with speaker cables. If you can drill holes and solder it would not be hard to make.

The cabs would be unchanged so could still be used on their own.

John

jtm-series player · 11-09-2008, 04:10 AM

hey! that sounds great!

any idea where I could get a wiring scheme?

JohnH · 11-09-2008, 05:14 AM

I don't know, but I could sketch a wiring layout. Maybe a metal box like a stomp box size , with four sockets in a line on one side for the cabs and one on the other to go to the amp? what do you think?

John

JohnH · 11-09-2008, 06:31 AM

like this:

John

ps, if you do it, we need a photo of you blasting away in front of 4 cabs!

jtm-series player · 11-09-2008, 08:11 AM

wow! thanks a lot john!!!
I guess I can even get the two of my left
hand to building such a connector box.
got to try it!!!
for the first try its gonna be my little
jtm cabs, but if it works I promise to
get another 3 4*10s and post pics of
both setups!

JohnH · 11-09-2008, 05:39 PM

No problem – one thing that’s important though, an oversight on my part, the jack sockets need to be the plastic type (like on a Marshall amp or similar), so ground does not get connected to the box. My picture shows the open metal type of jack socket, which would end up shorting out one pair of cabs. Or, you could use the metal sockets, with a plastic box.

John

Doomhawk · 11-09-2008, 11:19 PM

why don't just run the four 16ohm cabs in parallel off the 4 ohm tap on your head? do you not have enough speaker-outs or something?

jtm-series player · 11-10-2008, 09:28 AM

Quote:

Originally Posted by JohnH

No problem – one thing that’s important though, an oversight on my part, the jack sockets need to be the plastic type (like on a Marshall amp or similar), so ground does not get connected to the box. My picture shows the open metal type of jack socket, which would end up shorting out one pair of cabs. Or, you could use the metal sockets, with a plastic box.

John

wouldn't have thought of that! thanks once again!

I got a MXR-sized aluminium-box today -
will get the jacks somewhen this week

do they look like this?

http://1.1.1.3/bmi/media.conrad.com/..._00_FB.EPS.jpg

jtm-series player · 11-10-2008, 09:32 AM

Quote:

Originally Posted by Doomhawk

why don't just run the four 16ohm cabs in parallel off the 4 ohm tap on your head? do you not have enough speaker-outs or something?

the jtm-amps have 2 output jacks for 8 or 16 ohms use

JohnH · 11-10-2008, 02:53 PM

cant see your link
J

coldsteal2 · 11-11-2008, 11:08 AM

I used to run four cabs off of my Sunn Coliseum
what it had was a "through cab" output on each
cab made it easy, i have one of those on my
Crate cab to

I ran two 18" reverse cabs and two Fender Dual Showman 2 15" cabs (with JBL's)
with one head, for years worked great
they all had the same ohms so that helped

11-06-2008, 07:40 PM	#1 (permalink)
jtm-series player Senior Member Join Date: Apr 2008 Location: europe/austria/graz Posts: 331	1 head - 4 cabs? my PA-system features a poweramp, 2 fullrange-cabs (passiv), and 2 woofers (passiv). for small gigs I connect the 2 fr-cabs to the poweramp - for bigger ones I use the output-jack of the fr-cabs(!) to introduce the woofers to the system. question: can you do the same with guitar gear? lets say you have a head and 4 16Ω cabs - 16Ω + 16Ω = 32Ω 32Ω / 2 = 16Ω overall impedance! is it possible to wire 4*12 cabs like that? I know Steve Morse uses 6 (!) cabs along with just one of his signature amps, but he's got an extremely complicated and expensive Bradshaw-switching-thing... __________________ WTB: Ibanez AD202 Analog Delay (european version) Marshall JTM622 + JTMc 220 Marshall JTM600 + JTMc 410 Marshall JTM312 + JTMc 112 Marshall 2558 (silver jubilee) for sale

11-08-2008, 11:16 AM	#2 (permalink)
jtm-series player Senior Member Join Date: Apr 2008 Location: europe/austria/graz Posts: 331	Re: 1 head - 4 cabs? oh come on! no guitar-tecs or wall-of-sound-freaks in here? __________________ WTB: Ibanez AD202 Analog Delay (european version) Marshall JTM622 + JTMc 220 Marshall JTM600 + JTMc 410 Marshall JTM312 + JTMc 112 Marshall 2558 (silver jubilee) for sale

11-08-2008, 02:02 PM	#3 (permalink)
JohnH Senior Member Join Date: May 2008 Location: Wollongong NSW Posts: 640	Re: 1 head - 4 cabs? I think its OK, wire up the whole set of cabs in a series/parallel arrangement as per the individual speakers in a normal cab. Hence, 4 x 16 Ohm speakers in series/parallel makes a 16Ohm cab, 4 x 16 Ohm cabs similarly wired makes a 16 Ohm 'wall' John __________________ DSL401 8412 cab Crate Powerblock 1 x 12 Vintage 30 cab '76 Shergold Masquerader '93 Les Paul Studio '83 Roadstar

11-09-2008, 02:35 AM	#4 (permalink)
jtm-series player Senior Member Join Date: Apr 2008 Location: europe/austria/graz Posts: 331	Re: 1 head - 4 cabs? thx! sounds logic! but where to put the output-jack, and can you still use the cabs in "stand-alone mode"? __________________ WTB: Ibanez AD202 Analog Delay (european version) Marshall JTM622 + JTMc 220 Marshall JTM600 + JTMc 410 Marshall JTM312 + JTMc 112 Marshall 2558 (silver jubilee) for sale

11-09-2008, 02:46 AM	#5 (permalink)
JohnH Senior Member Join Date: May 2008 Location: Wollongong NSW Posts: 640	Re: 1 head - 4 cabs? Maybe you could have a special connector box with 5 jack sockets in it, four for the cabs with the appropriate wiring and one to go to the amp. Then just hook everything up with speaker cables. If you can drill holes and solder it would not be hard to make. The cabs would be unchanged so could still be used on their own. John __________________ DSL401 8412 cab Crate Powerblock 1 x 12 Vintage 30 cab '76 Shergold Masquerader '93 Les Paul Studio '83 Roadstar

11-09-2008, 04:10 AM	#6 (permalink)
jtm-series player Senior Member Join Date: Apr 2008 Location: europe/austria/graz Posts: 331	Re: 1 head - 4 cabs? hey! that sounds great! any idea where I could get a wiring scheme? __________________ WTB: Ibanez AD202 Analog Delay (european version) Marshall JTM622 + JTMc 220 Marshall JTM600 + JTMc 410 Marshall JTM312 + JTMc 112 Marshall 2558 (silver jubilee) for sale

11-09-2008, 05:14 AM	#7 (permalink)
JohnH Senior Member Join Date: May 2008 Location: Wollongong NSW Posts: 640	Re: 1 head - 4 cabs? I don't know, but I could sketch a wiring layout. Maybe a metal box like a stomp box size , with four sockets in a line on one side for the cabs and one on the other to go to the amp? what do you think? John __________________ DSL401 8412 cab Crate Powerblock 1 x 12 Vintage 30 cab '76 Shergold Masquerader '93 Les Paul Studio '83 Roadstar

11-09-2008, 06:31 AM	#8 (permalink)
JohnH Senior Member Join Date: May 2008 Location: Wollongong NSW Posts: 640	Re: 1 head - 4 cabs? like this: John ps, if you do it, we need a photo of you blasting away in front of 4 cabs! __________________ DSL401 8412 cab Crate Powerblock 1 x 12 Vintage 30 cab '76 Shergold Masquerader '93 Les Paul Studio '83 Roadstar

11-09-2008, 08:11 AM	#9 (permalink)
jtm-series player Senior Member Join Date: Apr 2008 Location: europe/austria/graz Posts: 331	Re: 1 head - 4 cabs? wow! thanks a lot john!!! I guess I can even get the two of my left hand to building such a connector box. got to try it!!! for the first try its gonna be my little jtm cabs, but if it works I promise to get another 3 4*10s and post pics of both setups! __________________ WTB: Ibanez AD202 Analog Delay (european version) Marshall JTM622 + JTMc 220 Marshall JTM600 + JTMc 410 Marshall JTM312 + JTMc 112 Marshall 2558 (silver jubilee) for sale

11-09-2008, 05:39 PM	#10 (permalink)
JohnH Senior Member Join Date: May 2008 Location: Wollongong NSW Posts: 640	Re: 1 head - 4 cabs? No problem – one thing that’s important though, an oversight on my part, the jack sockets need to be the plastic type (like on a Marshall amp or similar), so ground does not get connected to the box. My picture shows the open metal type of jack socket, which would end up shorting out one pair of cabs. Or, you could use the metal sockets, with a plastic box. John __________________ DSL401 8412 cab Crate Powerblock 1 x 12 Vintage 30 cab '76 Shergold Masquerader '93 Les Paul Studio '83 Roadstar

11-09-2008, 11:19 PM	#11 (permalink)
Doomhawk Senior Member Join Date: Aug 2008 Location: New York Posts: 133	Re: 1 head - 4 cabs? why don't just run the four 16ohm cabs in parallel off the 4 ohm tap on your head? do you not have enough speaker-outs or something?

11-10-2008, 02:53 PM	#14 (permalink)
JohnH Senior Member Join Date: May 2008 Location: Wollongong NSW Posts: 640	Re: 1 head - 4 cabs? cant see your link J __________________ DSL401 8412 cab Crate Powerblock 1 x 12 Vintage 30 cab '76 Shergold Masquerader '93 Les Paul Studio '83 Roadstar

11-11-2008, 11:08 AM	#15 (permalink)
coldsteal2 Senior Member Join Date: Sep 2007 Location: Chico, CA Posts: 1,555	Re: 1 head - 4 cabs? I used to run four cabs off of my Sunn Coliseum what it had was a "through cab" output on each cab made it easy, i have one of those on my Crate cab to I ran two 18" reverse cabs and two Fender Dual Showman 2 15" cabs (with JBL's) with one head, for years worked great they all had the same ohms so that helped __________________ http://www.youtube.com/user/kroftkarl http://www.soundclick.com/bands/defa...&content=music

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode