Speaker Cabinet Alterations

Fran · Post by **Fran** » Mon Dec 22, 2008 2:04 pm

Lucky me has just gained a battered old 4 x 12 cab loaded with Celestions fo' free. I intend to half it or build a seperate 2 x 12 from the cab and its components due to transportation reasons.
From a wiring point of view is this a simple task? I dont get the series and parallel thing, is it to acquire the right ohms to match the head?
I'm confident with the structural work just know nothing about the wiring. I was thinking i could use it as either an extension to the Marshall combo or maybe even with the Crate Powerblock to get more bass projection.
Any advice appreciated.

Post by **Mike** » Mon Dec 22, 2008 2:13 pm

Yeah mate, it's a complete doddle. Let me know what ohmage the speakers are and what ohm your amp(s) can take and we'll sort it out.

Post by **Hurb** » Mon Dec 22, 2008 2:14 pm

pics.

Fran · Post by **Fran** » Mon Dec 22, 2008 4:54 pm

Nice one mike.
I've not collected it yet hurb, my mate just wants it out of his way asap but he's keeping his 1970's Orange bass head. I told him it should fetch over a Â£1000 on ebay. He uses a Trace Elliot combo these days.

Post by **Mike** » Mon Dec 22, 2008 4:55 pm

Oooooh

is it an Orange cab or a Marshall thing?

Either way Celestion speakers in a 4x12" for free is awesome.

Fran · Post by **Fran** » Mon Dec 22, 2008 5:22 pm

Mike wrote:Oooooh

is it an Orange cab or a Marshall thing?

Either way Celestion speakers in a 4x12" for free is awesome.

I dont think its an Orange cab, he does'nt think it is anyway. Maybe old Carlsbro, theres a lot of that stuff around here with it being locally made.

Sloan · Post by **Sloan** » Mon Dec 22, 2008 9:53 pm

Please figure out how to make it into two 2x12's that can LOCK TOGETHER to form a 4x12. plz

Post by **Mike** » Mon Dec 22, 2008 9:55 pm

Fran wrote:
Mike wrote:Oooooh

is it an Orange cab or a Marshall thing?

Either way Celestion speakers in a 4x12" for free is awesome.
I dont think its an Orange cab, he does'nt think it is anyway. Maybe old Carlsbro, theres a lot of that stuff around here with it being locally made.

Carlsbro is good solid stuff in my experience. It could breathe new life into your DSL401

Fran · Post by **Fran** » Sat Jan 03, 2009 9:18 pm

Okay. I finally picked that cab up. Its a 'Leech Man professional', i took a look inside and its got MacKenzie speakers in it... not too bad for free. My mate used this with his 100watt Orange head bass amp.
Its got a big bassy sound and sounds great with my Marshall JCM 2000. Individual stompers dont sound so great with the Crate Powerblock but my Korg AX1000g multi-fx sounds good with the crate. I suspected this, Tubescreamers only ever seem to sound good with valves.
I've had a measure up and this cab is 8" smaller than my BNP cab, i feel its a shame to butcher it up and hoping that 8" less will fit it into the Fiat Brava easily. See whatchya think..

Will · Post by **Will** » Sat Jan 03, 2009 9:43 pm

Sloan wrote:Please figure out how to make it into two 2x12's that can LOCK TOGETHER to form a 4x12. plz

Oh man, this would be so awesome. You could make some sort of giant amp zord at the end of every episode.

Sloan · Post by **Sloan** » Sun Jan 04, 2009 12:28 am

That looks liek a BASS CAB?

Fran · Post by **Fran** » Sun Jan 04, 2009 1:15 am

Sloan wrote:That looks liek a BASS CAB?

I think it is. But it sounds good.

Post by **Mike** » Sun Jan 04, 2009 9:55 am

ROCKIN'

Fran · Post by **Fran** » Sun Jan 04, 2009 1:03 pm

Whats the science on this Mike? I know amps like the Fender Bassman were initially a bass amp but used more for guitar, do bass speakers move less Air or something because of the frequency?

Post by **Mike** » Sun Jan 04, 2009 1:05 pm

Nah they're just generally built to handle bass frequencies at higher volume rather than fart out (or blow in extreme cases), you might find the cab dark as a result, but the Marshall is a bright amp so I would imagine they sound great together.

Post by **Doog** » Sun Jan 04, 2009 1:09 pm

I've found the main difference between guitar and bass cabs tonally is the bass cabs tend to sound more scooped in the midrange- and obviously a little more low endy.

Fran · Post by **Fran** » Sun Jan 04, 2009 1:14 pm

Thanks guys. I found loss of mids/highs, but that suits my current situation. And yes, the Marshall does match well.
Is there an easy way of finding out the ohms rating of the cab? I suppose i need a multimeter for this? If its wired at 4ohms it does'nt match the Marshall. The Marshalls output is for between 8 - 16 ohms.

Post by **Mike** » Sun Jan 04, 2009 1:19 pm

Fran wrote:Thanks guys. I found loss of mids/highs, but that suits my current situation. And yes, the Marshall does match well.
Is there an easy way of finding out the ohms rating of the cab? I suppose i need a multimeter for this? If its wired at 4ohms it does'nt match the Marshall. The Marshalls output is for between 8 - 16 ohms.

Yeah, you could connect a speaker lead to the cab and use a multimeter set to ohms (<200 setting) to measure the resistance between the tip and the sleeve of the end of the speaker lead. Since impedance is a frequency dependant quantity and you're measuring resistance the reading will be a bit below what the cab impedance is, so for example if you read 6 ohms it's an 8 ohm cab, 12 ohms it's a 16 ohm etc.

william · Post by **william** » Sun Jan 04, 2009 1:57 pm

Fran wrote:Whats the science on this Mike? I know amps like the Fender Bassman were initially a bass amp but used more for guitar, do bass speakers move less Air or something because of the frequency?

really, they should move MORE air, for the same reason. bass speakers generally have longer travel, and have larger cone diameters, because they have to move alot more air to project those low frequencies.

have you ever played with an analog synth, and noticed that whe you play the low low octaves, its like they just arent audible? I remember playing around with subbass sine waves on my microkorg, thru my infiniti bookshelf speakers (with like 6" cones), and when i wasnt hearing the tones anymore, i looked at the drivers. they were moving SO slowly! i realised then why bass drivers are made larger.

anyway, that cab looks awesome. I will be trying to get ahold of something similar for my bassless setup.

Thom · Post by **Thom** » Sun Jan 04, 2009 2:08 pm

Good score Fran

Glad to see the Crate still getting an airing!