convert workingmans 4x10 into a 2x10 cab

dannysin · #1 03-27-2010, 11:15 AM

I have a 4x10 workingmans cab powered by a swr workingmans 4004. One of the speakers fried due to a drunken overdriven jam session. I have chances to play right now but due to funds I cant replace the speaker that blew...

I am thinking about cutting the cab in half, making it a 4ohm cab with 2 10's... this will run @ the full 400 watts correct? CAN THIS BE DONE???

I'm dying to play and just wanna make this happen, I'm not too worried about killing the speakers in the long run, I just don't wanna fry the amp. Thoughts???

jmseeley · #2 03-27-2010, 11:20 AM

thats what im going to do.. my super redhead came to the same demise.. i still need to load it .. when i do.. i'll be putting speakers that can handle the full power of the head .. and im going to drop the internal cab to 4 ohms.. but note you may not be able to use an external cab with this set up.. if you do, turn off the internal speakers to avoid ohms dropping too low.. i have abused my swr entirely way to much in the last 3.. its held up nicely anyway though and i would recommend swr to anyone who would treat it well.. it should last for many many years treated properly.. and without the drunken jams.. save that for a cheapo

dannysin · #3 03-27-2010, 11:31 AM

OK, so... it should be cool as long as I don't plug other cabs into it reducing the ohms further correct??? I am imagining it to be pretty thunderous with 400watts into just the 2 10's.

jmseeley · #4 03-27-2010, 11:44 AM

correct .. and yes it should up the output because of the dropped ohms. so of course you'll want your new speakers to be able to handle it as well

dannysin · #5 03-27-2010, 11:53 AM

well, they are going to be the same 10's from the cab... no idea what they are rated at besides both being 8ohm speakers! now ya got me nervous!

BassmanPaul · #6 03-27-2010, 01:39 PM

Why not just sell the 4x10 for what you can get for it and buy a 2x10. Butchering a cabinet will only make it worthless when it comes to resale. It would be much better in the long run to just replace the blown driver.

Paul

LesS · #7 03-27-2010, 01:56 PM

My opinion -
No - I would not modify it into a 2x10.
With 400 watts, the two tens would be pretty easy to blow.

If you don't want to put much money in it now, just look around for a low cost 8 ohm driver (should be easy to find) to hold you over until you can replace it with a proper driver.

If you have an amp that would handle it, you could run the speaker temporarily as a 3x10 - wire the three 8 ohm speakers in parallel (2.7 ohms).

BassmanPaul · #8 03-27-2010, 03:54 PM

Quote:

Originally Posted by LesS

My opinion -
No - I would not modify it into a 2x10.
With 400 watts, the two tens would be pretty easy to blow.

If you don't want to put much money in it now, just look around for a low cost 8 ohm driver (should be easy to find) to hold you over until you can replace it with a proper driver.

If you have an amp that would handle it, you could run the speaker temporarily as a 3x10 - wire the three 8 ohm speakers in parallel (2.7 ohms).

The problem with this as I see it is that a cheap driver is going to degrade the cabinet and probably blow. Wiring as a tri 10 will cause the blown speaker to vibrate in sympathy with the others. If it has a rubbing voice coil it will distort. If you remove the bad speaker the resultant hole will completely unload the other speakers and destroy them in short order.

Replacing the blown driver with an identical one is the best possible solution.

Paul

LesS · #9 03-27-2010, 04:39 PM

"The problem with this as I see it is that a cheap driver is going to degrade the cabinet and probably blow. Wiring as a tri 10 will cause the blown speaker to vibrate in sympathy with the others. If it has a rubbing voice coil it will distort. If you remove the bad speaker the resultant hole will completely unload the other speakers and destroy them in short order.
Replacing the blown driver with an identical one is the best possible solution.
Paul"

He said he can't afford to replace the speaker right now and I was trying to suggest a possible low-cost solution based on that.

johnk_10 · #10 03-27-2010, 04:57 PM

i definitely wouldn't go to the trouble of cutting it in half. the cab wouldn't be very loud and would be pretty much worthless (in resale) after that. i'd beg or borrow to replace the speaker and then stop pushing it beyond its limit.

dannysin · #11 03-28-2010, 08:47 AM

OK, so I want to do the 3 speaker thing... seems like the best idea. can someone help me with how to wire them from the input jack?

LesS · #12 03-28-2010, 09:04 AM

As long as your amp can handle 2.7 ohms, you just wire the + on the terminal to the plusses on the three drivers and the minus on the terminal to the minusses on the three drivers.
You could leave the bad driver in there, or a better choice would be remove the bad driver, and plug the hole with a piece of plywood (approx 11 inches diameter).

dannysin · #13 03-28-2010, 09:05 AM

min. impedance is 4ohms

is there another way to wire them?

stflbn · #14 03-28-2010, 09:14 AM

I think this is a recipe for you to end up with no working cabinet, or usably decent cabinet. Often the dangled carrot of saving money ends up costing more money in the end.

Not sure if it was mentioned, but you could just rewire the existing cabinet as a 3 x 10 if one of the speakers is blown. This way you would not ruin a desirable 4x10.

Honestly, if you don't want the 4x10 I'd sell it and buy what you want.

.

Quote:

Originally Posted by dannysin

I have a 4x10 workingmans cab powered by a swr workingmans 4004. One of the speakers fried due to a drunken overdriven jam session. I have chances to play right now but due to funds I cant replace the speaker that blew...

I am thinking about cutting the cab in half, making it a 4ohm cab with 2 10's... this will run @ the full 400 watts correct? CAN THIS BE DONE???

I'm dying to play and just wanna make this happen, I'm not too worried about killing the speakers in the long run, I just don't wanna fry the amp. Thoughts???

dannysin · #15 03-28-2010, 09:33 AM

"Not sure if it was mentioned, but you could just rewire the existing cabinet as a 3 x 10 if one of the speakers is blown. This way you would not ruin a desirable 4x10."

How do I do this and be ABOVE 4ohms??

tdogg · #16 03-28-2010, 09:40 AM

Quote:

Originally Posted by dannysin

"Not sure if it was mentioned, but you could just rewire the existing cabinet as a 3 x 10 if one of the speakers is blown. This way you would not ruin a desirable 4x10."

How do I do this and be ABOVE 4ohms??

this is a BAD idea. you can wire them to be above 4 ohms (series wiring would be 24 ohms right?). but taking out a speaker will change the volume/driver ratio and change the tuning of the cab. more than likely you will end up with a cabinet that will be unsatisfactory with 3 or 2 drivers. and the chances of you blowing another driver go up exponentially. i would say either scrape together a few bucks for another driver or build a seperate 2x10 box so you dont destroy your 4x10 box.

Pilgrim · #17 03-28-2010, 09:41 AM

If the OP means LITERALLY cutting the cab in half, the result will probably be a mess. a ruined cab, no design to make it work, and an unsatisfactory result.

if it was a good cab before, it will be a good one with the correct speaker in it, restored to the original working configuration. If there's no $$ to repair it, park it until there is.

dannysin · #18 03-28-2010, 09:45 AM

^ yup... parking it, it's a great cab. now off to find some POS to tide me over. Thanks guys.

tdogg · #19 03-28-2010, 09:47 AM

Quote:

Originally Posted by dannysin

^ yup... parking it, it's a great cab. now off to find some POS to tide me over. Thanks guys.

good call, wrecking that cab is something ou would most likely regret. what area do you live in? maybe the TB gang can watch for a cheap cab for you.

dannysin · #20 03-28-2010, 09:52 AM

I'm in Manchester NH. I just put an ad up on CL looking for any cab to trade for a fender telecoustic guitar... it has been a year since my amp worked, didnt even have it with me for 6 months, now I have chances to play but cant and am going CRAZY.