Sorado into a homemade cab.

[moenkopi o)))]

I've located two vintage 12" Sunn speakers, one from a combo amp, one from a 412 cab, (listings below,) that I'm thinking of loading into a custom 212 cab and running with my Sorado.  Are there any problems with this idea?  Any specific modifications I should make?

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=270122351250&ssPageName=STRK:MEWA:IT&ih=017
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=260119435592&ssPageName=STRK:MEBI:IT&ih=016

[Johann]

well, the only real problem with that idea is that one speaker is 4 ohms and the other one is 8 ohms, so if you put them together you'd risk sending each one weird power amounts and it wouldn't be good for the amp

[moenkopi o)))]

If I was to pair a different brand speaker, with similar power ratings, to either of the above, am I better off with the 4 or 8 ohm setup?

[stanner]

well, the only real problem with that idea is that one speaker is 4 ohms and the other one is 8 ohms, so if you put them together you'd risk sending each one weird power amounts and it wouldn't be good for the amp

ummm...i "think" thats wrong...
the Sorado has <2> spkr outputs-
the main spkr output is labeled 8 Ohm
the external spkr jack is labeled 4 Ohm
so i "think" an 8ohm and a 4ohm spkr arrangement would work on this amp.
s

[EdBass]

well, the only real problem with that idea is that one speaker is 4 ohms and the other one is 8 ohms, so if you put them together you'd risk sending each one weird power amounts and it wouldn't be good for the amp

Correct. If the speakers were wired in parallel the 4 ohm driver would see about twice the power of the 8 ohm driver, it might sound cool, I've seen stranger setups.
The problem is that you would have a 6 ohm load on an amp that's looking for a 4 ohm, 8 ohm, or 16 ohm load.

ummm...i "think" thats wrong...
the Sorado has <2> spkr outputs-
the main spkr output is labeled 8 Ohm
the external spkr jack is labeled 4 Ohm
so i "think" an 8ohm and a 4ohm spkr arrangement would work on this amp.
s

A 8 ohm and 4 ohm speaker would probably work, but not because the jacks might be 8 ohm and 4 ohms. The Sorado has two output jacks, they are either 8 and 4 ohms, or 16 and 8 ohms. In either case, when you use both jacks they both default in parallel to the lower impedance tap. If you plugged the 8 ohm driver into the 8 ohm jack, and the 4 ohm driver into the 4 ohm jack you would end up with a 6 ohm load on the 4 ohm transformer tap. The mismatch would probably be OK from a safety standpoint, but not what the amp was designed to do, and you wouldn't get optimum performance out of the output stage.
There are tons of impedance posts on this forum, if you do a little digging you will get amp/speaker information ad nauseam.

[Robbie Nuke]

An 8 Ohm and a 4 Ohm in parallel is about 2.3 Ohms, too low for this amp (not 6 Ohms which would be OK, however)! I would highly recommend either finding a third speaker that matches one you have (look for another 8 Ohm, you can run it in series, 16 Ohm, or parallel, for 4 Ohms,  with your existing 8 Ohm speaker.

If you can afford it, though, just do yourself a favor a get a good 2x12 w/ some Jensens or Eminence. Maybe even a Peavy, Crate, Kustom... any good name brand. You have a good little amp there and I wouldn't chance f'ing it up experimenting with a bunch of crappy 30 year old speakers that are worn out at best.

[JoeArthur]

An 8 Ohm and a 4 Ohm in parallel is about 2.3 Ohms, too low for this amp (not 6 Ohms which would be OK, however)! I would highly recommend either finding a third speaker that matches one you have (look for another 8 Ohm, you can run it in series, 16 Ohm, or parallel, for 4 Ohms,  with your existing 8 Ohm speaker.

If you can afford it, though, just do yourself a favor a get a good 2x12 w/ some Jensens or Eminence. Maybe even a Peavy, Crate, Kustom... any good name brand. You have a good little amp there and I wouldn't chance f'ing it up experimenting with a bunch of crappy 30 year old speakers that are worn out at best.

Ed's been having problems with his ohm calculator lately.

8 & 4 ohms in parallel would be: 1/( 1/4 + 1/8) = 2.6667

to split the hairs... as it is... 

[moenkopi o)))]

I think I'll go the safe, 8 ohm Eminence/Jensen route.  Thanks for the help.

[stanner]

well, i did say i 'think'  that would work-pardon me.
for me  i use multiple Sunn amps/cabs and as a  rule always plug one amp into one cab and always make sure the ohmage is a correct match.
sounds good to me.
s