Sunn Coliseum techy question..

[chadinati]

Getting ready to pull the trigger on a Concert Bass, rated 150w @ 4ohms. But I've seen old as hell ads advertising them as 200w @ 2ohms. I currently play through two 16ohm Traynor YT-15's (2x15's)

I've read about ohm's law thousands of times and I'm still a dumbass. All I know is my cabs combined create an 8ohm load. Obviously I would like the head to run at the lowest amount of ohms possible as I'm already worried about it not being loud enough. What would the head output with an 8ohm load?

My plan was to get another concert bass or a coliseum bass, and run each head into it's own cab for maximum rock & rollness. But it would be underworking the heads a **** ton correct? With a 16ohm cab what would the head be running at? Is wiring the cabs to 4ohms possible?

Just trying to figure out what I should do here.. As I have a really loud guitarist & drummer to keep up with (guitar player plays through a 250w sunn coliseum/stagemaster fullstack and a Traynor YBA-1 halfstack together).

I currently play an unusually loud v4 dimed into the two cabs and it's just barely too quiet.

Any help would be appreciated..

[BassmanPaul]

If each cabinet has two drivers and the result is 16Ω then each driver is probably 8Ω wired in series. If you wire the drivers in parallel each cab will drop to 4Ω.

[craig.p]

I don't mean to drag this off into left field, but I have experience with both those heads from the '70s, and I can tell you that those power ratings are optimistic relative to their perceived output. Even with the cabs rewired to four ohms, two Concert Basses won't be enough. Two Coliseums might be. Another dynamic to this is that Coliseums are considered collectibles by many players and because of that often go out at high premiums.

My advice is that you try to make a BIG jump in power, not an incremental one. There are many ways to accomplish this. Also consider your AC/line requirements while you're doing that, and plan accordingly.

[derridiandrift]

Originally Posted by chadinati

I have a really loud guitarist & drummer to keep up with (guitar player plays through a 250w sunn coliseum/stagemaster fullstack and a Traynor YBA-1 halfstack together).

I currently play an unusually loud v4 dimed into the two cabs and it's just barely too quiet.

Try rewiring the speakers in parallel and see what happens. My prediction: you still won't be loud enough.

I'd suggest that you keep the V4 and ditch the cabs. Your band is loud and changing the amp isn't going to help very much. Consider an Ampeg 810. It would be as big as the cabs you're currently using but way more efficient and a great match to your V4.

In a loud band always go big with power. 300 watts of tube amp would suit you just fine if you have the coin.

[billbern]

You guys are probably right about not being loud enough, but in the '70's i used a Coliseum into a 4ohm 4x12 and a 4ohm 1x18 and it was pretty darn loud, could hold my own with two 100wat marshall stacks. What a durable piece of gear that thing ran pushed hard at 2 ohms every night for years.

[craig.p]

The comment about the 8x10 being more efficient than the four fifteens doesn't line up with my experience. (But I admit this was with a late-'70s tiltback, not with the modern kit which may be different.)

Also consider that the 8x10 may roll off much sooner than most 2x15 cabs and therefore MAY become a liability if the OP likes a full tone. If he likes something more "barky" then it won't matter, except I'd still stand by my first comment.

When I owned a V4B head, at one point I ditched my two 2x15 cabs and moved to an SVT cab to save van space. I had to run the head WAY louder and lost lots of my bottom end. Seemed like the amp had to work much harder than before to achieve any given volume level. After a few months I'd had all I could take, ditched the SVT cab, switched to Sunn reflex cabs, and breathed a huge sigh of relief.

[protoz]

Originally Posted by craig.p

The comment about the 8x10 being more efficient than the four fifteens doesn't line up with my experience. (But I admit this was with a late-'70s tiltback, not with the modern kit which may be different.)

I have to agree here. My single Sunn 2x15 keeps up or is louder than the Ampeg 8x10 that is in our practice space. I couldn't imagine the rumble from a pair of 2x15's

You probably just need a more powerful amp to push those cabs harder. I have an Orange Terror Bass for gigs and it keeps up beautifully in a death metal band.