original speaker set-up for Concert Bass Amp

[ricktunesmith]

I've been using a 1976 Sunn Concert Bass head exclusively since I bought it used in 1981. I originally used a 2-15 Acoustic cabinet with it. Around 1985, I traded the cabinet in for a 1-18 Bull Frog (BFI) and a 1-15 Bag End cabinet. I think these are 8 ohm each. I use the BFI for jobs and the Bag End for practice.

The band I play with now is pretty loud. My volume is usually around 6 or 7. The bass setting is usually around 6, mid 5 and treble 4 with the bright switch off. I also use a fender precision with bright flats. The Sunn head has always given me that good Motown sound, but at this volume the bass has been breaking up.

Should I use the Bag End and BFI together? If I need to use both of my cabinets, should I plug each one into the head (speaker 1 and speaker 2 jacks) or should I plug the speakers together? Do I need a different cabinet? Any ideas on what type I need? What was the original cabinet set up for this bass amp? Is what the head was designed for and sounds best with?

[Geoff]

If you are playing at higher volumes, your Concert Bass alone might not have enough power for the clean output you expect.  According to the Sunn Museum, it's rated at 150W RMS?  By today's standards, that's a tepid output rating.  Even the low- to mid-end heads by the common brands (Ampeg, GK, SWR, etc.) boast 200-400W RMS output, some with an additional biamp capability for highs.

Though I thoroughly think the Sunn heads are pretty sweet, you might find that in your current playing situation, it alone just doesn't have the power you need.  You could always daisy chain off another CB head and use them together.

Also consider using speakers with higher efficiency ratings.  This will help get the most volume out of your amp.

As far as the two cabinets go, I'd say to try it out!  See what it sounds like.  Plugging each cab into paralleled outputs 1 and 2 respectively should work fine.  Assuming they're both 8 ohm cabs, the amp will see 4 ohms.  Assuming the wiring at the cabs' input plates is correct, daisy chaining the cabs will work the same.

[ricktunesmith]

Thanks Geoff. I'll try to run both cabinets at the bigger jobs but it will be difficult to load them into my Mitsubishi. I don't have the money available to upgrade the bass head at this time. Hopefully running the cabs parallel will help.

[bcomnes]

Have you considered using a Concert Slave...you can pick these up used for $50-$100...They just plug into the Pre-amp out jack on the back and  back into the Power-Amp in jack....I've seen a lot on eBay recently.....that gives you 150W X2, and only one preamp section to mess with.... one head  for each cab, and very consistent sound.

[ricktunesmith]

Thanks, I've never heard of a concert slave. I'll check that out.

[Geoff]

Concert Slave is a great idea.  Also consider any of the other Slave-series or similar amps (Coliseum Slave, Power+, etc. come to mind).  Since you aren't running in stereo, matching the power of the two amps isn't a concern.  More powerful, the better.  bcomnes is right that slaves can be had pretty affordably.  I've found that a lot of people don't even know what they are because they only have a sensitivity knob and don't look like a traditional power amp.

Good luck!

[bcomnes]

check out

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=923531647

[RichBriere]

Rick......along with all of the other fine comments that you've heard here you might consider one other. I'd consider selling the BFI and picking up a BAG End 2x10 to go with your 1x15. First of all, it'll sit on the front seat of your small car. The efficiency should match and you'll get a much smoother tone. By adding mids and/or highs you'll also find that you get a lot more punch for the buck. While BOOMING bass sounds good "onstage", it's usually the first thing to get muddy and ends up being lost 10' in front of the stage.  

Bass-ically Yours,
RB

[ricktunesmith]

Thanks Rich,

I'll check out the 2-10. I'm not a big fan of 10's because they seem to be missing something onstage. I wasn't aware that the 18 didn't project as well.

Rick

[RichBriere]

Hi Rick.......10's are mysterious little buggers. If you look at any of the "pro" bass amps today you'll find that most of them are heavy users of 10" speakers. Look at the "King of Bass Amps", the SVT.......they brought out 10's when nobody else was even thinking about using them. Stick 8 of them in a cabinet and you can get both definition AND volume........while still getting killer tone.

Stage sound is a funny thing. Many bass players try to get a "heavy" sound on stage. IMHO, this is the worst thing that you can do. You use up wayyyyyyy too much of your amps available headroom as it tries valiantly to reproduce frequencies that demand maximum pump........and, for what?........In my work with some major acts I learned quickly that the "on-stage" tone for many of my bass-playing "heros" was more closely related to a banjo than a double bass. Stand 50' in front of their amps, however, and you're listening to thunder..... because bass frequencies are much longer and need to travel further to really open up.    

Bass-ically Yours,
RB