2 channels or bridged?

[u84six]

Question for the amp/pre crew. Do any of you use multiple channel setups? I can see an advantage to that if you're going for always having a clean bottom sound on one channel, and then some grit on another. Is that your setup?

On the other hand, bridged gives you more power.

[RickenBoogie]

Only if the load is right, and the speakers can handle the increased power. Usually, about HALF the rated RMS wattage.

[DD_BigBottom]

A two channel set up comes in handy for running a bi-amp set up, running mixed speaker
sizes full range, running multiple speakers that would take the load speaker below the
minimum load rating of one single channel amp, etc.

Example, running 4x10" cabs stacked on 1x15" cabs. A two channel amp works perfect
for this so if the two different cabs have different speaker sensitivities, the output levels
of each type can be controlled independently and get them to sum together as they should.

Bridging a two channel allows you to combine the output of both channels into one load at
double the impedance. You don't get any extra magic power, you're just putting the two
channels together in series the same as stacking two 1.5 volt batteries in a 3 volt flashlight.

The minimum allowed load impedance of a bridged amp is 2X the min load of the single channel.
In other words, if the min load of a two channel amp is 2 ohms per channel, then the minimum
useful load in bridged mode is 4 ohms.

Example, you have a nice pro 2-channel amp rated at 600 watts per channel at 2 ohms and you
have an 8x10 speaker cab rated at 800 watts at 4 ohms. This is the perfect situation to bridge
the amp. You get 1200 watts of power potential driving the 4 ohm cabinet and with some power
amp headroom to spare. With this headroom you just don't want to drive the amp into clipping
very often.

[u84six]

Thank you for all the info. My plan is to get a 2 channel amp and use 1 cab per channel so that I can tweak the settings independently (like you described). I'm thinking about getting a 2x12 and 2x10. as much as I love 15" speakers, I don't think they're necessary anymore. I'm also thinking of getting 2 preamps for each channel, too. Have you seen setups like this? Also, what would you recommend for a power amp? I know crown, qsc, and crest. Is there any model that you favor?

[DD_BigBottom]

Originally Posted by u84six

Thank you for all the info. My plan is to get a 2 channel amp and use 1 cab per channel so that I can tweak the settings independently (like you described). I'm thinking about getting a 2x12 and 2x10. as much as I love 15" speakers, I don't think they're necessary anymore. I'm also thinking of getting 2 preamps for each channel, too. Have you seen setups like this? Also, what would you recommend for a power amp? I know crown, qsc, and crest. Is there any model that you favor?

I'm a bass player and worked as stage tech for other bass players and have had the opportunity to build and
play through all kind of rigs.

I've heard of setups using 2-channel preamps for each channel of a 2-channel amp but the setup can get
complicated real quick. For instance, you are running your bass in stereo (neck pickup to one amp and the
bridge pickup to the other) and then you want to use A/B settings on each pickup. Neck pick up set up with
A = Big, B = Bright, Bridge pickup A = EFX, B = Distortion, etc.
This a lot to keep track of and set up time could be a disadvantage.

Most of the time one two-channel preamp is more than plenty for any kind of setup you would use on stage.
Say you are running your bass normal and then going into stereo EFX. If you connect your bass directly into your pedals,
then you would hook up your stereo EFX out into separate channels on preamp and amp. Or you could run
the bass directly into your preamp and then EFX loop your stereo device and then go into the stereo amp
inputs. There are many ways to set up a two channel rig. I would set up the 2x12 channel as my clean
big-bottom channel and then the 2x10 channel as my EFX/Lead channel.

As far as amps go everyone has their own favorites. I used to work at QSC so I must admit that I am biased
in favor of QSC amps and the PLX 1802 would be my first choice for a bass rig. Crown is also good and
the XTi1000 would be my 2nd choice and I've seen some killer deals on the net for these. There are many
other good brands on the market as well, I just like to keep resale value in mind when I invest in equipment.
Be sure your preamp has enough output voltage to drive the power amp you choose.
Both of the amps I mentioned require more than 1 volt of input signal to drive the amp to full power.

Whatever amp you choose, you want it to be able to run a 2 ohm load in stereo mode so if you want to bridge
it, it will be able to drive a 4 ohm load.