I have two questions...
1) I have a 450w Behringer head which says it's designed for 1 x 4 ohms OR 2 x 8 ohms. Both my cabs are 8 ohms each, but one is 250w/500w (1x15) and the other is 500w/1000w (4x10). will this configuration work ok without starting a bonfire?!

2) I want to purchase a used Rogue RB120 combo for both practice and as a stage monitor. The one I'm contemplating buying is used, everything on it works and it is in great shape. Dude wants $65 for it. Good deal ???

Any help or advice would be great !!!

When you have two 8-ohm cabinets, they equal 4 ohms ( 8 divided by 2 = 4). The Behringer owner's should tell you how many watts it puts out a 4 ohms, which would be the minimum load. My guess is that the 450 watts is into 4 ohms, and about half that at 8 ohms). The wattage ratings on your cabs indicate how many watts they can handle at certain ohmages. The higher wattage figure is probably at lower ohms. With both cabs hooked up to the Behringer, each can would be getting roughly 225 watts -- no worries about fire. Either cabinet alone is still rated for more watts than the Behringer can deliver, so you're safe running wither cab by itself, too.

I'm not familiar with the Rogue, but the street price on it when they first came out appears to be around $200. $65 isn't a bad price for that much power -- it's a 120-watt amp. BUT, most of the comments I can find about it online are negative: reliability isn't listed as good.

Yeah, I'll second the Laklander on the Rogue. It's not a very good bass amp, even for practicing. Even on Ebay it hasn't been able to sell for more than about $40 at best. Do yourself a favor and get a cheap Danville or a Behringer combo. It's worth the extra $20 you would have to spend.

Thanks guys. On the subject of the Behringer 450w and the two cabs, with the specs as you know them to be, how high can I turn the volume up and still keep from clipping? What is the gain for, and how can I best utilize it in this configuration?

I'm not familiar with the Behringer controls. Does it have a clip indicator light on the front panel? Having the clip light flash on occasionally isn't a bad thing, but you don't want to have it come on and stay on. Here's what Genz-Benz says about the Clip (or limiting) Light on my Shuttle:

"The “LIMIT” LED indicates that the power amp is near its maximum power and has entered its soft clip/limit mode. Under high output conditions this LED will light with the strongest pulses of the signal. Driving hard beyond this point will cause the amplifier to gradually begin to clip."

If you continually see that light and you haven't yet reached the volume level you want, you may need a more powerful amp. If you have no light, you'll just have to, literally, play it by ear. You should have sufficient headroom on your amp to allow you to keep the Vol & Master Vol knobs at less than full. If you have to crank the amp to be heard, you probably need more power -- or a softer band. Genz-Benz says that the Shuttle Vol is usally run anywhere between the 9 o'clock and 3 o'clock positions on the dial. I have never run my master Vol ( pushing 600 watts) past Noon.

I assume your amp has, at least, Gain and Volume. Some amps, like my Genz-Benz Shuttle, have Gain, Channel Volume and Master volume. In this setup, the Gain is used to overdrive the preamp -- my GB has a single AX7 tube preamp. This is to give you the sound of n all-tube amplifier being overdriven while using a solid-state power amp. If the amp has only Gain and volume, try cranking the gain and keeping the volume low to get tube distortion -- the higher the Gain, the more distortion. If you have Gain, Vol & Master Vol, the Master Vol simply sets the overall volume.

I also have a Line 6 Lowdown 110 with Drive and Master Vol only. On thisamalso gives you distortion. I very seldom overdrive my preamp becasue I prefer clean sound and it fits best with the music I play. If I were in a metal band or doing classic British rock like Cream or Deep Purple, I'd use some light OD.

Yes there is a small red light on the panel marked "clip". I've only seen it come on a few times, and then it only blinks 2 or 3 times. When this happens, I generally just tweak the volume down a hair and it goes away completely. It also has an analog meter on the front, and the needle moves to the rhythm of my playing, rarely going over "noon".

With that said, and I need just a bit more volume, should I turn the gain up some? And is there any rule of thumb for gain vs. volume? i.e. If the volume is at Noon, the gain should always be somewhere lower than noon? And so on... ?? I know on the one hand I'm being extra, extra careful not to clip or damage anything. But I would like more volume.
Also, can I use a 120w combo as a monitor hooked up to this head in this particular config ?
You've been extremely helpful and I want to make sure I "get it right".
Thanks.

I run Gain and Volume on my Genz about equal -- at noon or slightly above. If you're happy with the sound you're getting, try boosting the Volume till you get the loudness you want. I'd say the meter being in the middle is a good sign that you have headroom. Again, you don't want the needle "pegging" -- staying all the way to the right all the time. Occasional ventures into red are OK.

There are a few ways to use the 120W amp as a monitor. If the Behringer has a line out and the other amp has a line in or effects in, run out of the Behringer using a regular guitar cable -- NOT a speaker cable -- to the input of the other amp. You should be able to control the volume separately, but if you turn up the Behringer, it should also make the other amp louder.

Another way would be to run out of the Behringer line out jack to the front panel input of the second amp, but that might not work so well because of impedance mismatch between the two. A line out signal is usually a lot hotter than a guitar signal and might distort the second amp easily.

Yet another way to do this would be to run a splitter A/B box that allows you to run both A&B at the same time. Plug the bass into the box and run one cable out of output A to the Behringer, a second from output B to the other amp. This gives you independent volume control at each amp. Radial Engineering makes the Bigshot AB Y box that will allow you to do this. $80 at musiciansfriend.com. http://guitars.musiciansfriend.com/produ...cher?sku=153931

You could do this with a mono Y cord that has a 1/4" plug that splits into two 1/4" female jacks, then run a standard guitar cable from the each side of the Y to each amp. Like this one ($7): http://accessories.musiciansfriend.com/product/Live-Wire-14MDual-14F-Y-Cable?sku=331080

The Behringer has line out and DI. The 120w only has line out and headphone jacks, will that work?

It does have a send/return jack. Maybe that's the one I'm looking for ???

A send/return jack is a stereo jack where either the tip or ring (the metal shaft just behind the tip of the plug) will be the signal input and the other will be the output. The common wiring is tip send, ring return (TRS). It's designed to be used with a stereo Y cord that has two mono 1/4" jacks on the other end of a stereo jack.

Try taking a standard guitar cord from the Behringer out to the send/return on the other amp. Plug it all the way into the send/return jack and see if you get signal to that amp. If you don't pull the jack out slightly and you should get signal. I suspect you'll have to pull the plug out slightly to get a signal to the second amp.

This may be enough of a connection to allow you to use it this way. Otherwise you'll have to get a stereo Y cord that has the 1/4" stereo plug and two 1/4" female mono jacks on the other end. Then you can run a cord from the Behringer into whichever side of the Y jack is the input.

If this works, that's great. The cheapest and simplest option may be to get that mono Y cord I mentioned previously and send two signals from you bass.

So my bass would then have two "pigtails" running from it, right?
Ok, now at what point in the "chain" would my wireless system need to appear? Remember, I currently have the BOSS GT board as part of my rig.

Bass, GT, <wireless>, combo, Behringer amp.......

I'd always put the wireless first so it gets the cleanest signal from the bass.

Of course that makes sense, so the wireless receiver plugged into the Behringer, wireless transmitter plugged into..... where? The effects pedal, or guitar? I guess I can't envision exactly how everything would be hooked up when the wireless is part of the setup !! (Somebody hand me a dunce cap !)

The wireless transmitter has to go into the bass. You could run a standard guitar cord from the send jack on the front of the Behringer to the input of the GT6, then come out of the GT6 to the effects return on the front of the Behringer. That way you could plug the receiver right into the Behringer and the effects loop will handle the GT6.

If you don't want to use the effects jacks, put the receiver out into the input of the GT6 and the output of the GT6 into the Behringer. Then run the line out on the front of the Behringer to the combo effects in or input, whichever sounds better.

Aha ! I think I've got it !!
Thank you so much..... I may be a bassplayer of some years, but definitely a noob when it comes to wireless. I'm brand new to it !!!

I've never used wireless, but the new units are pretty good and certainly give you more freedom of movement onstage. Good luck!