I have two identical cabs I really like. They are 4 ohm cabs. The only amp that I have that can go to 2 ohms is a Quilter BB800 and the advice on their site is not to run it at high volume with a 2 ohm load.
So should I get another Quilter and run a stereo or biamp set up?
Thanks for any advice!
BFG
If you're going to buy an amp just buy one that goes down to 2Ω and be done with it. There are fewer amps today that will handle a 2Ω load but among others Mesa has 800-watt rms amps that will handle a 2Ω load. A LOT, but not all, of the older Eden WT amps will handle a 2Ω load. Drawback with them is they are the class AB amps and typically weigh around 19 to25 or even 30-lbs. They pretty much all sound great, they're just heavy and old.
I think you are mistaking running two cabs at once as running in "bi-amp" mode. Bi-amp is running one amp that can send the lows to a cab with woofers and the high mids and highs to a cab with a tweeter and typically has a "crossover control" that allows you to set what frequency you want to use to divide the two signals. That was real popular back in the 80's when GK put out their RB800, which put out a total of 400-watts rms.
If you ran that RB800 in bi-amp mode, it would send 300-watts with the low frequencies into a woofer cab and 100-watts with the highs and high mids to "high" cab. The high cab was typically a full width tweeter horn back then like you'd see on a voice of the theater cab above the woofer. With modern day cabs, it would be a waste of a full frequency cab to run the highs into one of them because the only thing producing sound in such a 212 would be that round tweeter horn. Those additional two 12" speakers would be totally quiet in the "high" cab. Nothing would come out of the woofers in that cab. So don't confuse bi-amp with a dual-mono set up. That's dual-mono is also sometimes called stereo although it's not a true stereo where different parts of the signal are panned to one or the other side. Both sides would produce the same sound, so I think dual-mono is a better description of it.
I have an Eden WT500/800 that has two power channels. Each power channel will produce 400-watts rms into a 4Ω load. So I can plug a separate 4Ω cab into each power channel and each cab will get 400-watts. If I only want to use one cab, my amp will bridge those two power sections together and put out 800-watts into one 8Ω cab. Has to be an 8Ω cab for me because each channel has to be operating at a 4Ω load to run bridged and it has to go into 8Ω because, as best I understand it, it has to run those two channels together with an internal series connection to produce a bridged output. The much later Eden WT800C could bridge into 4Ω, but that's because each channel could handle a 2Ω load themselves.
If you don't want to buy an amp that will handle a 2Ω load, another option is to run a master/slave amp scenario. That allows the "master amp" to send a preamp signal directly to the power section of the second "slave" amp. The only thing that works on the slave amp is the master. So you set it up and adjust both amps to the sound blend that you want and then any changes to the EQ in the master amp will automatically be carried through to the slave amp. You'll get two amp+212 cab rigs that sound exactly the same. Even if your using different brand amps, they will produce a sound that matches the master amp because the master amp is supplying the EQ and character of that amp and the slave amp is only using its power section. Be aware though that if you turn up one amp, you will have to adjust the master of the other one to keep that balanced sound you had before you decided to increase or decrease the sound level.
I did that for a while before 2010 when I was using separate amps for my two cabs and then used that same trick again in 2016 to bypass the preamp in a small Peavey 112 combo with the Eden WT preamp built into my WTDI pedal (DI with Eden WT preamp included) by plugging my pedal into the effects-in/return. Suddenly that little Peavey 112 combo sounded like my Eden amps and cabs.
To accomplish that with a master-amp/slave-amp rig, you just have to run the effects-out/send from the master-amp to the effects-in/return of the slave-amp. Depending on how your master amp's preamp is made you may need to use a Y cord in the middle of that connection so you can send that effects-out signal both to the slave amp and back into the master amp's effects-in/return as well.
But really, if you have to buy another amp instead of using something you already have, just buy an amp that will handle a 2Ω load and be done with it.
