Connecting 2ch poweramp and two speakers

Can the amp bridge into 4ohms? Lots of old amps don't.

You may have channel linking on board the amp.

 

Either add a second parallel jack on one of your cabs or build a simple cable box. One 1/4" jack for input from the amp to two 1/4" output jacks for speakers, the box can be plastic or metal.

 

Because that is not what I was talking about, that is for instrument level not speaker (high power). I don't think anyone makes a commercial box for speaker level. It would be about $30 retail for the parts at the most. Drill some holes in a project box and wire all the tips together and all the sleeves together inside the box.

That box would split your bass to two different amps, a stereo preamp or two mono preamps.

 

Functionally yes, the box just being a bit more reliable than a "Y" cable.

 

Are you sure you NEED to bridge your amplifier?
If your cabinets only have 1/4" jacks I suspect they may have lower power handling.

Can you give more detail on your cabinets?

 

Never ever bridge an amp using 1/4” Phone plugs! They simply cannot take the voltage and current put out by an amp in bridge. People do it but it is simply not advisable for your personal safety and the safety of your equipment. If your cabinets only have phone sockets replace them or have them replaced with NL4 type Speakon connectors. it’s a simple job and cheap to do even if you have to pay to have them changed. In bridge both the tip and the sleeve of the plug are live with respect to ground. If the plug pulls out of the socket and shorts, as they do, you short the outputs of the amps to each other. that’s not very good for the continuing operation of your amplifier.

 

I understand perfectly and my comments still stand. Once you get past a couple of hundred watts phone connectors are completely inadequate for the duty. Have them changed out for Speakons.

In case you don’t understand how bridge works, one channel is fed your signal. The other is fed an identical one but 180 degrees apart. Thus as one output goes positive the other goes negative by the same amount. Accidentally shorting these together will cause damage to your power amp.

Speakons can’t short during connect and disconnect. Phone plugs do - every time.

 

Additionally, I have used stereo power amps since the early Eighties, the first of which I designed and built.. I’ve yet to feel the need to bridge any of them. I run mine parallel moro so each output carries an identical signal. I hang a 4Ω cabinet from each one. This is the same as I have done from day one.

 

What you need is a signal level splitter Y cable to split the output of the comp into 2 outputs to drive the stereo inputs if the amp. Presumably you are using the XLR output from the 160, and your amp has XLR inputs so all you need is an XLR female to 2 XLR make splitter Y cable. Standard stuff for pro audio shops.

I recommend against bridging for this application. The amp's ratings skirt around 3 ohm stereo and 4 ohms bridged operation which may be that under hard drive conditions the amp may not perform as intended. Operating at stereo 8 ohms is only a dB or so lower maximum SPL anyway.

 

I was not suggesting that you change anything per se. The difference in volume between an 8Ω cabinet and a 4Ω version is not all that much. If you switch both cabinets to speakon you will be safe from an accidental shock. Our friend @agedhorse can attest to how bad a shock you can get from an amp in bridge.

 

With big amps, bridged voltages can be high enough that you may wet your pants if not seasoned to shocks. There are amps now that swing >250V peak.