Bi-amping 1 cab

[J42]

If I am Bi-amping and plug both amps into a 8ohm 4x10 cab (input jacks are wired parrallel) does this change the load that each amp sees, or are they each seeing an 8ohm load?

[MNAirHead]

depends on the head and cabinet...without more info the answers can't be trusted.

[Tim Skaggs]

It's difficult to say what impedance each amp will see because not only will they be connected to the speaker cab, but they will be connected to each other. That impedance is unknown.

[NateS]

That screams "DON'T DO IT!" in my head. Really LOUDLY.

[Never_grew_up]

Biamping or bridging? Biamping usually requires an electronic crossover to separate the line-level sigal from a preamp into high and low frequency sections that are then amplified separately and connected to speakers that reproduce each frequency range - like a 1-15 cab for lows and a 2-10 or 4-10 for mids * highs. (Though I've Y-ed my bass into 2 different bass head/cab combinations and eqe-d each differently as a poor man's biamp setup.)

Bridging combines the 2 sides of a stereo amp into a single mono output at roughly the combined power of each channel.

[sawzalot]

DON'T DO THIS!!!!!!

Biamping requires you have TWO speaker cabs--one for each amp. Otherwise you are connecting the output of one amplifier directly to the output of the other! The result will be smoke and at least one burned up amplifier.

I know this because unfortunately I did it once. Cost me a a perfectly good SWR SM-400.

Tom

[J42]

Originally Posted by sawzalot

DON'T DO THIS!!!!!!

Biamping requires you have TWO speaker cabs--one for each amp. Otherwise you are connecting the output of one amplifier directly to the output of the other! The result will be smoke and at least one burned up amplifier.

I know this because unfortunately I did it once. Cost me a a perfectly good SWR SM-400.

Tom

Thanks for the heads up.

[Plstrns]

Originally Posted by sawzalot

DON'T DO THIS!!!!!!

Biamping requires you have TWO speaker cabs--one for each amp. Otherwise you are connecting the output of one amplifier directly to the output of the other! The result will be smoke and at least one burned up amplifier.

I know this because unfortunately I did it once. Cost me a a perfectly good SWR SM-400.

Tom

+1 but, I've never done it for the reason above!

[billfitzmaurice]

Originally Posted by J42

If I am Bi-amping and plug both amps into a 8ohm 4x10 cab (input jacks are wired parrallel)

What you'll get doing that is at least one blown amp.

[Arthur Strand]

DO not do that!!! It will clash! Something will blow!
There is a way round it if you rewired the 4 speakers into 2 separate pairs and linked each amp to each pair of speakers. You would need to know what you are doing though.
Otherwise, add another separate cabinet for the other amp and divide the signal from the bass to the inputs of each. A cheap Y splitter will do that and will cost very little.
I built my Tonehenge in the mid-1970s for stereo bass.
www.escutcheonmedia.com/home
picture there of rig.

[Zooberwerx]

A handful of PA & bass enclosures can be bi-amped but your's is not one of these as per your description.

Riis

[VisualShock]

if you're handy with a soldering iron, desolder the connections, and then resolder two 10s to one input, and the other two 10s to the other. that will, in effect, give you two 2x10s.

NEVER connect two aplifiers to one cab in the way you stated!

[Zooberwerx]

Originally Posted by J42

If I am Bi-amping and plug both amps into a 8ohm 4x10 cab (input jacks are wired parrallel) does this change the load that each amp sees, or are they each seeing an 8ohm load?

Exactly why are you considering this move? Are you trying to achieve individually adjustable high & low end reinforcement from the same cab or just an increase in overall power? Any way you look at it, its not a good idea. Give us an idea as to the desired results....we may have some better ideas.

Riis

[sawzalot]

My story on this was a gig where I got there late and was distracted while setting up...1st time biamping. I wound up plugging the output of a crown DC-300 into the input of one 4x10 and the output of my swr sm-400 into the same cab, parallel input. Didn't catch the mistake. The story is in the "gig stories" forum.

The Crown won.

Biamping is nice if you have separate cabs--like a 2x10 for highs and a 15 for lows, something like that. I'm not sure it would really buy you anything by rewiring a single 4x10 except less low end (2 fewer 10's reproducing the lows). I've never biamped my live rig since the above debacle, but he collective wisdom here can give ideas about what would sound good.

[BassmanPaul]

Originally Posted by sawzalot

Biamping is nice if you have separate cabs--like a 2x10 for highs and a 15 for lows, something like that. I'm not sure it would really buy you anything by rewiring a single 4x10 except less low end (2 fewer 10's reproducing the lows). I've never biamped my live rig since the above debacle, but he collective wisdom here can give ideas about what would sound good.

The information you are basing this statement on is completely wrong. In a bi-amp system you want the lows to go to the woofers that's 10s 12s, 15s and 18s. Sometimes even 8s. The highs typically around 4-5KHz and above. That's tweeter territory. A ten won't go that high.

Paul

[ulrich]

Originally Posted by BassmanPaul

The information you are basing this statement on is completely wrong. In a bi-amp system you want the lows to go to the woofers that's 10s 12s, 15s and 18s. Sometimes even 8s. The highs typically around 4-5KHz and above. That's tweeter territory. A ten won't go that high.

Paul

Unless by 2x10, you mean 2x10/1 (two 10s and a passively crossed tweeter) In such a case, there's at least a chance that bi-amping with a sub might sound good. Yes sub, not 15" full-range bass cab.

FWIW I'm currently listing to bi-amped 8/1 speakers. (JBL 6208) If I added a sub, I'd be try-amped.

Y-ing two amps to one speaker (with Y cable, or parallel inputs) isn't Bi-amping - it's BUY-amping, 'cuz your gonna be buying a new amp, or two.