Cabling - LFE to Multiple Plate Amps

[Warmon]

Hi guys,

Working on a little project here and have a question about cabling four active / powered subs to a single LFE / Sub out on a AV receiver. The subs don't have a pass thru RCA for daisy chaining. I have all the tools and such to make RCA cables using RG-6 Quad Shield...rca, bnc, F/coax, etc. Can I use 2way splitters / diplexers with in this connection with no probs?..call em diy "Y" adapters.

[BoomieMCT]

It should work. Some people find that if you split the signal too much it can weaken to the point it won't wake up auto-on subs. Mileage may vary. Also unless these are all stacked on top of each other I hope they have some sort of phase adjustment!

[Mike P.]

At one time I had four plate amps connected to a receiver the way you mentioned. I had no problem with "signal loss". As Boom stated, a phasing adjustment is a definite plus.

[Warmon]

Thanks guys! We are rehabbing a small public theater here at work and putting 4 new Infinity PS-212's on a 10' wall right under the screen. Strange room - was round, but now sorta fat crescent shaped. We added two small rooms in the space - one for the AV equipment and one for chair storage. They'll be front firing right at the audience of about 30 people with a short 12 minute video. The subs main role is to give low end impact to civil war artillery / cannon fire in the video. Do you see any phasing problems with this setup?...choices are 0 & 180.

[ccdoggy]

well the phase could be fine, could be bad. you wont really know till you get them in there and playing. But you can always move them and try and fix the phase issues since you have a large area to play with.

[deromax]

Mike P. wrote:

At one time I had four plate amps connected to a receiver the way you mentioned. I had no problem with "signal loss". As Boom stated, a phasing adjustment is a definite plus.

The signal may not get attenuated (no loss of gain) but I'd be more annoyed by the loading impedance becoming too low for some preamp out to cope with. Paralleling 4 inputs decrease the impedance seen by the source by a factor of four. So a 20 kOhms impedance become 5 kOhms. The preamp output may not like it and may actually overload at high output levels. Or maybe it won't care!

Try it. If you hear headroom issues, but have enough gain available, you may add resistors in your splitter to up the impedance value, then add gain to regain level. Or even better, you could use an audio distribution amplifier. You could probably build one with a few OP amp for cheap.