Powerful sub amplifier needed

[ostie01]

HI, my brother have some PA speakers and he would like to add some subwoofer to his set up but like to carry large and heavy power amp.
Could it be possible to build powerful small amplifier to drive those subwoofer, don't need to be high end, maybe a built in crossover. Would like to have minimum amount of components and at least 500W.
Any ideas. Thanks

[Nigel Goodwin]

Check the other thread in Loudspeakes/Sub-woofers about PA amps, something like the Behringer EP2500 should do it fine, but you need an electronic crossover as well, and again Behringer make decent ones at decent prices.

[jaycee]

If you want to build, check out Rod Elliot's P68, he also has a number of sub related circuits on there.

[dfdye]

If we're talking about weight, wouldn't a class D amp be a better option? Smaller transformer and heat sinks translate into less back strain hauling the thing around.

Though Rod's P68 amp looks pretty small, You might also want to check out the P116, but I admittedly have zero experience with this amp nor other class D amps (other than using them) so you would probably want to ask over in the Class D section of the forum.

David

[myhrrhleine]

You could consider 2 smaller amps bridged.
Can be easier to carry than 1 (weight wise)
Otherwise, consider digital (class D)

[LightwaveDude]

Originally posted by myhrrhleine
You could consider 2 smaller amps bridged.
Can be easier to carry than 1 (weight wise)
Otherwise, consider digital (class D)

How do you bridge two separate smaller amps?

[richie00boy]

To bridge totally separate amps would take some severe modding. The power supplies would need to be linked together.

[Nigel Goodwin]

Originally posted by myhrrhleine
You could consider 2 smaller amps bridged.
Can be easier to carry than 1 (weight wise)
Otherwise, consider digital (class D)

Except bridging an amplifier doesn't provide any more power, just the same power into a different impedance!.

For example, 200W into one 8 ohm speaker (mono) as opposed to 100W+100W into two 4 ohm speakers (stereo). Exactly the same power, into exactly the same total impedance - the difference being one speaker instead of two.

[Tubby621]

If you want big sound without a lot of weight to carry around you may have to make some compromises. Definitely go with the Behringer active crossover. The CX2310 offers a great deal of flexibility ( see www.musiciansfriend.com $89.00 US ) For power amp weight is just a fact of life. Consider QSC RMX series. Tons of power with big sound. I use RMX1450 to drive a pair of JBL bass horns and it sounds very nice. For BIG but compact bass output you may look at Eminence LAB12 from Parts Express.com Folded horn plans are available if you have cabinet making skills and tools. Also, I suggest going to a pro sound company ( not necessarily a music store ) in your area. They often have consignments or used gear they will get rid of for cheap. Find some 15 or 18 scoops or short throw bass horns. Good luck!!!

[dfdye]

Originally posted by Nigel Goodwin


Except bridging an amplifier doesn't provide any more power, just the same power into a different impedance!.

For example, 200W into one 8 ohm speaker (mono) as opposed to 100W+100W into two 4 ohm speakers (stereo). Exactly the same power, into exactly the same total impedance - the difference being one speaker instead of two.

I think the point isn't to use two chanels of the same amp (like in car stereo) but to actually use two different amps to provide double the power of one amp. Using two small amps will certainly give you more power than one smaller amp.