how to get a 4 ohm load

[mikegraveling]

i have two sp10 subwoofers that are 4 ohm each, i am wanting to run them with the rack mountable 1000 watt amp from parts express, but if i hook them up in series or parrallel thay are going to be drawing 2ohm or 8 ohm, the amp will not go down to 2 ohm, and at 8 ohm there is only half the power and these speakers are power hungry. anyways is there anyway to get around the problem or does anyone have any other suggestions for an amp that will run these.

[brianpowers27]

I assume you are referring to the 1000watt dayton rackmounted sub amp. I can't answer your question definitely without a few more details.

PS. Please post a link to the amp and sp10 subwoofers.

[mikegraveling]

i don't know how to post a link, but here are the parts express part #'s
297-460 (subwoofers )
300-810 ( amplifier )

[brianpowers27]

i don't know how to post a link, but here are the parts express part #'s
297-460 (subwoofers )
300-810 ( amplifier )

It looks like you may need to wire them series for 8 ohms. If you do, keep the resistance to a minimum. 500 watts rms should be plenty for these subs. Your other option is to buy 2 more and wire back to 4ohms.

[philiparcario]

I assume you own the amp> If you do wire them to get 8ohms only if they share the same box. Will they be in the same box? If you are using 2 separate boxes for the subs you will need a second amp. Series wiring is risky if you use separate boxes. Basically unless the subs are perfect copies they will present a complex load to the amp. This can cause amp destruction. If they share the same box series wiring is fine.

there is a lot to be said to buying a second amp. in your case if you want two sub boxes I would consider using two amps.

[Paul O]

You can't wire two 4ohm speakers to achieve 4ohms, so the solution to your problem is buy another amp or better yet use a single larger 4ohm driver like this one.. http://www.parts-express.com/pe/show...number=295-420

[mikegraveling]

i already have 2 500w rms plate amps from a previous system, do you think i would be better off runing one to each sub? they are in seperate boxes and i really don't have the xtra money to buy two amps. the only downside is i don't want them attached to the sub box ( trying to keep enclosure extremely small ) i will have to make a spot inside my entertainment center for them.

[billfitzmaurice]

i will have to make a spot inside my entertainment center for them.

That's almost always a better idea than on-board mounting anyway, since the short distance between the receiver and amps for both power and interconnect cables minimizes potential for ground looping.

[HT-EXT]

The Re value for those subs is around 3.2 to 3.4. It should be fine to hook them in series, with around 6 to 7 ohm total. I sure this will change with heat but you will prolly see 300w to 350w per sub with the 1000w amp, maybe a little more. This is an estimation and alot of factors could change these numbers. You should see more power from the two separate amps if you run a sub with each. Just my opinion hope it helps.


HT-EXT

[philiparcario]

i already have 2 500w rms plate amps from a previous system, do you think i would be better off runing one to each sub? they are in seperate boxes and i really don't have the xtra money to buy two amps. the only downside is i don't want them attached to the sub box ( trying to keep enclosure extremely small ) i will have to make a spot inside my entertainment center for them.

then it is a no brainer use the 2 500w plate amps make a seperate case for them and use short rca's and long speaker wires to the sub boxes. less hum pick up.

[philiparcario]

it also allows easy movement of the sub boxes they will only have a set of speaker wires to worry about.