resistance for three subs

[hilton 0]

I've noticed for some time now that it's complicated to figure out the power for a three sub setup. If you have three 4 ohm DVC subs wired together in series (in think thats right) you get a 2.67 overall ohmage.

Now if you have a KX600.1 for 600@2ohms, or perhaps a DX700 for 700@2ohms; how would you figure out how much power the amp would put out at 2.67 ohms? Looking into possibly 3-10" compvrs with that setup.

Also, I was looking into a two sub setup with the Brahma 10. I'm thinking maybe a bpx1100.1 to power that setup. This one is more expensive, but alot louder and more SQ. After all that 29mm one way linear xmax sure isnt dissapointing!

Both setups would be in a ported box, and the three sub ported box setup would prove to be quite challanging.

Thanks for your help.

[bigger_george 2]

I used to own a DX700 and 3 10" compvr's, sealed though. Personally, I'd go for the brahma/jbl any time. They sound better and can get louder with right enclosure and power.

You can't really figure out power output exactly without benching it but a solid guess would be since the dx700 does 350 at 4 ohms and around 700-800 at 2 ohms that it would do around 600 or so watts (just mathematically since halving the impedence doubles the power).

[Peteyglad 2]

Ok, what you are doing is called series-parallel wiring. You series the subs to 8 ohms each, then parallel the 3 subs to achieve your 2.67 ohm load. I would agree with bigger, it is tough to tell how much power the amp is putting out. First, the coils are usually not exactly 4 ohms, they are a tad off. Then you have the in box impendance rise to worry about. But probably on a DX700 you would see 600-650 at 2.67 depending on what the bench test is for 2 ohms.

[hilton 0]

thanks for the replies, I think I'll avoid the three sub setup for now and stick to the brahma jbl setup. How nessecary would a subsonic filter be for the brahma jbl setup, I'd hate to blow $700 worth of subs because they went too low. I think FMod makes a 30 hz highpass filter that rolls off at 12db/octave. As far as I know, that bpx1100.1 doesnt have a subsonic filter.

[Peteyglad 2]

The need for a sunsonic filter depends on where your box is tuned to and what music you listen to. The safe bet is have a subsonic filter set around 5 hz below box tuning. For a dialy driver the box is usually tuned to around 35 hz and the subsonic would be set at 30.