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View Full Version : What JL audio Amp to use with 3 JL 8W3x2 subwoofers



Alcorn
02-14-2005, 10:45 PM
my buddy is looking at running three 8W3x2 subwoofers in his car. i am going to build his enclosure and help him the with instalation. the question i have is what sorta amp should he buy to run the subs (how many watts?, mono block or # of channels?). how should they be wired for optimal sound quality (in series or in parallel?) he would like to use JL audio amp so please recomend only JL audio.

Thanks
Brett Alcorn

lsc2g
02-14-2005, 11:27 PM
500/1

'93 SR-V
02-14-2005, 11:38 PM
Are the subs 2 ohm or 4 ohm? Also , what’s the rms power of these subs? (300w?)

Alcorn
02-14-2005, 11:42 PM
Nominal Diameter: 8 inches (200 mm)
Continuous Power Handling: 125 Watts
Voice Coil: 1.43" diameter, 4-layer, Kapton former
Available Configurations: Dual 2 ohm, Dual 4 ohm or Dual 6 ohm
Xmax (one-way, linear): 0.38" (9.5 mm)
Sealed Enclosure Range: 0.30-0.50 cu.ft. (8.5-14.0 liters)
Ported Enclosure Range: 0.60-0.90 cu.ft. (17.0-25.5 liters)
VRC™ Technology: YES
Elevated Frame Technology: No


that is all i know

'93 SR-V
02-15-2005, 12:02 AM
Alright, that’s all you need to know. JL makes two amp models. The original mono amps (250/1?, 500/1 and 1000/1) which put out the same wattage regardless of ohm load (1 through 4 ohms), and a new lower priced line of mono’s with power output varying according to ohm load. The originals are the best (cleanest sound), but you pay for them…

Anyway, you’re looking at a total demand of 375 rms watts, so you could go with the original line, and under power them a bit with the smallest amp (it’s either 250/1 or 300/1 or something) or you could step up to a 500/1 and have some power to spare. These amps are one ohm stable, so you could use 3 4-ohm subs and run them in parallel for a final load of 1.33 ohms, or 3 6-ohm subs wired in parallel for a final load of 2 ohms.

Alternatively you could use the newer line (I think they are only 2-ohm stable) in which case you would want to use 3 6-ohm subs in parallel to give you a final load of 2 ohms.

Both will give you the same power output if wired how I mentioned, but the newer line is cheaper (although THD is a little higher).

fresh
02-15-2005, 10:53 PM
try to get the higher with the final load. the slash series amps will run better at higher loads try to get 3 or 4 OHMs
by the way those amps are not 1OHM sable the recomended lowest load is 1.5 Ive tried it

BumpinTalon
02-15-2005, 11:10 PM
Originally posted by fresh
try to get the higher with the final load. the slash series amps will run better at higher loads try to get 3 or 4 OHMs
by the way those amps are not 1OHM sable the recomended lowest load is 1.5 Ive tried it

x2 when I had my 500/1 it hated running at one ohm, it shut off in seconds.
no matter what ohm coils you get on the subs, you will have to series together the voice coils and then parallel the subs. it'll even work with the dual 2s, but I would stick with the dual 4s or 6s if you can.
you couuuld get the 800 watt "e" class monoblock and dual 6 ohm coils but you would be running it at 3 ohms, getting around 600 watts, which is probably a bit much. as well, I think the e800 costs more then a 500/1 does now so that is probably not the best way to go.

as well, fundamentally, both amps are exactly the same. all you sacrifice going from the "e" series to the "slash" series is flexibility - the slash series has either a 12dB or 24dB crossover, fully parametric bass EQ that lets you choose center freq, Q, and boost, and an AMAZING preamp section. the e has a fixed freq & Q bass boost and the crossover slope is not variable. if you do not know what those things are, you do not need them, and should just save your money and get an "e" series 400 watt monoblock and hook it up at 3 ohms.