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      09-01-2010, 05:10 PM   #1
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Question 2 or 4 ohm Earthquake SWS-8?


I cant work out if i need 2 or 4 ohm earthquake sws8 subs.
My set up already is

Alpine headunit with 2 phono/RCA outs, With a JL audio G6600 Amp.
I have the 'front' out on the headunit split at the amp to power the front and rear speakers, The Rear out is going to the Sub channel.

I ran seperate speaker wires to the stock subs.I want to change the underseat subs to the Earthquakes to run as mids,and then add another amp and have another 10 inch sub in the trunk. The specs of the amp are here.
Hope you can help.

Rated Power 14.4 V Stereo: 75 W RMS x 6 @ 4 ohm 100 W RMS x 6 @ 2 ohm
Rated Power 14.4 V Bridged: 150 W RMS x 3 @ 8 ohm 200 W RMS x 3 @ 4 ohm
Rated Power 12.5 V Stereo: 55 W RMS x 6 @ 4 ohm 75 W RMS x 6 @ 2 ohm
Rated Power 12.5 V Bridged: 110 W RMS x 3 @ 8 ohm 150 W RMS x 3 @ 4 ohm
THD at Rated Power: <1% THD, 20 Hz - 20 kHz
S/N Ratio: >104 dB referred to rated power (A-weighted, 20 Hz - 20 kHz noise bandwidth)
Frequency Response: 10 Hz - 25 kHz (+0, -1dB)
Damping Factor: >200 @ 4 ohm per ch. / 50 Hz >100 @ 2 ohm per ch. / 50 Hz
Slew Rate: ± 22V / µs
Input Range: 200mV - 8V RMS
Dimensions (L x W x H): 17.70 in. x 9.25 in. x 2.50 in. 450 mm x 235 mm x 63.5 mm
Description: Class A/B Six-Channel System Amplifier
Patented Technology: Absolute Symmetry™ Class A/B Circuit (U.S. Patent #6,294,959)
Differential-Balanced Input Topology: For superior noise immunity, RCA jack inputs
On-board Crossover: State-variable, 12dB / octave Butterworth with continuously variable cutoff frequency selection from 50 - 200 Hz. Configurable as Low-Pass or High-Pass
Bass EQ (Channels 5&6 only): +6 dB fixed frequency, fixed 'Q' (defeatable) with port for optional remote bass control (RBC-1)
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      09-01-2010, 05:39 PM   #2
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I'm not sure why you pasted "War and Peace" in here, but:

1) You can use 2 or 4 ohm. You get a little more power with 2 ohm, but...25 watts? 33%? Won't be noticeably louder. Be a little tighter.

2) EQ 8" are not the best midbass in the world, as has been noted by many. I sell them, but I would probably use a different underseat if you have a 10" in the trunk and no equalizer to massage the SWS's output.

3) You want to bandpass them if you can, and the JL doesn't have that ability with its internal xovers

4) Personally, I'd run 4 ohm and then run the 10 bridged. If you run the 10" bridged AND the 8" at 2 oh, I'd personally be thinking that power supply would be running near redline (so to speak). Probably wouldn't hurt anything, but you wouldn't be getting a ton of extra power, either.
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      09-01-2010, 08:18 PM   #3
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Kicker SSMB8 under the seats would probably be your best bet. If you can, high-pass the "front" signal from the HU at around 50 - 60 Hz and then use the amp's low-pass filter, set to around 150 Hz, to bandpass the signal going to the underseat woofers.

The other split from the "front" signal, going to the door speakers, should be high-passed at the amp, at around 150Hz. However, if they are crappy OEM base system speakers, expect to replace them in the near future.
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