I need a sub suggestion for a Fosgate 700s amp.

[Bipolar 10+ year member]

I just want a single DVC sub, 12" or 15" that will work best with the amp I already have. Its a Rockford Fosgate 700s. Also what Ohm sub do I need and how should I wire it? Thanks, im not to bright.

Amplifier Type Dual Channel

Bridgable Bridgable

RMS Power at 4 Ohms 175 W x 2

RMS Power at 2 Ohms 350 W x 2

Performance

Frequency Response 20 Hz - 20000 Hz

Signal to Noise Ratio 100 dB

THD at Rated RMS Power 0.05 %

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[Bipolar 10+ year member]

What about a Solo L7? would that be a OK choice? Also, When you read the specs on a DVC sub and it says 400 watts RMS or what ever, is that per voice coil or total?

 

[iamamp3pimp 5,000+ posts]

well whats the specs on your amp?

 

[iamamp3pimp 5,000+ posts]

what a dee dee dee

 

[iamamp3pimp 5,000+ posts]

its bridgeable, at 4 ohms, right?

you need something that is a single 4 ohm sub, or a dual 2 ohm sub

whats your budget

 

[Wkbdkid 10+ year member]

mostly whats it do bridged? and thats more than likely going to be at 4ohms

edit: what he^^ said

 

[iamamp3pimp 5,000+ posts]

i'd imagine 700@4 which would be thermally perfect for an L7

 

[dleccord 5,000+ posts]

thats a sweet amp

 

[Bipolar 10+ year member]

well whats the specs on your amp?

Amplifier Type Dual Channel

Bridgable Bridgable

RMS Power at 4 Ohms 175 W x 2

RMS Power at 2 Ohms 350 W x 2

Performance

Frequency Response 20 Hz - 20000 Hz

Signal to Noise Ratio 100 dB

THD at Rated RMS Power 0.05 %

 

[thatkidbob 10+ year member]

yeah... so 700 @ 4, and probably closer to 850 or 900 in real life.

I'd feel comfortable putting a 15" L7 on that. Just give it plenty of room to work with and a nice port and you'll do fine.

 

[Wkbdkid 10+ year member]

theres a lot of subs that can work with that kinda power. whats your budget and what are you looking for out of the sub? spl?sq?sql?

 

[Bipolar 10+ year member]

OK, I bought a 15" L7 today. Dual ohm coils. Do I just wire it straight up, As in, one channel to each coil. Im pretty sure thats right...Its so stupid simple I always worry about getting it wrong.

 

[TeoTorriatte 10+ year member]

OK, I bought a 15" L7 today. Dual ohm coils. Do I just wire it straight up, As in, one channel to each coil. Im pretty sure thats right...Its so stupid simple I always worry about getting it wrong.

Did you get one with dual 2-ohm voice coils?
If you did, wire the voice coils in series and wire them to your bridged amp. If you don't know how to bridge the amp, consult the manual or go to http://www.rockfordfosgate.com/rftech/rftech.asp to download one.

To wire the VC's in series, see this diagram... http://www.rockfordfosgate.com/rftech/woofer_wizard/1_2ohmDVC_4ohm.gif

 

[Bipolar 10+ year member]

That diagram shows that wiring as a 4 ohm load, or a 1 ohm load, I dont think this amp is 1 ohm stable. If its a 2 channel amp and it will push 350 per channel @2ohm and I have 2 channels, why dont I just hook each channel from the amp to each 2 ohm channel on the speakers? Wont that give me what I want?

 

[TeoTorriatte 10+ year member]

That diagram shows that wiring as a 4 ohm load, or a 1 ohm load, I dont think this amp is 1 ohm stable. If its a 2 channel amp and it will push 350 per channel @2ohm and I have 2 channels, why dont I just hook each channel from the amp to each 2 ohm channel on the speakers? Wont that give me what I want?

Where do you get wiring to a 1-ohm load from that diagram? It clearly states, "4-ohm Load"... the voice coils are wired in series, it is impossible to get a 1-ohm load out of that.
Bridging the amp is typically as simple as using the left positive and right negative speaker leads... or at least it was on the old school RF amps. Running bridged ensures that both voice coils are getting exactly the same signal... you really don't want to run a stereo signal to the sub.
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