[titanium3]

ok i searched and read a lot of threads on this topic but i still have a few questions...

i'll first give you the background... i'm planing on getting a complete system for my 3... i have to buy all the parts from bestbuy up her in canada becasue i can get them at cost +10%... therefore my choices are limited... i'm building a single 10" custom ported box and doing the installation myself...

the sub i'm gonna use is a Rockford Fosgate Punch Stage 3... its a dual voice coil sub and it comes in either 2 or 4 ohm configurations... my first questions is which one should i get (2 or 4ohm) if my choice of amps is as follows...

Rockford Fosgate Punch P3001 (1 channel)
Rockford Fosgate Punch P3002 (2 channel bridgable)
click here for a comarison chart of the two amps

i'm a little confused because the sub has a dual voice coil and i don'l know if that means i have to connect them separately or if they share the same terminal... also i don't know if its better to run at 2 ohms or 4...

i found the following picture at one of the websites refered to by a thread on the tipic...

what i gather from this picture is that the dual 4 owm sub would require an amp running at 2 ohms and the dual 2 ohm sub would require an amp running at 1 ohm... is this right?

any input is appreciated... some links to some sites where i can learn more about this tuff would be great too...

thanks

 

[JohnA]

if you were to get the dual 2ohm version you can wire it for a 4ohm load if you wire the coils in series or a 1 ohm load if you wire the coils in parallel. 4ohm load is what you are after if you go the 2 channel amplifier bridged wiring the coils in series.

The dual 4 ohm sub can be configured for a 2ohm load in parallel or an 8ohm load wired in series, so if you were to get the monoblock amp which can handle the 2ohm load get the dual 4ohm sub.

 

[titanium3]

thanks... i found a great tool on the rockford page that helps you determine the different wiring options for your sub...

i have two more questions... which is better, to run the mono amp at 300Wx1 with a 2 ohm load or the 2 channel amp bridged at 300Wx1 with a 4 ohm load

and are there any advantages or disandvantages to hooking up a sub in either serial or parallel... i remember reading something about this but can't find the thread now.... :?

the 4 ohm load being a 2 ohm dual voice coil 10" Punch P3 wired serial as follows

the 2 ohm load being a 4 ohm dual voice coil 10" Punch P3 wired parallel as follows

 

[JohnA]

i like to use monoblocks to run subs purely because they usualy have a better power supply.

As for wiring your subs, when wiring voice coils together it doesn't realy matter but if you were wiring to subs together they recommend to stick with parallel wiring rather than series and the reason for this is back EFM, basicaly it can cause the speakers to modulate each other or make one another move causing distortion, but wiring voice coils together in either configuration is fine

 

[titanium3]

i think both amps are pretty much the same as far as the power supply... if you look at the specs they are pretty much identical except one is mono and the other 2 channel...

i'm just wondering if one amp is working harder than the other because the mono has a 2 ohm load and the 2 channel has 4 ohm load but its bridged... is there a difference?

 

[JohnA]

the 2 channel actualy still is running at 2ohm, if you think about it look at the power figures.

2 x 75wrms 4ohm
2 x 150wrms 2ohm so combine that to get your 4ohm mono load of 300wrms

 

[titanium3]

i see... thanks for all the info... i'm gonna go with the mono amp setup then...

 

[Roan]

you can work these sorts of things out pretty easily with some simple math.

ok, your dual 4ohm coils with a single woofer:

in Series __0______0___
you have 4ohms + 4ohms
=8ohm load on the amp.

in Parrallel
___0___
|__0___|
You have 4ohms / 2 coils
= 2ohm load on the amp.

then you can combine these if you have 2 woofers.

two woofers with their coils in series and the woofer in series = 8ohms + 8 ohms = 16 ohm load on amp
two woofers with coils in parrallel and woofers in series = 2ohms + 2ohms = 4 ohm load
two woofers with coils in series and woofers in parrallel = 8 ohms / 2 woofers = 4 ohm load
two woofers with coils in parrallel and woofers in parrallel = 2ohms / 2 woofers = 1 ohm load.

easy huh.
Series adds the impedance.
parralel divides it by the number of loads i the chain.