Question about an AMP hook up to subs


New member
Username: Illz

Post Number: 1
Registered: Aug-05
I have a Crunch Drive DS-4002 amp and 2 Polk EX12 12" Subs. The subs are 400 watts max with an RMS of 150W. The amp according to (specs I got online) will push 400W x 2 @ 4 Ohms or 200 RMS x 2 @ 4 ohms. I believe I can also brige it to make it MONO @ 800W.

Now my question is, I hear you get more power out of the amp if you hook it up MONO and hook the speakers in parallel. Is this true? How do I do this. Sorry this is all new to me but I am a very smart individual and any advice is greatly apprciated. I want to hook this up the best way and get the best sound but unfortunately this is the equipment i have to work with. I know its not the best so i figrued you great people here could give me a hand in maximizing the performance out of this setup.

What is the best way, and if anyome could give me some background and details i would really appreciate it.

Thanks in advance,



New member
Username: Illz

Post Number: 2
Registered: Aug-05
Thanks for the reply, but I need more info.

Since I have 2 4-ohm speakers, if I wire them in parallel, it will run at 2-ohms.

Now I have a 2CH AMP.

Can I hook these speakers up in parallel PLUS bridge the AMP?

I heard that will make it 1-ohm. If I could brige it and wire in parallel and have it ay 2-ohms I think that would be best but I fear it will run at 1-ohm but I am not sure if that is correct.

Anyone have any insight??

Unregistered guest
bear with me -newby

the way i read you posts and bearing in mind only the equipment you have ie, this:

the amp reads to me like its either 2x200rms @4ohms OR 2x400watts max @4ohm OR in bridged configuration 1x800watts max @4ohms

forget max power ratings they are usualy nonsense (imo)
always look at nominal, RMS or continuous ratings especialy wen doin the maths lol

think of a bridged 2 channel amp as being a minimum of 4ohms stable, -(by this i mean how you hook up speakers to draw current - as impedance(ohms) is sort of like resistance for the amp to prevent over working ie, a resistor in series prevents a dead short)
a good way of getting your head around this is that the min impedance (ohms) of each channel is usualy 2ohms (i would guess yours IS as its bridgable) so we simply add them together for a new minimum impedance @ 4oms -(when bridged)

-by bridged i mean hook up speakers in parallel or series and connect them only to the positive of one terminal pair (channel 1)and the negative of the second terminal pair (channel 2)

anything lower eg. a 2ohm bridged load (of the speakers you hook up) will result in a 1ohm load on each amp channel which will draw a heck load of current (more than the amp was designed for) through the output transistors, causing at best hot, hot, hot and at worst melt, smoke, pop.

hope i am making sense so far as i said above i am a newby to this lol.

you also have the subs you mention which i could not find - sorry!

but again on the info you have given i reckon they are what we call single voice coil or SVC, which is when the subwoofer, would you beleive lol- only has a single voice coil, similar to a standard coaxial speakers -but designed for lower frequencies obv.
this makes wiring relatively simple as many subs inc mine on the market today are DVC - you guessed it Dual Voice Coil - but thats another lesson lol.

anyway back to it with your single voice coil subs at an impedance of 4ohms each we are quite limited to safley hook them up, firstly and most easily we can simply take each sub and hook them up to each channel as "normal" providing each sub with 200rms this i (imo) a very good way of doing things as amps tend to be more expensive than subs and so using the amp at 75% of its max is a good idea - just tweak back the gains a smidge (or just dont take the p*ss with volume lol) - this would be the way i would chose as we are not 100% this amp is designed for 2ohms loads but here goes again:

what i did with a rockford fosgate 2ohm stable amp was to connect the subs together in parallel which halfs there impedance too a single(remember they are connected together) 2ohm "load" (see link abvove or thhis one from Rockford: =Single+Voice+Coil+-+4+ohms&image.x=12&image.y=8&image=Submit

then connect the subs to one channel of the amp which in theory double the current drawn so the subs are both still seeing 200rms each, then you can use similar parallel wiring on your comps or rears and utilize the remaining channel (althought the rockford does have two inputs, and separate front and rear Gains, Crossovers adn Frequency Adjustments)
this one i wouldnt recommend with your amp without seeing it but its an option.

as for you thoughts on parallel wiring the subs AND bridging the amp i would say NO!! as i mentioned above this would draw way to much current and probably pop!

hope i have helped you out on this, the basis of my opinion is go simple as poss with smaller or limited impedance amplifiers, do not stretch your eqiupment even if you think is not all that, Cheers for your time Col

New member
Username: Illz

Post Number: 3
Registered: Aug-05
Thanks Audio Freq,

Your reply is helpful. You are the first person to explain that to me making me understand.

I have more questions if you don't mind...

Hooking up 2 4ohm subs (1 to each channel) will that make the amp run at 4ohms or 8?

Am I correct in assuming that if i bridge a 2-ch amp, it will half the impedance?

Bronze Member
Username: Rovin

Trinidad & T...

Post Number: 91
Registered: Jul-05
Michael try reading here OR OR tuturials on Crutchfields website & save it on your harddrive like i did cause sometimes i forget & i have it on hand now ...
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