how to hook up subwoofer with no sub out on amp

Neale13

i want to add a sub.my pre amp has 2 sets of outputs .no sub outputs. with one set feeding 1 amp,the other set feeding another amp.i thought i could split on of the outputs on the pre amp and run a set of rca cables to the sub. guy at best buy told me that will not work.that i need a deticated subwoofer output from my pre amp. the guy from crutchfield told me i would need a sub with a low pass freq. confused, so i came here to the real experts. thanks

codyc1ark

You should have two sets of speaker inputs on the back of your sub. Run your wire from the amp, to the sub, and then out of the other speaker inputs to the speakers. MOST subs have the speaker wire option, but not all. Which sub are you looking at?

Neale13

when you say run wire from amp do you mean rca jacks? because my speaker wire from my amps goes directly to my towers

Neale13

my pre amp is a rotel rc 1070

Neale13

sub i am thinking of getting is polk dsw 660wi

classic carl

Neale, you are correct. The guy at Best Buy and the guy at Crutchfield do not know what they are talking about. You can connect a Y-splitter from either output on your preamp and run RCA cables to your sub and your power amp. It's that simple. You can adjust the crossover on the sub to your preference. I also have two outputs on my Yamaha C-4 preamp. One output is connected to my power amp and the other is connectd to my sub. You could add a second sub by splitting each output if you wish.

BigGilles

second sub the best way
or an other pre-amp,
for speaker hook-up
my last option :sad:
keep up the good work !

SDA1C

I have found that Cody's suggestion lends the best (to my ears) sound when using a pre with no sub out. Run the speaker wires to the sub and then from the sub to the mains.

Tbone289

SDA1C wrote: »

I have found that Cody's suggestion lends the best (to my ears) sound when using a pre with no sub out. Run the speaker wires to the sub and then from the sub to the mains.

That has always sounded best to me also. However, I prefer to just run two sets of speaker wires directly from the amp's output. One set to the mains, the other set to the sub. I figure that will eliminate any possibility of "coloration" the sub connections might impart to the mains signal. The amp won't care, because the sub's input impedance is very high, so it will have virtually no effect on the current requirement.

classic carl

There are many ways to skin a cat. The reason that I connect mine as I do is because my preamp has two sets of outputs and there are two switches on the front to turn each of them on or off independently. I can turn off the output to my mains and listen only to the sub, which helped immensely when I was dialing the sub in. It also comes in handy when a recording is too bass heavy. I just turn the sub output off. I also have a single input passive pre between my sub output and the sub to control the volume without having to reach behind the sub for adjustment.

The OP mentioned using RCA cables, which is why I answered as I did. At least we here all know more than the so-called "experts" at BB or Crutchfield, who are actually paid to know this information.

SDA1C

Does the sub with the line level ins and outs filter the out after it feeds the sub. I would think using 2 sets of wires, one to the sub and one the mains, would negate this effect.

I am fairly certain a bucket of ****, missing a handle, knows more on average than the typical big box retail associate.

Tbone289

classic carl wrote: »

The OP mentioned using RCA cables, which is why I answered as I did. At least we here all know more than the so-called "experts" at BB or Crutchfield, who are actually paid to know this ****.

Indeed. All three of our answers are "correct", as far as I'm concerned. I suggest trying all options and use whatever sounds best.

Tbone289

SDA1C wrote: »

Does the sub with the line level ins and outs filter the out after it feeds the sub. I would think using 2 sets of wires, one to the sub and one the mains, would negate this effect.

No. Most subwoofers (including all Polk models) have a low pass filter--not a crossover. The low pass filter blocks frequencies above the setpoint sent to the subwoofer, but doesn't alter the frequency spectrum sent from the output to the mains. Your method of connection and mine will both result in the entire signal being sent to the mains.

20hz

if you want all adjustment at your fingertips look at a energy EAC electronic crossover it has both preamp plugs and a internall convertor so you can hook up speaker wires to it than to the amps

Tbone289

reported