Sub woofer hookup

steve0202
steve0202 Posts: 28
I just purchased the PSW-250 subwoofer. The audio out for the sub on the back of my receiver is a single RCA style jack. The PSW has two line in jacks (left and right). Can I get a simple RCA style cord with one plug on one side and 2 on the other to hook the sub up to my system? If so, would this be better than running the subwoofer thru the speaker terminals as in suggested hookup? I don't really understand the hookup process using the main speaker terminals. Does the sub amp still work when hooked up thru the main speakers? Will it defeat the sound of my RTi70's which are my main speakers? I'm a little confused. Can anyone clear this up for me?
Thanks,
Steve
Rti70's
Csi30
PSW-250
RM5000 series II sats
Denon AV2802
Denon DVM 1815
Toshiba 32" TV/Monitor
Post edited by steve0202 on

Comments

  • organ
    organ Posts: 4,969
    edited May 2003
    You don't have to use a Y-splitter. You can just hook up the cable to one of the inputs. If you're subwoofer output on the receiver is filtered, make sure to turn the subwoofer's crossover all the way up to prevent double filtering.

    The subwoofer's amp will still be powering the subs even if you use speaker cables for connection.

    Maurice
  • steve0202
    steve0202 Posts: 28
    edited May 2003
    Thanks Maurice. I'm new to the high-end audio world(so please bear with me if this sounds dumb) but I'm still not clear as to the hookup of the sub to the speaker terminals. Example: In the manual for the PSW-250 the suggested hookup would be to run the wires from my main speakers to the terminals on the back of the sub and then run wires from the sub terminals to the back of the receiver. By doing this are my main speakers being powered solely by the sub? If so, wouldn't it be better to have your main speakers being powered by the receiver? Also, when running your speakers through the sub, are you compromising the real sound of the main speakers?

    Instead of hooking the mains through the sub, can I wire the surrounds through the sub instead? I always have them on anyway.
    Rti70's
    Csi30
    PSW-250
    RM5000 series II sats
    Denon AV2802
    Denon DVM 1815
    Toshiba 32" TV/Monitor
  • burdette
    burdette Posts: 1,194
    edited May 2003
    Originally posted by steve0202
    1. Example: In the manual for the PSW-250 the suggested hookup would be to run the wires from my main speakers to the terminals on the back of the sub and then run wires from the sub terminals to the back of the receiver. By doing this are my main speakers being powered solely by the sub?

    2. If so, wouldn't it be better to have your main speakers being powered by the receiver?

    3. Also, when running your speakers through the sub, are you compromising the real sound of the main speakers?

    4. Instead of hooking the mains through the sub, can I wire the surrounds through the sub instead? I always have them on anyway.


    1. No. Your main speakers are NEVER powered by the sub. Either you have speaker wire going from the receiver straight to the mains, or you have speaker wire going to the sub first and THEN to the mains. But either way, it is ONLY the receiver powering the mains. If you run speaker wire to the sub instead of line-level, then the sub 'picks off' a small sample of the signal to amplify for the sub, and the receiver powers the mains.

    2. They always are.

    3. It shouldn't really make a difference. Think of it this way... you have speaker wire running from your receiver to your mains.. right? You can do that and run an RCA line-level from the LFE output on the receiver to the line-in on the sub. Now, both the mains and the sub have power and a signal. Turn the sub's crossover all the way up (highest freq), and use the receiver's bass management to set the crossover for the LFE signal.
    OR.. you could take that speaker wire running to the mains and take a detour through the sub amp. The receiver's power still flows to the mains, but the sub amp can now take a sample of the signal on the speaker wires and feed that to the sub amp. The receiver is still powering the mains.. you are just letting the sub have a small sample of THAT signal, rather than feeding the sub a signal via the LFE input. In this case, it is the sub's crossover that determines the crossover point.
    Either way, the receiver powers the mains and the sub amp powers the sub. The only difference is how you're feeding a signal to the sub. That can matter due to characteristics of both your receiver and the sub amp (crossover frequencies, etc).

    4. I don't think so... if you take the speakers wires for the surrounds and run them to the sub first, then the sub is NOT getting a full signal to sample, it is getting only the surround signal. Some guys DO have a separate sub with the surrounds, but you still need a sub for the "main" signal.
  • steve0202
    steve0202 Posts: 28
    edited May 2003
    Thank you so much Burdette, you have cleared that up for me rather nicely. I appreciate your time.

    Just a side note: do you think just getting a Y type RCA cable would be the easiest way to hook up the sub? I have no problem hooking up the sub thru the speaker terminals (now that I understand it) but just thought the Y adapter might make things simpler.
    Rti70's
    Csi30
    PSW-250
    RM5000 series II sats
    Denon AV2802
    Denon DVM 1815
    Toshiba 32" TV/Monitor
  • burdette
    burdette Posts: 1,194
    edited May 2003
    I use the line-level LFE output on my receiver to drive my sub. The sub amp will accept either L/R inputs, or a single input on the R. The sub amp combines the two inputs anyway.. so the splitter only splits the signal for a short distance on the signal path (through the Y) before the sub just recombines them. If your sub says you can feed it with a single line, I wouldn't bother with a splitter.

    I was having a problem with the auto-turn-on feature on my sub amp, so I used a Y-splitter to feed the LFE signal to both the L and R input on the sub. That change changed *nothing* as far as I could hear - neither did it solve my auto-on not auto-onning.

    So.. in my opinion, if your sub amp accepts a single line-in, which I'm sure it does given the LFE output is a single line, you can use one.
  • TonyPTX
    TonyPTX Posts: 545
    edited May 2003
    Originally posted by steve0202
    do you think just getting a Y type RCA cable would be the easiest way to hook up the sub? I have no problem hooking up the sub thru the speaker terminals (now that I understand it) but just thought the Y adapter might make things simpler.

    Here is where you need to make a few decisions based on how good your receiver is and how you like bass management. If your receiver is an older model w/out a built in cross-over setting, then it may be permanently set to something based on what the speaker size is set to for your speakers. You need to find this out first!

    If your reciever has a built in x-over (and it can be disabled or turned off) then run a single RCA cable (75 ohm rating) from the receiver and plug it into the left channel of the sub. If you CAN NOT disable the internal x-over in the receiver, then set it to 80 or 90hz and turn the low pass filter knob on the back of the 202 all the way to max.

    If you want to use the speaker level inputs (not the recommended method), you can. Run the left/right channel to the line-level inputs on the sub, then plug your 70's into the line-level out of the sub. Adjust the low-level filter knob to your liking (somewhere between 50-90 would be about right) and be sure that you reciever has your left/right speakers set to LARGE and the subwoofer is set to NO or OFF.
    Damn....8 lines...I've gotta put my sig on a diet now....
  • organ
    organ Posts: 4,969
    edited June 2003
    Tony,
    Just wondering why you suggest using a 75ohm RCA for the sub? Is there a difference in sound quality compared to regular RCA? Is this just for the LFE in HT or music as well?

    Maurice
  • TonyPTX
    TonyPTX Posts: 545
    edited June 2003
    Well IC's come in multitude of flavors, but they basically are one of two different types of designs, either a coax design or some sort of twisted pair. I would say that my comment was incorrect in that I should have said COAX rather then 75 ohm. 75ohm makes no sense here when refering to an analog sub cable. I chose coax over twisted pair because usually sub cable runs are long and coax is less prone to RF interference (assuming it's got decent sheilding). As for sounding better, well, hell it's all in your ears man. I recently replaced a Monster THX certifed cable with a SignalCable subwoofer line based off of Belden 89259 and I was immediately impressed with the stronger bass signal I was getting from the sub. You may find some comments about the material selection used for the cable. Copper tends to give tighter bass, silver tends to add higher detail in the highs at the cost of giving a bit of brightness to the signal.

    Just my two cents.
    Damn....8 lines...I've gotta put my sig on a diet now....
  • [Deleted User]
    [Deleted User] Posts: 7,658
    edited June 2003
    Thanks for the great advice, guys, I appreciate the help!
    Regards, Ken