sub single wire or y wire

newpolkman
newpolkman Posts: 23
edited December 2003 in Subwoofer Hookup & Bass Management
I have seen where you can either hook up sub to receiver with a single wire or a y wire. Is one better than the other or are they the same as far as sound quality? rex
Post edited by newpolkman on
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Comments

  • gatemplin
    gatemplin Posts: 1,595
    edited December 2003
    On some subs using a Y splitter will defeat the crossover so you can avoid double filtering. I also have heard that the signal is 3dB stronger this way.
    Graham
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  • Ceruleance
    Ceruleance Posts: 991
    edited December 2003
    Spec, if you answer this question please clarify why the signal is boosted 3 dB.
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  • PolkThug
    PolkThug Posts: 7,532
    edited December 2003
    There is no SQ difference.
    Never Forget
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  • Loud & Clear
    Loud & Clear Posts: 1,538
    edited December 2003
    My CT series velodyne doesn't have an unfiltered LFE input on it, all it has is the left and right RCA's. Velodyne told me to use a y-splitter for better performance. So I did.

    Two Channel Setup:

    Speakers: Wharfedale Opus 2-3
    Integrated Amp: Krell S-300i
    DAC: Arcam irDac
    Source: iMac
    Remote Control: iPad Mini

    3.2 Home Theater Setup:

    Fronts: Klipsch RP-160M
    Center: Klipsch RP-160M
    Subwoofer: SVS PB12NSD (X 2)
    AVR: Yamaha Aventage RX-A2030
    Blu Ray: Sony BDP-S790
    TV Source: DirecTV Genie
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  • Dr. Spec
    Dr. Spec Posts: 3,780
    edited December 2003
    Originally posted by Ceruleance
    Spec, if you answer this question please clarify why the signal is boosted 3 dB.

    If you have a L and a R input, you are essentially sending the same voltage to each input when you use a Y splitter. Measure the voltage at each end of the Y splitter with a sine wave signal and you will see this is true.

    The sub amp simply sums the voltage at the L and R inputs, so a doubling of the signal strength yields a 3 dB increase in sound pressure level.

    If you don't believe it, try it, preferably with a sine wave signal. Run the sub with a single input and measure the SPL. Then connect the other half of the Y and measure again.

    A Y splitter doesn't "add" any power or wattage on its own, obviously. It's just a friggin' piece of cable. You can accomplish the exact same effect by upping the AVR sub level 3 clicks.

    The only reason to use a Y splitter is if the sub has a "sleepy" auto-on circuit.
    "What we do in life echoes in eternity"

    Ed Mullen (emullen@svsound.com)
    Director - Technology and Customer Service
    SVS
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  • Pauly
    Pauly Posts: 4,519
    edited December 2003
    LFE input if you got it, then set your crossover to your liking, tweek, crank er up and enjoy.
    Life without music would♭
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  • walk
    walk Posts: 178
    edited December 2003
    If you use the LFE input, you don't need to touch the crossover dial, since it is by-passed - that's the point of the "unfiltered" LFE input. Your avr does the filtering/crossover...ing (hey I think I invented a new word!)

    My sub (a CSW BassCube 8") is so "sleepy" that even with a Y-cable I have to boost the output on the avr by +9db to prevent it from going to sleep when the volume is at medium/low settings...
    - Sony 50"A3000 SXRD; Onkyo TX-SR 805
    - Polk RTi150 mains; CSi30 center; FXi3 surrounds, R15 backs
    - Velodyne CHT-12 subwoofer
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  • Seaward
    Seaward Posts: 56
    edited December 2003
    what is a sleepy sub??
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  • scottvamp
    scottvamp Posts: 3,277
    edited December 2003
    It is in reference to the auto "on" and "off". If a signal is weak it will shut off during low volume and queit scene's. But using a "y" will yeild a higher signal gain and keep the sub "awake" more.
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  • michael_w
    michael_w Posts: 2,813
    edited December 2003
    So is it better to just flick your sub to "on" instead of "auto on" and just use the single rca - no splitter? then you can just turn it off after your movie or whatever.
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  • michael_w
    michael_w Posts: 2,813
    edited December 2003
    So if it has some quiet scenes will the sub keep doing its stuff if it is set to auto on as long as there are explosions (or just loud scenes) every 15 - 30 mins or something?
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  • scottvamp
    scottvamp Posts: 3,277
    edited December 2003
    It should.......
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  • michael_w
    michael_w Posts: 2,813
    edited December 2003
    lol ok thx :p
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  • walk
    walk Posts: 178
    edited December 2003
    If it's a huge problem you can switch it to "on", yes. Chances are you probably won't need to. Even with a "sleepy" sub - the timeout is set to 15 minutes, so it's not like it's constantly flicking on and off. We are talking some low volumes here, like watching TV late at night. In my case, even at very low volumes the sub stays on, all I had to do was boost the AVR's sub output +9db (and reduce the volume on the sub's control by roughly the same amount).
    - Sony 50"A3000 SXRD; Onkyo TX-SR 805
    - Polk RTi150 mains; CSi30 center; FXi3 surrounds, R15 backs
    - Velodyne CHT-12 subwoofer
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