Port Noise PSW505

well i bought the psw505 and it sounds good untell it gets to some songs with different bass you can hear the Port( Cant hear it fromt where your sitting Just up closer to it 5 feet and up) is there anyway to Fix that , is this causing any damage to the Speaker or amp ?. it is hooked up buy Rca with a y spliter if that makes a difference
- This your Bush?
Pioneer Elite Sc-25
Polk Lsic,15's,9's, PSW1000
Post edited by Frank840 on

Comments

  • polkseller
    polkseller Posts: 184
    edited March 2008
    Port noise can be cause by distortion, also Y splitter reduce the impedance of the signal by 2, causing the amp to give more power sooner.

    Remove the splitter now, and see what happen. Carefully adjust the volume control on your sub and make sure your subwoofer volume is set to 0db in your receiver/amp.

    Thats it!

    One other cause is sub out voltage is too high for your sub. Usually polk sub can take around 8volts RMS without problem( HK and denon receiver). The usual receiver sub output is 2 volts.
  • dorokusai
    dorokusai Posts: 25,577
    edited March 2008
    Port "chuffing" can certainly be caused by distortion or overdriving the subwoofer but it has nothing to do with the Y-Splitter or impedence.

    I woud suggest turning the volume down a bit, play the same media and see if the problem remains.
    CTC BBQ Amplifier, Sonic Frontiers Line3 Pre-Amplifier and Wadia 581 SACD player. Speakers? Always changing but for now, Mission Argonauts I picked up for $50 bucks, mint.
  • polkseller
    polkseller Posts: 184
    edited March 2008
    I advise to not use y-splitter, they usually lower the sound quality and for example, when used in a poweramps to split channels, the impedance change sometime cause problem if your amp cannot accept the lower impedance. The amp will play bright or thin sometime.

    This cause the sound to distort faster or it will play louder faster.

    Impedance matching is very important for any audio components. If I remember well, to be optimal, you should never use a source impedance that is more than 10 times the amplifier input impedance.

    From a website: It results in maximum POWER transfer from the source to the load. In contrast, suppose the source is low Z and the load is high Z. If the load impedance is 10 times or more the source impedance, it is called a "bridging" impedance. Bridging results in maximum VOLTAGE transfer from the source to the load.
    Nowadays, nearly all devices are connected bridging -- low-Z out to high-Z in -- because we want the most voltage transferred between components.
    If you connect a low-Z source to a high-Z load, there is no distortion or frequency-response change caused by this connection. But if you connect a high-Z source to a low-Z load, you might get distortion or altered response. For example, suppose you connect an electric bass guitar (a high-Z device) into an XLR-type mic input (a low-Z load).
  • dorokusai
    dorokusai Posts: 25,577
    edited March 2008
    You're a crackpot. The voltage is shunted if its too high.
    CTC BBQ Amplifier, Sonic Frontiers Line3 Pre-Amplifier and Wadia 581 SACD player. Speakers? Always changing but for now, Mission Argonauts I picked up for $50 bucks, mint.
  • polkseller
    polkseller Posts: 184
    edited March 2008
    I'm not speaking of the voltage, I'm speaking of the impedance. Voltage is usually not the problem with receivers.

    Anyway, try it, you'll see.

    Frank, You can also try a better sub cable. with solid copper core. This will help control the sub movement when powered hard.

    try the monster bass 300, under 13 feet long.
  • dorokusai
    dorokusai Posts: 25,577
    edited March 2008
    So what was post #2 about? I agree that impedence matching is important for electronics but it's got nothing to do with the LFE input for a subwoofer, let alone the cause of port noise.
    CTC BBQ Amplifier, Sonic Frontiers Line3 Pre-Amplifier and Wadia 581 SACD player. Speakers? Always changing but for now, Mission Argonauts I picked up for $50 bucks, mint.
  • polkseller
    polkseller Posts: 184
    edited March 2008
    I was writting about another cause, just read.. and be polite

    the 2nd post is all about impedance. Impedance cause voltage to be highter on the output amplifier, thus reducing the ability to control the gain with smaller increments and can cause more distortion.

    did many testing in my store with many different cable and receivers, some gives better results than others, often HK receivers with their triple or quadruple crossovers and high output sub out are around 6-8volts gives a nice clear sound and pure signal without clipping and 0% distortion.

    some older yamaha had more than 10% distortion on the sub out with only 2volts...

    I give more than one advice, we will see what will work.
    Adjust your sub to a volume, add a y-split and another sub, mute the second sub and see what happen with your sub output with a db meter..