subwoofer bangs

[lmr]

While listening to some music, the sub will make a banging noise occasionally. It has it's own amp but does it when the music is turned up. It will move a lot more then usual and at no purpose in sound. What would cause this?

[Topend]

Maybe the driver is bottoming out?

Dave.

[geebo]

Oct 19, 2013 17:00:36 GMT -5 Topend said:

Maybe the driver is bottoming out?

Dave.

Sounds like it to me. I had an inexpensive Polk 12" sub that would do that occasionally.

[Jim]

Could be clipping - but more likely bottoming out.

[DYohn]

Could be caused by your amplifier dying and sending DC to the driver. Best advice: turn it down.

[hemster]

I think it's due to DC on the line. Turn it down as DYohn says and see if it is reduced (likely) or eliminated (unlikely if the amp is dying).

[Deleted]

LMR, I recommend you go back to your thread on "speaker size" and read our comments again about your sub.  You never gave us the precise dimensions or much other info your about your room. Sounds to me like you are over-driving your sub and it is bottoming out.  That can be due from too much volume for your room size for your specific sub or also possible that you have the sub not set up correctly.  By that I mean the gain/volume on the sub is too high versus the other 5 channels.  Many folks have the sub gain set too loud because they like the audible thump of the lower bass.  Don't leave it the way the Yamaha YPAO sets it but change it manually.  Try a 2 or 5 channel music selection with a very clean and strong low bass line.  If you are aware of the sub playing as a separate bass sound source then the sub is set too high.  Turn up the sub volume knob until you just barely begin to hear the sub playing and then turn the sub volume back down very slightly.  Now you should not be able to distinguish the sub as a separate bass source. Visitors should not even be  aware that you have a sub in the room and that all the low bass is coming from your L&R main speakers.  Now if you turn off the sub you will suddenly hear the lowest bass disappear that the sub was reproducing but you were not aware of.  Just like the tweeters, mids and woofers blend seamlessly in your L&R speaker the subwoofer driver should continue that extended blend down below the bottom of the 802N's to the low end of the sub.

I highly recommend, depending on your budget, you consider a sub from SVS, HSU or Rythmik.  A sub from one of these online direct companies will far outperform a sub from Polk for anywhere near the same price.  


emotivalounge.proboards.com/thread/33234/speaker-size

[stiehl11]

I had the same problem with my Phase Tech sub. I replaced it with my SVS sub (for quite a bit less than what I paid for the Phase Tech) and have not had the issue ever since. I have a lot more power and SPL with the SVS than I ever had with the Phase Tech.

As other have said; you're over driving your sub.

[lmr]

My room is 12' by 16' and the sub is plugged into the XSP-1. The sub itself only has up and down buttons so I have no idea where it is set. I set the LF bypass to 60 on the sub. This was happening while listening to the TT and as far as I know, the only adjustment for the XSP-1 is with the db increase which was left at 0.

[geebo]

Oct 20, 2013 8:52:07 GMT -5 lmr said:

My room is 12' by 16' and the sub is plugged into the XSP-1. The sub itself only has up and down buttons so I have no idea where it is set. I set the LF bypass to 60 on the sub. This was happening while listening to the TT and as far as I know, the only adjustment for the XSP-1 is with the db increase which was left at 0.

Does your Polk have an LED on the front that blinks when you push the buttons? My DSW PRO500 had the buttons for volume but you could decipher the setting by watching how many times the light blinked.