Replace the table? Build better isolation? Possibly but there are other reasons more likely to pursue first.

Posted by tubesforever (M) on August 6, 2005 at 23:59:28

In Reply to: think about what that posted by chiggy on August 6, 2005 at 16:23:19:

Look! Woofer pumping is almost entirely limited to speakers with port tuning and bass reflex models. They do not dampen the cone under their tuning frequency so the woofer is free to flap in the breeze. An accoustic suspended speaker rarely has any issue with pumping so all you AR-3 and AR-4 users have nothing to be concerned with.

A cartridge can ususally reproduce down to 2-5 cycles with no problem. Just tracking a warp will cause woofer pumping to some extent. So isolation or a better turntable will do NOTHING. It really depends on what is creating the woofer pumping. Ususally it is warped vinyl.

Maybe a vacume type Sota would do something to improve this, but every Sota I have listened to sucks the life out of the music. PRAT disappears, and a lovely homogenization overtakes your soundstage.

Ultrasonic filters all deteriorate the sound quality of your set up. I know, I have tried more filters than I care to remember.

The idea that woofer pumping will damage speakers is somewhat misleading. Most amps will reproduce down to 2 cycles. Good woofers will reproduce down there too if they are port tuned or bass reflex. My woofers pump on warped albums, but there is no sound from the pumping because you cannot hear a tone from information under 16 hz. You can sometimes feel the air pressure or hear your ports huff. I stuff my ports with cocktail straws, something I learned from Linn Speakers.

If your woofers pump and you play the pump too loud I have seen the voicecoil pop out of the gap and land on the metal surface of the motor assembly. We see this alot in car stereo if the cones are not properly damped. It is usually simple to just reposition it and rarely is there any physical damage.

Of course if you have old drivers with poor surrounds, there is a chance the voice coil will rub in the gap and that will create a quick demise unless you replace the worn surrounds.

If I have a vinyl record that causes a lot of pumping the last thing I am going to do is turn it up extra loud. Interestingly, the pumping ususally only goes in a track or two on most albums. So play it quietly until the pumping abates then you can crank on it.

I usually look for a good replacement LP for anything that I love to listen too that is pumping away.

Cheers.

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Follow Ups Full Thread

Topic - Why do my woofers do this when playing an LP? - wengler 16:20:12 08/06/05 (19)

Arm/cartridge resonance and TT isolation - paul_s 11:38:39 08/07/05 (0)

Re: Why do my woofers do this when playing an LP? - user510 02:35:31 08/07/05 (1)

Re: Why do my woofers do this when playing an LP? - wengler 11:10:24 08/07/05 (0)

It almost surely won't harm your speakers, but . . . - Tightwad 22:23:13 08/06/05 (2)

Re: I have good isolation down to about 2-3hz, but.... - PeterBGood 15:33:11 08/08/05 (0)

Re: It almost surely won't harm your speakers, but . . . - Todd Krieger 01:41:24 08/07/05 (0)

Re: Why do my woofers do this when playing an LP? - Eli Duttman 16:56:20 08/06/05 (1)

Yes! KILL the beast! And get rid of that MDF stuff, it rings like crazy. nt - Dan_ed 17:30:36 08/06/05 (0)

your stylus is picking up super low level information - danny kaey 16:24:00 08/06/05 (0)

think about what that - chiggy 16:23:19 08/06/05 (9)

Replace the table? Build better isolation? Possibly but there are other reasons more likely to pursue first. - tubesforever 23:59:28 08/06/05 (1)

Re: Replace the table? Build better isolation? Possibly but there are other reasons more likely to pursue first. - Peter Olofsson 00:51:26 08/07/05 (0)

Re: think about what that - wengler 16:34:09 08/06/05 (6)

Re: think about what that - chiggy 17:14:18 08/06/05 (5)

Re: think about what that - wengler 17:21:42 08/06/05 (4)

yes - chiggy 17:30:32 08/06/05 (3)

Re: yes - wengler 17:51:30 08/06/05 (2)

Cinder blocks - castironandtubes 20:11:04 08/06/05 (0)

Re: yes - chiggy 17:56:02 08/06/05 (0)

Follow Ups

Replace the table? Build better isolation? Possibly but there are other reasons more likely to pursue first. - tubesforever 23:59:28 08/06/05 (1)

Re: Replace the table? Build better isolation? Possibly but there are other reasons more likely to pursue first. - Peter Olofsson 00:51:26 08/07/05 (0)

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