subsonic tones

[basite]

i now have a luxman pd282 tt with a ortofon om5e cartridge on it, when i play a record and turn the volume up (halfway up) my woofers start to move when there's no bass at all, i think i once read something about it on the forum but that thread is gone. Are these subsonic tones that we can't hear but the speakers can give? Is it bad ffor your speakers?? what to do about it???

[Jimmy C]

i now have a luxman pd282 tt with a ortofon om5e cartridge on it, when i play a record and turn the volume up (halfway up) my woofers start to move when there's no bass at all, i think i once read something about it on the forum but that thread is gone. Are these subsonic tones that we can't hear but the speakers can give? Is it bad ffor your speakers?? what to do about it???

...your speakers (played at reasonable levels), but it's wasting power.

Another possible problem is a cart/arm mismatch.

My "woofer-pumping" problem went away when we moved from our suspended floor apartment to our slab floor condo. All the while I thought it was the filter thing.

Sorry, I'm no expert, but I'm sure you can remedy the problem with something outboard. My Bellari has a built-in that I engage, but there is really no discernable difference, using or not, visually or otherwise.

Good luck...

[basite]

i've done some 'investigations' and stated that when i put my hand on the tt and push it down a little bit, the speakers move harder then otherwise, also, they move less/not when there aren't any bass tones, i guess this could mean that the woofer-pumping is created by shocks that the basses create. any other suggestions??

[Jimmy C]

i've done some 'investigations' and stated that when i put my hand on the tt and push it down a little bit, the speakers move harder then otherwise, also, they move less/not when there aren't any bass tones, i guess this could mean that the woofer-pumping is created by shocks that the basses create. any other suggestions??

.."HiFiTommy" has tried a bicycle tube under the table for some isolation. I'm sure he'll chime in the not-too-distant future.

Some say suppress (like my sprung Perspective), some say funnel the vibes (cones). Might be something you'll have to play with.

Again, sorry, I haven't experimented with different solutions. I simply lived with flapping woofers until we moved. Audioasylum.com might be able to help if you don't get too many responses here.

There are a LOT of vinylheads there, mucho experience.

By the way, just realized you were from Belgium... my friend recently returned (still drunk, along with a virus that made him see double...lol) from Antwerp. His wife drove him around all day to different pubs/restaurants.

He loved every minute of it, met a lot of foreigners/locals - even someone that resides 20 minutes from us! What are the chances?

I'm enjoying a Corsendonk as we speak (err, uhh) type...

[Woochifer]

It's pretty normal to see some kind of subsonic rumble with vinyl playback, since the turntable, the audio rack, feedback, and the vinyl itself are all potential resonant sources. A decent rig that's properly calibrated can minimize it, but vinyl is an imperfect medium and this rumbling is just part of it. Part of the reason why you see the cone movement on speakers is also because these frequencies are below the tuned frequency on most ported speakers, which means that they are in the range where the back pressure from the port no longer dampens the cone movement. You don't hear anything, but the speaker and the amp are both getting worked.

Amps used to frequently include subsonic filters that roll off the inaudible frequencies, because all of that undampened cone movement could also affect how the higher frequencies sound. Nowadays, you can still find those switches on some preamps and phono preamps. Here's a link to a previous discussion on this subject.

Why do bass drivers go nuts when playing vinyl

[JoeE SP9]

Sometimes the cone pumping you are seeing can be greatly reduced by changing the cartridge.
You could try changing the effective mass of the tonearm by adding a weight to the headshell and re balancing and re-setting the stylus force. This would increase the effective mass of the tonearm. This would make the cartridge appear to the TT as having higher compliance. However, in this instance I believe a less compliant cartridge would help. There is no easy way to decrease the mass of the tonearm. Decreasing the mass of the tonearm will effectively lower the compliance of the cartridge. Most MC cartridges have lower compliance than MM thats why most of them work better in medium to high mass arms. A Shure cartridge with the stabilizer brush may help with your problem. Shure used to mention that was one of the reasons they put them on their cartridges.

[basite]

By the way, just realized you were from Belgium... my friend recently returned (still drunk, along with a virus that made him see double...lol) from Antwerp. His wife drove him around all day to different pubs/restaurants.

He loved every minute of it, met a lot of foreigners/locals - even someone that resides 20 minutes from us! What are the chances?

I'm enjoying a Corsendonk as we speak (err, uhh) type...

lol, thnx, glad to hear he liked belgium, hope you like the beer, you should also try belgian chocolate if you get the chance.

Amps used to frequently include subsonic filters that roll off the inaudible frequencies, because all of that undampened cone movement could also affect how the higher frequencies sound. Nowadays, you can still find those switches on some preamps and phono preamps.

i know about the subsonic filters, my current amp haves one, but in a few days my new amp will arrive and then i don't have the filter anymore, but, now after alot of drastic changes in my room (moved the bed, removed all chairs, used matras as room acoustics, moved amp, moved tt and placed it on something higher then the ground) the cones move less.

thnx for all the help btw

[jrhymeammo]

I used to have the same problem, drove me nuts.

Try getting yourself a very sturdy and heavy table for your TT. I'm prettu sure your problems are caused by external vibration. One way to check this is to careful walk around your TT while it's spinning. If you woofers start chucking more, then try placing sheets of concrete (45cm x 45cm x 10cm) under your TT. Cones and Spikes work best under your TT. Try something like these. http://www.madisound.com/cgi-bin/ind..._id%%&pid=1603

Happy BD. Mine was on the 20th.
Peace

[basite]

thnx jrhymeammo, the the spikes (somekind of) are in consideration, in the meanwhile, finding a place to sleep is difficult, since half my room is now set for audio and the other half is desk, so i guess i'll have to place my bed in the middle for tonight

[JohnMichael]

Here is a link to a thread covering some of the same issues you are having. In the thread are some good links that might help.

Cartridges with brush good for subsonic problem?

The woofer pumping you see when playing records is more obvious with ported speakers and much less with acoustic suspension. If your speakers are ported you may still see some pumping even if everything is working well together.

[basite]

tried some things (cushions, lego bricks, wooden plates, combination of all the previous, a lego rack (plastic rack with boxes in them for lego) with the bricks and the wooden plate on) and finally i was going round my room and felt what was moving due of basses and i found that the matrass that i put against the wall behind the speakers and the tt was moving from the basses, i removed it and now the woofer pumping is alot less i have to turn the volume half way open before it starts to pump (half way up is really loud) so it's partially fixed. thanks for all the advice, i'll remember it and make use of it in the future, when i move out to my own house