Issues with cone pumping with Vinyl playback on one channel...

Hi All,

So this is what happens when I go back to finally listening to music - I run into problems which takes me away from the enjoyment of my audio setup in being able to listen to my precious LP's!!!

I am experiencing issues again with the speaker cones pumping during quiet passages of music with my right speaker. The bottom two cones seem to be pumping and very apparent during the needle drop at the lead in groove at the beginning of the LP. It doesn't seem anywhere near as bad when the stylus is around the mid to end of the LP at the same volume levels. The left speaker is totally fine with no cone movement.

I tried moving the speaker out further in front (about a foot or so) which didn't help. I also moved the speaker further back closer to the wall but that didn't make much difference. I can't move the speaker much further to the right as you will see from the picture, I don't have any further space to play with. Is the issue due to the speaker being too close to the Prime or do I have another issue/area to solve?

It seems like my system is causing some acoustic feedback or there is excessive rumble being generated but only to the right channel it would seem. I believe the solution would be for me to introduce something like the KAB RF-1 filter which is highly recommended. However, I would like to avoid adding another component and which would mean I would need additional interconnects in keeping to the same quality as I have now between the phono stage and preamp.

Has anyone experienced this and found a solution...? Could it be a compliance issue between the tonearm and cartridge. I believe my TT is well isolated and I don't suffer from any foot falls. Just odd that the issue is only happening with my right speaker.

I am open to any suggestions at this point and appreciate any help/advice in advance. Thank You.

Cheers,
Vin.

IMG-4441

 

Before you blame the right speaker, try swapping the connections to the speakers. If the problem moves, it's not related to the speaker or speaker position. If the problem stays put, it might be related to the speaker and position.

I'll bet the problem moves.

BTW, the last two images are broken.

 

I can't see your pictures. Speaker being to close to the TT could be an issue but most of the time it should be on both not just one. There could be a problem with the cartridge, again without seeing the pictures is harder to tell.

 

It seems your first problem is determining why it is only showing up on one channel. Could be the speaker or anything else in the chain. I'd start swapping leads between left and right to try and isolate that issue first.

Woofer pumping usually just means your tonearm is high mass and you are playing a warped record. A test for this is to just set the tonearm on the record without the platter spinning and see how much woofer bounce you get. If you are still seeing a lot of bounce, then it is compliance matching issue.

 

Sorry, is the link to IMG-4441 not working? There should be a link at the very bottom of my posting - please let me know and will try to fix if still an issue... Thanks/

 

Thanks - I'll play around with the connections tomorrow and report back - Just FYI, the LP is very flat and no warping going on to be an obvious issue here. I am also using the VPI periphery ring which clamps the LP down nice and flat. But appreciate the thought...

 

IMG-4441



Hoping these links work!

 

The link initially gave me an error message but it works now plus the photo in your last one.

I think what the others have said is the best advice. I agree with your feeling and I would not use a filter, normally this shouldn't happen.

My idea is that if it was vibration related you should get it on both channels. Unless under the carpet, the floor is very unstable, moving the speakers might not solve the problem.

Try swapping cables along the line until you are sure where the problem is coming from. Start with the TT cables and work your way down from there.

 

Thanks and will do. Just to add and FWIW, I did swap the left and right RCA cables from the TT to the phono stage and that did not move the issue over to the left channel.

Sorry and to add, I have the speakers on Isoacoustic feet which sit on top of dense wood platforms on top of the carpet with concrete flooring.

 

Any chance your speaker is having issues or the phono stage? Food for thought.

 

Someone correct me if I am wrong but I would say one of your components is having a problem and has nothing to do with your TT. Keep swapping until you find the culprit.

 

It just occurred me whether your phono stage might have switches or jumpers to select the different options and you might have one channel set differently to the other.

 

Honestly, this just looks like plain old acoustic feedback from your right speaker to turntable.

 

Honestly, LF acoustic feedback wouldn't show up in one channel only, even if it was caused by one speaker coupling to the TT.

I think @Uglyversal had a pretty good idea to go looking for a difference between channel settings, but I'd swap speaker connections first and see if the problem moves.

 

Thanks for the great feedback everyone. I have a list of things to run through and will report back in the next day or so. A couple of things I was able to rule out, is that its not being caused by the subwoofer as I took it out of the chain and still same behavior with the right channel. I also flipped the preamp into 'mono' mode as recommended by someone on another forum and still only seeing the issue on the right channel.

More feedback to come...

 

Agreed, seeing it only on one channel is peculiar, and would typically eliminate compliance, warps, etc because they'd show up in both.

In general though, warped records and compliance are two obvious suspects.

Woofer pumping can be an interesting phenomenon - one where rumble caused by speakers or sub too close to the TT could cause it too.

I've had woofer pumping suddenly surface on one LP, where every other plays with no issue. All with the same set up. Not sure why, the LP wasn't warped?

A few weeks back I was re-installing a TT in my shop that had been sitting for a while (16 months?) with the cartridge mounted. Started playing the first couple of LP's and the woofers were pumping. It wasn't compliance, wasn't warped record, wasn't speaker / sub placement and rumble.

Turns out the cartridge suspension had been sitting so long it needed to "loosen up" and after a few LP's it stopped. How did I determine that? Well, I read it , and after it stopped after a few LP's like the article / write up said, I concluded that had to be it.

But Davey - in essences, isn't that really the same thing as a compliance issue as the cartridge suspension was acting like it was higher compliance because it was stiff? So in essence it could be called a compliance problem as the root cause.... but not because of cartridge rated compliance, but the suspension was stiff replicating higher compliance? I am asking as well as semi-concluding, but not 100% sure.

 

Nice setup, passes the "looks the part" test for sure!

 

Nice system! Just thinking on the info we have so far, the pumping lessens as the stylus plays the middle to inner bands. This is normal. But the rest isn't. The strange part of this, as mentioned by other members, it's highly unusual or impossible a turntable isolation problem or feedback problem to occur on the Rch only.

Some additional (general) info as we try to isolate the problem.
I too suggest to continue channel swapping downstream, also see if this occurs at all playing a CD.

1) Some woofer pumping is normal while playing an LP. This DOES diminish somewhat as the stylus traverses across the record to the inner bands.
2) Normal woofer pumping occurs on both channels. I have never observed nor heard of this occurring on one channel
3) Woofer pumping at "warp frequency" is different than acoustic feedback pumping
4) Acoustic feedback usually occurs at a threshold level, suddenly builds at a specific volume setting, and above that setting. Normal woofer pumping will be present also at lower volume, just less of it. Acoustic feedback disappears entirely at lower volume.
5) woofer pumping is always inaudible (but sometimes may be felt) Acoustic feedback sounds like "fluttering" or in some cases a low frequency tone.
6) Acoustic feedback always affects BOTH channels, even when it has been "triggered" by a speaker too close in one channel.
7) additionally, a subsonic filter remediates both normal woofer pumping (warp frequencies or subsonic) AND acoustic feedback
8) a subsonic filter should not be necessary for a well set up system, but arguably does allow full excursion of the woofer by elimination of all pumping.
9) acoustic feedback can be compounded by compliance/ arm mismatch (even marginal) and poor isolation.

I am perplexed by this occurring on only one channel.

 

I don't know, a stiff suspension would actually equate to low compliance, which would seemingly make it less susceptible to low frequency resonance. But woofer pumping can come from other sources, including the electronics with a leaky capacitor or even transistor, some circuits could have a low frequency oscillation under some conditions set by an R-C time constant. And some records do have rumble and other low frequency noises pressed into the vinyl.

But sure, a stiffer suspension could push the tonearm resonance up into a trouble area.

 

My bad, I meant lower compliance and said higher in error.... but you're point is still taken.

 

@VinBob
does the pumping happen if you turn the amp volume all the way down ? If it does its probably acoustical feedback between the speakers and the TT.
One other thing to try is to place the needle on the record but dont play it. Does pumping happen then ? If it does then it has nothing to do with compliance matching.

 

I had the same problem!! Sadly the amp was to blame. Sent it back to Cyrus and all was resolved. Can you borrow another amp just to try it out?

 

Move the speakers as far away form the TT towards the center of the room and test. Get temp cables if you have to.

 

@VinBob
forgot to mention in my previous post, its obvious from your picture that the TT is much closer to the problem channel (right). So move the TT rack towards the center and maybe little front of the speaker line The more closer its to the wall the more the chances the tt will be in spot where there may be a standing wave / resonance. Side vibrations from the speaker cabinet walls could reach the tt as well.

 

Hi all and truly appreciate the excellent feedback!

So I checked the speaker connections first and noticed that I had the left and right cables incorrect on the back of the speaker - I thought to myself 'YES' how stupid am I and this must be the simple reason for the issue. I swapped them over to match correctly but unfortunately, the problem remained.

So I started to work my way down again and swapping the RCA cables from the turntable to the phono preamp didn't change anything.

So the next step was to swap the output cables from the Sutherland phono preamp at the preamp input and guess what... the problem moved over to the left channel. I tried a different input on the preamp and got the same issue. I also tried another set of good quality RCA cables (Chord Company) and still the same issue - I am using the high quality Audio Sensibility cables so would have been quite surprised if the cable went bad on me all of a sudden.

To add, the cartridge manufacturer VAS confirmed that there should not be a compliance issue between the cartridge and tonearm. I also placed the stylus onto the vinyl with no platter rotation with volume at max and no cone pumping whatsoever.

Anyone have any further thoughts, or have I essentially found the culprit here and need to reach out to Sutherland at this point regarding the phono preamp? Again, interesting that the problem is more pronounced at the beginning of the LP rather than when in the middle to end...

Cheers,
Vin.