Rumble in LP and effect in speaker

[Hiten]

Don't modern phono preamp attenuate frequencies at both end of audio range ?

 

[Selvin]

If you are using extenal phone stage you can add subsonic filter easily. I am using one filter which I made myself. If you are using internal phono stage of Amplifier, it is better to add one external phonostage with Rumble filter and that will solve your problem.

 

[pratimbayal]

Hi Selvin

Do you find any audible deifference when the subsonic filter is on. I have an external phono preamp.


Regards

 

[Thad E Ginathom]

I think rumble filters are thing of the past. Phono preamps on the contrary boosts the low fq. range (RIAA).

That's what RIAA is, and always has been, about: the necessity to seriously distort the sound so that vinyl recording and playback becomes physically possible and to reverse that distortion on playback. Rumble is tangential to that. Being one of those measurements indicating a thing that we do not want, I'm sure it can be engineered out, but many people did not spend very much on their turntables, back in the day, and some do not now. Also, in a new age of vinyl interest, there is enthusiasm for restoration, even of modest turntables: they were not expected to play perfectly in their day, and certainly should not be expected to be perfect a couple of decades later.

Vinyl now has romance attached to it. Those entering its world do need to recognise that not every second-hand-shop turntable will produce impeccable sound just because its vinyl. I've been listening to vinyl since 1960-something, but I don't think I ever had (or could afford to have) a deck that was any more than mid-level. I'm sure our experts could find lots of things wrong with the TT that have now owned since 1990.

 

[pratimbayal]

Hi Thad E Ginathom.

Thanks for very nicely writen experience from your tt listening. But from what I know our member Mahiruha has VPI classic II . A modern and expensive turntable. Even he experienced some rumble under some particular circumstances. So can we conclude that it is inherent in this hobby however at various degree. We need to manage it on a case to case basis.

Have I understood properly ?

Regards

 

[kuruvilajacob]

I used to face this problem of woofer vibration when I first entered vinyl scene. The records I was using were not as good as the ones that I am using now. Also, with my present KLH speakers I have not had any experience of woofer vibration. I do believe that the quality of record and the related systems create this problem. To test this, if you can use the same record on same TT and different phonostage and see if there is any difference. If not, try different speakers. You can only identify this by trial and error method

 

[Thad E Ginathom]

Hi Thad E Ginathom.

Thanks for very nicely writen experience from your tt listening. But from what I know our member Mahiruha has VPI classic II . A modern and expensive turntable. Even he experienced some rumble under some particular circumstances. So can we conclude that it is inherent in this hobby however at various degree. We need to manage it on a case to case basis.

Have I understood properly ?

Regards

Misunderstanding all mine. Yes, I think your comments are exactly correct --- but kuruvilajacob is here now, and he, according to me at least, is the expert

 

[Selvin]

Hi Pratimbayal

First I will answer your question about any audible difference when the subsonic filter is on:

The answer is not much but no cone movement. Please read below for root cause.

Most of old vinyl records will be warped to some degree. Any warp in a record will generate an output in the subsonic region i.e. below 20Hz which are below the audible spectrum. For example, a 33 1/3 RPM album with a single warped section will create a signal in the pickup at 0.55 Hz (33.3 RPM / 60 = 0.555 Hz). This is a signal that will cause significant cone movement in speakers / sub woofers but not audiable by ear. This is undesirable if it is Large. Hope now you can understand the root cause. In good records the speaker cone movement will be minimum and you may verify this by playing a perfect flat record.

Now we will discuss about the fix.

A good engineered Tone-arm will handle such records wraps nicely and so impact on speaker will be less. But from my experience, most of entry level turntables have this issue. At last, damaged cantilever of cartridge also cause this problem. So you may try with some other stylus if you have or if you can loan from friends.

Now we will discuss about the views of other most respect forum members like changing speaker, Phono stage, amplifier etc.

All these are mater of immune or inability of respective components. This may be explained as below. A speaker may have good immune to signals below 15Hz which may obtained by tuned crossovers or cone / coil design. Or they may be inability to handle such low frequency signals. So you will not see any such cone movement. Same theory is applicable to other components.

So if you have affordability you may do trial with changing each component one by one. Simple solution is add one Sub-Sonic / Rumble filter. There are many products available in market and you may switch of this filter when playing good records.

 

[pratimbayal]

Mr. Kuruvila

What I have seen - it is more visable with older records. With new one it is almost not there. I will try cleaning the records with your method of cleaning and after that will see if there is any thing. Will also try with "Sadma" Lp that you sent.


However if something to do with older pressing or other gears in the chain then probably I need to use a filter.


Regards

 

[reubensm]

I actually ran a check playing brand new records and my oldest ones, could not notice anything, probably my woofers are not good enough to reproduce these minor differences.

 

[Tanoj]

Hi

i had this issue, however not sure what fixed it, but below are the changes which i did

1. connected Earth wire to all the phonostage, preamp, power amp

2. introduced Pass B1 pre amp , and disconnected the inbuilt pre of my integrated amp

3. upgraded the rca cable of the TT

4. upgraded the leads of the headshell

5. upgraded the interconnects

6. using belkin serge protector as power box

7. upgraded TT from Philips to Sony Direct Drive ... ( i strongly Doubt its either TT or pre amp )

All the Best

Tanoj

 

[Hiten]

I actually ran a check playing brand new records and my oldest ones, could not notice anything, probably my woofers are not good enough to reproduce these minor differences.

Just guessing.
Provided your phono stage and amp is proper and as we tick off other possibilities like turntable bearing rumble or badly pressed Vinyl. I think this is a very good sign. Because it means your cartridge is aligned properly and it matches well with tonearm.
-x-x-
Still don't understand why to add more electronics of rumble filter in the chain unless one is using subwoofer. Very Low frequencies on vinyls are mono anyways. Lower range (Below 20hz) is attenuated anyways. Turntables of 80s had very good rumble specs. Modern turntables are mechanical marvels. So that leaves us with problem of either badly pressed vinyl or misaligned cartridge which are causing movements in the cone. If we presume most speakers can't output 20hz or below it and still there is a cone movement and a rumble filter eliminates it chances are some music signal will also be lost. I may be wrong though.
regards

 

[kuruvilajacob]

Dear Pratim,
The 'Sadma' album from me is cleaned. As you mentioned, please try that as a test case. If you do not get the rumble, then it could be uncleaned records.

 

[reubensm]

I must mention another odd finding, a friend of mine had a Technics DD (I think it was the SL1700, if I remember correctly). It had a unique problem, the rumble would be less while playing the outer tracks and would increase as one would get closer to the end of the record. The issue was solved when the turntable was serviced and the bearing assembly was lubricated. Not sure but I think he was using a MC cart.

 

[jls001]

Rumbles below 8 Hz are usually caused by warped records. And those in 13 to 20 Hz range can be due to very low frequency bass like those produced by organs (which go down to 14-16 Hz). Hence the attempt to get cartridge-arm resonant frequency to within 8 to 12 Hz.

However, to the best of my limited understanding of the issue, one need to worry about rumble if one has a speaker capable of producing subsonic frequencies. But assuming there is rumble in the subsonic range, it will have harmonics which may intrude into the audible range.

 

[mahiruha]

Hi Pratim ,
I have noticed this excessive cone vibration in my speakers as well with Nighthawk phono stage and ortofon 2m red combo in some cases. It looked a bit scary but the moment I switched over to using moving coil cartridges with nighthawk it doesn't happen anymore. I can't recall which particular record it was. Btw what cartridge you are using? It may well be the case that hgh gain of moving magnets are making this rumble effect more pronounced than it should be and nighthawk is missing something.
Thanks.

Hi,
I think my observation was bit incorrect. I read about what is rumble.http://en.wikipedia.org/wiki/Rumble_(noise) It says the problem area is 10-30 Hz region. What I saw with my speakers cannot be due to rumble because the driver visible to me can only produce sound upward of 90 Hz and I specifically set it as cut off frequency of my inbuilt sub woofer. The cone movement I observed was probably from a noisy record as I have never seen anything like that again. Nighthawk is perfectly ok with all the clean and noise free records so far cone vibration is concerned.
Thanks.