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howze

how to stop my speakers from "fluttering"

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Hi all ive got a small problem of my bass drivers on my aaron ats5's flutter at a low frequency when its turned up louder, it seems to have gotten worse changeing to an mc cart, i dont wanna hange my phono pre as i just got it and quiet like it, is there an external low pass filter i can use or something similar

Thanks jamie

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G'day mate, well the simple answer is that you need a good sub bass filter however your situation suggests some tonearm/cartridge incompatibility, exacerbating the production of considerable sub bass energy, clearly evident as 'woofer pumping', or as you put it 'fluttering', an equally accurate term.  Regards, Felix.   

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Isolate the TT better? Also a mate of mine had some crazy movement going on, and turned out the earth for TT wasn't conected properly the little spade had broken off, reconnected it and problem was gone,

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Guest Hensa

Harrison labs passive sub sonic high pass filters would do the trick. About $35 and they sit between the phono pre and amplifier.

Sent from my iPhone using Tapatalk

Edited by Hensa

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Harrison labs passive sub sonic high pass filters would do the trick. About $35 and they sit between the phono pre and amplifier.

Sent from my iPhone using Tapatalk

Cheers for all the sugestions, will have a look into the filter and worse come to worse its just $40 gone

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Hi all ive got a small problem of my bass drivers on my aaron ats5's flutter at a low frequency when its turned up louder, it seems to have gotten worse changeing to an mc cart, i dont wanna hange my phono pre as i just got it and quiet like it, is there an external low pass filter i can use or something similar

Thanks jamie

Mate are you speakers ported? If so, I would say it's more likely woofer pumping that can occur on vinyl even if you have your TT setup properly in which case I would just go straight to a sub filter, if they aren't ported I would look at TT setup first, in particular the compliance of your cart and mass of your tone arm, their are calculators on line that let you calculate res freq. from my experience a lot of ported speakers will just give woofer pumping with vinyl without any issues with TT, if not then look at isolation, res freq etc..

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Guest Muon

I have had woofer pump as a result of a table that was not inert enough and not isolated well enough, and that is with ported speakers.

 

Changed to a better table/arm and better isolation and no pump.

 

So you need to work out what is the cause and address that, whether it is isolation or a filter.... but sometimes the only way is through trial and error.

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Gonna try and isolate the tt a little better anyways, and yeah the speakers are ported and the mc cart has seemed to make it worse, according to my project manual the cart is compliant with my tt

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Guest Muon

Could be the table/arm, or isolation issues.

 

A filter might be the quickest fix and has been suggested here.

 

Either way, Jamie... it will be interesting to hear how you go by addressing isolation.

 

Edit: @@howze I have forgotten what table you have?

Edited by ortofun

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Project 1.3, who knows i may not have set it up right but it seems to sound good and play well but i really have no idea if its set up right as it was my first cart change

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You seem to have an issue with poor matching between the arm mass and the compliance of the cartridge. This is not necessarily a reflection of the quality of the turntable, or the tonearm, or the cartridge or the base it is sitting on. A good setup has a cartridge with a compliance that suits the tonearm mass so that the tonearm is able to move fast enough to keep the cartridge at the correct height above the vinyl, without overshooting. Think of a vehicle (the cartridge) on a bumpy road (the non-perfectly flat record) with underdamped shock absorbers - it will bounce around all over the place, which is what your setup appears to be doing.

 

If your tonearm mass / cartridge compliance combination is such that it is causing your speakers to "wobble about" it is also likely that your cartridge is wandering in and out of its "sweet-spot" for linearity. You may be able to hear some modulation of the sound level that correlates with the woofer cone movement. If so, this is not something a rumble filter can fix.

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Guest Muon

Gonna try and isolate the tt a little better anyways, and yeah the speakers are ported and the mc cart has seemed to make it worse, according to my project manual the cart is compliant with my tt

 

 

You seem to have an issue with poor matching between the arm mass and the compliance of the cartridge. This is not necessarily a reflection of the quality of the turntable, or the tonearm, or the cartridge or the base it is sitting on. A good setup has a cartridge with a compliance that suits the tonearm mass so that the tonearm is able to move fast enough to keep the cartridge at the correct height above the vinyl, without overshooting. Think of a vehicle (the cartridge) on a bumpy road (the non-perfectly flat record) with underdamped shock absorbers - it will bounce around all over the place, which is what your setup appears to be doing.

 

If your tonearm mass / cartridge compliance combination is such that it is causing your speakers to "wobble about" it is also likely that your cartridge is wandering in and out of its "sweet-spot" for linearity. You may be able to hear some modulation of the sound level that correlates with the woofer cone movement. If so, this is not something a rumble filter can fix.

John, did you read that bit in bold?

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John, did you read that bit in bold?

 

Yes, but clearly the evidence indicates otherwise. BTW I can't see any reference to compatible/recommended cartridges in the online version of the owner manual, the critical property being the static compliance (or "springiness") of the cartridge to suit the moving mass of the tonearm. It might help to know which model Cartridge you are using.

 

The static compliance is not the same as the dynamic compliance, which is the compliance of the stylus "seen" by the record. The static compliance is that "seen" by the moving mass of the tonearm. This kind of information is rarely given and perhaps one reason why so many people end up with poor matches between cartridge and arm. In the old days turntable reviews used to show a plot of the tonearm / cartridge resonance because poor matches were easily exposed.

 

Have a read of: http://www.gcaudio.com/resources/howtos/tonearmcartridge.html

 

There is a good discussion of why a rumble filter is not an ideal solution here: http://www.vinylengine.com/turntable_forum/viewtopic.php?f=19&t=51244&start=15

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I really only gatherd that as i can set up the right tracking weight and etc who knows it may not be compliant but the 2m red the tt came with did the same thing just not as much

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Guest Muon

I'm out of my depth as I'm not familiar with the table/arm, and compliance always messes with me anyway.

 

Maybe the cart specs can help John and others here that may be familiar with your table/arm.

 

BUT! it doesn't list compliance, so maybe someone can work it out from the weight and VTF specs.

 

Model: LP-MC80H
Type: MC

Stylus : Diamond,
Cantilever: Aluminum
Height: 16mm
Weight: 5.5grams

Internal Impedance (DC  resistance): 125 Ohm
Output Voltage: 0.8mv, 1KHz@ 33 1/2
Freq. response: 20 -20KHz +/-1dB
Channel separation: > 25dB@1KHz
Channel balance: < 1dB

Recommended loading : >100 ohm or MM 47K ohm, 150 ohm (MC transformer)
Tracking Force: 2.2 grams
Optimum Track Force: 1.8 - 2.5 grams
Break-in Period: 20 hours

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Sorry, I can't find any compliance information or a manufacturer's website.

 

If the moving mass of the tonearm is know (which it isn't) and the compliance of the cartridge is known (which it isn't) then it would be possible to estimate the resonant frequency of the combination. However that still would not reveal the "Q" (or severity) of the resonance, which also depends on the degree of damping inherent on both the arm and cartridge, both of which are unknown as well! See: http://www.resfreq.com/resonancecalculator.html

 

Unlike sealed speakers, bass reflex speakers have almost no acoustic loading at frequencies well below the box tuning frequency, which is usually ~25-35 hz for floor standers and ~35-45 Hz for bookshelfs. Very small signals at the tonearm/cartridge resonant frequency (usually between 5 & 20 hz) will cause noticeable cone movements. It would be more surprising than not if this wasn't the case.

 

I am personally not a fan of high order (2nd, 3rd, 4th etc.) rumble filters because they alter the sound of the recording, although many people would argue it is a worthwhile trade-off. A first order rumble filter would be relatively sonically benign, but probably of limited usefulness in removing the resonance unless the corner frequency was 50 hz or higher, which will cause audible loss of bass.

 

Another alternative is to add damping to the tonearm. See: http://www.enjoythemusic.com/magazine/bas/0809/

 

The bottom line is that if Howse likes the sound of the cartridge, and there is no audio problem (e.g. fluttering of sound when the cartridge goes over a bump on a warped record, or warbling of tone as the speaker cones move in and out) then the issue of cone movement is probably best ignored.

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Guest Hensa

I don't think you can work out the compliance of the cartridge from the above specs as it is a separate measurement of the 'give' inherent in the cartridge's cantilever. It's a little odd that no measurement is provided but I don't know a way to calculate it other than to use the measured resonance frequency with a known arm mass and then do the resonance frequency calculation in reverse to obtain the compliance figure. Sorry I can't be of more help.

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Can anyone work out the compliance of the above cart?

 

@@Hensa

 

@@johnmath

 

@@andyr

 

Anyone ?

If you know the effective mass of your arm and weight of your cart, you could run the Hifi News test LP and watch where the cantilever resonates. You could then apply that freq response to the 'total effective mass vs res freq' graph to find compliance.

It would be approximate as those test LPs aren't the be all and end all in accuracy. It's just fun to watch the cantilever go nuts at around the required 10hz! :)

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Given the lack of available information about the arm & cart, I would follow Omegaspeedy's suggestion and get hold of the Hifi News Test LP and play the cartridge horizontal & vertical resonance tracks on Side 2.  If you can see the cantilever vibrating at 10hz +/- 2Hz then your arm & cart are compatible.  In which case, the "woofer pumping" is due to one of the issues mentioned above.

 

If you see the vibration outside the range of 8-12Hz then your arm & cart are not compatible, irrespective of what the manual says.

 

Andy

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Ok then cheers guys, where would i get one of these vinyls from

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http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR0.TRC0.H0.Xhifi+news+test+lp.TRS0&_nkw=hifi+news+test+lp&ghostText=&_sacat=0

Btw, if your speakers are longish throw bass reflex type (as mine are), even the slightest record warp causes dancing of the woofers. It's pretty normal I reckon but disconcerting. I've got a few LPs that when played, the woofers dance more at the beginning where the warp is worst, then it settles down as the stylus moves to the region of less warp closer to the centre. I've matched my arm/cart compliance and it still does this. Full range short throwers don't do it as much nor sealed or restricted/lossy designs ie aperiodic, BBC.

It would be interesting to hear reports from other vinyl/bass relex users as to the behaviour of their woofers. I suspect that the majority will dance a bit. I don't want subsonic filters in the chain and have accepted this trait.

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I don't want subsonic filters in the chain and have accepted this trait.

 

You could always change your speakers! :P

 

Andy

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