Vinylmasters
Super Member
That's what the subsonic filter is for. Save your money on the Harrison Lab filters and such. Been there, tried that. It won't work right at all.
Unsolvable Woofer Pumping (Phono only)
- Thread starter branden_8091
- Start date
That's what the subsonic filter is for. Save your money on the Harrison Lab filters and such. Been there, tried that. It won't work right at all.
branden_8091
Member
Thanks. I've already bought them so will try them out when they arrive. If they don't work I'll likely get a KAB RF1.
Vinylmasters
Super Member
Trust me on this one: don't bother to open the package. All it does is snuff out the highs and all 'air'. Your woofers will still rumble too.
I like the KASB RF1. I just wish they could get one to work with receivers and integrated amps too.
There's a reason why so many of the vintage preamps, receivers, etc had subsonic filters.
I have the 9.1 with a 9.3 motor upgrade. Very nice table. AK’s own Gordonw says with an Ortofon 2M Black cartridge the 9.1 will hang with some very impressive turntables. I tend to agree. Very happy with it.
branden_8091
Member
branden_8091
Member
I may as well try, as it's not worth my time/money to send them back. International shipping is crazy. Also, I believe you can get it to work by attaching it in a tape loop (I believe from your tape record out to main in)
Finding the resonance frequency will help tell you if the setup of the tonearm is a problem.
Good luck!
Hasn't the OP said the problem occurs with multiple tirntables?
Looks like the KAB RF1 has an active filter circuit. These usually work better than the passive one, the Harrison device uses.
Mister Pig
Pigamus Maximus
My guess would be a combination of two issues. The location of the stand in relation to the speakers, and the stand itself. Since you can tap on it and induce this noise, a certain component of the problem is the stand itself. Especially since other turntables do this. Can you describe it, and how the turntable shelf itself is situated? Is it glass, are there isolation pads between the shelf and the stand?
Secondly, the location of the equipment to the speakers, how far are speakers away from the turntable and gear? Even with going to the concrete floor if you are too close to the speakers you could have this issue.
That would be the two areas I would explore, it certainly would seem there is a feedback loop between speaker and turntable.
Cheers
Mister Pig
Secondly, the location of the equipment to the speakers, how far are speakers away from the turntable and gear? Even with going to the concrete floor if you are too close to the speakers you could have this issue.
That would be the two areas I would explore, it certainly would seem there is a feedback loop between speaker and turntable.
Cheers
Mister Pig
I have always used a subsonic / rumble / low filter when playing my stereo. That's about 45 years now. You cannot hear any frequencies that low anyway. That's why it's called a subsonic filter. Its purpose is to prevent your woofers from doing exactly what you are describing.
I was going to ask how high your bass control knob is set until I read that you have the loudness button ON. The loudness button is basically used to boost the bass during lower listening levels. At higher levels it will cause your issue, especially if you have your bass boosted excessively with your tone control knob. This also strains your amp. If you need more bass than what you are getting from your speakers, then perhaps you need a subwoofer.
branden_8091
Member
I understand about the loudness button, but I turn it off once I'm in a louder range of volume. Even at a very low level the pumping happens.
branden_8091
Member
Mister Pig,
Those were my initial thoughts too, until I did the experiment with the digital recorder (recording with no speakers on) and when playing it back it reproduced the same issue. I've tried the turntable on another shelf (wooden table) and right on the concrete floor, no change. My stand is rather cheap, it's glass shelves with aluminum vertical supports. I have my CD transport under the TT, all on top of the top shelf. Vibrapods are under the CD player to further isolate the table.
My stand is about 2.5m away from my speakers at the side of the room. Speakers are at the front of the room...a rectangular shaped room apprx 8m x 3m.
Vinylmasters
Super Member
Yep. I have a killer clean Sony receiver that doesn't have a subsonic filter on it. My JVC QL-Y55f will feed back and rumble, but my Technics SL-1301 does not (wood vs. metal body would be my guess anyway). I just wish someone would make an inline subsonic filter between the table and amp/receiver.
Vinylmasters
Super Member
It won't work. I tried it through the tape monitor too. These work by snuffing out the highs to the sub - the LAST thing you want for a turntable!
Can we ask the OP how loud he has his amp cranked up and is he using the loudness button on along with the bass boasted up. If you do that, you won't even have to play music just a needle dragging in a groove with the loudness and the bass boasted will create a situation where your woofers will be over extending.
branden_8091
Member
I've tried several records, it's uniform across the board.
branden_8091
Member
I do use the loudness button at lower listening levels, if I take it off the woofer pumping decreases but it's still there (a little)...and increases as I turn up the volume. The bass is up a couple of notches...but I've tried with other preamps and left everything totally flat, the problem still happens.