Anyone Use the KAB RF-1 Rumble Filter? CB
Anyone Use the KAB RF-1 Rumble Filter?
- Thread starter Cactus Bob
- Start date
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received the rf1 last night, got it all hooked up.. what a world of difference it makes! I think the bass rolloff for my sansui’s low filter is around 50hz?? (passive I’m sure)..it was definitely cutting into the audible bass..
I was always worried about overworking the amp.. as with some slightly warped records I got pumping. I know for certain it was not the turntable as some records do not cause the pumping. I leave the grates on, so I can’t visually see cone pump for each record, so I just left the low filter on all the time.
I hooked the rf1 up in the tape loop and turned the sansui’s filter off.. sounds much better, tighter for sure. changes the whole game. I feel more comfortable cranking it up.
Very happy.. my ears are still ringing!! Haha..
Very transparent and brought out the low end I was looking to regain.
Great product.
My setup
Technics 1200mk3
Kab rf1
Sansui qrx-4500
Front speakers sansui sp1700
Rear speakers sansui sp2500
hope this helps someone...
I was always worried about overworking the amp.. as with some slightly warped records I got pumping. I know for certain it was not the turntable as some records do not cause the pumping. I leave the grates on, so I can’t visually see cone pump for each record, so I just left the low filter on all the time.
I hooked the rf1 up in the tape loop and turned the sansui’s filter off.. sounds much better, tighter for sure. changes the whole game. I feel more comfortable cranking it up.
Very happy.. my ears are still ringing!! Haha..
Very transparent and brought out the low end I was looking to regain.
Great product.
My setup
Technics 1200mk3
Kab rf1
Sansui qrx-4500
Front speakers sansui sp1700
Rear speakers sansui sp2500
hope this helps someone...
mythless
Looking for projects!?
Probably, but most likely set at a different point. I find some subsonic filters set too high. I think one of my amps is set to 30hz, which I think is low enough.
I bought a Kab rf1 shortly after starting this thread in '09 to use with my Sansui 9090db which doesn't have a subsonic filter and it worked fine, but I haven't used it in a couple years now after moving into separates. I'll have to try it with my preamp instead of using the preamps subsonic filter to see if there is a difference in sound.
dosmalo
T-Totaled
I bought one thru KAB a couple of years ago and love it! It keeps all the SQ intact but gets rid of the subsonic nasties.
Bass is as good or better now and the speaker drivers don't do the funky chicken anymore!
I highly recomend one if you have probs with the subsonics and your TT.
Bass is as good or better now and the speaker drivers don't do the funky chicken anymore!
I highly recomend one if you have probs with the subsonics and your TT.
The difference from a typical vintage receiver/preamp rumble filter is that it is a more conservative (20Hz 3rd order) highpass, and it is summing to mono below 140Hz. The justification for that being that LF should already be in mono on vinyl, and a vertical warp is equivalent to a loud bass signal with the channels 180° out of phase, so summing cancels out vertical warps.
I think it would be nice if KAB put some information on the buffering / input-output impedance of the device on their site, but I suppose they'd share if asked.
I think it would be nice if KAB put some information on the buffering / input-output impedance of the device on their site, but I suppose they'd share if asked.
twiiii
Lunatic Member
I know for sure Sheffield, Original Masters and Telarc didn't combine the bass below 140 hz and that goes for Command, and Mercury Living Presence. I agree with the 20 hz filter. McIntosh starts rolling off their phono inputs just below 30 Hz to tighten up the sound on later units. Comparing my former C-22 with the C-29 and 28 showed what the filter did. My grill cloth no longer flapped in the wind. I now use a C-34V for phono and I can crank up the 30 HZ graphic control with out fear of damaging my woofers.
If they didn't sum the bass, they either limited amplitude of the stereo component, or simply recorded and mixed in such a way that bass frequencies ended up in the middle in the first place. If you know for a fact, then mustn't you know what they did do? In any case, you get problems if bass frequencies aren't approximately mono, in-phase.
I can see Mercury and Telarc not electronically summing as their simple mic techniques would lend itself to a degree of mic bleed which would cause a "natural" bass summing effect.
But Command? I dunno...their most famous records (non-classical at least) are so extreme ping-pong stereo and close miked that I take that claim with the same grain of salt I use when reading about Pickwick, Somerset/Stereo-Fidelity, Tops or Crown's back of jacket statements that they used "only the finest virgin vinyl" for their pressings.
It's easy enough to examine the mix yourself if you're curious, and you've got a mono switch. Just swap the +/- headshell leads for one channel, play the stereo record in mono, and see how much bass you get. Keep the volume setting the same as when you played it in stereo with normal wiring, as that's your reference level.
Buffordsdad
New Member
KAB RF1 Record Rumble Filter
Just installed, Best money I ever spent no more speaker pumping I can actually turn my subwoofer on now with my records nice to see some gizmos really work Bass is tighter world of difference
Just installed, Best money I ever spent no more speaker pumping I can actually turn my subwoofer on now with my records nice to see some gizmos really work Bass is tighter world of difference
Blue Shadow
Waiting for Vintage Gear from this century
Interesting that this device shown on the KAB site does not have any means of receiving power but it is a powered unit. Does it have a cord that is not shown?
illini
The Past is Alive
It comes with a 'wall wart' style power supply.
armytanker
New Member
you can use this with the built in stereo phono amp right? you just go through it then hook up the RCA cables and the ground to the stereo.
Yes, that is correct.
