My subwoofer hates my turntable

Well. I give up!

 

I wall mounted my (Rega) RP6 and as a result my (REL) T3 has no interactive issues. They are separated by approximately 5'. Amp Rega Brio R.

 

I'm honestly quite stumped, just like several others. I have my Pro-ject 2 Xperience Classic connected to a Pro-ject Tube Box S phono pre, and just like you, connected to my CD inputs. I am using an Audio Technica AT-OC9MKII moving coil cartridge. Unlike you, I'm not using a power amp. Have you tried taking that out of the loop and just using the internal amps in the Denon? I'm not suggesting you give up on the B&K amp, but I don't recall seeing that you've tried to eliminate that piece as a possible source of the problem. I'm really just shooting from the hip here. Oh, I do live in a house that is built on a concrete slab, so no vibrations can go through the floors (or rather are sufficiently damped by the mass of the slab.) BTW, I agree that Denon could have a more user-friendly interface; I think that there are too many menu levels and it can get confusing. It's nice to be able to give each input device its own settings, but it can get pretty hairy if you have to do it all again (like if your wife hits the "restore defaults" button..... oy vey!)

 

I did think about doing that but if I use the LFE input on the REL it bypasses the Amp taking it out of the mix with the same result. I would much rather live without the sub than I would the amp.

This is something I have been trying to solve for about a year and a half. and by that I mean the Sub has been in a closet and I try to make it work every for or five months. Perhaps in another five months I'll get a VPI TT and if that doesn't work, I will just be stuck with a sweet new table. and then five months later a new receiver and then a new sub...it never ends.

 

I would try a subsonic filter before spending on a new turntable. The resonant frequency of the TT is probably around 10 Hz and feeding back through the sub. If the sub has a port you can try stuffing something in it to block it off just to see if it helps.

 

Other things to try;

Flip the phase switch on the sub, lower the level on the sub.

I would run the denon with just the sub, not the sub + main setting and set the crossover on the sub to the main speaker low frequency roll-off for best sound.

Sorry if you have tried all these already. The subsonic filter seems the the most likely at this point though.

 

I understand how that can be.

Well, the only other thing I can think of is what others have suggested: a subsonic filter. It might just do the trick.

 

But do you have the preamp grounded to the receiver as well? If not, try that. It could be a ground loop. You may have to use a screw on the receiver's case to get a ground connection (be sure to clear away any paint). In the old days, you could use the AM antenna ground lug.

Speaking of ground loops, it can't hurt to try an isolation cable like this one: http://www.radioshack.com/ground-loop-isolator/2700054.html. It's cheap and won't affect your sound if it works.

BTW, I once had a cartridge wire that seemed solid but when I touched it with my finger, it caused hum like you wouldn't believe. I pulled the wire off and used some DeoxIT before re-connecting it and the hum went away.

 

so when we say "subsonic filter" is this what were talking about?

http://www.amazon.com/gp/product/B0...rd_t=36701&pf_rd_p=1970566542&pf_rd_i=desktop

 

Yes.

 

To use these, you'll have to change to the low level inputs for the sub, which you should be using anyway as it is a cleaner way to bring in the signal, and use these on the cable to the sub. If you want to PM me with your mailing address I'll donate a 15'-18' RCA cable to the cause. I have many of those laying around here from my car stereo days. You'll have to switch the receiver back to LFE out.

I also don't get why using the B&K and the LFE output at the same time is a problem. Maybe I don't remember the internal settings well enough on the Denon (I used to sell it). I'm going to look up your manual along the way today.

 

Its not a problem to do it like that, it only gets one signal at a time. I hoped there was a setting adjustment to be made in the Denon. I am order in the filter. 20hz and hopefully that will work. Do I plug that into the RCA out on the TT?

Thanks for your help.

 

Word on the street is that in actual fact, your turntable hates your subwoofer...

 

You're welcome. This is exactly what I did for a living. I wish you lived near La Crosse, Wisconsin (you don't, do you?) so I could stop by and check your stereo out. I think I could figure it out in 15 minutes. It's something obvious, a question you don't know to ask, that's the true cause of the feedback loop. I'd walk in and say, "Of course. Here's the problem. You listen only to William Shatner LPs. That explains everything."

As for one signal at a time, it's OK to plug into just the left input on your sub, at least it is with every one I've used (What is the model number of your REL sub? I'll look it up, too.). If you don't like doing that, and it has always bothered me a bit so I don't, then a Y connector with one male RCA and two female RCAs to split the sub output of the Denon does the trick. Then you can hook up both the left and right inputs on the sub.

Don't use these filters after the turntable. You would hear that they are somewhat cheesy $30 devices there. Put the filters on the inputs to the sub. You don't care where in the signal path you kill the subsonics and putting them just on the sub won't affect the sound of your mains.

I realized after I posted yesterday I have two pairs of Harrison Lab devices on my whole house music system, not just one. I use Harrison Labs filters. I like them. You just got to know where to place them so that they don't hurt your sound. When used correctly, they help the sound a lot.

 

My REL is humming, possible causes?
Hum is almost always the result of a ground loop—too many grounding points resulting in induced hum coupling through the amplifier. Systems are complex devices with numerous ground attachment points. A/C mains ground varies throughout many homes, various source components can have different grounding schemes and are all a potential source of noise. The best approach to tracking noise issues is to start by disconnecting everything from the REL except for the a/c mains power. If the hum goes away, then the REL is not the origin of the grounding issue, only the victim of a problem upstream in the system. If the hum persists after the a/c test then re-connect the High Level but lift the black ground wire. If the Hum goes away, turn on some music and if the REL operates normally (it usually will) then your problem is solved (ground has been obtained through some other connection point) and the black wire should be clipped and taped so as not to make inadvertent connection in future.
Another possible solution to eliminate hum is connecting the REL to chassis ground on the main amp and connecting REL black ground to an unused line level (RCA) connection. In some markets, especially North America, using an a/c mains ground-lifting plug on source components can eliminate hum, as this is the source of the ground loop. If all else fails, disconnect the high level and connect via the low level input as your system’s ground problems are beyond the scope of this FAQ section to resolve.

 

Ground loop hum and buzz will sound like, hum at 60 Hz or buzz at 120 Hz; it's not the type of thing that's going to give you woofer pumping. You can try things like the above troubleshooting methods and cheater plugs to lift chassis grounds to see if you have a problem with a ground loop; but woofer pumping doesn't sound like a symptom of a ground loop.

 

and if it were a ground loop wouldn't it be that way with all sources not just the TT?

 

Not necessarily if the ground loop involved the turntable and was really making the turntable signal change a great antenna for noise, but generally yeah, if you have a ground loop you will get hum or buzz in the system even when you're switching between sources. But turntables can be great at picking up and amplifying induced noise from environmental sources -- I've had to ground an equipment rack to get rid of very low level turntable hum even though nothing was actually touching any of the conductive surfaces of the rack, but the whole rack seemed to be working as an antenna for noise that was being injected into the analog rig that was sitting on it. Still, if it's woofer pumping that's probably not a ground loop and if you're getting it even when the record's not spinning that's weird. Of course, could be that you have more than one problem -- some kind of undamped tonearm/cart resonance or acoustic feedback that's causing woofer pumping, and hum from one or more sources.

 

You need a subsonic filter imo. Vinyl HAS subsonic noise cut into it. Some worse then others. The High End new vinyl is actually very good regarding this. You do not want your amp trying to reproduce these low frequencies. I have been through multiple turntables, cartridges, amps, preamp, speakers, and even 2 houses. I have mounted the tt's on just about everything you can think of. The subsonic filter is the only thing that worked for me. Back in the golden age of vinyl, the amps all had filters.....I wonder why. The ONLY reason most new phono pre amps do not have them is to cut costs. Some pre amps do and I wish more added them in.

 

Try high level connection from sub to amp's spk out ;
try another cartdridge...
try an amp of a friend

 

Today I switched my turntable to a VPI Classic and the issue is resolved. I believe the reason is because the power cordon the VPI has a ground plug.

 

Oh really, why do I have a sneaking suspicion we were all part of an involved plot to convince your wife you needed to upgrade to a VPI!?

 

I don't know your speakers at all but I just looked at a picture of them,
they look like they should able to produce decent bass? Do
you really need a sub?
I have never heard them work well with music, with movies yes,
but unless you have satellites you should try without the sub.

 

she is in for a surprise when she get home.

 

And that is the irony, now that it works, I have it turned off. I don't need it or prefer it wen listening to records.