@yogiboy Yes it has one, I’ve tried removing it, no change. Of course, I always play with it up anyay.
Unsolvable Woofer Pumping (Phono only)
I'm at a loss for trying to find the source of my "woofer pumping." It's most noteworthy when playing something that is mostly/all treble, and the woofers of my Focal Aria 906s are going nuts (inaudibly, of course). Turntable is a Debut Carbon with Ortofon 2M Blue.
Initially I was told it's an isolation problem, so I better isolated my TT, even put it right on the concrete floor to test! Next I thought maybe a problem with the TT itself, so tried a couple others, no change. So I figured it must be acoustic feedback, as with the TT stopped and stylus on a record, I could produce woofer pumping by tapping on certain parts of my stand...but it is also not this! I turned off my amplifier and recorded from the pre-out to a Tascam digital recorder and played that back afterwards and the pumping STILL happened! So I tried an Schiit Mani phono stage, no change in woofer pumping...I was sure it had to be my pre-amp...
So a local audiophile came over with a couple of pre-amps and we tried those. The only time the problem went away was when the subsonic filter that one had was engaged. So, I've ordered some Harrison Labs "FMODs" (20Hz high pass) to see if they will help. If they do, I may order a KAB RF1 one day...but don't want to spend that much if I don't have to.
Any other ideas on what could cause this?!
tl;dr: Woofer pumping not caused by isolation, acoustic feedback, phono/preamp or a compliance issue...what's happening?!
Initially I was told it's an isolation problem, so I better isolated my TT, even put it right on the concrete floor to test! Next I thought maybe a problem with the TT itself, so tried a couple others, no change. So I figured it must be acoustic feedback, as with the TT stopped and stylus on a record, I could produce woofer pumping by tapping on certain parts of my stand...but it is also not this! I turned off my amplifier and recorded from the pre-out to a Tascam digital recorder and played that back afterwards and the pumping STILL happened! So I tried an Schiit Mani phono stage, no change in woofer pumping...I was sure it had to be my pre-amp...
So a local audiophile came over with a couple of pre-amps and we tried those. The only time the problem went away was when the subsonic filter that one had was engaged. So, I've ordered some Harrison Labs "FMODs" (20Hz high pass) to see if they will help. If they do, I may order a KAB RF1 one day...but don't want to spend that much if I don't have to.
Any other ideas on what could cause this?!
tl;dr: Woofer pumping not caused by isolation, acoustic feedback, phono/preamp or a compliance issue...what's happening?!
Showing 21 responses by branden_8091
Mike, @mijostyn Ahhhh thank you! Little pieces of this puzzle keep coming in. I can’t afford and don’t have the equipment to drive a subwoofer...but would a more full range (i.e. floor standing) speaker be a better choice when I do decide to upgrade next? That entirely makes sense about the frequency limit as well. |
@lewm Sorry about the lack of detail, I didn't want to make it too wordy. I'm new to forums! Fair enough about the filter. I ruled out the unstable stand as the problem by putting the turntable right on the concrete (with thin carpet) floor. And yes that's what I did for the Tascam recording!...speakers are Focal Aria 906. It seems (based on all the input I've received here and other forums) that this behaviour is normal for ported, bass reflex speakers such as mine. Especially with a (in the world of hi-fi) an entry level TT. I bet if I spent the same on my turntable as I did on speakers I wouldn't have this issue (better bearings, motor isolation, etc.). The low freq of the speakers on the spec sheet is 55Hz, this is well below that though. They're both on hard surface with focal stands (which have spikes). Thank you! |
@millercarbon Thank you! I've grown up with both, but my earlier systems weren't as high quality (I started at about 6 years old with some crappy BSR changers). I can understand that a little bit is normal, but this seems a little excessive to me. At lower volumes I enjoy the extra musicality the comes from turning on the "loudness" function. I realize many audiophiles scoff at this, but, whatever. I like it. Since it turns up lower end a fair amount, the woofers really show this problem then. I have the acrylic platter, but no weight/clamp...I've been meaning to get one and can see how it would improve my situation. I'll definitely look into a clamp instead of a weight though! Thanks. Here is a video of the intro to Hotel California, at a normal listening level, loudness on. https://youtu.be/sZG5fL4HwN8 |
@three_easy_payments I see. I will more likely go the filter route rather than clamp, at least until I get a better system. If that needs a clamp then no problem. I do plan on upgrading my system relatively soon, which is why I'm hesitant to spend on a filter I may end up not needing once I've upgraded. I have another thread on upgrading if you'd like to chime in on that :) I can't see myself ever having more than a $10 000 system. My current one has cost me about $4000. |
@mijostyn Very interesting. I don't have any equipment to drive a subwoofer yet, just good old fashion two channel stuff. A subwoofer will be something to look into in the future possibly! @lewm I'm just itching to audition some speakers now! Ha ha. I was more asking if a more full range speaker would be about equal to adding a subwoofer now? I'm currently not able to have a subwoofer...and still my heart prefers old fashion two channel setups. |
@sonicjoy I've just finished doing some more experimenting...and I think that after alllllll of this, it is just record dependent. I'm relieved, but not overly happy that it's something so simple! My Hotel California LP must be particularly bad, especially the way I was playing it with loudness on. I found that if I moved to certain records and cranked it (with loudness off of course), there was very little/no woofer pumping. I still would like to try a filter to get rid of it, just for peace of mind...but now I'm not so worried. It was set up by my dealer, so I'm not worried about that. They're experienced. I do intend to get a test record one day though. |
Neat. I was unaware that that's how they worked. I'm not dissatisfied with them per sé, just a little underwhelmed in some cases. A sub-woofer seems like it may be a viable solution though! One of my potential upgrade paths are the 936s, simply because they have more range/volume. Maybe a sub would be a viable alternative! I'm just trying the Harbeths for fun (mostly)...they offered to let me borrow them so I said sure, why not? :) |
@audiorusty You're more than likely right about it being some sort of power related problem (to an extent)...but I think what's causing most of what I'm experiencing is just certain uneven albums, with a little too much bass from my settings @yogiboy I did try a subsonic filter, it fixed it, but it's not mine so will be getting my own soon. |
I've done some critical listening and found that unless my speakers are above a whisper, the loudness kind of makes them muddy anyway. If I play a smoother record (especially in the inner tracks), the woofer pumping is not there, even at high volumes (loudness off). I guess the issue is solved! Thanks to all. |