I'm having the same problem. A simple experiment demonstrates that it is not "air feedback" - but vibrations through the floor/room. I simply put the needle on the record and increase the gain until I start getting the feedback. If I lift the subwoofer, the feedback stops as soon as it is decoupled from the floor. Any other recommendations for subwoofer isolation tweaks? I will look at the iso-pucks. Note that the second subwoofer (across the room) does not create any feedback and I assume that is due to positioning in the room. I have an old house (230+) and the floors are original.
Subwoofer rumble issue
I’m having a hard time solving a problem that seems to come and go. My subwoofer will rumble uncontrollably when playing records at a higher volume. If I turn the volume down sharply it goes away but when I creep the volume back up it comes back. I’ve tried isolating my turntable as much as possible with diy books, isolation feet, etc. (I don’t want to buy an expensive isolation platform unless that really is the issue.) Any thoughts on what I can do to fix this? Thx!
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I had this when I added 2 Rhythmik 12” subs to my system. Ended up trying 4 iso pucks https://isoacoustics.com/iso-puck-series/ under the subs which solved the issue. |
I’m having the same problem. I have a Technics 1200 M3D and KEF LS50s. No issues. I just added a REL T7i and have the runaway feedback rumble at high volume. I added Isonoe footers to the table which didn’t do much. Unfortunately the table and speakers sit on a big media cabinet from Design Within Reach which is not ideal. Not sure what the right next move is. More table isolation, put footers under the cabinet legs, new turntable, new furniture, or new house? |
what I notice on this topic is that when listening to recordings posted on youtube if the track is from vinyl you can often tell as there is obvious woofer pumping, I assumed wrongly that a signel might have been high passed to get rid of some very low frequency hash, apparently not. Many dance/electronic 12 inches not available on digital format have been uploaded and show this. |
big_katydidYes, this is another way the air-born runaway feedback oscillation can start. The wrap was the initializer, then the air-born takes over and just runs away getting louder and louder till something goes bang! Cheers George |
years ago I lost a bass unit on a rega jura. The combination of TT, room, track and record warps led to a loop that saw the drivers very quickly oscillate more and more until the paper cone literally tore open around the center area, this took less time than I could get over and turn the volume down....the other driver survived the experience, I don’t think the voice coil burnt out but somehow the extreme excursion caused the cone to rip. |
No not telling you to, would never do that Paul, but beside putting the TT in another room, it was the only other fix for me with bass that goes to very low frequencies. Just dawn on me, if you have any tubes in the chain, these can go "microphonic" some call it "euphonic" (w**k w**k) and this can cause runway bass oscillation also. If you have then do the finger nail light tap test on these just like the plinth test, but without the stylus on the record this time. Cheers George |
LOL you guys are funny. There’s gotta be a solution that doesn’t involve moving my tt to another room. Would a different tone arm help? One that doesn’t use magnetic stabilizing? Ugh this is no fun. So strange that it developed over time too. I’ve had this set up for about a year now and it just started a month ago. I did have woofer pumping issues with my mains at first but fixed it by putting them on stands vs. the same surface at the tt. Do you think going to the Herron phono pre will help at all? |
He's already proved he has air-born feedback, do the test above as in my first post, the way Ivor Tiefenbrun laid out all those many years ago, (know who he is?) Or sell the OP your useless car valve springs, or your magic pebbles, better still give them to him as they will end up in the bin, even better still give something constructive to these forums, instead of your constant malignant voodoo talk. http://www.machinadynamica.com/machina31.htm |
Yeah unfortunately you have to live with the negatives of the rumble filter is doing to the low bass, shame as that was what getting a sub woofer was all about. Like I said the only way to totally get rid of "airborn feedback" as you found you have with the way I said to test for it, is to have the TT in another room as I did and which worked a treat, best bass ever, as my 2 x Kef B1814’s in 2 11cu ft enclosures were tuned down to 19hz fs each. Cheers George |
George - so I removed the filter and the rumble returned ☹️ even with the homemade iso platform. So even if I’m missing out on super low frequencies, it’s better than the earthquake situation. I’m planning on upgrading my phono pre so we’ll see if that does anything to alleviate the rumble like one guy said earlier. Thx! |
Subsonic rumble filter! All better! I understand it’s a “bandaid” approach but it totally worked and my stereo sounds amazing again! YES!!! Thanks again everyone!Yes until you figure out how to stop the airborn feedback, it is a band aid, as it’s taking away what stereo info there is below 140hz Quote: "The circuit "monos" the low frequencies below 140 Hz" I still don’t understand how this will fix the airborn feedback test I asked you to do though, did you try it again with this filter in place? Cheers George |
Wow! This sounds like what happened to me few weeks ago when I moved my equipment around, the higher the volume goes the more rumbles the sub makes. The Preamp and the Phono-Stage Preamp originally were in the same cabinet, w/i 3' from each other. The problem happened after I moved them apart almost 3 times of that distance. I believed the fix was moving both equipment back in the original position. You might also want to look into the cable orientation relative to each other, like power cables and interconnects should be crossed instead of parallel. Good luck in your troubleshooting. |
Try a different phono preamp. I had the exact same problem and spent two years and a lot of money trying to solve it. I relayed my story to a well known vinyl writer and he suggested I swap out phono preamps. I was surprised when a friend brought a spare unit over and we hooked it up and the rumble/feedback immediately went away. My preamp was later bench tested and measured perfectly, it just didn’t play well with my setup and stereo subs. Good luck! |
I had the EXACT same problem. Get some long cables, move the table, it'll fix it immediately. My subs were on isolation platforms, turntable on a wall shelf with a symposium ultra under it. I even borrowed other tables, nothing. The turntable was in a room node and no matter what I did, nothing worked. I moved it, never had another issue. |
@paulgardner: I had the rumble problem for quite a while. I built a suspended TT platform that is isolated from the floor and walls, using dampened springs. I also recently purchased a DBX Venue Driverack 360. I haven’t had a problem since. It incorporates a graphic, as well as a parametric EQ, with “Q” adjustments that come in very handy. The “360” has many other features that I enjoy. You can control the unit with a smartphone or laptop. ALL speaker’s phase can be adjusted from your chair, as well as ALL speaker’s timing. Of course each speaker has it’s own level control and shelf roll offs. I can even use it’s subharmonic synthesizer for deep bass, although sparingly. If you’re not familiar with this unit, it would be wise to check it out. (I’m using two JL Fathom 113’s as subs, with my TT platform on the left side wall). Placing your TT in between or in back of your speakers will exasperate the problem even more. |
for better of for worse I use EQ on my power amp (crown xti) to make a high pass filter that slopes steep below 30Hz, this removes any subsonics from record warps. If I place the needle down on the record you see the cone bounce without the filter, you see almost no movement with the filter engaged, I find it very reassuring especially as it should prevent any feedback. It may be a band aid to an underlying issue but It does work. |
It is s Must ,saying what brand,and model it is cheaper ones Has minimal control small amplifiers, magnets and pole pieces As well as cabinet construction all important factors How to you adjust it ? The SVS 3000 line SB with app For just UNDER$1K 13 inch aluminium driver beat my $1500 JL Audio in every respect The split coil poll piece works for great bass even at low volume And the app works great . #1 sub and buy of the year. |
Hi Paul I just added a Clearaudio Ovation to my system this week and I to am having some feed back issues. Needless to say I am very disappointed, but it is what it is. Mine seems to be feeding back approximately at 30hz and 120hz at volumes ranging from 85 to 95 db. Some of the contributing factors that I think are helping cause my issue is my listening room is very small at 14 x 10 x 9, located on the second floor of a 122 year old house and I have the turntable sitting on a very cheap fiberboard end table along an outside wall about 3' feet in front of my left sub. I placed some anti vibration pads under the feet of the turntable (available from amazon for about $10 to $15 for a four pack) which helped reduce if not eliminate the feedback at 30hz and added a little more detail to the recording. I use an active crossover to integrate my subs that has a digital graphic eq built into the inputs that I used to reduce the 120hz output of my system thus eliminating the feedback. My next move is to build a prototype table out of 2 x 4 pine so I can relocate the turntable so it is above and slightly to the rear and left of the sub. If this works I will then have Saluda River Audio Stands build me a permanent table out of maple and walnut. Also when you said that all hell broke loose when you switched polarity on your sub I believe that was when your subs were actually in phase, at least with the turntable. |
If your current setup (preamp/receiver) has an "infrasonic" filter, it is the same thing. I'm guessing the turntable is a direct drive? Usually direct drive turntables aren't as isolated from the base as they could be..... Subsonic/infrasonic filters work well with them. Beware of any "in line" subsonic filters unless they are designed specifically for the phono stage.... |
Yeah I’m not into the spring thing. Never gonna happen. The REL has a phase switch. 0 or 180. My system likes 180. Flit it to 0 while music is playing and the Sub rumbles uncontrollably. Earthquake time! I understand that a properly set up REL should go unnoticed but apparently I Guess I like more bass than most “purist audiophiles”. I absolutely love my set up (aside from the recent sub rumble issue) and am blown away by how good some recordings can sound. I’ve always been into listening to music and sound quality but only up until recently (about a year) have I really discovered what a very good stereo sounds like. Partly due to financial reasons. I’ve always had a nice stereo set up but never really nice stereo. It’s a different game when you get into the $10k+ realm. I have a subsonic filter on the way. I’ll play around with that - otherwise I’ll learn to live with a sub crossover/volume combo that sits below the earthquake rumble reaction. My next upgrade is a new phono stage. The MS Phonomena II+ is great but I do miss the all tube experience I once had. A rabbit hole this game really is! |
wolf_garcia Note that Dylan does NOT say "best of luck to you" at the end of his records. >>>>Dylan said he does. He said so in an interview in San Francisco. He even has a song about it. https://youtu.be/uWaKrLLtQPg |
A subwoofer on springs? Help, I’m gonna die laughing. That’s a joke right? Tell me it is a joke....Yeah it’s called the humanless pogo-box. Just GK with his voodoo Isolate the sub from the rest of the system by putting it on short stiff springs. You know, like Super Stiff Springs. Trademark. Problem solved!Yeah, they're called valve springs from an auto engine, $1 each from auto wreckers, not $13 each!!!!! |