|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
68.194.97.24
In Reply to: Why do my woofers do this when playing an LP? posted by wengler on August 6, 2005 at 16:20:12:
miserable lack of isolation is doing to your music. you really need a better turntable and if not, some serious isolation.depending on your speakers, they might be able to handle the abuse, but why risk it?
Follow Ups:
Look! Woofer pumping is almost entirely limited to speakers with port tuning and bass reflex models. They do not dampen the cone under their tuning frequency so the woofer is free to flap in the breeze. An accoustic suspended speaker rarely has any issue with pumping so all you AR-3 and AR-4 users have nothing to be concerned with.A cartridge can ususally reproduce down to 2-5 cycles with no problem. Just tracking a warp will cause woofer pumping to some extent. So isolation or a better turntable will do NOTHING. It really depends on what is creating the woofer pumping. Ususally it is warped vinyl.
Maybe a vacume type Sota would do something to improve this, but every Sota I have listened to sucks the life out of the music. PRAT disappears, and a lovely homogenization overtakes your soundstage.
Ultrasonic filters all deteriorate the sound quality of your set up. I know, I have tried more filters than I care to remember.
The idea that woofer pumping will damage speakers is somewhat misleading. Most amps will reproduce down to 2 cycles. Good woofers will reproduce down there too if they are port tuned or bass reflex. My woofers pump on warped albums, but there is no sound from the pumping because you cannot hear a tone from information under 16 hz. You can sometimes feel the air pressure or hear your ports huff. I stuff my ports with cocktail straws, something I learned from Linn Speakers.
If your woofers pump and you play the pump too loud I have seen the voicecoil pop out of the gap and land on the metal surface of the motor assembly. We see this alot in car stereo if the cones are not properly damped. It is usually simple to just reposition it and rarely is there any physical damage.
Of course if you have old drivers with poor surrounds, there is a chance the voice coil will rub in the gap and that will create a quick demise unless you replace the worn surrounds.
If I have a vinyl record that causes a lot of pumping the last thing I am going to do is turn it up extra loud. Interestingly, the pumping ususally only goes in a track or two on most albums. So play it quietly until the pumping abates then you can crank on it.
I usually look for a good replacement LP for anything that I love to listen too that is pumping away.
> > A cartridge can ususally reproduce down to 2-5 cycles with no problem.> >Couldn't this be remedied by using a cart with lower compliance, raising the tonearm/cart resonance out of the warp region? Ideally, the stylus shouldn't move inside the cart during the warps, only the tonearm should move. BTW, does anyone know the exact lower frequency limit for vinyl, meaning the lowest allowed frequency for disk-cutting?
Best regards,
I already have a pretty good turntable, a Pro-Ject Debut III. As for isolation, I just bought four Vibrapod cones and I had planned to place them under my CD player. I guess I could use them on my turntable, I would have to get a piece of MDF or something first then place the TT on top and the cones under the MDF.
hello,listen to eli....the rumbles are very damaging on many levels. what kind of phono are you using? does it already have a filter that you perhaps have not actuated?
as far as touching your rack leading to that kind of woofer flapping, you really don't have the isolation necessary for your setup. i was in this same sort of position a few years ago with a bouncey thorens table. the before and after is quite substantial. a cost effective solution could be a heavy sandbox. its a nice product, but i'm not sure the vibrapods will help in this situation.
I think that a part of my problem is that my equipment rack is very cheap; it is a K-mart bookshelf made out of MDF and plastic. Would a better quality rack help isolate the turntable better?
you could always move your TT to a different platform just for the purpose of isolation. even some ikea table + a sandbox will be 10x better than a plastic rack.
Well, I have two problems: space and money. I'm going away to college at the end of the month and even though I will be living in apartment style residency that will allow me much more space than an average cramped dorm room, I don't want to take up space with a seperate platform or large unwieldy audio rack. Also, I really don't want to spend much more than 100 dollars on a new rack. I'd rather spend that money on new music. If I must get a new rack, would something like this work out fine?:http://www.target.com/gp/detail.html/ref=br_1_16/602-7204349-0162242?_encoding=UTF8&frombrowse=1&asin=B0000DZDYV
Cinder blocks are usually less than a buck each, four of them and a piece of wooden shelf cut to size on top would do good job, or at least better than your plastic unit. All you really pay for is the shelf so that would get you in waay under $100. Pain in the ass to move though...
you do realize taking your table to college is not exactly the best way to keep it alive? :-) i had 1200's and even those were in jeopardy every time i threw a party.i have zero experience with the thing, but i'm gonna take a wild guess and say a 120 buck target stand won't cut it. if you're gonna be a proper student and all, you need to get some cinder blocks and MDF going...it'll work. i've done it.
This post is made possible by the generous support of people like you and our sponsors: