sda 2's and sda 1c's are feeding back

ShadesPG

this may be a simple fix thats not speaker related but:

when i play my turntable and crank up the volume on the amps that run my sda's i start to get a moaning feedback type response. it seems bass related but that might just be where the most amount of sound is. the symptom does not occur for any other intput or source, just my record player. yes the record player is in front of the speakers which is why (im guessing) this is happening.

any suggestions to remedy this?

thanks

sda2mike

does your amp-pre have a low-filter?

F1nut

Your turntable cartridge is picking up vibrations/sound waves and causing the feedback. Personally, I would get rid of the TT and get a top notch SACD/CD player, but realize some of you actually think vinyl sounds good.

You need to isolation the TT from any and all vibrations, which would include moving it from in front of the speakers.

danger boy

if your receiver/pre amp has a low level filter.. turn that on... i don't remember the exact term of that low level feedback...

pitdogg2

ultrasonic?

pitdogg2

F1nut wrote: »

Your turntable cartridge is picking up vibrations/sound waves and causing the feedback.

This is exactly why i ditched my TT many years ago. It drove me nuts trying to get rid of the rumble whenever i cranked the volume. Truth be told I'd love to have it back it was Yamaha's TOTL for that time period.

heiney9

subsonic filter, but that rarely defeats the feedback. A subsonic filter is designed to eliminate "rumble" from an inexpensive TT especially when the LP is less than perfectly flat. Feedback is just as F1NUT described. It's picking up vibrations from the speakers becasue A) the location of the TT inexpensive TT have very poor isolation C) the spot the TT is setting in is suceptable to transfering the vibration.

Solutions are to isolate and/or move the TT to a position away from the speakers or buy a better TT or get rid of a TT completely, or play the volume at lower volume so as not to cause vibrations.

H9

BeefJerky

F1nut wrote: »

Your turntable cartridge is picking up vibrations/sound waves and causing the feedback. Personally, I would get rid of the TT and get a top notch SACD/CD player, but realize some of you actually think vinyl sounds good.

You need to isolation the TT from any and all vibrations, which would include moving it from in front of the speakers.

Vinyl does sound good if you have a decent setup. However, a Fisher-Price turntable doesn't really count as Hi-Fi.

pitdogg2 wrote: »

This is exactly why i ditched my TT many years ago. It drove me nuts trying to get rid of the rumble whenever i cranked the volume. Truth be told I'd love to have it back it was Yamaha's TOTL for that time period.

Sounds like it was a nice turntable. I think your issue was primarily due to placement and/or the type of rack you had it on.

heiney9 wrote: »

Feedback is just as F1NUT described. It's picking up vibrations from the speakers becasue A) the location of the TT inexpensive TT have very poor isolation C) the spot the TT is setting in is suceptable to transfering the vibration.

Solutions are to isolate and/or move the TT to a position away from the speakers or buy a better TT or get rid of a TT completely, or play the volume at lower volume so as not to cause vibrations.

H9

Exactly. Some turntables are much better at isolation than others. For example, I have a Technics SL-1200MK2 on a rack right next to my left speaker and I get no feedback even at ear bleeding levels. That's not surprising considering what kind of use the turntable was designed for.

As others have said, try moving the turntable to a different location and see if that help. You can also try an isolation platform of some sort. If neither of those do the job, you will probably need to look at getting a different turntable.

inspiredsports

Look, I like you guys who are saying to deep-six the TT, but just go away unless you have a solution that doesn't call for quitting vinyl

I'm glad the OP knows that vinyl is definitely worth the effort.

Shades, what TT/Tonearm/Cartridge are you working with? You may have a simple compliance issue.

george daniel

F1nut wrote: »

Your turntable cartridge is picking up vibrations/sound waves and causing the feedback. Personally, I would get rid of the TT and get a top notch SACD/CD player, but realize some of you actually think vinyl sounds good.

You need to isolation the TT from any and all vibrations, which would include moving it from in front of the speakers.

he,he

SCompRacer

george daniel wrote: »

he,he

lol Have you drank the vinyl sounds good kool-aid too George?:cheesygrin:

ALL212

Face the SDA's towards each other and reverse the speaker inputs on one of them...that should eliminate any feedback. :eek:

ShadesPG

i love vinyl. for many many reasons, some sonically, some non-sonically. i have what i thought was an okay turntable but i did nab it off of craigslist so it may not be so awesome. its a stanton str8-50.

changing the location of the turntable is not really an option. there is not place really to put the turntable so that its not in the listening field.
im open to the idea of upgrading the TT. i have a line of some technic 1200's for 250 a piece but to be honest, ild rather not spend that much at the moment. what are some other TT's that are recommendable?

what if i just replaced the cartridge?

any other ideas for isolating the sound?

inspiredsports

ShadesPG wrote: »

i love vinyl. for many many reasons, some sonically, some non-sonically. i have what i thought was an okay turntable but i did nab it off of craigslist so it may not be so awesome. its a stanton str8-50.

changing the location of the turntable is not really an option. there is not place really to put the turntable so that its not in the listening field.
im open to the idea of upgrading the TT. i have a line of some technic 1200's for 250 a piece but to be honest, ild rather not spend that much at the moment. what are some other TT's that are recommendable?

what if i just replaced the cartridge?

any other ideas for isolating the sound?

I looked briefly and didn't find anything online indicating the mass of your tonearm, but I'm guessing you might have a cartridge that is mismatched to the tonearm.

Heavier mass tonerarms require lower compliance cartridges (stiffer cantilever) and lighter mass tonearms require higher compliance cartridges (more flexible cantilevers)

The portion on compliance near the middle of the page at . . .

http://www.soundfountain.com/amb/ttcartridge.html

. . . will give you a background of what you are up against.

inspiredsports

I see the Stanton 520 SK "Craze" is a $40-$50 cartridge that originally came with that turntable/tonearm. Is that what's on it now?

SCompRacer

I like vinyl too. I grew up with it and have never been without a turntable. Like some folks mentioned, a turntable is a mechanical pickup system. The sensitivity of a turntable to vibration depends upon the room acoustics, the turntables location in the room, and how it is supported. Isolation is great for floor/rack vibrations but the table is still susceptible to airborne vibes. It is possible a better table or cartridge won't solve your problem if the table stays in the same spot.

I have quite a bit invested in vinyl playback (high mass table, nice arm and cartridge), and even I can get feedback with my turntable between the speakers of my South wall setup. My South wall setup has a room corner by each speaker. Moving my gear to a side wall solved the feedback problem, but you mention that you can't move the gear. A turntable between the speakers can be a problem area. My West wall setup has one speaker open to the main level, and I have no problem with the turntable between the speakers, no matter what volume level. And I do have room acoustic treatments.

By far, the best turntable isolation I have used is the Gingko Audio Cloud 11. I bought mine used as they are pricey new. Basically it is handballs supporting the platform the turntable is on. I can pound my fist on the rack and the table does not skip, jump or make a thump at the speakers. Jay (agfrost) did witness this a few weeks ago when he was here. If a guy is handy one could make one. Or try a small partially inflated inner tube between two pieces of wood.

george daniel

SCompRacer wrote: »

lol Have you drank the vinyl sounds good kool-aid too George?:cheesygrin:

yep,,it was so good that I went back for another glass

inspiredsports

It's odd that unit would have much feedback though as it's designed as a DJ table for use in loud environments where acoustics would normally be less than perfect.

I also noted the tracking force required for the Stanton 520 SK Craze Cartridge (if it still has that stock cartridge in place) is designed to track heavy (from 2-5 grams). If someone set that up under 2 grams it might cause a problem.

heiney9

inspiredsports wrote: »

Look, I like you guys who are saying to deep-six the TT, but just go away unless you have a solution that doesn't call for quitting vinyl .

But, you have to admit it is a viable alternative and will definitely solve his problem. He didn't say he wanted to keep the TT, he wanted to know how to get rid of the feedback.......the above is one way to get rid of the feedback. :razz:

inspiredsports

You got me there .

I do love digital too, but heck, I'm the guy who's purchased not 1 but 2 R2R machines in the past few months. So you know I'm hardcore old-school.

SCompRacer

Room modes are the collection of resonances. It sounds like you are mode rich where the table is now. I've owned several different brands of turntables and don't recall any of them being totally immune to feedback. My turntable weighs 60 pounds and I can get it to feedback placed directly on a lead shot filled rack on a suspended floor positioned between my speakers that are symmetrical to room corners (speakers 3 foot from sidewalls and 4 feet from back wall). Suspended floors also transmit bass vibrations to the rack. (Concrete floors are ideal for a turntable). Either change the position of the table (can you move it further from the back wall), or make what the table is sitting on acoustically dead. Got a pic of your setup?

This is a pic of the South wall setup where I get turntable feedback above 75dB at the listening position (on a Radio Shack dB meter) with the turntable between the speakers. Even with all the acoustic treatments the bass loading is intense back there with the speakers symmetrical to room corners. And that is with transmission line bass modules where 90% of the woofers rear wave is cancelled. My West wall setup is longer and open to the main level at the right speaker. I can have the turntable between the speakers there at ear bleeding dB levels with no feedback at all.

gmcman

Shades, can you post a pic of the listening area of concern?

I'm fairly certain you will need to move the TT somewhere or isolate the vibration.

Does the TT have a lid, if so, put a couple pieces of Dynomat on the lid to reduce the resonance.

Isolate the feet of the TT with some foam pads from HD or Lowes or the likes, the ones that have adhesive on one side work great, the 4"x4" square black pads that are generally kept in the aisle with velcro, chair feet etc.

ShadesPG

first off, a thousand thank you's to you all for the input both constructive and comedic. i would also like you to know that i am fairly new into the hobby of hifi stereo so if im making some major errors, please go easy on me. and finally, im young and i dont make a fortune so im very price conscience and a tremendous deal hunter.

that being said: the room is 17' x 13'.

here are some pics:
http://www.flickr.com/photos/69073634@N07/

regarding the photo showing my speakers: keep in mind that the components on the left are no longer there.

all criticism and suggestions are accepted..i can take it.
thanks

pitdogg2

Dude you need one more milk create for that reel to reel nice wall of sound

ShadesPG

2% or skim?

nooshinjohn

pitdogg2 wrote: »

This is exactly why i ditched my TT many years ago. It drove me nuts trying to get rid of the rumble whenever i cranked the volume. Truth be told I'd love to have it back it was Yamaha's TOTL for that time period.

I love my Yamaha PX-3... I will never part with it.