[bluemike]

Yesterday I finally got my tt running and noticed that when I played a song my woofers in both speakers would vibrate quite a bit ..something they don't do when I play digital

I also realized that my project phono is missing it's jumpers
Does the high Gain cause the speakers woofers to react that way
i'm currently using a denon 160 with a rega RB300

I'm new to Vinyl and wanted to get some input from the experts

[macrojack]

My first thought is feedback. If the table is not isolated from external influences (including the woofers) the stylus will pick up on the vibrations and your system will amplify them through your speakers.

The other possibility is distortion if you are overdriving your preamp with too much gain from the high output phono pre. I'm not familiar with the phono pre you have so I can't say whether missing jumpers are the cause.

Analog is pretty simple. You just have to fix a couple of early glitches and you'll be on your way to fun and fetish.

[Wayner]

Is it hum, like 60 cycle or do your woofers go in and out kind of slow when the record is playing?

If it's the later, you are witnessing "wow" which is usually caused by a warped record. The stylus is picking up low freq mechanical movements. The platter or outside platter ring may not be seated either (not knowing what table you have). This low freq "wow" or rumble can be filtered out with a low freq filter if your preamp or receiver has one, or check your table for mis-alignment of the platter.

Wayner

[Paul Hynes]

Hi Pat,

This could also be sub-audio arm/cartridge resonance. It might be worth checking the compatibility of the arm and cartridge. Some form of record clamp should help with warped records. Check the platter bearing for wear. With turntables in general it is also worth checking idler wheels, or belts if a belt drive, for wear and/or contaminants that could cause slipage.

The IEC modification to the RIAA curve in phono preamps was designed to alleviate these problems by implementing rumble/wow/resonance filtration.

Regards
Paul

[blakep]

Could be all of the above, but if your speakers are ported you can do everything in the world short of using a subsonic filter when you play vinyl and you won't solve the problem. Woofer pumping when playing vinyl with ported speakers is just part of the game and you'll want to make sure you have a subsonic filter for the sake of your woofers, your amplifier and your ears (as engaging the subsonic with non-sealed speakers will improve sound quality). The purists may argue otherwise but the argument doesn't make much sense to me both in theory and in practical terms.

[lcrim]

I believe you are experiencing rumble and as the others have pointed out, this low frequency noise can be caused or made worse by a number of things including a  lack of TT isolation, tonearm resonance,  warped or uneven records or main bearings.   Many people simply ignore it if not audible.   It can actually cause intermodulation, canceling frequencies if unchecked.
If after correcting for all obvious causes and its still present,  I agree you could use one of the rumble filters available but I would first try to find the cause.

[bacobits1]

I have single driver ported speakers here. I do get it on occasion especially on the lead in groove.
KAB does make a Subsonic Filter at $169ish ??

D

[bluemike]

Thanks guys for your help

I'm running a project phono at 100 ohms my preamp has 20db gain
the cart is a denon 160 with rb300 arm

I've tried to level the table and i'm still experiencing this woofer pumping

does the rumble filter affect the sound

Paul thanks for chiming in does your phono help with this issue

[Wayner]

No, but it is sucking up amplifier power as the amp is amplifying this low frequency information.

Wayner

[bluemike]

The rumble filter doesn't fix the issue it masks it ..is that correct
What do I do to fix the problem if anything or do I look at another tt

[woodsyi]

Check this out and see if your cart and arm matches. 

http://www.theanalogdept.com/cartridge___arm_matching.htm

Do you have another cart with different compliance/mass to try?


P.S.  I found these informations for you but I don't know your fastener weight.  See if you can calculate your resonant frequency.

Denon DL-160 Specifications
# Output: 1.6mV
# Stylus: .1 x .2mm special elliptical diamond
# Cantilever: aluminum
# Frequency range: 20-50,000Hz
# Compliance: 14x10-6cm/dyne
# Tracking force: 1.3-1.9g
# Weight: 4.8g

What are the Rega arm specifications?
Technical Specification

Low effective mass 11 grams
Effective length : 240 mm
Overhang : 17.2 mm
Offset angle: 23 degrees
Mounting distance: platter centre to arm hole centre : 223 mm
Diameter of mounting hole : 24 - 25mm
Size of base mounting nut is 32mm A/F (across flats)
Maximum armboard thickness: 27mm
Total Weight 436 grams
Capacitance 0.002uF
Resistance 0.002 ohms

[bluemike]

Thanks Rim
I only have one cartridge at this time
I understand the Denon 110  works well with the RB300

I know my tt is in a corner and that doesn't help things
I also suspect i'm using an incorect setting on my phono

New to Vinyl and learning the hard way 

[bluemike]

So sorry Rim
I actually have the denon 110 (red in colour)

[woodsyi]

No problem.  Denon 110 spec.

#


Specifications
# Type: Moving coil
# Output voltage: 1.6mV (1kHz, 50mm/sec)
# Frequency response: 20Hz-45kHz
# Output impedance: 160ohms
# Channel separation: More than 25dB (1kHz)
# Channel sensitivity difference: 1dB or less
# Tracking tip: 0.1 x 0.2mm special
# Needle: Elliptical solid diamond
# Compliance: 8x10-6 cm/dyne (100Hz)
# Tracking force: 1.8g ? 0.3g
# Weight: 4.8g

Lower compliance means it's stiffer than 160.  Stiffer cantilever on a Rega RB300 with lowish effective mass of 11 grams may have something to do with your result.  160 with higher compliance may be a better fit.  I have used Benz Carts with compliance value of 15 to work well with RB250. 

Good general information from Galen Carol Audio.
http://www.gcaudio.com/resources/howtos/tonearmcartridge.html

[bluemike]

Thanks Rim

A few things
The arm has been rewired with the incognito wiring. It also has the tungsten counterweight

 

[jonners]

I'm running a project phono at 100 ohms my preamp has 20db gain
the cart is a denon 160 with rb300 arm

If you mean that you're using 100 ohms input impedance in your phono stage, that's probably too low. The output impedance of the DL160 is 160 ohms and the manufacturers recommended load is 47Kohms. Most people seem to prefer the DL110/160 at 1k - 2k ohms. That may not help you with your problem though.   

[bluemike]

Jonners
Thanks for response
I corrected my inital post to say that i'm using the Denon 110
The phono stage I'm using is a project tube phono se 2 which has variable MC and MM settings
What is a good setting to use if 100 ohms is too low

[jonners]

bluemike -

The 110 is much the same as the 160 - use at least 1Kohm input impedance and see what you like best.

I've just looked at the specs. of your phono stage. The mc input impedance only goes up to 220ohms so I suggest you try going in to the mm input, which is a standard 47k. If that doesn't give you enough gain we'll have to think again.

John

[loki1957]

From what I've read about set up the cart isn't set up perfectly. Mine does the same thing at the beginning of a record and by the time it reaches the middle the in and out movement pretty much stops. The geometry changes as the cart tracks inward.

[bluemike]

From what I've read about set up the cart isn't set up perfectly. Mine does the same thing at the beginning of a record and by the time it reaches the middle the in and out movement pretty much stops. The geometry changes as the cart tracks inward.

Thanks for chiming in.  I have a buddy who is good at this sort of thing to check my table and settings I'm mostly worried about this woofer pumping action damaging my speakers .. I will look into the filter however i've been told it does effect the sound