Inaudible Hum - Ignore or Not?

[abdo123]

What are you getting?

The Audient EVO 4

 

[antcollinet]

TLDR for the most part just curious why would you want to ignore hum or not consider it an audible issue?

if it's inaudible - it's inaudible. That is how it was described in the OP. And in the thread title.

 

[abdo123]

if it's inaudible - it's inaudible. That is how it was described in the OP. And in the thread title.

Just to give you some perspective, I have the best phono stage measured on this forum and the mains hum is JUST below hearing thresholds.

Granted most people won't listen at levels where 0dBFS is 120 dBSPL, but if the mains hum is @ -40 dBFS or worse and you see and feel the woofer moving then it's definitely inter-modulating into the mid-range.

Having the woofer produce a lower amplitude sub-bass tone is the worst case scenario when it comes to intermodulation distortion.

 

[abdo123]

-1.2 dBFS is 2Vrms, new measurements with the Audient EVO 4. Groove noise is surprisingly lower than what i expected.

Nothing On:

Cambridge Audio Duo On

Groove noise (needle on LP, quiet passage)

 

[pjug]

Sorry if this is not helpful as I have only skimmed the thread. But since the problem is related to the subwoofer is it possible that it is a feedback (vibration) problem? I had a feedback in the form of a rumble when my subwoofer was too close to the turntable. I was able to solve it without moving the subwoofer by using isolation under the sub.

 

[Angsty]

I’m glad @watchnerd posted this question as I also have a hum problem with a newly acquired phonostage. I am testing out a vintage Bryston BP-1.5 in place of my Sutherland Insight. Although I love the detail and transient response of the Bryston (which has integrated SUTs) I get more hum than I do with the Sutherland at similar gain with my Hana MC cartridge. The Sutherland doesn’t really have hum per se; it’s a broader band of noise.

My Bryston amp is in the shop and I’m using my NAD C272 in its place right now. The Bryston has balanced inputs while the NAD only has single ended. Before I freak out over the hum, I’ll wait to see if the balanced connection to the preamp helps the situation.

 

[Chrispy]

if it's inaudible - it's inaudible. That is how it was described in the OP. And in the thread title.

Yeah still trying to wrap my head around the concept of an inaudible hum....

 

[DanielT]

Yeah still trying to wrap my head around the concept of an inaudible hum....

Take it easy, our ears and hearing are what it is. Make the best of the situation instead.

 

[TBone]

Have you physically moved components near the phono stage or moved the phono stage to see if this changes the level of hum? Another trick is to take a metal plate which you ground and place on different sides to see if it blocks or diminishes the hum in the vicinity of the phono stage itself. For instance this could be a piece of aluminum foil taped to cardboard and connected by jumper clips to ground.

ground loops r a pain.

moving/rearranging components can often surprisingly reduce hum tho ive found too many gr.loop issues caused by compromised turntable grounds, poor wiring, poor soldering, poor connections, poor design, grounding screws/connections that loosen over time.

very thin internal arm wires become brittle & snap, often at the terminal point. (my 50yr old super thin silver monocrystal wires r extremely delicate (quality silicone spray=longevity).

 

[Angsty]

Found this list of tips from Hagerman Audio Labs, but I tend to think my problem is actually within the phono at this point. I get hum even when the phono is connected to nothing other than the preamp and headphones.

http://www.hagtech.com/pdf/eliminatingnoise.pdf

 

[Lou Garou]

This discussion is surreal! Do you people ever listen to music or are you just too busy listening to (or feeling) inaudible hums ? Get your finger off your woofer and enjoy the sounds

 

[watchnerd]

This discussion is surreal! Do you people ever listen to music or are you just too busy listening to (or feeling) inaudible hums ? Get your finger off your woofer and enjoy the sounds

Distortion is distortion

It masks details.

That causes you to miss out on some of the sound when you listen.

 

[sonitus mirus]

Distortion is distortion

It masks details.

That causes you to miss out on some of the sound when you listen.

Distortion is not all equal. In this specific scenario, from what I have read, the sound being listened to is masking the distortion.

 

[Robin L]

Distortion is distortion

It masks details.

That causes you to miss out on some of the sound when you listen.

It's only since I got on ASR that I own an audio system with low measured distortion, at least from 100hz on up. "Audiophiles" listen [often] for "subtle details"---often low-level noises that shouldn't have made their way to the commercial master. But the difference I'm noticing isn't noises popping in the mix, but the ease I can hear countermelodies, that is to say low-level musical detail, is improved. Less of the masking effect as regards music.

 

[watchnerd]

Distortion is not all equal. In this specific scenario, from what I have read, the sound being listened to is masking the distortion.

If I can feel it, it's almost certain to rank higher than any electronics that ASR craps on for having SINAD that is too high.

 

[pseudoid]

TITLE of POST >> Inaudible Hum - Ignore or Not?
#1. Obviously "audible"
#2. The answer, then and always, is a big fat NO!
I think all replies should be deleted and then replaced with that 2 letter word...
EDIT: I meant "NO" as to mean DO NOT IGNORE it. Good to hear that you fixed it. Different AC mains phases?

 

[Bob from Florida]

TITLE of POST >> Inaudible Hum - Ignore or Not?
#1. Obviously "audible"
#2. The answer, then and always, is a big fat NO!
I think all replies should be deleted and then replaced with that 2 letter word...

Normally, you might call this OCD. However, the audiophiles version of this disorder is called "audio nervosa". Once deeply immersed in "audio nervosa" it becomes increasingly difficult to ignore things.

 

[watchnerd]

TITLE of POST >> Inaudible Hum - Ignore or Not?
#1. Obviously "audible"
#2. The answer, then and always, is a big fat NO!
I think all replies should be deleted and then replaced with that 2 letter word...

Or just fix it so it goes away.

 

[antcollinet]

Or just fix it so it goes away.

Have you fixed it? Interested to learn how.

 

[watchnerd]

Have you fixed it? Interested to learn how.

I did.

Changed the amplifier to use a different outlet and surge protector strip from the TT motor.