10 replies to this topic

[eclipse_DYN]

I have always had noise in my system, but up until now I have had other issues that needed attention first. Now that most of my components are installed nicely, an acceptable level of sound deadening has been reached, this is my latest focus.

The noise can be described as staticy humming sound I guess, with a very faint (but audible) high pitched whine in the background. It is there when I change tracks, and also at the beginning and end of each track, where there is no other sound playing. It is also audible during pauses in the song, where no music playing, and also when the volume is very low. The noise gets louder when I increase the volume, and softer when I decrease, but it is always there. I have played Sheffield's My Disc, and expected to hear noise on Track 41. But there was none, Track 41 was completely silent. Track 42 however, revealed the noise in all its glory.

So where should I start? Grounding of amps, grounding of head unit? Should I run some 8awg straight from the battery to the head unit? At the moment, the head unit wiring is just running off the standard loom. The RCA leads are Stinger HPM2 series, but I am currently only using cheapo Directed Audio Y Splitters. Speaker wire is good quality Stinger pro.

This is from Sheffield Labs, but I dont quite understand what it means......

"This track [Track 42] contains the high-frequency signal of low level with alternating values of 0000 and 1111. On this path nothing must be audible. This signal is useful for evaluating the converter Cd of record player and its interaction with the analog circuits."

[BMWTurbo]

Have you D/C'd the RCA's to see if the noise still exists with no input from the HU?

You need to identify 'where' it's coming from exactly. The fact that it varies with volume suggests a HU induced noise however.

Edited by BMWTurbo, 11 May 2009 - 02:52 PM.

[eclipse_DYN]

No I havent done that yet. I'll be buying a decent multimeter tomorrow when I get back to work. What is involved in that? Hey I just noticed we have the same amps. Gotta love those Eclipse's

[BMWTurbo]

eclipse_DYN, on May 11 2009, 03:20 PM, said:

No I havent done that yet. I'll be buying a decent multimeter tomorrow when I get back to work. What is involved in that? Hey I just noticed we have the same amps. Gotta love those Eclipse's

With the power OFF - disconnect the RCA leads behind the head unit and make sure they can't short on anything. Power the HU/Amps back up and see if you have the noise still.

I'm almost certain you will find it gone, but best to idenitfy it's the source first.

IF you identify the noise is HU originated, then you can start to identify what needs to be rectified.

[blanketman]

what headunit are you using?
and the rest of the equipment



BTW i have disabled the signature view so if its in there i cannot see it

[eclipse_DYN]

Hey Blanketman, gear is in my sig but I'll copy and paste it for you too.

Car - Subaru Liberty RX
Battery - Optima Yellow top D34
H/U - Alpine 9887
Processor - Alpine KTX-100EQ
Front Stage - Dynaudio System 362
Front Amp - Tru Tech S44
Subwoofer - Eclipse 15" Aluminium
Sub Amp - Eclipse DA7122

[blanketman]

is it coming from both sides?
passive?

[eclipse_DYN]

yes it is coming from both sides. Running passive at the moment, although soon will be semi active. Adding another Eclipse amp for mid bass duties. Tomorrow I will take the RCA leads out of the back of the Head unit and see if it disappears.

[BMWTurbo]

eclipse_DYN, on May 11 2009, 08:56 PM, said:

yes it is coming from both sides. Running passive at the moment, although soon will be semi active. Adding another Eclipse amp for mid bass duties. Tomorrow I will take the RCA leads out of the back of the Head unit and see if it disappears.

Adding another PA5422? I'll be doing the same when I get some time

Interested to see if the noise is evident with RCA's D/C'd at the HU.

[blanketman]

thats what i suspect it is also

[Pulse-R]

I think it's the processor "processing" the audio.
since it converts digital->analog->digital->analog-> each conversion adds noise, and with the EQ processing, it adds more noise.

ditch the imprint and see if it's still got noise.