Help on setup

[Sarong1]

Mikadosg, IMHO, P80 should not match with 701. This is because P80 has a full load of digital processors onboard, adding the 701 in the signal chain, the quality of the signal could be more than doubly processed and some signal will be lost to a certain extent. I understand that P80 has no way to off the DSP onboard, so you may want to consider changing the HU should you intend to keep your 701.

Edited August 4, 2007 by Sarong1

[Mikadosg]

ya p80 is easy to use..i decded to keep my processor and change my HU instead.tho i juz bought my p80 a month back. any gd condition alpine HU to swap?

[Kwongwing]

If you want to connect an Alpine HU to the H701 via an optical link - u cannot just get any Alpine HU.

 

Only selected Alpine HUs have optical outs - be careful when you commit.

 

Anyway, if the gains are properly adjusted on your HU and the H701 - hiss can be eliminated to an almost non-existent level. Check the cables you are using too - make sure that they are properly shielded.

 

BTW I have a 8-metre run of analog RCA from my HU to the H701 processor, and hiss is not a problem.

[Hyun]

kwongwing,

 

this is interesting. user12343 once commented that it's not just due to input sensitivity, overloading of voltage. it's an inherent thing in all 701's analogue inputs and can ONLY be eliminated by optical link. i haven't experimented and do not know.

[Kermit]

A few possibilities....

 

1. The hissing noise is lost along the way somehow.

2. The hissing is masked by EQ.

3. His dashboard is so far away that you cannot hear the hissing.

4. KW, age is catching up? hahaha...

 

Actually, unless you really really listen at close proximity to the speakers than you can hear lah. And if your internal car acoustics is so quiet, external road noise so low, at night etc...then can hear, when changing tracks...hardly noticeable if you dun purposely hear out for it.

Edited August 6, 2007 by Kermit

[Kwongwing]

Hyun,

 

All analog connections would have inherent hiss - unavoidable - but can be managed to an acceptable level.

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Kermit,

 

Agreed - I old liao

 

-------------------

 

Anyway, the way I listen out for hiss is / adjust for minimal hiss is:

1. pause the CD in the HU

2. boost the HU's volume

3. whilst balancing the volume control on the H701

 

*The above is provided the amp gains are adjusted properly in the first place.

 

Nothing too technical, scientific about my methods.

 

Edited August 6, 2007 by Kwongwing

[Mikadosg]

hi,

first thing i did was the amp gain which i believe i did correct,my p80 have to be turned up to 35-40 to be juz the rite vol..is it too high?the hissing sound can only be heard when i off the HU.but while playing and changing track ..hissing can be heard,but u have to listen closely..

[Sarong1]

That will mean you have to redo your amp gain again such that the hissing noise is minimised but not diminished. What speaker/RCA cables are you using by the way? My recommendation would still be to change the HU...

Edited August 6, 2007 by Sarong1

[Kwongwing]

Usually, the HU volume control should be between 70 - 90% of the HU's maximum volume.

 

But the threshold of the H701's input is lower than that of the amp, therefore you should adjust the gain of the HU, the H701, then the amp gain - in that order to ensure that all the gains / controls are properly matched.

 

Don't get you, hissing only heard when HU is off - presume that is inherent sound from the H701 to your amps?

 

Then the fault could lie from anywhere from the H701, the RCAs from the H701 to the amps - if the H701 is also off can the hiss be heard - then it could also be that the gains of the amp could be adjusted too high.

 

What is the level setting on your H701 - should be between 23 - 28? The max setting of the H701 is I believe 35.

 

[Mikadosg]

i am using focal 165v1 and rca is soundstream...hmmm for tuning was not did by me..i know how to spoil it only

[Kermit]

When HU is off, by right, everything else should be off...that includes 701, amps, whatever other things you have in between (the sound system). Unless, of cos, wrong connections somewhere lah. So, if assuming right connections, how to have sound from the speakers?

[Zambik]

I agree... When HU off, should not have hissing because power should be off for the rest as well. Which could spell connection problem...

[Kwongwing]

Agreed.

 

"Don't get you, hissing only heard when HU is off - presume that is inherent sound from the H701 to your amps?"

 

Which is why I did a presumption - meaning HU "volume" is off.

 

Anyway, for any system - there are lots of causes for noise to creep into the audio system - be it the power supply, audio signal lines, loose connections, etc.

[Mikadosg]

nono...i mean thrs hissing sound juz before my hu is off.follow by a soft pop sound frm woofer..any thing wrong with the connection?