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Bronze Member Username: PalanzaPost Number: 47 Registered: Dec-05 | Just wondering if anyone has any idea why I may be hearing a little *click* sound in my speakers everytime i notch my volume up once on my headunit. It isnt that noticeable until I turn the volume up a bit and I swivle the volume nob quickly. Any ideas what might be causing this? Thanks in advance :D |
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Bronze Member Username: PalanzaPost Number: 61 Registered: Dec-05 | Any1 have any ideas? |
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Gold Member Username: Mikechec9Http://www.cardomain.c... Post Number: 2240 Registered: May-05 | Zipper noise perhaps. Not certain as to the HU your refering. But the Alpine pxa-700 unit has the same issue. Werewolf (ECA, CS&E) opened it up and did a review of his inspection: "... But one thought I have regarding the "poping" or clicking noise during volume changes. Especially since it's worse at high volumes ... this may be a classic case of so-called "zipper noise" ... essentially the audible artifact of "step" changes in volume with electronic (that is, not analog potentiometer) volume control chips. Generally speaking, there are two ways to combat zipper noise : 1. Algorithmically "ramp" the volume in a gentle fashion when the user requests a volume change. This must be implemented in a DSP chip inside the unit. 2. Wait for a "zero crossing" of the signal, before you implement the volume change requested by the user. The signal will NOT have an abrupt level change ... the culprit of zipper noise ... if the gain change occurs when the signal is zero This can be implemented in a DSP chip inside the unit, or there are some volume control chips (like the lovely Wolfson) that have this function built-in. Now I recall in my review of the H900, that the volume control chips used did NOT have any of these options in them. So we concluded that the DSP chips in the H900 must be implementing one of the two above algorithms to avoid zipper noise (since there have apparently been no complaints of zipper in the H900). So here's a speculation ... perhaps, since the DSP horsepower of the H700 is of course less than that of the H900, some shortcuts were made in the volume control algorithms? I know that's not a very satisfying answer for the user" |
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Gold Member Username: Mikechec9Http://www.cardomain.c... Post Number: 2241 Registered: May-05 | Entire thread: http://forum.elitecaraudio.com/showthread.php?threadid=87972 |