HELP: tweeter got 'piak piak' sound after changing HU

[ryws]

After changing my stock HU to pioneer 4950, my tweeter suddenly got 'piak 'piak' sound when turn on loud.

Anyone sifu here knows how to solve this problem? Is it the wiring din connect properly ? positive negative wired wrongly? HU got problem? Or something need to be configured?


I'm using ALPINE component set, and ALPINE 4 Channel AMP.

 

[Kippo]

just your tweeters or the midbass and woofer (if u have one) gets louder as well?

i suppose your new HU Pioneer 4950 has higher RCA pre-out voltage and you need to lower your amplifier gain.

If only the tweeters doing that, lower any gain that has to do with tweeters eg. EQ in HU and in outboard EQ eg. parametric equaliser.

perhaps describing your setup will help i.e. the whole chain of setup from HU to speakers.

 

[ryws]

hi kippo, here's my basic setup

HU: Pioneer DEH-4950MP (3 pre-out0
AMP: Alpine MRV-F250 (4 channel)
Front Component Set: Alpine SPR-17LS
Rear Component Set: Direct from HU.
Subwoofer(bridge from amp)

Previously, with the original(Blaupunkt CD51) HU, there is no problem at all reaching max volume that I intended.

However,after changing to the new Pioneer HU, it seems that the volume can go up only till 70% of my previous HU max volume. I'm trying to pull up & down the gain. However, it's still the same when it reaches the 70% max volume, then the 'piak piak' sound will come out ONLY from the tweeter. (It only happens when it tries to hit certain nodes). The midbass & subwoofer are doing well,as usual. Just the tweeter somehow got strange piak piak sound. I have put EQ everything flat.

I'm abit worry whether the installer has done his job well. Coz,

1. The RCA left right cables were put wrongly. Left become right, right become left. But the direct HU speaker is correct. Making a 'X' stereo, very weird sound

2. The problem is that the rear speaker direct from HU and front component set from AMP can't be adjusted because he uses the rear preout for the AMP.(Yap, my 4 channel AMP only use 1 preout). So, the rear speaker volume is much more higher than the front because it's direct from HU. I tried to increase the AMP gain , but it's not a good idea though... I can't understand why the installer doesn't use the front pre-out for the AMP, so that I can use HU fader to control the volume.

Is there any wiring mistake on the HU, which can cause the 'piak piak' problem? Or, the pioneer HU can't be as loud as blaupunk HU.