Just had a 150 installed with an Alpine ktp-445u universal head unit amp.

When I turn on the Pioneer, I hear a hissing noise from the speakers. This happens when the sound is set to zero. It's faint, but it's there.

When I turn up the volume a hissing noise gets louder and louder. By the time the unit is at 14 it's pretty loud.

Could this be the Alpine? Is this just "normal" for the Pioneer.

Also, there is a slight buzzing sound every 30 seconds or so. This happens when the engine is off or on.

Finally, I am having no luck getting the video bypass to work. I purchased the overpriced wire from Amazon and had my auto installer do it, but it still prevents video while moving the car.

Any advice or help would be greatly appreciated.

Just had a 150 installed with an Alpine ktp-445u universal head unit amp. When I turn on the Pioneer, I hear a hissing noise from the speakers. This happens when the sound is set to zero. It's faint, but it's there. When I turn up the volume a hissing noise gets louder and louder. By the time the unit is at 14 it's pretty loud. Could this be the Alpine? Is this just "normal" for the Pioneer. Also, there is a slight buzzing sound every 30 seconds or so. This happens when the engine is off or on. Finally, I am having no luck getting the video bypass to work. I purchased the overpriced wire from Amazon and had my auto installer do it, but it still prevents video while moving the car. Any advice or help would be greatly appreciated.

The pre-amp output of the Z150 is 4V, which is higher than many HUs.  Is there a gain control on the Alpine? If so, turn it down a little and see if it improves. Don't know about the buzzing. 

AFA the bypass, odds are it wasn't done correctly.

Thanks. I am switching installers and will tell him your advice.

Update: sure enough, it was the Alpine unit turned way too high. Now even with the Pioneer at volume 40, there is no BG noise at all! Nice.

They also did the bypass, so I can finally use my head unit while driving, not to watch videos, but to have full functionality of the settings, etc.

I have a Z140BH and I'm experiencing the hissing and noises that others have mentioned coming from the head unit. I originally thought it engine noise because at times it sounded like the old ignition noise you used to have to get rid of with a noise suppression filter (which I tried, by the way). But this noise is there even with the engine not running.

My question is for people not experiencing the noise. What volume level do you normally listen to your unit at?

I've heard that the problem seems to be the high output level from this head unit, although they mostly referred to the Z150. So I'm wondering if I just need to reduce the input level on my amps. But before I did that, I wanted to get some input.

Thanks, Buddy