hiraga class a 20w. hum

[moochinazz]

You don't have many choices. The amp was not designed to be used in a car. You have to redesign the input circuit, float the secondary ground or use the LOC. Using a source that's not connected to the vehicle is another choice but would leave you re-charging the battery every night.

im sure some guys here in lithuania have used hiraga in car and had no problems with it, but they are not very generous with advice as i said. i have already my grounds separated and the noise became significantly less noticeable. mayde the noise still remains because ive connected it not to the battery that is in the car, but to the battery tha i have for testing purposes? i mean the second battery that is not installed/wired up in the car

 

[Perry Babin]

You need to install it like you intend to run it.

With no RCAs plugged into the amp, do you read infinite resistance between the RCA shields for the amp and the amp's main ground?

If you run a set of RCA cables over the seats or outside of the vehicle, do you get noise using your head unit?

 

[riotpack]

I have had a problem like this and the only way I could solve it was to run the headunit and amp ground wires back to the battery (individual wires back to the negative terminal)

 

[JZatopa]

Use a ground loop isolator as was previously suggested. Car amps must have something that will eliminate ground loops. Most use isolated secondary grounds. Others use balanced or otherwise active input circuits. The ground loop isolator is the easiest way to break the loop without redesigning the input circuit.

The noise isn't present with the laptop because its shield ground is not connected to the vehicle's ground.

I'm assuming that you've checked the head unit's shield ground and it's intact.

Perry I don't believe it was confirmed that the sound disappears when he connects the amp to a laptop. Until we know this, there is no way to find if the ground loop is internal to the amp or not.

A ground loop isolator is just a bandaid fix that people used to use when they ran out of options. I would only recommend that as a final option as it will kill the SQ and usually only lowers the level of the ground noise, it doesn't eliminate it.

 

[JZatopa]

for now i have modified pioneer p88rs hu. rs audio spl 6.5 midrange and old scan speak d3804 tweeters. i run them bi amped off an audiosystem f4 amp and also a jl audio 10w3 sub that is hooked up to audiosystem f2 amp. the wires and cables are not smth special. planning to go passive when hiraga works ok

When you say bi-amped do you mean you are using active crossovers and each driver is directly connected to your speakers?

Are you using a distribution block on your grounds? If so you need to get rid of it. You need to make a star ground for your amps.

Let us know what you try and what makes a difference. did you get a chance to measure DC while the amp is in the car?

BTW I would never use the hiraga to power a passive setup. I would only use it on my tweeters or high efficiency mids.

 

[moochinazz]

i have no issues with current setup. all amps are grounded to the same point. thanx for lots of advise, guys. ill report when i come up with some testing results

 

[moochinazz]

i have no issues with current setup. all amps are grounded to the same point. thanx for lots of advise, guys. ill report when i come up with some testing results

hey, i'm back with some test results from my car. the dc is slightly higher in the car but its adjustable. i was testing with the battery that i have for testing purposes, not he one installed in the car. speaker cones were being pushed out by the amp, but not until i have connected smps ground wit a car chassis by a heavy gauge wire. the speaker seems to be pushed out when the amp switches on, but then the cones come back to default position, the hum seems to be gone. will be testing more when weather gets warm in here