Alright... this was annoying to diagnose because I was having so many problems with the other amp and my headunit... but at the time I was having the "internal noise" from the headunit playing through my four main speakers... I hooked up my hifonics amp to my subs... as soon as I hooked up the RCAs my other amp got a little 'noisier'... the subs would play fine, except a slight hissing... (yes they were playing a subtle high-pitched sound) -- needless to say I figured the headunit was toast.

Now that I've gone through the whole testing phase, I've learned that my power and grounds to the amp are good... well in this situation.

I plugged in an inverter to the front cigarette lighter, an AC>DC supply for my mp3 walkman, and ran the lineout directly to one amp at a time... the 4channel autotek played flawlessly, and so did the Hifonics... EXCEPT I still heard that high-pitched hissing through the subs!!! I hear it EVEN when I pull the RCAs completely off the Hifonics... then I hooked up the Hifonics COMPLETELY to that secondary isolated car battery on my homemade bench.... still got the hissing... what gives? did I get a DOA??

Problem:
- Amp outputs high frequency hissing to 15" subwoofers, regardless of amp gain, cutoff freq, subsonic freq, as well as headunit output voltage.

Horrified Conclusion:
Amp has bad internals, but I'd do anything to convince myself otherwise.

Ordered amp from sonicelectronix.com, and before I ordered I specifically asked them via email what I should do in the event of a malfunctioning amplifier... because their warranty states that if the amp has been turned on, that warranty is void... I was assured I could get it replaced for free through them... I guess we'll see

Can anyone think of another test I can do on my BX1605D to get it to stop hissing? Any kind of noise-suppression hardware would be a last resort, because it would just be covering up the problem... but if it came down to it, the hissing is about as loud as someone dragging a pencil on a piece of paper... I could actively filter it... if need be necessary.

Thanks guys. Hopefully I didn't get the shaft on this...

BTW the hifonics sounds great, I just don't know if I believe its 1100 watts RMS @ 2 ohms... eh, but if this amp is damaged, who the hell knows, right?

 

Does it have a fan? My PG1200.1 fas is loud enough that I can here it in the front of the car

 

it has a fan, but it was not runnning, and I know for certain it is coming out of the woofers... not the amp itself. I even hooked up some other non-subwoofers, and I heard the sound even louder than before...

definitely the amp... I just wonder if there is anything I can do so I don't have to send it back.

 

lame...

Sonic Electronix was gonna make me pay for shipping THREE separate times!!

$15 - initial shipping charge
$17 - to send back to them to get them to replace it
$15 - to have them send it back to me

what a friggin' joke! they send me a pile of crap, and then they expect me to pay $47 to get an amp that I already paid for??? hrm... dunno about that.

I called up the sales department and told the guy... "From a customer's point of view, it seems like I'm getting screwed... It's totally not my fault that this amp is DOA... Why should I have to dish out so much EXTRA money to get the problem resolved? The seller is assuming the risk on merchandise they aquire for their customers... it shouldn't be the customers who are assuming the risk by buying from you guys."

He said he agreed.... then he talked to some people, and told me he could waive the return shipping costs... so I wrote that on a note inside the box...

this better work out... or there will be a few nasty reviews for Sonic Electronix popping up all over the place.