Old amps in new F150 - Noisy signal

Dr Zeus

Member
2010-10-17 5:12 am
Hey folks,

I've finished building my 'Q' system in my 2016 Ford F150 Lariat SYNC3/Sony system. I used a Rockford DSR1 Maestro with AF02 vehicle specific interface to integrate/delete the factory Sony amplifier.

Amps are:
Hifonics Generation X Goliath (Zed Audio amp) running the door speakers.
Soundstream Reference 700s running a pair of 10" subwoofers.

I've set the gain controls using an SMD-DD1 with -5db track with head unit at 95% volume. Gain on the Hifonics is maybe 1/4 the way up. On the SS its about 1/2 way up.

Installation used 0-gauge Cerwin Vega wire from battery positive to distribution block in the trunk, split to both amps. 200A fuse up near the battery, and a 100A after the block to each amp. Both amps grounded to chassis in trunk. RCA cables are DBLink MagCore cables which I am told are very high quality cables and are only 2 feet long from the DSR1 to the amp. I've electrical taped each RCA to prevent connection contact with grounds or other contact points.

I strongly believe the DSR1 may be adding noise into the system. I have an AudioControl SA-4140i RTA which I've posted images for here showing both with the amps powered up and then off. Images were captured through my cell phone, using a calibrated AudioControl microphone - held about 3" from the door speakers with no music source.

The noise happens no matter if the engine is running or not - still noise exists.

I tried T-grounding the DSR1's black ground wire to chassis and to the amplifiers' ground per suggestion from Rockford. I've also called iDatalink who makes the Maestro but they couldn't help much. Also tried running a temporary 12v- ground wire from the battery to the grounding point of the amp/DSR1/RCA shields/etc. Noise still.

Sometimes the noise gets louder and softer all by itself for no real reason, though the noise actually gets about 6~9db louder for about 10 seconds before the system finally shuts off the amplifiers. This being an integral system, the DSR1 is in complete control of amplifier power state aside from the actual radio.

Both the Hifonics and the Soundstream amp are passing noise through them. If I shut down one amp at a time, the amp still powered still persists with noise.

I tried temporarily tapping amp ground to RCA shields and still noise. Removing all RCAs from the Hifonics eliminates the noise on the hifonics. Same with the soundstream.

Not sure what to do. I cant stand the sound of it.

Any suggestions?
 

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Dr Zeus

Member
2010-10-17 5:12 am
OK so I disconnected all RCAs from the amps but left the amps in the car with the vehicle ignition on, DSR1 on, signaling the amps to power up.

From an old android tablet, I went from 1/8" jack to L/R RCAs. I put one RCA in the Hifonics amp, and one in the Soundstream amp. The amps play music. When I pause the music from the tablet there is some noise but barely any compared to when its plugged into the RCAs of the DSR1. Minimal to almost no noise like this from a tablet.
 

Dr Zeus

Member
2010-10-17 5:12 am
Thats correct, except for the subwoofer output. Subwoofer output of the DSR1 is crossed at 100hz lowpass/24db/octave. Thats going to the SS amp which is set to full range. The SS amp has a weaker crossover than the DSR1 so I chose to use the DSR1 for crossing subwoofer frequencies.

Signals are all FLAT, uncrossed, and full range going from the DSR1 into the Hifonics. The Hifonics 4CHX-4 input module is handing active crossover at 90hz Highpass to all 4 channels.
 

Dr Zeus

Member
2010-10-17 5:12 am
I'm tempted to try my other Hifonics input module. Its a 'standard' 4CHB-6 module. 4 inputs, two gain controls, and a botton for either full range, or 1-2-UP, 3-4-DOWN. I'd need to use it at full range.

Only problem is, the gain controls on this module are quite scratchy.
 

Dr Zeus

Member
2010-10-17 5:12 am
4CHB-6 module seems to be much better. Check out the RTA between on vs off. Same speaker as before. I’m going to stick with this input module for awhile.

Images:
LEFT | RIGHT
ON | OFF

Maybe I should fix the 4xch-4 sometime?
 

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