Help with settings on amp

[johnnygoat 10+ year member]

I have a 71 GTO convertible that back in the day I thought nothing to cut up dash or door panels but now I'm keeping it original looking as possible. here's what I got going on and my problems. The head unit that fits in the dash without cutting it is probably a retro sound unit(not sure) I bought from a Pontiac parts web site. I will attach a picture of unit and it specs. This is no high end set up it just something the fits so I can have a decent sounding system for those rides to the car shows.

Front speaker (fits in factory location center of dash) retro sound full range loud speaker 2-way 4"x10" full range DVC speaker

nominal impedance (ohms) 4+4 DVC freq response 43hz-21khz power handling(watts rms/peak) 90/160

RetroSound R-410N 160 W Peak (90 W RMS) 4x10" 3-Way Coaxial Car Speaker

This is ran thru speaker wires off head unit to amp to speakers

Front speakers in kick panels these speakers came with factory looking kick panels. Kenwood KFC-1665s ^ 1/2" 2-way

nominal impedance 4 ohms freq response 35-22000hz power handling 30 watts rms 300 watts peak

These speakers do not run off amp they run directly off the head unit (I think as per somebody on this forum)

Kenwood KFC-1665S 6.5" Sport Series Coaxial Car Speakers

Rear speakers I made a box out of wood for these speakers they sit on the rear transmission hump between front and back seats

.J.L Audio 5"x7" coaxial loud speakers C2-570X

nominal impedance 4 ohms freq response 53hz-22khz continuous power handling 60 watts

These are ran thru speaker wires off head unit to amp to speakers

JL Audio C2-570x 450W 5" x 7" / 6" x 8 2-Way Evolution C2 Series Coaxial Car Speakers

Sub woofers (there are 2) are located in the convertible top well there are cut outs in there for 6"x9" speakers. ( this is where convertible top fold into)

CDT Audio CL-69sub 6"x9" mid/sub woofer

nominal impedance 4 ohms freq response 45-4000hz power handling 100 watts rms / 200 watts music ( 100hz high pass)

These are ran thru rca connections on the head unit to the amp to 2 subs wired parallel

CL-69SUB - CDT Audio 6x9" Mid/Subwoofers

Amplifier is in trunk

Soundstream Picasso Nano PN.5>640D

Rms power @4ohms 60watts x 4ch + 200watts

Soundstream Picasso Nano PN.5>640D | Sonic Electronix Search

First Set max clean volume

I set my gains by a digital muti meter front and rear speakers square root of 60 x 4 = 15.49 target output voltage sine wave test tone 1khz this was no problem. Here is my first question how do I or where do I set hi pass for front and rear channels should these be set before the gains. Also there is a button there for front and rear channels should I set that on HPS or Flat. Right now I have it set at HPF front 125hz rear HPF 125hz.

I set my two subwoofers gains the same way with a digital muti meter square root of 200 x 4 = 28.28 target output voltage sine wave test tone 50hz, This is where I had a problem I could nowhere get the gain set that high without turning gain all the way up and the bass boost 1/2 up. Is this the right way to do this or is something not right does it have something to do with coming off the rca outputs on the head unit I would think that's what they are for. I set my low pass at 50hz Could somebody help me with this and tell me what's wrong

Should gains be set before low and high pass filters. right now I set my filters first do these settings for filters sound alright.. Thanks

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[shamim93]

I'm a little bit confused! So u have a 5 channel amp. Running 4 speakers out of speaker channels and 2 subs out of the sub channel if I'm right.

Your calculations for speakers are right but your subs are wrong.

If you are connecting 2 svc 4 ohm subs in parallel you will get ~2ohm impedance in total.

I don't have any experience with 5 channels, not too sure if you can have diffrent impedance for subs than speakers.

But if you can this is what you need:

Square root of 200 x 2 = 20

Btw if you don't wanna damage the drivers, don't ever touch the bass boost. Also, your gain shouldn't go over 3/4.

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[shamim93]

The best way to tune is by hearing. 50 hz tone is too low for mid subs. You will probably need to go over 60 or 80 on mids to get less distortion. If you can set the hpf and lpf on your headunit, it's better to leave the amp on full range and tune it of the headunit. Not sure what hpf lpf you need. I'm running my 12inch subs 40hz to 80hz, mids 80hz to 3500hz, tweeters 3500hz.

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[johnnygoat 10+ year member]

Thanks Shamim93 It is a 5 channel amp. The way I have the subs wired is plus to plus and neg to neg so yea they are wired parallel for some reason I did not realize it changed ohm impedance. I thought I did a enough research and had wired right Is there a way to wire them so they maintain 4 Ohms. Do you think I screwed up the sub side of the amp by having them wired like this because I did played it way more then a couple times and I'm lucky if I can get a reading of 10 volts with meter with gain turn all the way up. Also can you suggest some options to fix problem Thanks again

 

[Jeffdachef 5,000+ posts]

Head unit settings. Sub level max, volume at 80% bass boost and loudness off.

 

[johnnygoat 10+ year member]

Thanks Jeffdachief but head unit does not have settings. I'm thinking the amp is not right for the subs wired the way they are at 2ohms. Also may have screwed up amp because now I cant get higher then a 10 volt reading.

 

[johnnygoat 10+ year member]

I am not a car audio guru but did do some reading and research and this is the first amp I installed but when I rechecked the specs on the amp

•Picasso Nano Series 5-Channel Class D Car Amplifier

•RMS Power Rating:

◦4 ohms: 60 watts x 4 chan. + 200 watts

◦2 ohms: 80 watts x 4 chan. + 350 watts

◦4 ohms, Bridged: 160 x 2 chan.

I seen it has a 2ohm rating also so does this mean the subs can be wired at 2ohms and the other speakers at 4ohm and would my new calculations be the square root of 350 x 2 = 26.4 for the subs.

does it sound like something is wrong with the amp from the factory that I cant get a higher then 10 volt reading or does it have something to do with the head units rca connections I am using.

 

[Boomin_tahoe 5,000+ posts]

Jeffdachief lol

Yes that amp has the ability to run at either 4 ohms or 2 ohms. Speakers and sub.