# Best way to add a sub to pre 1990 headunit?



## jlindsey86 (11 mo ago)

I want to run a period correct HU in my truck however I have noticed that most of the higher end decks from this time period only have a set of preamp outs for the front speakers. I did find a couple of decks that have a preamp out for the front and a sub-out. 

Did the decks with a sub-out have a HPF and LPF built into them? If not how should the sub-out be utilized?

This JVC model from 1989 has pre outs for the fronts and a line out for the sub.









If a head unit only has pre-outs for the fronts, what would be the best way to incorporate a sub? I am using an ADS PS5.2 to power the front component speakers. The amp does not have a HPF or LPF.


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## Slave2myXJ (Dec 18, 2021)

You'll need an active crossover, EQ or ideally, a DSP...


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## Slave2myXJ (Dec 18, 2021)

Nice piece of kit here if you're going 3-way...









Old School PPI EPX-223 Crossover


Selling a PPI 3 way crossover - in good shape and worked when last removed from the car. Have been holding onto it but let's be honest it won't get used again so might as well pass it on to someone who can pair it up with some sweet PPI Art Series amps 😁 Located in Canada but will ship to the...




www.diymobileaudio.com





Another option here









Cheap 8 channel LOC with signal summing and crossover


Cache COE8 8 channel line out converter with signal summing and 8V rms out. Comes with remote level control. $60 $40 + shipping Cache CEX 6 channel crossover with remote level control and bandpass capability. 8V rms out. $50 $20+ shipping




www.diymobileaudio.com





No reason you can't install a modern DSP and keep it hidden...


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## jlindsey86 (11 mo ago)

That makes sense, now I see what active crossovers are for.

In regards to the old JVC HU posted above, if it has a dedicated sub out, should it not also have a LPF built in even though it is from 1989?


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## Slave2myXJ (Dec 18, 2021)

I would agree that it probably does...


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## ckirocz28 (Nov 29, 2017)

Wanna keep it really old school? Some rca y-adapters and some of these:





Line Level Crossovers


Line Level Crossovers



www.hlabs.com


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## jimmyjames16 (Dec 12, 2006)

Old School PPI FRX-456


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## jlindsey86 (11 mo ago)

Thanks for the replies! I found a NIB Pioneer CD-625 2 way active crossover I will be installing.


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