need assistance with blocking bass

Hello!

I have a 98 Mustang Cobra with the factory Mach 460 audio system.  I've installed an Alpine CDA-9865 head unit and 13kv.2 sub w/ a Nine2x amp.

The head unit is connected to the factory amps, and sub is run off of the head unit's sub output.

The problem is, Alpine didn't put a lowpass crossover in this head unit, so ALL speakers get the bass.  It's fine at low volume levels, but the bass distorts on the factory speakers WAY before the sub runs out of steam.

I was thinking that bass blockers would be the solution.  Although after a little research here, it seems maybe they're not.

What would you do to block anything from ~80hz from the factory speakers?

haemphyst wrote:

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Harrison Labs FMods. Perfect for your situation. Just order the desired frequency...

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Thanks for the response!

Unfortunately, those are line-level.  I'd need some sort of high-level solution.  The output from the head unit to the factory wiring harness is all high level.

Anymore ideas?

aznboi3644 wrote:

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get some of these

Non polar caps

These should do the job

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Being an ameture...  How do I install these?  I'm gussing I just solder them into the speaker level connections?  Is this the correct resistor I need for a 80hz crossover?

I don't know what impedance those Mach factory speakers are, so if you're not sure, you should disconnect one and test for resistance with a multimeter.  You might read something like 3.2 ohms for a 4 ohm impedance, or 1.5 ohms for a 2 ohm speaker.

Once you know what impedance speaker you are putting the cap onto, find the cap value for the frequency where you want attenuation to start.  A 6 db / octave slope has a very shallow rolloff, so you should think higher in frequency than the 80 Hz you mentioned.  Keep in mind that the active crossover in the sub amp, set at 80 Hz, is of a higher order, so the crossover slope is much steeper.  You should use a value for a 1st order crossover of no lower than 100 Hz, and I might even think 120 Hz is more appropriate.  That would put 60 Hz at -6 db.  Your better equipment (the aftermarket sub) can be crossed a bit higher, too, and cover the 80 + Hz range a bit more.  You ARE dealing with factory speakers.

HERE is a guide for a 4 ohm impedance.  Look for the value listed under the column "1st order 6 db, C1".  You can see that the12volt provides data for other impedances, too.  And HERE is a depiction of how the cap is attached.  You MUST solder this component with the wire.  I would solder it close to the end of the input wire and still have an F-disconnect on the end of the wire to attach to speaker.

I just bought those 200uF - 100V Non-polarized capacitor that aznboi3644 said to get.  I have a question, Do I have to connect them close to the speacker, or can I connect them where the Amp is.  I have an Ex Cab 1995 Chevrolet Truck with a BOSS CH350 which power my tweeters, 6.5 and 4X6.  I want to get the bass out of those spekers. but I do not want to rip into my doors or take the whole truck apart again to get to the speakers.  I am not worried about the bass because I have a separte Amp for that, a Lanzer 1200HP with 2 Lanzar dc 12's.