I have a question about setting up my new stereo rig. In particular I want some advice on setting the crossover points.

First let me describes the system.

Stock Bose HU
AudioLink Line out converter
Alpine F340 4 X 55 w RMS amplifier
Front Speakers: Infinity Kappa 62.5
Rear Speakers: Infinity Reference 6002i
Subwoofer: Infinity Basslink

The alpine amp will let me run the 4 channels in high pass mode. (block the bass). The crossovers are 12db / octave and settable from 30 - 400 hz. (front and back can be set seperately to)

The basslink low pass fiter is settable from 50 - 120 hz.

Should I set the amp high pass and the subwoofer low pass to the same frequency? (I am assuming yes). Also, what crossover point would you recommend?

I am leaning towards setting them both to 100hz. This puts a lot of the bass on the subwoofer (and out of the small speakers), but it is not pushing too close to the upper limit of the Basslink.

Does this sound right?

Bonus question: Can I assume that the 2 line outputs on the Alpine F340 are not filtered even if I set the high pass filters for the speaker outs? (I hope so).

Here are a few handy links if you need more technical details than I provided.



BassLink info

Alpine Amp Details

 

Andy, there's really no "perfect" way to set crossovers. It depends on the speakers, amp, acoustics of the vehicle, etc.
Having said that, here's what I would do:

1) Turn the sub off completely [ unplug RCAs running into the Basslink if you have to ]

2) Select a good CD with a lot of midbass that has drum solos, etc.

3) With 6 1/2 inch drivers I would start by setting the High-pass at 75-90 Hrtz and listen to that CD with just your mids and highs playing. Listen to see how accurately they can play the selection at that setting. Play it as loud as you can within reason.

4) Experiment by adjusting the High-pass either up or down. The sound should be tight not boomy or distorted at all.

5) Once you've established a good setting for the mids and highs, go turn the sub back on

6) Start the sub Low-pass x-over at around 60-70 Hrtz. It is not necessary to have the high and low pass on the same frequency. You can have a gap between the frequencies. With 12Db sloped x-overs, this will work well. They have a slower rolloff than 24Db.
There should be a seamless transition between the midbass and sub. Again not boomy or distorted.

7) You've just set your crossovers, enjoy.

Note: It is also important to note that a good EQ will greatly help to smooth out the midbass and sub frequencies as well as the rest of the sound.

 

Thanks, that sort of makes sense.

Sounds like I should figure out what the small speakers can handle first, then use the sub woofer to fill in the bottom.

Do you have any idea if I should run the basslink in phase or at 180 degrees ? I know I can try both, but sometimes there is an obvious answer to these things that can save time during the install.

 

As for the phase, that's something that you'll have to try both ways. Can't say one way or the other. Good luck with it.

 

thanks for posting this. I'm trying to make my system actually sound good, and the basslink arrives tomorrow! In the next week, I'm installing it, having my technos ecu reflashed for some upgrades, installing the crawford plenum and installing eibachs!

Probably wind up replacing my blaupunkt components for infinity too, later.

 

Remember that going too high on the low pass and your ears will divert your attention to where the sub is located. You want the bass to sound as if it is coming from your fronts, so I would not go any higher than 90, the lower you can get away with the better. Here is how I have my x-overs set.

High Pass 80 ish

Low Pass 75 ish

I say "ish" because Eclipse does not detent their crossover points. They label 50-80-200 and you get the screw in the ballpark.

 

Good point. You are right that I shouldn't go too high since iI will be able to detect that it is behind me.

Maybe I will experiment with lower corssover points. (like 80 as you suggest).

Although, 100hz is pretty darn low to.