i have a set of boston acoustic pro series 6.5 components up front... and rear factory oem speakers in the rear.. i dont have PREMIUM setup, so no 6x9 woofers. Anyhow I think im running my system as a 2way, since im using the crossovers that came with my bostons... I heard someone saying that the best setup is to forget about those xovers that came with the speakers and directly hook up my tweeters and mids to the my amp... I have a 4 channel amp. They say to use all 4 channels for my components... and use the built in xover on my alpine headunit.

So wire my tweets directly to the amp for the front channel, and the mids directly to the rear channel of the amp... and then use the xover on my alpine headunit. Does this make sense to you guys or no? This is what you call an active xover setup right> And it gives you the most flexibility to adjusting the speakers? Since i dont plan on using my rear speakers, i heard this is a good SQ setup... someone please help me decide on this.

The bad thing about this is that i have to rip apart my entire dash again just so that i can flip the switch under my alpine headunit from 2way to 3way, sigh... But if this makes a big difference in sound quality, its worth it for me. So can someone whose an audio genius tell me if this is worth it before i spend a long time taking apart my dash and rewiring my components again?

 

I'm not A G35 owner (yet,heh). But I have been into car audio for over 5 years. I current am running my speakers active and have intensely enjoy it. At first, after switching over the active, your system will sound worse than before. BUT after about a few days of driving and tweaking the EQ, you can achieve sound that's way better than when you used the passive xovers.

One advice is before when you power the tweeters, they are sensitive and you don't want to cross them too low.

Good luck,
David

 

ok, my alpine headunit has built in active x-over... when i switch my headunit to 3way mode at th ebottom, i have 4 options when i go into the X-OVER menu:

LOW: 20Hz to 200Hz (in 1/3 octave step)
MID-L: 20Hz to 200Hz (in 1/3 octave step)
MID-H: 20Hz to 20kHz (in 1/3 octave step)
HIGH: 1kHz - 20kHz (in 1/3 octave step)

My boston components freq range is 50Hz - 22kHz...

So what should i set these 4 xover points on my alpine headunit to? I have no idea, and i do not want to blow my speakers by giving them the wrong freq response...

 

MID-H: 20Hz to 20kHz (in 1/3 octave step)
HIGH: 1kHz - 20kHz (in 1/3 octave step)

Those are your obvious choices. There isn't any more customizing you can do? You are losing the top 2kHz. I would personally not worry about the 50Hz to 1kHz, because that will be covered by your mid, and go with the High setup.

 

ok so what about the low and mid-l xover points, do they have an effect on my speakers or no? also on my headunit i have a sobwoofer level control, will this have an effect on my components too or does that only effect the sub?

 

The LOW output will be the only one effected by your sub output.

I would recommend you running the following:
LOW: 63khz (-6db/oct)
MID-L: 80Hz (-12db/oct)
Mid-H: 2Khz (-6db/oct)
HIGH: 3.15khz (-12db/oct).

You can play around with those settings and slopes to find what works best in your car. Don't forget about EQ'ing features as well.

What you should be careful is crossing the HIGH too low will hurt your tweeters. Crossing the MID-L too low will damange the midranges. Playing the LOW too high will hurt your sub. If it doesn't sound right (a lot of distortions) turn off the stereo and check the settings and wiring RIGHT away.

David

 

Can someone please explain why you would switch from using passive to active crossovers? (Other than having the flexibility of choosing the frequency thresholds?)

I figure the manufacturer picked the best point based on the capabilities of the speakers???

(I have Diamond Audio Hex s600a components with 24 db/octave passive crossovers)

The above setup is not an option for me anyway with my Infinity 7451a amp. But if there's really something special about active crossovers, then I might look into a separate unit for that. My amp does have active crossovers but they are NOT digital (so hard to set without an RTA) and they are only 12 db/octave (not as steep) AND they are designed for low-pass/high-pass around 32-320 Hz - nothing way up there in tweeter territory. The frequency response is 10 Hz-100 kHz though!

(I have played around with a RTA and using a sine wave signal generator I have also found that I cannot detect sound above 16 kHz. My wife could not either. My kids could, barely, hear something at 17 but I think they were pulling my leg. My folks couldn't hear anything past 12 kHz. So I wouldn't worry too much about frequency responses that high - especially in a noisy environment. It's eerie to see the spike on the RTA display and hear NOTHING!)

 

Running active can have very dramatic benefits, although can be extremely dangerous to your speakers if you dont know what your doing. Other people can suggest what theyre using at their own crossover points, but what speakers you are running is what will make the difference. Not all mids/tweets/etc all correspond to the same frequency. I have my Illusion Nd8s bandpassed @ 55-2400, Rainbow tweets 2400+ as per Rainbows suggestion. A bit more tuning from my end would help the sound, as the set frequencies are currently from manufacturer suggestions.

rcdash...do you have a dog? He may be able to hear them

 

Manufactures tune their components to the "best" crossover, in terms of theoretical conditions. Every car is different and the installation is different. Hence, you MUST tweak your speakers accordingly.

David

 

The manufacturers also typically set them to be a bit "safer" for the general consumer as well.

 

Safer sounds better to me.

I do agree every environment is a little different. So adjusting mid vs. tweeter volume seems reasonable (and some passive crossovers permit this). Once you've got that worked out, the rest should be workable using an EQ. I have an EQ right before the AMP (3/4 band, 4 channel parametric Alpine 3402) which I used to make the entire setup flat and then I use the EQ in the HU for fine adjustments (to taste) based on music I'm listening to.

It's still not clear to me what the advantage is of adjusting the crossover point, at least on higher end speakers from reputable companies who should've set it correctly in their crossovers during R&D. I guess it is nice to have added flexibility though - to suit those who like the way it changes the sound characteristics...

 

Actually alot of higher end companies offer their component sets active. Your just buying the mids and tweets. Diamond,Arc,Rainbow,Alumapro,Focal,DLS,etc all offer this. As well as selling just drivers/tweets individually.

Running active also give the option to have a DIY setup. I personally didnt care for the tweets that come with my Illusion 8s, but I have loved for years Rainbow tweets, hence the reason I went active and ran the CAL26 VOFs

 

Ahhh - mixing and matching components - great example. Never thought about that...

 

Eliminating the passive crossover can also free up some loss. Many times there is a lot of loss of power through a passive crossover. One less component to go through equals less color to the sound. Also many times the passive crossover can be the weak link in a component set. Going the Active crossover route is not for the average user. One last thing depending on the active crossover that you use, you can achieve a much flatter slope at the crossover point. My processor has the capability to go 72 db/octave, this is basically a flat cut off. Hope this answers some questions.

 

Well my Diamond Audio passive crossovers are HUGE - I don't know if that means good or not... Just trusting the brand I suppose (and my ears).

But 72 db/octave is a steep crossover - holy crap! Ok, maybe I'm convinced . I gotta look into it now... (thanks alot!)