# Sending bass only to subs



## Sean8 (Jul 21, 2011)

Hi everyone.

I just found diyma and thought this would be a good question to start out with. 

I just did my first car audio set up ever in my car. While its not finished, I did add a critical piece today: the subwoofers.

I added two 10" Alphasonik QW10's in a sealed box with an Alpine MRP-M500 amp. I wired them in parallel and each sub gets 250w RMS. And they sound really good.

My question is, now that I have the subs, is there a way on my Alpine CDA-9887 head unit that I can send bass only to the subs? I have Rockford Fosgate 6x9 speakers in the rear and Pioneer speakers in my front doors and liked how they put out bass before, but they always rattled slightly. Just enough to annoy me. So now that I have the subs, I thought it would be a good idea to remove bass from them completely and let the subs handle the bass.

Is this even possible? Or is it a good idea? I want to get rid of that rattle. I know it only happens when they are playing a bass tone and only at certain volumes (after about 19 on my head unit), but I want to avoid using Dynamat or other similar materials.

Any help would be great.

Thanks,
Sean


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## tseng2394 (Jun 12, 2011)

Turn the bass down and the subwoofers up. I'm guessing you're mid bass is crap?


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## Sean8 (Jul 21, 2011)

The thing is, I've never been able to find the "bass" setting on this head unit, just like I've never found the "treble". It's a strange EQ that I never really understood. My whole range of bass is pretty good, but I want to remove the duty of the bass from the cab speakers as much as I can.


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## Aaron'z 2.5RS/WRX (Oct 24, 2007)

SPend some quality time with your manual.... 

The 9887 is a hell of a HU, it should have a dedicated sub out, sub crossover with independent sub level control.. 

It should also have a high pass crossover for your mids/highs... 

Good first question I suppose, but all you need to know is IN YOUR MANUAL...http://vault.alpine-usa.com/products/documents/OM_CDA-9887.PDF


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## ecbmxer (Dec 1, 2010)

Yep, use high pass filters for your speakers, set at maybe 60-80 Hz or so, and then low pass your sub at the same value to start out with. All this can be done from the head unit. Then you can tweak things from there to your liking.


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## BowDown (Sep 24, 2009)

You will need to use the Crossover functionality on your headunit. Manual is a good place to start. Remember 'Low Pass' means you are setting the highest point you wish to have a speaker play. 'High Pass' is the lowest point you wish to have the speaker play.


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## trojan fan (Nov 4, 2007)

Crossovers....crossovers....crossovers....please review the owners manual for instructions on how to set them...good luck


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## goodstuff (Jan 9, 2008)

As you read this site, you will come to know that most people here don't think of the subs as being the uber critcal piece of a system, some are even subless....but save that for another day for you.
Yes some good advice is to read the manual, scratch that 
Spend every free minute of your time with it for a week, when you ****, while you shower hold it up in the air with your one dry hand, put it under your pillow, read it with a flashlight under your blankets before you go to bed...you get the point. That 9887 is a very powerful unit and you have only begun to learn what it is capable of. To answer your original question about removing the bass from the speakers, that is an awesome idea and that is exactly what crossovers will do. I am almost proud of you for thinking of that yourself, even though I've never met you. Where are you located in Mass? I could possible be able to help, and myself and a few other guys from this site are having a meet in August in Oakham. I think one guy even has a 9887 so he will know it well. I've never used it myself. I'll post up the link to the meet in a minute.

http://www.diymobileaudio.com/forum/12-volt-events-team-diyma/107540-northeast-mega-meet-saturday-sunday-august-13th-14th-2011-oakham-ma.html


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## BowDown (Sep 24, 2009)

After crossovers look into Time Alignment.


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## trojan fan (Nov 4, 2007)

tseng2394 said:


> Turn the bass down and the subwoofers up. I'm guessing you're mid bass is crap?



Start with the crossovers first, then go from there


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## goodstuff (Jan 9, 2008)

BowDown said:


> After crossovers look into Time Alignment.


Hope I didn't scare you off. Wanted to say, less can be more. Once you get time alignment you shouldn't need rear speakers. I know it sounds crazy, but the speakers can cancel each other out if they play the same frequencies so you end up with "holes" in the sound.


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