# Opinion - Coaxils or Midrange only for Rear Fill?



## ribrown (May 2, 2012)

Hi there. Just want to know what people prefer for there rear channel sound. Either Coaxil full range speakers or straight midrange drivers with no tweeters? I've always run full range in the back with matching tweeters but am anxious to know other enthusiast's opinions. I am designing a system in a new full sized Silverado truck with a 3 way JL Audio C5 set up front with high power and am trying to decide what to try first in the back. Thanks to all responses!


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## gstokes (Apr 20, 2014)

My rear fill is a 12" subwoofer and i prefer my mids mounted in front doors with tweeters on the dash...

If you're referring to the JL C5-653 i would mount the woofers in front doors, mids and tweeters in/on the dash..


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## ribrown (May 2, 2012)

gstokes said:


> My rear fill is a 12" subwoofer and i prefer my mids mounted in front doors with tweeters on the dash...
> 
> If you're referring to the JL C5-653 i would mount the woofers in front doors, mids and tweeters in/on the dash..


The FRONT speakers I will be using will be the 653s. Midbass in the doors with tweets and mid range in kick panels. But I am referring to an additional set of drivers for my rears. Thanks for the input.


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## gstokes (Apr 20, 2014)

ribrown said:


> The FRONT speakers I will be using will be the 653s. Midbass in the doors with tweets and mid range in kick panels. But I am referring to an additional set of drivers for my rears. Thanks for the input.


IDK why you want speakers in back doors, do you have passengers in the back ?


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## ribrown (May 2, 2012)

gstokes said:


> IDK why you want speakers in back doors, do you have passengers in the back ?


I want speakers in my back doors for Rear fill.


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## gstokes (Apr 20, 2014)

ribrown said:


> I want speakers in my back doors for Rear fill.


I can't help you there, most of us including me use a subwoofer for rear fill..


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## ribrown (May 2, 2012)

I like a subwoofer as well. But I also like a little midrange coming from behind me too. So I guess my question is directed at those who also like rear full range sound.


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## T3mpest (Dec 25, 2005)

Most of us dont' run any rear fill in the manner your describing. There are lots of technical reasons why. Mainly being that there is no "rear channel" in stereo, so your just adding more sources that hurt your overall frequency response.

Honestly, since it's not the "right" thing to do anyways, but your doing it because you prefer it, then do whatever your preference is, as that's what really matters. Your the one that has to listen to it.


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## gijoe (Mar 25, 2008)

No coax. You don't want high frequencies behind you, that will ruin your staging and imaging. I don't run rears either, but if I wanted to (which is something I do consider from time to time) it would strictly be midbass/midrange, and attenuated significantly. Although I think for 95% of the time the rears should be off, if I were to run rears I wouldn't run full range without proper L-R, delayed, and attenuated.


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## Lycancatt (Apr 11, 2010)

personally, and I'm usually the odd man out lol, I'd have a full range coaxial, but only if I had the processing power to properly implement them. reason? if I have one preset with only mid frequencies going to the rears for a bit of depth/involvement, and another running full range for rockin out on the way home from the club..i wouldn't want to limit myself.

if you are not going to run a dsp with enough channels to separately process the rear speakers, I would suggest a midrange only speaker though.

how do you plan to process this system? are you running the 653s passive? if so, your going to want a lot of power since those crossovers eat up the juice and starve the drivers a bit.


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## ribrown (May 2, 2012)

Lycancatt said:


> personally, and I'm usually the odd man out lol, I'd have a full range coaxial, but only if I had the processing power to properly implement them. reason? if I have one preset with only mid frequencies going to the rears for a bit of depth/involvement, and another running full range for rockin out on the way home from the club..i wouldn't want to limit myself.
> 
> if you are not going to run a dsp with enough channels to separately process the rear speakers, I would suggest a midrange only speaker though.
> 
> how do you plan to process this system? are you running the 653s passive? if so, your going to want a lot of power since those crossovers eat up the juice and starve the drivers a bit.


Thanks for the input. Yes, I will be running the 653s with their supplied passive crossover. I'll be using a JL XD600/6 with two set of channels bridged to feed them 200 watts each front channel. So I'll have 75 watts for each rear channel.
Signal processing will be connected to the factory head and will most likely be an Audiocontrol DQ-61 as opposed to a computer tuned DSP since I want to keep this somewhat simple.


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## Jroo (May 24, 2006)

If you had to do it, I would find a full range driver and let it roll off. I would have anything with a tweeter like a coax back there. A mid range would work if you had a way to bandpass it.


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## ribrown (May 2, 2012)

Jroo said:


> If you had to do it, I would find a full range driver and let it roll off. I would have anything with a tweeter like a coax back there. A mid range would work if you had a way to bandpass it.


Using my AC-DC DQ-61 I can certainly filter the high pass of the rear drivers to something like 250hz. But the only way I could cut off the high frequencies is with a custom low pass passive crossover or with a pair of those inline RCA crossovers called FMODs. I was thinking a 6.5" or 5.25" mid would naturally roll off at 5000 he or so. What do you think?


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## trumpet (Nov 14, 2010)

I ride in a 4-door 2016 Silverado often and I have never noticed the rear speakers. The front seats and center console block the sound too much. I think upgrading them would be a waste of money if you want to improve the sound for yourself in the driver's seat.


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## Andeval (Feb 22, 2016)

I have a 2006 Trailblazer and just finished swapping out the factory HU and front/rear speakers. I used JBL P660's in the front with the tweeter mounted high on the "A" pillar with the mid's in the factory door locations. In the back I replaced the factory speakers with Infinity 6032cf's. I'm currently running a 300w Clarion Amp @75WX4 into 2 ohms. I'm using the RBE feature of my Sony HU and running the rears as bass fill until I can get my sub box built in the coming weeks.

I spent quite a few hours of position testing the tweets before deciding on the "A" pillar placement, and the extra time and effort paid off, as my front stage is just at, or a little above the dash and sounds phenomenal. I do not experience any negative soundstage effects running the Infinity's as rear bass fill.

However, if I defeat the RBE function, and run the rears as coaxials, I do find that my sound stage is adversely affected, and no amount of timing/positioning or EQ fixes this(well, what my HU provides, that is).

If I had to do it over(and I probably will), I'd go with mids only in the rear, add a processor and go active once I get the sub built.


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