The main question is what are you wanting or going to use the Center Channel for ???
...a Two Seat front tune, OR is the Center Channel just for the OEM warning chimes?
I honestly wouldn't bother with a Center Channel for a Two Seat front tune
unless the DSP has an actual Licensed Center Channel Upmixing algorithm. And FYI, even the Helix with ACO, virtual channels, and "Real Center" is NOT a true Center Channel Upmixer. So there's that.
SECONDLY, you DO NOT need a 4-WAY Front Stage...
"Just Because I Can" is NOT a smart or beneficial approach! Before you do this, why not ask a Professional system installer and DSP tuner such as Nick Apicella, Jeffrey Hald, Mark Eldridge,
@audiophile25, or Jim Becker their opinion on your system design and how difficult it will be to tune? AND how much they would charge to tune it, LOL?
The more speakers you have to time- and phase-align through the crossover regions and integrate overall, the more chances there will be for you to lose dynamic transients & impact, sharp image focus, and excellent linear L-to-R sound stage quality, because each speaker will be in a different location and will have completely different (non-matching) direct vs. reflected energy and more comb filtering and phase issues to deal with.
K.I.S.S.!
The ideal goal is to make all of the speakers in a front stage "act as single point source". The fewer speakers you need to have in order to cover the necessary bandwidth at your desired SPL, the better off you are! This gets exponentially more complex as you add additional drivers to the front stage that all play above the Schroeder Frequency. This is why a lot of carefully-designed 2-way home bookshelf speakers with a good, separate subwoofer will outperform a lot of much larger and more expensive 4-way tower speakers. And a 4-way home tower speaker is much simper to implement because all of the individual drivers are on the same baffle and in ideal enclosures!
THIRDLY, you DO NOT need MW182s in your Rear Doors! Get some good 6.5" pro audio midwoofer/midrange drivers or high-quality 2-way coaxials for the rear doors, such as the Alpine X-S65 or
Morel Hybrid Integra 624 for example.
If you don't have Amplifiers yet, look at the 14-channel
Alpine STATUS HDP-D90 with it's built-in 12-Channel Hi-Res Amplifier. You can get it for substantially less at a local authorized Alpine dealer.
You can run your Front Tweeters + Midrange drivers + Rear Door Coaxials + D-pillar Rear Fill with the built-in 8 x 50 watt amplifier channels, and the remaining built-in 4 x 80 watt channels can be Bridged for your front midbass. (You cannot bridge the Eight 50w channels). Add amps for your subwoofer(s) or a more powerful amp for your front midbass drivers.
The Alpine Tuning Software is actually Really Good. It has an excellent I/O routing matrix and versatile mixer, with automatic source signal switching like the Helix. The mixer functionality is also good for routing and mixing any OEM warning chimes into the system.
And one other really nice thing about the Alpine software is that the GUI window is Scale-able for different display sizes and screen resolutions. You can also use a Touchscreen for adjustments in Windows 10, or the arrow keys, mouse slider, or keyboard to input exact values. And Alpine has an iPad app for this DSP/amp.
It also has a built-in Test Tone Generator and signal RTA.
There's a 10-band Independent L & R
Input P-EQ, and 31-band Independent Output P-EQ (or Graphic EQ) for every output channel. You can do your independent L & R EQ, and then very easily LINK the L & R EQ to apply Global changes to That Channel Pair (or Link as many independent channels as you want), and it will Not Over-ride your original independent L & R EQ settings when you "Un-Link" the channels again.
There is a simple 0
°/180
° phase switch for each channel, OR completely Variable Phase Rotation adjustment for Each Channel.
The channel muting/solo-ing/combining/Linking selection is easy once you learn how to do it.
AFAIK, the only real disadvantage IMO is not being able to import & apply generated EQ Filter Sets from REW. But that may be something that can be implemented with an update.
Yes, it may be expensive, but it is 14 channels at up to
32-bit/192kHz, and loaded with features. And remember that ANY solution that is available that will give you over 12 channels of processing (even at lower bit depth & sample rates) is going to be $$$$, and this also has 12-channels of very low THD & High SNR "Hi-Res" Amplification built-in...and will likely fit under most front seats. That's a BIG ASK.
The following video is a bit old and the software and features have been updated even further since then, but it is a good overview of the HDP-D90's DSP hardware, features, capabilities, and software...
