Thanks! This was my first try at all this.
The Left and Right Channels were easier to set up. The left and right rear doors mostly reinforce and enhance the left and right stereo channel separation. Keeping the tweeters up high also helps a lot, as they tend to be more directional, whereas the lower frequencies tend to be more mono.
Instead of installing some type of center speaker in middle of the dash and finding a matching center channel amp solution, I decided to experiment a little. After bench testing a number of setups I found that two center speakers, one on either side, sounded even richer when playing true 5.1 audio. Moreover, there were already existing mounts in the dash that were perfect!
Most systems are set up to automatically “Fill” these speakers with some sort of reverb matrix and much of the separation becomes blurred unless a true 5.1/7.1 source is played like a 5.1 DVD or 5.1 audio CD. Most 7.1 systems use an additional set of “surround fill” speakers in the side or rear, blurring separation even more. VST Plugins allow me to correctly set all the channels and clean up the blur.
There were only a few true 7.1 recordings so it was really more of a proof of concept even though I did test a SDDS movie, and it really did work. Mostly I use the center mounted Ribbon speakers behind the rear view mirror as 10th Octave Transient Optimized Upstage tweeters via VST to reinforce left and right channel separation locally, so each front seat has optimum stereo separation. I did this by putting them close together, reversing channels, and pointing them to the rear. Because they are very unidirectional only a little “leaks” into the critical listening areas providing the all-important image to the center stage and left and right channels.
With the Ribbons playing down the center of the car from front to back, and the subwoofer playing from back to front, it's like a 3rd sound dimension correctly centered in the middle of the vehicle. The result has been described as an extremely well balanced and pleasure to listen to system.
I went with the Xenarc MDT-X7000 to avoid fabrication and because of the built in Computer CD and the only choice at the time (2009). Even though the reviews were mixed, I took the gamble. It sat over a year in the box before the project got underway and soon discovered an audio problem. They stood by their warranty and even exchanged it for a new one. Again, it took a while to get back to the project and this time there was a ground hum in the CD. Again, they stood by their product and exchange it for a third unit. The latest unit has game and seems more Paul proof. I used it on the bench for almost six months putting all this together before installing it and it has worked excellent.
Knowing it would be delicate and need maintenance like the CPU, my plan expanded to have a backup unit that could be easily swapped in an out. I bought the Nakamichi ND-7 as a backup unit because of the audiophile 5.1 control, and also had to exchange it three times before Woofers etc got it right. Now they are both mounted in the same Metra in-dash mounting kit adaptors and quick connects so I can swap them out in under 30 min.
Following that logic, I did the same for my old class A Sony 4 Channel analog amp so I can now switch from a total digital to total analog system, whenever I want to test out different sound combinations. Mix and Match Heaven...
“Curious…Can you share with us the 7.1 speaker schematics?”
Be glad to share!
Jeep Grand Cherokee 7.1 Computer Audio System
Main Audio Components
Source/Preamps - 2
Xenarc MDT-X7000 VGA/DVD/Receiver
MCS Atom 330 Computer
Amplifiers - 4
Brand XXL-800.8 Marine- 16 Channel x 37.5 Watts RMS @ 8 ohms Bridgeable
Nitro Mini 4 Channel X 50 Watts RMS @ 4 ohms
Pyle Mini Marine 4 Channel X 100 Watts RMS @ 4 ohms
Dual 200 Watt RMS @ 4 ohms Built-In Subwoofer Amplifier
Speakers - 13
(Two Pair) Boston SR-60 Bi-Amp/Bi-Crossover Mini Pro Separates (Thin Depth)
One Pair Boston S35 Center Speakers
One Pair Elite Kapton Ribbons
Dual 12" Dual Bass Reflex 200 Watt RMS Self Powered Subwoofer
Professional Audio RCA Interconnects
EFX HeXaD Litz Type 6 Pro
All exactly 6’ matching cable length runs
OFC Copper Accuflow Frequency Tuned Conductors
Low Profile Rhodium Plated RCA Connectors
Litz Individually Insulated Strand Construction
HeXaD Braid Geometry with Dual Opposing Ground Path
Professional Audio Speaker Wire – 200 Feet
Scosche EFX E2 ES3BL-200 Blue 3mm Pro Litz OFC
OFC Litz individually insulated strand construction
All speaker runs are exactly 12 feet so the load on the amp is exactly the same
All speaker runs are exactly 12 feet for 4-meter wavelengths
All speaker wire runs extrude in the correct direction
The speaker wire is the correct gauge for the amplifier at full load
The speaker wire is the perfect gauge for the length of the 12' speaker runs
The speaker wire is the exact gauge for the speakers at full load
Here are some more pages from the reference manual I made for the system...
What operating system are you using? That is my greatest struggle is figuring out OS/software that works efficiently. I am currently using Tiny-XP with winamp for music and MapFactor Navigator for gps. However, these are only so touch/user friendly and have made me want to look for better alternatives. What would use suggest for a 'frontend'? (I do not want to pay for Centrafuse and since the features are not really that great)
Vista Ultimate so my HTC Tilt Windows PDA CE Pro 6.1 match and do dash screen in screen sync touch with all apps
Same at home so the Bluetooth internet network tether works all around
No apple, android or sys 7/8 alternative yet that does what I can do now...
The key was a great little free program called "MyMobiler" that lets you see and operate the PDA phone screen on the in-dash VGA monitor including sync touch screens. "(mymobiler.com)". I also have a 32gig in the phone with all the music, videos, pictures, internet tether, cell and GPS voice turn-by-turn data. My cell phone is what actually drives the system.
Best part is the full blown smartphone, car and home all sync via Bluetooth whenever I get in or out of the car. After filming fireworks we watched the playback in VGA Hi-Fi the way home...and then finish at home. It’s like having your own cloud.
For the in dash screens I just used a simple background and set all the icons for extra large so they were easy to touch and simple to operate while driving. The fuse snapshoot look comes from a pic I copied and edited using (Slide-Slide) just for fun (wishful options thinking)…
As for music Winamp is ok, but I wanted more. So I setup VST and Virtual DJ with performances.
Guessing OS is win 7 doing by one of the screen shots up above and possibly using windows media center as well?
I have to question... Why would people think 7.1 does not work in a car? Wiring is not a hassle. Balancing is about the only problem that we have come across..
Check out more of the system software used under the “software used” section of my doc.
In answer to your question true discreet 7.1 is only used in SDDS movies. All the other 7.1 systems do some sort of channel mixing. Maybe because most systems just muddle everything up…
With this 7.1 car computer you can control each channel/speaker independently including EQ, time delay, phase, etc. Each speaker in the system also has its own crossover, amplifier and discreet channel assignment. VST software lets you clean up the mess and set up the perfect balance, EQ, phase array and multi-speaker channel assignments including real time spectral analysis. I also like the warm sounding “tube amp” plug-in…
Actually it is a 12.1 system as the 4 Boston Pro Components are all Bi-Amped. The secret is the $650 on 650 ft in the wiring harness, all perfect OFC, Litz and braided 3mm and RCA interconnects. I built all the snakes before installation, all lengths are exactly 12 feet to match the 1 meter audio sound wave, all gauges are optimized for 12 feet and all wire extrudes in the correct direction. All that work made a huge difference in the overall sound quality, almost like a separate high-end component. The first comment people make is how clear and balanced the computer system sounds and feels.
Cables I used...
The Litz wire used in the HeXaD audio cable consists of a number of individually insulated copper strands designed to minimize signal losses. When Litz construction is used with a broad range of frequencies such as the audio spectrum (20Hz -20KHz), high frequencies travel more efficiently on a larger number of smaller strands where low frequencies travel more efficiently over a smaller number of larger strands. Our multiple gauge AccuflowTM frequency tuned conductors overcome this limitation and allow all audio frequencies to pass with extremely low impedance.
Dual Opposing Ground Path Braid Geometry is designed to minimize losses caused by the Proximity Effect. The configuration of the braided conductors is designed to cause cancellation of the Proximity Effect by equalizing the magnetic currents in opposing channels. HeXaD Audio Cables are braided by hand because here is no machine capable of producing this unique design.
Rhodium has a very low contact resistance as well as an extremely high resistance to oxidation making it the ideal material for use on the contact surfaces of RCA audio cable connectors. Because Rhodium is many times the cost of gold, Rhodium connectors are a feature generally only found in ultra high end home audio cables. We chose to use this material because it was the only way to be sure we truly achieved the goals we set out or our HeXaD cables.