At the time of the original installation May 1996, part of the system included a center channel. The Eclipse ESG-8220 Ambient Center Channel speaker - mounted on the rearview mirror (picture 6). This worked out good - some of the time... For one, it likes to slip off during SPL or bass demos. I have managed to get the clamps tight enough such that it doesn't actually fall off any more, the mirror just angles such that it looks straight down... Plus, I wasn't totally happy with the sonic response quality. It is very echo-y and hollow sounding if turned anything close to too loud. Plus it only received signal from the processor if the DSP was on. It operated as an "early reflection" rather than a center channel. That's just how it's designed. But I like having it in there, it's an attention getter :-) .
As time went by during the summer of 96, I decided that I wanted to beef up the center channel to help with the sound staging and imaging. I tossed about some ideas and decided that I wanted to add a pair of Rockford Power 3.5" drivers in the center air vents. I wasn't sure how feasible a job this would be but I pulled out the vent (a single self-contained unit) and saw that it looked like it could be done.
I came across a steal of a deal from a friend on a Rockford 2600x amp - she had bought it to use and never did, so I bought it, new in box never used for only $75. Ordered a set of 3.5" drivers. Once they showed up I had Radio Shack install them, I just didn't have the time at that time. Well, they put them in, tapped the signal from the processor from the center RCA output, and put the speakers in the center vent with bass blockers in line.
I got the car back, and wasn't really happy with the speaker install. They didn't flush them down in and the vents didn't work as they had before. There was still airflow but there was no way to close the vent. So I went after them myself one evening after work. Ran lights down to the car and worked well into the morning. I pulled the vent and speakers out and went at them. I got the speakers a little further back into the vent and flushed them lower down in. This left the vents with complete normal operation. Excellent! Plus they are now resting slightly angled forward. I played with tuning the gain on the amp as well and got it set where I liked it. The amp is tucked neatly down under/behind the center console/dash. It's literally between the driver's and passenger's toes. There's plenty fo ventilation because there is about 3" clearance over the amp and vents in the plastic panels right there beside the amp (I'd say look down there for yourself but I have the car ;-)
Well, after playing with things for a while after that, I realized that I wanted two more things. One, I wanted to re-route the signal path to the center. I didn't like having it coming from the center-out on the processor. I got no music unless I was using the DSP, and I really didn't use that much at all. So I rerouted the signal through my center amp. My front amp, the 250m2, has a pass-thru on it. I ran an RCA from that up to the 2600x under the dash. Tweaked it a bit and, man! That made a difference! I had music without the DSP on, so no echo-echo-echo...
Next, I wanted a volume control for the center, too, so I could adjust it for various musics (or off for SPL), without having to climb down and try to get at the gain on the amp. I didn't want a gain control, I could use the amp's, just a variable resistor from zero resistance to full resistance (off). Well, I just picked it up yesterday (11/6/97) and it's a monster! Weighs in just under a pound and has no case. Hmmm... Another mounting project. Well, I think I've already got the place for it, but since the car's about to be tucked away for the winter, I'll probably wait til spring...
As you can see from the last three pics, installation was actually quite easy. I popped out the little piece that rests in front of the head unit. My intention, of course, to put it right in the middle of the little recessed area beside the 12v aux plug. I drilled a hole just barely big enough for the shaft of the volume knob to fit through, pushed it thru, and screwed down the outer nut - REAL tight. Then I just popped the rubber knob back on.
Picture 7 shows the bulk of a volume control that it is. It's a stereo controller, thus two of the big coils. I ran new wire from the 2600 amp between the driver's and passenger's toes to the volume controller and then again new wire up to the speakers in the air vents.
I think it was at this point that I also installed a new set of 3.5" speakers in the center air vents. I put a big piece of poly-foam under/around them (they're kinda nested in it) to baffle them a little since there's no box or chamber for them to work in. Helped MAJORLY! Plus I put higher bass-blockers on them to prevent them being blown.
MAN! Those changes made a whopping difference. The center sounds a lot better being able to use the knob to adjust volume and having the foam baffle in the vent. Of course, the air vents still work as designed!!
Pictures 8 shows the finished knob, and 9 is a closer-up shot. Pretty cool, eh?