Hello Again to All. Well having changed the door speakers and rear 6x9's with Alpine Type S, I was pleased with the result. However, being a basically discontented individual, I had to add an amp. I happen to have an older Alpine 3555 (50x4 RMS) and an 8" JL Audio Sub in a bandpass box amp and installed it. In the process I have learned that the front doors receive a different signal than the rear doors. Ok...so here it is:

The front doors have a slight roll-off of the high frequencies and a boost to the bass. I believe Acura did this because of the front dash tweeters and to give a slight bass boost in the front.

The rear doors appear to have a high pass filter and the bass rolls off somewhere around 100-120Hz as near as I can tell. Accura probably did this because of the rear 6x9's receiving only bass.

The rear deck is alow pass and apears to be frequencies below 100 Hz.

I did get the amp installed using line level converters off the front and rear door speaker outputss. I went crazy trying to figure out how come the sub would not light up off of the rear channels then the above observations hit me.

So..here is what I did. I used a tri-mode crossover off of the fron channels of the amp (PAC TM-100) to provide stereo output to the front doors and a bridged output to the sub off of the fronts. The PAC TM-100 crosses over a 100hz 12db/octave, so the front doors recieve frequencies above 100Hz @ 50 watts/channel. The sub recieves a bridged output below 100Hz @ 150 watts. Off of the rear channel. I am running the 6x9's and rear door 6.5's in parallel providing aprox. 75 watts per channel.

The result?.........WOW!!!.

 

so let me ask you this... BEFORE you did this and added ur amp to the system. You had both a set of coaxes in the door and a set of coaxes in the rear deck (all type-s speakers) did you ever feel like the system was "Rear Heavy" that is it seemed liek the rear had more sound coming from it than the front? Its the reason why I want to just add the 6x9s and just disconnect the rear door altogether because I'm afraid that the rear will be too loud. Btw I've also decided to go with Type-R's in the front powered by a small MTX amp. and to have the rear deck type-s's off the stock amp... I'm afraid to have the rear door's also intalled with the stock amp because i'm afraid that the back is still going to outpower the typeR-s in the front... and under NO CIRCUMSTANCES WHAT SO EVER should the rear be louder than the front of the sound stage. (i dont know much about car audio but that i know for sure)

But i'm starting to think taht since the front type-R Components are gonna be external MTX amp powerd; taht even if i keep both the rear door type Ss and the rear deck typeSs that it shouldn't be louder than the front because i'm still going to run those off the stock amp...

What are your thoughts?

 

Not at all....it sounded really good before I amp'd it. not rear heavy at all...quite balanced. I wanted to expand the stage by giving the speakers more power to play with. Plus, with the 4 channel amp, I addressed the issue you raised with the gain controls. I really like the type R's. The magnet size and depth scared me away. The type S 6x9's magnet comes within a 1/4 inch of the trunk torsion bars in the trunk and I was worried that the Type R magnet would interfere. I really like the Type S (not as much as the type R's) and the amp really lights them up. Ironically, the Type S has a significantly broader frequency response than the Type R's; however, the type R's tweeters are nicer.

 

ps- based on your findings of them recieving different signals I am thinking that its even MORE of an incentive to do go ahead and still keep the rear door type s coaxes (instead of d/c them alltogether for fear of them overpowering the front) beacuse the kind of sound i'll be getting from em' wont be the same as the 6x9's up in the deck OR the Type-R components in the front.

thoughts?

 

It's all a matter of taste. In my setup I have the flexibility to fade everything to the front and then have the front door 6.5's the sub and the dash tweeters. Or, I can run them all for that "sitting-inside-a-par-of-headphones" experience. for critical listening, fading to the fronts set's up a nice stage.

 

Silver,
Regarding your type-s door installation:
1. Did you have to do any cutting?
2. Did you have to use spacers or did the magnets clear everything in the back?
3. Did you use the stock grill, and did you have to modify them at all?
Thanks

 

The alpine Type S required no cutting at all. They came with a mounting bracket that I used but there was no danger at all of anything clearing. The trunk torsion springs are close when closed but even there no problem. The Type R's I would think would require some cutting.

 

Any idea if the signals are different both before and after the factory amp? That is, is the amp the Xover and EQ, or is the head unit doing that at the preamp stage?

thanks!

 

While I would not bet my TSX on it (I might bet yours though lol) it seems that the EQ and crossovers are handled by the amp. I am saying this only because I read a thread by a panasonic engineer that worked on the new TL system, and, he said the EQ and crossovers are burned into the amp circuitry for the new TL. I would suspect that Acura had Pioneer do the same thing for the TSX.

 

The fact that the x-o's are in the amp, and that the 6x9's are old info. The sound comming out of the cd player is 4 channel, full range, and RCA level. If you search or look around, there is a ton of info on this.

I will not swear that the eq is also in the amp, but from an oem design, build, and cost point of view it is logical.