Best Location for Aftermarket Tweeters
 

Hi everyone,
I'm in the middle of installing a new stereo system in my '03 Boxster S. The car was equipped with the upgraded Bose stereo. I'm replacing the factory CDR-23 headunit, Bose amp, and all speakers. I've chosen to do this because of the incompatibility of the fibre-optic driven/MOST bus factory amp with aftermarket head units, and the subsequent incompatibility of the factory speakers with aftermarket amps.

I'm installing a double-din Pioneer headunit and a 4-channel Alpine amplifier. I'm replacing the 5.5" drivers in the rear Bose enclosure with the same size of speaker except in the correct ohm rating for my new amp. I'm abandoning the small 3" mids in the enclosure. Up front, the upper dash co-axial speakers and door mounted subs will be replaced by a set of Infinity kappa series 5.25" components. I will mount the woofer of the component set in the existing door enclosure in place of the Bose 5.25" speaker. The upper dash speakers will be eliminated.

My question is where would the best spot be to install the component tweeters. I know I'm changing around the sound stage by eliminating the mids in the rear speaker box and the upper dash co-axials, so I want to ensure that I put the tweeters in the best spot for balanced sound.

I was thinking about 3D printing a panel for the tweeter and placing it in the spot once occupied by the upper dash speakers. But I'm not sure if this will make the sound distorted because it relies on reflection off the windsheild or too 'bright' because a closer proximity to the listener relative to the lower mounted speaker in the door.

What is your experience and recommendations?

Thanks.

(I also posted this on Rennlist)

First, congrats on your decision to eliminate the upper dash speakers. Even though I kept mine, they are turned down so low that they are basically inaudible. The dash is not a good place due to the echo and resulting increased harmonic distortion.

For tweeter location, my experience is that the best location is where you can get the most distance and still be line-of-sight. This will usually be the A-pillars or the kick panels in most cars. In the Boxster it's the kick panels. There is a very good video from Car Audio Fabrication that explains why this is so.

Check out my post on how I did this. It's a very simple and easy install for the tweeters and they sound great. It's virtually impossible to localize the sound. You just hear a wonderful frontal image.

Thanks for the reply!

So your advice is to mount the tweeters in the kick panels rather than in the door panels or in the upper dash?

Our setups seem pretty similar. I'm actually using the same Alpine amp as you and running the wiring to the speakers through the factory wiring, after de-pinning from the amp plug. How did you end up mounting and securing your amp?

Here is the Pioneer AVH-X2800BS mounted. I used the new Metra 99-9605B mounting kit, which also includes the parts to relocate the HVAC to the lower panel. I believe I may be one of the first to get this kit, I hadn't come across it at all in my research and I think it was released only in November. Although it had a minor scratch when it arrive in the package, overall I'm happy with it. It fits well and I think it looks great:

http://img.photobucket.com/albums/v5...psouacbp4z.jpg


Here is the driver's side woofer of the Infinity Kappa 50.11cs mounted. The original Bose speaker had three mounting bosses so I needed to dremel out the opening to accept the larger speaker basket. I applied a thin film of silicon sealant to seal the back of the speaker to the enclosure, and also filled in a few gaps with the same sealant to make it air tight.

http://img.photobucket.com/albums/v5...psalj7cv3u.jpg

As I mentioned, I removed the original Bose woofers from the enclosure and replaced them with a pair of Dayton Audio DC130B-4, which only cost $28 each. They are wired in parallel and I'm going to be running them from the rear bridged output of the 4 channel amp (effectively making this a three channel system). I needed to notch the mounting holes since the mounting PCD of the old speakers was a big bigger than the new ones.

Dayton Audio vs. Stock Bose:
http://986forum.com/forums/uploads02...1487640960.jpg

Mounted:
http://986forum.com/forums/uploads02...1487641002.jpg

I'm about to do the same exact retro as you, only with an '04. I was planning on getting the Avic-6300. Still trying to decide on the Amp. Which installation kit and harness did you order? I thought you could still use the Bose speakers. I've read others have used the Bose speakers and they sounded great.

The Bose speakers are a weird impedance so they won't work with aftermarket amps or wired directly to the new head unit. Plus one of mine was blown anyway.

I used the new Metra installation kit which I mentioned in my previous post. I'm pretty happy with it. I also used the Metra wiring harness, but found that it wasn't really necessary since there are so few wires you can actually get from the factory radio plug. If I did it again I would have just taken ground, constant 12v and switched 12v from the likely unused telephone connector, which is where I had to take switched power from anyhow.

Illumination wire was tapped into from the back of the cigarette lighter. I wired the factory antenna power and amp turn on to the switched 12v output off the back of the new deck. I'm using the existing white/red wire in the factory harness as an amp turn on.

hmmm, interesting. How did you fish the wires from the HU to the Amp?

To mount the amp, I just slid a piece of plywood behind the carpet with double sided tape, and screwed the amp to the plywood. Once the carpet is buttoned up, it is very solid.

Also, I'd suggest putting your tweeters on extra long cables and auditioning them in various locations before you commit yourself. The kick panels are the best in my opinion, but it may not be for everybody.

Another tip, I also used a Metra wiring harness and the red and orange wires are reversed. I think it's the same for everyone.

Your system is looking great so far. Nice job!

There is a nice big unused grommet which you can only see once you pull the battery out. It feeds directly under the dash above the accelerator pedal and to the left of the HVAC duct. I ran 3x RCA pairs through it.

I added my component tweeters to the doors. Sounds great in this location.

http://i66.tinypic.com/16440j.jpg

http://i63.tinypic.com/uaf4m.jpg

Great looking system you have there. Very professional. Did you manage to squeeze your crossovers in the doors?

B6T, is there anything you had to do to extend the wiring on the HVAC controls when you used the Metra kit? How straight forward was getting the controls lower?

No there is enough length in the factory wiring to reach down to the lower console. Keep in mind, some cars came with the HVAC mounted in this position, so they had to design the wire harness to accommodate either position.

Fishing the wire down there was a bit of a challenge though.