cpt_koolbeenz

Anyone that knows anything about sound staging knows that the rear speakers should not come in to play when designing a quality sound system. With that said, the only way to improve the SQ setup in our cars is to fit a competent component setup in the front. Opting for 5.25" components as opposed to 6.5" is a viable option for our cars. While 6.5" offers much more as far as audio is concerned, I determined 6.5" would just be too much up front to make fit without proper kick panels.

I chose a component set from CDT - CDT HD-52's. They were a little too deep to fit in the doors, so I made a spacer out of 3/8" plywood. It positions the speaker properly while covering the stock hole. It requires a LITTLE cutting of the door... Not a big deal with a Dremel.

Here is my template for the spacer. It is a 100% scaled image. If you print it out at 100% it should be the proper physical dimensions (Photoshop works well). I have not gotten pics of the install yet, but they will follow shortly...

NOTE: The zip file has the correctly sized image for making a template, the other pic is just for looks!

Supachink

looks good, i ended up getting a set of infinity kappa components from a member with his spacers, they ended up working out pretty well on my early car. Sound staging could be better, but I stuck a pair of 6.5 mid basses in the rears and a 10" kicker comp vx in the hatch for a lil bass. Dont know how much i like all the amps and stuff in the car, thinking about ripping it all out now that its done... lol

billthe3

Ok, why is there not supposed to be any sound from the rear for proper sound staging? The stereo sounds like crap when there is no rear speakers. And all home and theater stereos are surround sound, so its not like they only have speakers in the front.

cyinisis

I don't really get the lack of rear speaker planning either...the fact that in the 944 both of the front speakers face each other makes a negative stereo field...which emphasizes high frequencies, but absolutely kills lows...

Planning for speakers in the back, and the fact that they usually face parallel to each other eliminates cancellation of frequencies, which drowns out highs, and boosts lows.

So in my opinion, planning for all speakers would make for the most well-rounded sound system.

wolfenstein

use mdf instead of plywood
the only reason for rear speakers would be for rear fill
when you listen to a band etc. they are generally in front of you-hence "sound stage"
sub placement doesn't matter it's a low frequency non-directional sound
fwiw i used diamond audio 6.5 components that had a place on the cross over for rear fill
i used 1 8" rockford fosgate sub in a custom mdf enclosure in the rear cubby
sounds really good-imaging was very good as well-not bad considering i didn't build custom kick panels

cpt_koolbeenz

The problem with the concert or similar excuse for using rear fill is that the music is recorded in 2 channels. Time delayed cues and reverberated/reflected sounds are incorporated into the 2 channels. They are recorded to be output from these 2 channels (front to back). If you put rear speakers in, they are reproducing the same output as the front, which are supposed to contain front to back cues (along with all of the spatial cues). Now these spatial and front to back cues are being output from more than 2 point sources (front speakers and rear speakers), essentially changing the original sound stage.

the natural echoes and ambiance are recorded into the cd in 2.1. The echoes across the hall are already in the cd. Having that come from behind you isn't' helping, even if it somehow did, your still missing the fact that all the other sounds that ARE supposed to be only coming from the front no longer are. You have a confused sound stage with no real depth or imaging cues anymore. In 2.1 there is no front or back differentiation on the cd. Therefore, to reproduce it as intended, you need 2 channels, just in front, adding more WILL make it incorrect.

The best way to reproduce stereo would be with 2 speakers, unfortunately 2 speakers can't handle the bandwidth reproduction so we use more. Rear fill should be avoided.

(Post compiled form various examples of sound staging discussions)

cpt_koolbeenz

The interference of sound waves in your car has everything to do with wavelength, period, distance, and geometry. It is nearly impossible to tell what frequencies will cancel or superimpose inside your car, or where. The statement "drowns out highs, and boosts lows" makes little sense because both high frequencies and low frequencies have equal probability of canceling or superimposing given infinite time and modulation. Unless I am missing something, I don't agree with that logic...

cpt_koolbeenz

Finished product...
I countersunk 3 8-24, 1.5" carriage bolts into the wood. The top two fit into the stock speaker mounting holes. They attach via wing nuts on the other side. Now to install the setup!

cpt_koolbeenz

All Done! Last pic shows proof the window still rolls down all the way...
Sounds pretty good... Need a sub!

gregeast

Don't know what they sound like but they sure are pretty. Good work Chris!

danny951

Nice work. I would have suggested placing the tweeters down with the woofers to help with the sound stage. Them being at the top of the door means that the one on the left is much closer to your ear than the one on the right. Putting them both further away reduces this some. Otherwise, very nice looking finished product.

cpt_koolbeenz

Thanks guys...
I was thinking about that danny. I may get some image tweets to help with that. I only have one side in right now, so I cannot tell what kind of mess I have made. I may have to take the tweets off to paint them black. Not sure why they decided to change their color.

86 951 Driver

Old bump anyone else do this mod?Looks to be a really good clean one.

Richgreenster

That actually looks great. Nice job.

sparkyman215

I'm in the process of doing something very similar except I will be mounting the tweeter low on the door by the woofer and am using shallow 6.5" components instead of the 5.25. The speakers should be arriving Tuesday of next week and I am hoping to be done with the project by the end of the month. If it ends up looking the way I want it should look pretty nice and will post up pics.