My DIY Car Speakers

[sdclc126]

Hey Folks,

I thought I'd share my DIY car speaker project with you...

I wanted some nice but not too pricey speakers to replace the factory cr@p in my '06 Ford Focus, and I also wanted to put them in the factory locations, so I got a pair each of the Peerless 830341 sale ($10.25) woofers and SEAS 27TAFNC/G aluminum tweeters from Madisound.

I attached these to Scosche SA-68 adaptor plates - a direct drop-in replacement for the factory frames. The Peerless woofer was a perfect fit in these - I just needed to drill screw holes - I secured the woofers with basic nuts and bolts but used a little locktite on the threads for good measure.

The tweeters were more of a challenge - again, because I didn't want to cut out any holes in pillars or panels and run wire to new locations, and keep everything hidden away in the factory locations, I had to affix them to the adaptors also. They come with threaded holes on their underside, but I didn't have any bolts or screws of the same thread size for them; being too impatient and lazy to go to Home Depot and search for screws, I drilled holes in the adaptor plates just larger than the raised screw hole section that sticks up from the underside of the tweeter housing. Then I just dropped it into the little hole so that the flat bottom of the tweeter housing rests directly on the adaptor, and with a healthy dollop of JB Weld in between - let's just say they're not going anywhere.

Done after the pic was taken: I decided to cover the tweets with grille cloth to protect them from dust or whatever - I ran a bead of contact cement around the flanges and then stretched the fabric over them, then trimmed the edges - neat.

Now, in keeping with simplicity and economics there was no measuring or fancy crossover design here, especially given the tight spaces I had to work with. Madisound says the Peerless woofers are smooth out to 4.5k and may be used without a crossover - so that's what I did. I put an 80 Hz "bass blocker" cap on the positive lead, but no inductor to the woofers; after the split the tweeters were given 13 uF worth of electrolytic capacitor, providing first order attenuation around 3000 Hz - probably safe for this tweeter, as I don't plan to ever crank the volume to ridiculous levels, even when I get an aftermarket amp put in (factory unit is laughably anemic).

I didn't take any pics of the underside of the units, but the caps & wires were all fastened with thick double-sided tape and zip ties to the plate bottoms or woofer frames - it was actually very simple and easy, and all connections were soldered and covered with heat shrink tubing. Plenty of room for small parts under there but not much for inductors - so none was used.

When it came to actually dropping my custom speakers in the car doors the only issue was the factory wiring harnesses - they're little snap-together plugs. What I did was fabricate little "pins" from paper clips, soldered to the speaker lead wires, which fit quite snugly into the receptacles in the harnesses - I really had to pat myself on the back for that one - right before kicking myself in the rear when I realized I never had to make them in the first place - I only found out after installing them that there are adaptors for those too that have standard quick disconnect leads - but I still have to do the rear speakers so I will use a set then.

Listening impressions? The Peerless, despite their bargain basement price, are quite typical of their namesake, as well as are the SEAS tweeters - by far the most expensive components of the system, but at less than $30 per they are an exceptional value. Overall the speakers are very clean and satisfy my audiophile tastes for mobile sound.

Could they be better? I'm sure a more sophisticated crossover would help, but that is not in the current plans. The main disadvantage is that the speakers are in the doors and far below ear level; this is not so much an issue for the woofers but the tweeters are seriously off axis. A more ideal location would of course be higher up, facing the listener, but again that means cutting panels and I don't want to do that in my car. I can adjust the level on my head unit a bit, and without resistors the tweeters may be running a little "hot" anyway, so there may be some natural compensation built in.

What's next? Well it is a 4-channel system, and though I could repeat the same thing on the rear channels, I'm going to use them for bass only - I don't see the need for four fullranges plus separate sub - I'm the only person who's ever in the car and this will keep things simple and economical. I can't call them subs because I'm only using the 6.5" Silver Flute W17RC38 woofers, but they're the largest drivers that will fit in the factory locations, and they're a good value and I like their 5 mm X-max. I will use simple PE passive sub crossovers for them. No I don't expect to do any serious thumping and bumping with these, but with a compact car I expect they will give me all the bass I need for enjoyable listening.

Any questions?