Wrapping up Assembly + Audio System - 09/09/2015
My interior work continues but with the added task of building an audio system + more sound control. The elements of the sound system included:
- Headunit = Pioneer DEH-80PRS
- Amplifier = JBL GTO-5EZ
- Mid Range = Zapco ZSL-165 6.5” Component Woofers
- High Range = Zapco ZSL-165 1.5” Component Tweeters
- Low Range = Two 8” Image Dynamic IDQ Subwoofers in a DamonB inspired box
- Sound Control = Lizard Skin SC sprayed interior + Fat Mat prepped doors and most of the interior panels
- Wiring = 90A fused 4AWG Power, Bespoke RCAs, 12AWG speaker wiring
- Extras = PVC 6.5” Speakers adapters for the mid woofers from www.car-speaker-adapters.com
Nothing really fancy. Just a nice mid range system. I’ve never gotten hung up on dollar amounts or anything crazy with car audio. To me a car is the worst place for high fidelity audio, acoustically, so I can’t ever bring myself to spend more than ~$500 on a ‘system’. Keeping the price down was helped when I got the audiophile celebrated DEH-80PRS on a crazy sale about a year ago and I also got the pair of subs for ~$100 shipped. The components weren’t bad either. Speaking of the components, I had a hard time finding options that would definitely fit the slim working space that the RX7 door contains. The Zapcos ended up being the best slim option I could find for the money.
The speaker wiring was done as follows:
Subs = Two Dual 2ohm coils wired as a 2ohm parallel load to the amp. The amp has a subwoofer channel output of 500Watts RMS to a 2ohm load, so that’s the way I went. More than enough to satisfy the two meager 8” IDQ parallel subs.
Mids = 4ohms per channel. The GTO-5EZ sub is a 5 channel amp and my plan was to originally to run the mids and tweeters off of their own channel, but I decided to bridge 2 of the GTO-5EZ’s channels to deliver 150 Watts RMS to each woofer’s 4ohm load.
Tweeter – So I used up all my amp outputs above? WTF!? Haha! I solved this ahead of time by reading up on the DEH-80PRS and finding that in active mode the onboard amp is still powered and the high channel on-board amplified signal can easily handle the Zapco tweeters, so I wired them straight off the headunit.
So the speaker wiring revealed a little secret. This is my first 3 way active system. For those of you who aren’t into car audio…. It’s kind of a big deal ;) Haha! Nah, it just lets me run 3 separate stereo channels with digitally controlled crossovers on each channel. With separate audio channels I can individually configure things like time alignment which is why I didn’t really worry about mounting my tweeters in my A pillars (spoiler). Since the 3 channels allow me to control the respective crossover frequencies digitally I got to drop the clunky Zapco component crossovers and open up the amp for full range on all the channels.
All that just means I get to RCA my mid and sub channel to the amplifier and directly power the tweeters from the headunit. After it’s wired properly, I get to fine tune the TA, EQ, and crossovers with auto and manual adjustments.
