G8rboy

That's a very good point... one that I ran into myself with this box. When it's pushed all the way towards the rear seats, it's very snug top-to-bottom (I measured it to fix exactly in there), so it's held in place by the rear deck (and 6x9's). I did however slide it out to see what the sound difference would be in the middle of the trunk, and did exactly what you did, but fortunately my ground wire snapped at the ground point when the box rolled backwards, not at the amp. I would still feel better if I had some straps holding it in- something I'll look into.

G8rboy

Me again- this weekend I decided to tap into the line-level pre-amp inputs coming from the head-unit instead of the amplified speaker-level inputs I had been using. Part of this was just an experiment to see what the difference was between high and low level inputs as it would relate to a amplified sub box, but I also wanted to use the Bose AudioPilot feature again. When using the speaker level outputs, AudioPilot did some weird stuff with the bass signal- modulating between extreme bass and no bass when below volume level 10.

Anyway, below are some pics that should help anyone tap into the headunit's pre-amp outputs... I took the information from the Mazda wiring diagram as well as eXentric and Rotarygod's post regarding this subject and it did indeed work for the rear line-out. I like this option as you can use the fader if you need to dramatically reduce bass (i.e. kids in the back seat), as well as fine-tune the bass level.

As always, email or PM if you have any questions...

G8rboy

Here are the connectors removed from the rear amplifier:

G8rboy

After cutting back the electrical tape, here are the two wire bundles carrying the rear signals:

G8rboy

More pics of the wires to tap. I use these wiretap connectors since they're easy to use, carry a good signal, and can be removed if necessary and returned to stock with little problem.

G8rboy

oops... here's the pic

G8rboy

The connectors snapped back into the amp and the new wires bundled up with wire ties...

G8rboy

Slightly different topic, but here is my ground point- after removing the spare tire mount, I was left with holes and bolts on the right and left of the speakerbox- this one provided a perfect grounding point for the amp:

G8rboy

Lastly, here is a pic of the speakerbox with cleaned up wiring using the pre-amp inputs...

emailists

did you notice and sound difference using the pre's as opposed to speaker level?

G8rboy

Yeah- the bass seems to "blend in" better with the rest of the speakers. With speaker level inputs I had to adjust the bass level more often depending on what kind of song was on- might sound good with rap, but overwhelming with rock... so I was doing more adjusting to keep it optimal. Now with line-level it sounds more natural with all music, and I just crank up the Bass gain for rap/hip-hop if i really want to feel it in my chest. And I can use AudioPilot again, which keeps me from playing with the volume so much.

rotarygod

As an experiment I wired up a line level converter to eXentric's car to see the difference. The line level adapter was actually not as loud as the way I originally did it. Consequently it is back the other way, tapped into before the amp.

G8rboy

Rotarygod- The pre-amp output coming from the head unit is standard impedance and phase wiring, correct? Any idea if the rear Bose amp changes that to something proprietary or non-standard?

After driving around for a couple days now with the line-level inputs driving my sub amp, I'm definitely much happier with the overall sound from the system.

-Sean

mlino01

Yea buddy that's nice I want to do something similar.

Neep

That's actualy something I've been wondering too. I've tried a breif forum search to see if anyone else had the answer, but so far found nothing.

I don't yet have an RX-8, but plan to and am wondering if the premium sound system has a different output than the standard level. I want the premium, but I want to be able to throw an amp and subs in the back, however I have a book that states some factory premium level sound systems (like those from Bose in Fords) are designed for a different impedance level, and are resistant to modifications. Is the RX-8's sterio one of these?

Forgive me if my questions seem ignorant or stupid, but I've never actualy modified a sound systme before, so I'm learning here.