Originally Posted by dgage View Post
The problem youíre going to have is the Bose amp includes digital signal processing to make the factory speakers sound better and to address any issues with the car as a car isnít a great environment for quality audio. So if you add a speaker using the OEM Bose amp, it may sound worse. Also, you may lose some volume if the speaker you choose is less sensitive (needs more power for same output). I hate to say it but it would be a crap shoot as to whether it will turn out well, even if you use known good speakers.

I understand what youíre wanting to do but I would caution you that your results might turn out worse. If you decided to move forward with adding an amp and speakers (bypassing the Bose amp) that is what Iíd recommend as youíll actually have some control of the results. Youíd start by adding a JL Fix or similar, which takes the signal from the factory Bose system, uses digital signal processing to restore the signal (remove Bose DSP) to flat (or desired curve), and then feeds that signal to amps for speakers/subs.

And a wideband speaker is one that tries to cover the midrange from say 300/400 Hz up to say 15,000 Hz. Meaning it tries to cover the midrange (but not lower midrange/midbass) as well as some of a tweeter. Some like it and say they donít even need a tweeter. But this is a very wide frequency range and most would rather have a tweeter and midrange as then you donít miss any frequency coverage like a wideband usually does on the top end. And if youíre going to use a tweeter, why not just use a normal midrange, no reason at all for a wideband.

This is a copy and paste from rton20s in another post:

I noticed the same thing and I talked to Joe McCabe about it. (He has worked on similar Bose systems, but not the Mazda 6.) This is what he has to say...

"The amp will have Dynamic EQ which is the Bose version of loudness restoration. It uses a input level detector so it is constantly changing the amount of low frequency boost, based off the strength of the input signal to the amp. This means that the volume knob position has NO effect on the amount of boost!!! Obviously turning the volume up will reduce the boost but a set and forget approach won't take into account this aspect."

"First upgrade the loudspeakers, and then add more power to them. Use the Bose amp as a built-in DSP in that scenario and it has loudness in the Bose amp as well. If you need below 35-40Hz, then yes, tapping into the system between the H/U and amp should provide for this."

Just wanting to upgrade the dash drivers is my thought for now. Something efficient, warm and with some range. I have seen somewhere on the world wide web a Bose pdf that breaks down what each driver in the system is. It gave size, impedance, & I think efficiency. Don't recall if it had frequency response... I'll have to try and find and post it and maybe we can come up with something.