QuestionI have a 2008 Mazda Miata (2-seater) with a retractable hardtop that came with their terrible Bose stereo. I've already replaced the head unit (Kenwood DNX5120), and I’m planning a rip and replace on the door speakers and amp.
I drive this car top-down 99% of the time. My goal is not perfect imaging, but good sound quality at sufficient volume to be enjoyed even in a louder environment (such as on the highway).
I've decided on 2-way component speakers from DLS (the UP6i). This is a 6½” woofer and 1” tweeter with external crossover, and will be installed in the factory door locations. I haven’t bought an amp yet, but I’m considering an Arc Audio KS 300.4 (4 x 90w). I'm putting a Blaupunkt powered subwoofer behind the passenger seat.
My question is concerning the rear speakers - they are about shoulder height between the passengers. There are differing opinions among Miata owners on the value of using the rears in this car. Given my main objective of good quality sound with the top down, I think that while the rears might detract from the imaging they would more than make up for this by adding to the overall sound level (especially in a noisy environment). I could always fade them out the few times I’m driving top up.
My two choices for replacing the rears are the DLS UP1i, the same tweeter that will be in the doors, or the DLS UP2.5, a matching midrange driver. I can set up the amp to control the frequency range that they receive.
Am I better off with midranges or tweeters in the rear? Thanks for any help you can provide!
AnswerHi Patrick,
Between the two speakers, I'd choose the midrange driver for the rear, if only because its listed frequency range covers a much wider range of sound. I can't imagine a set of tweeters alone in the rear being anything but a distraction; they're designed to play only the frequency range of 5kHz and up, and there really isn't very much of the musical spectrum that falls into that range. (Of course, given the proper passive crossover filters, and a place to mount the tweeter, you could install both driver sets in the rear). The UP2.5, with a frequency range between 500Hz and 5000Hz, would be able to reproduce a lot more vocals and instruments.
The UP2.5's owner's manual includes a schematic for a simple bandpass crossover filter, including a resistor, inductor and capacitor. The amp you've chosen has a pretty flexible crossover which can take care of the high-pass filter, and because you can adjust the level through the amp and head unit, you don't really need the resistor either. That means the only crossover filter you might need is the low-pass filter, to cut off the driver's output on the high end of its range. I doubt it would hurt anything to leave this filter out, but if you decide you want to cut off the driver at the manufacturer's recommended 5000Hz, you'd just need to place the recommended inductor in-line on the speaker wire.
Hope this helps!
Brian
