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Discussion Starter · #1 ·
A few months ago I made this thread on upgrading the dash speakers on BOSE equipped cars here http://mazda3revolution.com/forums/2014-2016-mazda-3-skyactiv-how-guides/172802-bose-upgrading-dash-speakers-almost-plug-play.html

I finally got to wanting to upgrade the center channel speaker so I took it out to measure the resistance and compare it to the OEM side dash speakers and I was surprised at what I found

So the resistance measured at exactly 3.7 ohms, so any 4 ohm 3.5 speaker should work just fine
The regular side dash speakers measure at 4 ohms, so the center has slightly less resistance

Also, the 'cavity' where the speaker sits in the center has PLENTY of room
Any aftermarket speaker should fit without any modification at all, there is wire below the factory speaker but it easily moves out of the way

My biggest surprise was how small the manget/motor is on the center channel compared to the dash speakers, it's MUCH smaller
The driver itself is bigger in diameter, about the same size as an aftermarket 3.5", but it is still made out of paper material

Then I found GOLD in the Service Manual for the 14" Mazda 3.
I found the page that lists the 'official' specs of the speakers... Unfortunately it does not list what Wattage the speakers are rated for, only resistance
Also, the sizes don't seem to be accurate at all... it lists the front AND back as being 6.5" and we all know that's not true. It also lists all the front dash speakers as just being 3" when you can clearly see the center channel is bigger.

But at least the ohm range of speakers is listed!
Like I said before, my front dash speakers tested @ 4ohms and the Center Channel @ 3.7 ohms
The official specs are:
Front Door Woofers: 1.25 Ohms
Rear Door Speaker: 3.7 Ohms! (should be a perfect match for an aftermarket swap)
Front Side Speaker: 3.4 - 4.6 Ohms
Front Center Speaker: 3.24 - 3.96 Ohms
Rear Speakers: 3.24 - 3.96 Ohms (They are rated identical to the center channel for some reason but they are actually identical to the front side dash speakers)

The center channel is the speaker on the left on the pictures compared to the dash speaker

With this information in mind I may end up wanting to upgrade everything in the car (except the door woofers of course) to aftermarket 4 Ohm speakers
The 2 front dash speakers upgrades have been working beautifully
If I upgrade everything in the car I could have 5 matching 3.5" aftermarket speakers in the front and the back, and then I believe the rear door speakers are 5.25"
From what I'm reading getting a higher wattage speaker shouldn't really matter, it is better to underpower than to overpower a speaker
And resistance is what ultimately plays the biggest role, but since it's so close to aftermarket 4ohm specs it shouldn't be a big deal

let me know what you guys think


327 Posts
I JUST looked at all this yesterday as I was installing my new dash speakers. I went with JL Audio C2-350x and I actually bought 2 pairs as I fully intended to replace the center as well to have them all timbre matched. I went as far as installing one in the center channel and it sounded ok, actually blended really well, but to me not worth the extra $130 (CAN$) for that one speaker.

My guess is there's some EQ / sound processing work at play for that center channel from the Bose amp which didn't yield results nearly as dramatic as swapping the two outboard speakers. In the end after testing for a little while I put the stock center back in and called it a day at that. I'll be able to firm up this choice after a couple of days commuting this week at which time I'll decide if I'm going to go back and try a matching center again. I really doubt I'm going to bother though - so much so that I've already put the second set of JL's up for sale in local classifieds to try and recoup some costs.

Like the front door drivers the stock center also uses a Neodymium magnet instead of ferrite magnet whereas the two outboard dash speakers use ferrite magnets. This has no impact in swapping the speaker, it just explains the small magnet and light weight of the speaker and is not an indication of it's capabilities.

Neodymium Speaker Technology/Automotive/Bose ??

With all that said I can absolutely confirm the center is a standard 3.5" mount with plenty of space inside the dash. No clips to trim like the sides and yes, there's a harness in there that easily pushes out of the way enough to drop a speaker in.
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