2004 to 2016 Mazda 3 Forum and Mazdaspeed 3 Forums banner

1 - 8 of 8 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter #1
I’m planning to replace all the stock Bose speakers in my 2014 Mazda3. This means a DIY upgrade of all 7 speakers, including some basic noise damping of all the doors. However, this replacement has some key principles. First, I don’t want to replace the Bose amplifier. This means I will have to deal with the Bose amp not sending the full range frequencies to the different speakers. Second, preserve the original wiring, harnesses and brackets as far as possible. For the front and back door speakers I will have to do some serious dremeling and soldering, for the three dash speakers replace the harnesses by spade terminals and produce custom-made brackets for the new 45mm dash corner midrange/tweeters. Third, deal with the resistance/impedance of the stock speakers. Replace all these by 4ohm ones might be a slight problem for the door speakers only, because only these ones have a different impedance of 1.25ohm according to the Mazda 3 2014 manual (all the other ones have an impedance of almost 4ohm).
I’m a fan of Focal speakers. I had them in my previous Mazda6, where they produced an excellent sound for many years. For the rear doors in my Mazda3, I already bought a pair of coax Focal RCX-165. For the center dash speaker there is no affordable Focal alternative, so I bought JBL Club 322F.
Now for my questions regarding the selection of the front door and dash corner speakers.
Q1: go for option A: the combination of coax front door speakers and dash corner midrange/tweeters or go for option B: component ones (front door woofers and dash corner midrange/tweeters) without installing crossover filters because the Bose amp already did the job of separating the lows (front door) and mids/highs (dash corner).
Q2: what’s the cutoff frequency for the front door speakers and the dash midrange/tweeters? This question is important for selecting the dash corner midrange/tweeters in case of option A.
Q3: can the stock system handle replacing the stock 1.25ohm front door speakers by new 4ohm ones and the stock 4ohm dash midrange/tweeters by aftermarket 4ohm ones of will this result in serious balancing problems? That’s because the 4ohm speaker will not play as loud as a 1.25 ohm speaker.
Q4: any additional advice and information?
 

·
Registered
2018 Mazda 3 GT called Coffee.
Joined
·
2,145 Posts
I went to a shop and had an AudioControl LC8 processor hooked up the car and then an Alpine PDR-V75 amp with 4 100 watt outs and a 350 watt out for a sub.

That's hooked up to my Focal 165s flax series 6.5" speakers. Dynamat in all doors.

Sounds amazing.
CK
 

·
Registered
Joined
·
253 Posts
The Bose amp doesn't separate frequencies. The separation happens by using a low impedence driver in parallel with a high impedence driver. It's a cheap and clever way to get a pleasant sound, but it's not for audiophiles. Even of you match impedences correctly, you may still have a volume balance problem because volume is about efficency as much as impedence. Better speakers typically have lower efficiency, which is why they need a high power amp.
Good luck with your project, but there's a reason serious Bose upgrades usually start with a full Bose-ectomy. That said, there's some discussions of good results by replacing Bose speakers at Miata dot net.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #4
I went to a shop and had an AudioControl LC8 processor hooked up the car and then an Alpine PDR-V75 amp with 4 100 watt outs and a 350 watt out for a sub. That's hooked up to my Focal 165s flax series 6.5" speakers. .....
CK
Impressive configuration, but I'm planning an upgrade of $1000+.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #6
The Bose amp doesn't separate frequencies. The separation happens by using a low impedence driver in parallel with a high impedence driver. ....
Could you elaborate on this, because there are several posts indicating that the Bose amp separate its full range frequencies input into an output of lower and higher ones. It is possible to combine the Bose output into full range frequencies (channel summing) or to bypass the Bose amp totally using the head unit signal, but all I want is to replace the stock Bose speakers by aftermarket Focal&JBL ones.
 

·
Registered
Joined
·
253 Posts
Could you elaborate on this, because there are several posts indicating that the Bose amp separate its full range frequencies input into an output of lower and higher ones. It is possible to combine the Bose output into full range frequencies (channel summing) or to bypass the Bose amp totally using the head unit signal, but all I want is to replace the stock Bose speakers by aftermarket Focal&JBL ones.
I haven't seen the actual Mz3 system, but the Bose in my Miata has only to channels. It has a a 2ohm full range driver in parellel with a 4 ohm tweeter, for a combined impedence of 1.3 ohms. I don't know how the Bose amp is equalized, but maybe that's part of it. I think the reason the Bose amp doesn't work well with conventional crossover speakers is that the amp is designed for low impedence and high efficiency, but maybe there's some equalization in the amp as well.
That's all I can tell you. I don't know enough electronics to predict how any particular speakers will work on the Bose system. I'm still hoping someone will report good results with moderately priced replacement speakers, but here's a thread from a guy who got dissappointing results: 2018 Mazda 3 bose equalizer upgrade after replacing dash...
 

·
Registered
Joined
·
8 Posts
Discussion Starter #8
Short update regrading replacement of all the stock Bose speakers in my 2014 Mazda3.
In the first round, I installed three JBL Club 332F speakers in the dash board. The Bose center dash speaker was simple to replace by the JBL speaker (enough mounting depth and corresponding impendance). Replacing the two Bose corner dash ones by JBL's was a bit tricky because of the lack of mounting depth. Due to the magnet diameter, there is not enough space to easy accommodate the JBL's. However, I managed to install them by allowing higher mounting of the speaker ring. In both cases, I cut the speaker wires at the point just before they enter the Bose harness. I connected the positive and negative wire to the JBL speaker based on the Bose wiring giving by oblivioncth in his excellent post 2014-2018* Mazda 3 & Mazda 6 w/BOSE Full System Breakdown/Analysis (thanks!!)

278069


In the second round, I used the wiring scheme from the Mazda Service Manual for replacing the Bose rear door speakers.
278070

In this scheme, there are two possibilities for the rear door speakers, see the bottom left (in stereo) and bottom right (in mono). Although I have a Mazda 5 doors hatchback, the colours of the speakers wires is in accordance with the colours given bottom left. After installing the new Focals, I checked stereo/mono of the rear door speakers and I can confirm it is stereo. A second issue is the size of the OEM Bose rear door speakers. The speaker ring is 16,5 cm (6,5 inch), but the speaker itself is just 8 cm (3 inch).
Last round, installing the front door speakers, is scheduled this week.
 
1 - 8 of 8 Posts
Top