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Discussion Starter · #1 ·
Hello everyone.

I have a base 2014 MDX. Over the weekend, I was able to replace the rear door speakers and stock subwoofer. I did not touch the stock amp nor do I have plans to upgrade it.

I'm stuck on the front doors mostly because of how to wire the aftermarket crossover. I bought a set of components. I'm having trouble understanding the connections since my understanding is that there are/is capacitor(s) to block out unwanted frequencies (high/low) that come stock with the factory stereo.

My biggest concern is that each speaker (woofer/tweeter) has their own capacitor (in-line blocker). If that's the case, the full audio range will not even make it to the aftermarket crossover. Unless the capacitor is on the speaker itself, then that makes it easier.

Here's a few ways to go about it. I'm leaning towards #1. Even then, would I lose some power from the amplifier since I BELIEVE the power will now be tapped from the main speaker and eliminate the power going to the tweeter with the stock setup?

Please state which way is BEST and WHY:

1) Connect door speaker wire to crossover. From crossover, go to each individual speaker (woofer/tweeter). Cut and eliminate stock tweeter.

2) Swap door speaker. Only use crossover for tweeter.

3) don't use aftermarket crossover at all and just replace speakers.
 

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In a traditional "passive" analog crossover to tweeter, midrange, and woofer components there would be "high-pass" and "low-pass" filters that are analog circuits consisting of capacitors, inductors, and resistors. That's probably what is in that aftermarket crossover. But those signal filtering functions can also be accomplished digitally, and I suspect that's exactly what is done in the headunit of the current MDX. Also, there would be little benefit to additional amplification of the tweeter signal since it requires very little power. So I suspect the tweeter speaker wires come directly from the headunit, and the door speaker and subwoofer wires come from the outboard amplifier in the passenger footwell. None of which really matters if you are using the stock wiring cuz it all gets mashed up in wiring looms scattered throughout the vehicle. But as you were implying, there may be no opportunity to capture the full-range "front" audio signal outside the headunit.

If you see analog circuits on the front door speakers when you pull them, call me a liar.

But assuming I'm not lying, I say #3 replace the speakers and don't worry about the crossover.

If you wanted to go high-end and fine-tune the frequency response to the interior of the vehicle, you would want to worry about the frequency response of the the individual component speakers and cross-over frequencies, and roll-off slopes, and all that. But if you just want cleaner sound without a lot of fuss, you can just replace the drivers and use the crude "tweeter" and "woofer" digital adjustments in the headunit settings.

But be aware that high-quality drivers ( speakers ) may be less efficient than the stock drivers, and if you want to "crank it", you may need additional amplification.

Keep in mind I haven't dared to dig into the audio hardware of my wife's 2014 MDX, so this is a purely theoretical analysis...
 

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Discussion Starter · #3 ·
Thank you for the response Wanderlust.

I wanted to add that I called Crutchfield to get some advice from them. According to their diagrams, the woofer and tweeter are NOT in parallel. They actually have their own channels coming from the amp (but possibly the tweeter is coming from headunit like you suggested).

The rep was able to verify that the door woofer gets full range frequencies, so the ideal way to hookup component speakers would be to connect door speakers wires to crossover and from there split up to woofer and to tweeter. I would have to fish the new tweeter wire through the door jamb boot, and then simply disconnect and tape off the original wire connected to stock tweeter.

Now that I have this info, I'll tackle the project in the next few days and report back.
 

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Discussion Starter · #5 ·
So the crutchfield rep is saying both the separate tweeters AND the front door speakers get the high frequencies for the "front speaker" signal? Interesting.
Pretty much. Front woofer gets full range and the tweeter has a bass blocker (in-line capacitor). I'll test it out by connecting the crossover and corresponding connections to the door speaker wire. If both new speakers produce the correct sound, then it's fine.

I'm making time to work on it on Friday morning. <fingers crossed>
 

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OK. Found something. High-pass filter ( capacitor ) is mounted to tweeter. So full-range signal is sent to both tweeters and door speakers.

You wouldn't want to feed the full-range signal to a replacement tweeter, so use aftermarket crossover at front door speakers and fish new wire to tweeter, as Crutchfield says. Or wire up an appropriate high-pass filter at the replacement tweeter. Unexpected, this is...

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For what it's worth, that's exactly the way it is on my '03 as well. The wires from the front amp go to the door speaker, and a second set of wires is spliced in at the speaker connector which feeds up to the tweeter. No crossover in place, just full range to the door speaker and tweeter with filtering done at the factory tweeter.
 

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Discussion Starter · #8 ·
So I worked on it this morning. Pretty straight forward. The tricky, time consuming, part was fishing the tweeter wire through the door boot. Luckily there's space below the molex, so I didn't have to modify anything.

The only issue I'm having now is removing the A-pillar trim piece. My understing is that it's just clips, but it just won't pop off. I'm a little hesitant to use more force because of the side airbag that's tucked in there. Anyone have any experience with the
a-pillar?
 

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The gray plastic piece near the top of the a-pillar is actually a cover you can pop off to reveal a bolt and washer that secures the a-pillar trim to the chassis. After that, then you can pull. Even if you ruin it in the process, the a-pillar cover is only about $25 and the clips are $2 each (forgot how many, but i think 3 or 4). The airbag isn't attached to the trim, but instead the chassis, so don't need to really worry about it.
 

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Discussion Starter · #10 ·
Thanks Neoshi. I just finished watching a video from a Range Rover, and it was the same as you described. Pop off the cover that says AIRBAG to reveal a securing bolt.

I'm going to finish that side along with doing the full job on the other side. So far it's sounding great. I cant wait to finish!!
 

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Apparently, I am a poor prognosticator, because most of my predictions were WRONG!

Front tweeter signal comes from the outboard amplifier, not the headunit.

Front tweeter signal is full-range, but there is a high-pass filter attached to the OEM tweeter.

Front door speaker signal is full-range and comes from the outboard amplifier.

Back to raking leaves. I predict there will be more. ( But if I'm wrong, that's OK! )
 

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Discussion Starter · #13 ·
Apparently, I am a poor prognosticator, because most of my predictions were WRONG!

Front tweeter signal comes from the outboard amplifier, not the headunit.

Front tweeter signal is full-range, but there is a high-pass filter attached to the OEM tweeter.

Front door speaker signal is full-range and comes from the outboard amplifier.

Back to raking leaves. I predict there will be more. ( But if I'm wrong, that's OK! )
Yes, you are correct about everything. It's 4am here and I just got back from taking it for a spin after working on it for 3hrs. Everything is done. Sounds great. Highly recommend the swapout. I'll include the details of the speakers later today. Time for sleep!
 

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Discussion Starter · #14 ·
Here's a quick list of what was installed. I bought everything through eBay. Cost was about $225 and I performed all the work on my own, so I saved quite a bit. The rear doors were extremely easy. The subwoofer required me to remove the cargo "trap door" along with the side panel. The front doors were the most time consuming, but the most rewarding as far as improvement in sound clarity. The subwoofer was also a nice improvement. It sounds more controlled, tighter, and with little to no distortion. The subwoofer encloser required a tiny bit of modification. The inside had plastic "fins" on one side that would prevent the sub from sitting centered in the opening. This would leave a gap on one side...not good. Once I cut away some of that plastic, it was all good. Another tip, be careful with the speaker terminals. On one of the rears, it was touching the metal edge of the opening. This would cause it to work intermittently. Oddly enough, both rear doors AND sub would stop working. I guess that part of the amplifier was shutting down automatically for safety. I had to turn the speaker upside down to avoid the weird edge shape on the bottom. No biggie. Like I said, everything sounds great. Speakers are 3ohm, an de I didn't notice a drop in volume compared to the stock setup.


Front components (door woofer and tweeter):
Infinity Primus PR6500cs

Rear speakers:
Infinity Primus PR6502is

Subwoofer:
Pioneer TS-SW2002d2

Speaker adapters (4):
HSB524

Speaker harness (4):
Metra 72-7800
 

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If both the front A-pillar tweeter and the door woofer are powered from the same audio amp, why not just install the passive crossover that comes with the component speakers at the amp, using the amp woofer out for both? It would save a lot of hassle trying to run a wire from the door to the pillar. Am I missing something?
 

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So the stock subwoofer has a dual voice coil? Your replacement subwoofer does so I am guessing that is the same but would like confirmation.

Did you consider putting in sound deadening while the speakers were out? That seems to be a popular option but I have no experience with the results.

I appreciate your posting about this. There was another thread that described putting the same speakers that you used in the rear in the front as well, which seemed to me would create a lot of high freq's. This is a better approach IMHO. If I can mount the crossovers at the amp that would make it a very clean installation.

Thanks again,

Greg
 

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Discussion Starter · #17 ·
If both the front A-pillar tweeter and the door woofer are powered from the same audio amp, why not just install the passive crossover that comes with the component speakers at the amp, using the amp woofer out for both? It would save a lot of hassle trying to run a wire from the door to the pillar. Am I missing something?
I guess that could have also been done. I never checked, but I'm pretty sure there's a molex plug coming from the amp. You'd have to get a wiring diagram to make sure you tap into the right ones. Also, not sure if it's recommended to have the crossover as close to the speaker as possible...not sure where I've heard that.
 

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Discussion Starter · #18 ·
So the stock subwoofer has a dual voice coil? Your replacement subwoofer does so I am guessing that is the same but would like confirmation.

Did you consider putting in sound deadening while the speakers were out? That seems to be a popular option but I have no experience with the results.

I appreciate your posting about this. There was another thread that described putting the same speakers that you used in the rear in the front as well, which seemed to me would create a lot of high freq's. This is a better approach IMHO. If I can mount the crossovers at the amp that would make it a very clean installation.

Thanks again,

Greg
Hi Greg. Yes, stock 8" woofer is dual 2-ohm. The Pioneer sub was a direct replacement with the two sets of terminals.

No, I didn't bother with the sound deadening. With the Infinitys, the highs are pretty bright. I had to turn the treble down a few notches. Sounds nice and clear now.
 

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Discussion Starter · #19 ·
The BIG question I have now is how the amplifier between the base, tech, advanced packages compare. My understanding is there's a bump in power between the 3 trim models. If all the connections are the same, and it's more or less the same footprint, it would be a direct replacement.

I'd love to get a hold of one of those amps. I'd much rather use a stock piece over any aftermarket amp. Any thoughts on this?
 

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Have you considered upgrading the center dash speaker as well. IIRC it is 3.5". Sonic Electronix on eBay sells a pair of Infinity Reference 3 Ohm ones for $50 delivered. That should give better spatial performance. If you want to go that way we could split one pair: $50+shipping for mine/2 (or I could order and you pay the same)?

I wouldn't worry about the amplifier. The Tech version has something like an additional 25% more power out, and it is powering an overhead speaker in the back so it has a different connection. Hearing is logarithmic, which is why things are measured in dB (deciBells). You would barely notice the additional output even if it were available to your speakers, and it may not be (it may be for the additional speaker). The only reason to put a larger amp in the car is to drive your speakers even louder - not at all necessary IMHO and not a safe driving practice. Unless you were putting in top end speakers that require more power to drive. As long as you are happy with this just stop - from here on out the improvements are small and expensive. Well, other than the 3.5" speaker :)

Greg
 
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