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Discussion Starter · #1 ·
I wanted to use the factory location (without getting a "box") and since I'm just an ordinary guy and not "hardcore-audiofile" per se, I wanted to improve the sound with minimal cost and minimal upgrading. I did the "Infinity Speaker" upgrade last Dec. and though that improved the sound, the bass was still very-lacking. So since then, I've been looking and learning to upgrade the factory subwoofer.

Upgrading the speakers was very simple (screwdriver, some dynamat, and a utility knife) but the subwoofer was a whole different animal.

There is the issue of ohms. The factory subwoofer is a 2 ohm and most after markets that will fit in that location are 4 ohms which means the resistence is "doubled."

Another issue is location. Because it's not an enclosure, I needed a "free air" subwoofer. Though they are not that difficult to find, there is very limited space due to the shallow depth of the location.

And another big hinderance is my lack of car-audio knowledge. For a newcomer into the world of car-audio, it is very intimidating to ask seemingly "basic" question like: what is dual-voice coal, power handling, rms, etc.

After posting for help on this forum, I decided to "just do it" and buy a subwoofer. I considered these factors when I made my decision.
1. Sensitivity- Since the OHMs (resistence) was going to go from 2 to 4 ohms, I needed a subwoofer which had a very high sensitivity.
2. Depth - According to this forum, others had tried to install a subwoofer with 5" depth and failed, but other's were able to install a sub with a 4 11/16" depth.

My choice of subwoofer:
Cerwin-Vega Stealth III S-10.4 because it had a high sensitivity of 93 DBA, a depth of only 4 1/8", and not only that, and it was on special for only $50 at (otherwise around $90).

Although the factory sub is also 10 inches, the metal bracket around the factory-woofer will not allow the aftermarket subwoofer to fit properly. I ended up going to a stereo shop and getting them to make a wood ring that mounted between the factory location and new subwoofer. Because of the thickness of the wood-ring, I probably could have fit a 5" deep subwoofer.

After installing the subwoofer, the sound was very disappointing in that it sounded the same and IMO, it sounded quieter and more muffled than the stock unit. My final conclusion was to get an amp. The stereo shop workers warned me that without getting a box, the sound improvement even with the amp would be very nominal.

I got an amp but I realized the installation was somewhat beyond my expertise. It required new wiring and some modifying of the old wiring to the factory amp that powered the factory subwoofer. I had the pro's do it. It took 3 hours but the labor was only $50 total. I checked around and the going rate seems to be $50-$55 (al & eds, bestbuy, circuit city, goodguys, etc).

The installer gave me the option of having the amp installed either under the front passenger seat or the headrest compartment behind the thirdrow. I opted for the front passenger seat location since I know that someday I will eventually spill something in the cargo.

What a tremendous difference that amp made!!! Being that it was the factory location, the improvement even surprised the installers since they figured it would be minimal. The sound improvement is substantially louder and clearer than before. I can "feel" the bass from the driver seat and it's even better from the middle row.

If I knew that I was going to end up getting an amp, I think I would have gotten a better subwoofer since "sensitivity" and ohm wouldn't have been such an issue.

For those who are curious:
1. Subwoofer - CERWIN VEGA STEALTH III S-10.4 = $50
2. Wood-ring for the SUBWOOFER = $50 (It took them only 15 minutes to make but they said it was considered "custom work.")
3. Amp - ALPINE MRP-T130 = $197 (including amp, installation-labor, all wires, etc.)

Though the damage was right under $300, I think this is a low-end figure to upgrade the subwoofer especially since an aftermarket amp is also must with the subwoofer...

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153 Posts
Discussion Starter · #3 ·
I did ask for the adapter plugs for the subwoofer. Because the MDX is not listed, I asked for the ones that would work on the latest Accords. They seem to be the same speaker wire adapter for the door speakers and though they did fit on the factory-subwoofer-wiring, the ends did not fit the aftermarket subwoofer.

I also asked about a ring to make the subwoofer fit but only speakers up to 6x9, have them.

As far as advice for upgrading, most places are limited in data for the MDX and/or have not dealt with many MDX at all. The people at Crutchfield are very knowledgable but when it comes to the MDX, they too just spoke about things in general.

*A couple of places even kept insisting that I had a BOSE system and gave me "he doesn't know what he's talking about look" when I told them that base-models have a different system.

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Discussion Starter · #5 ·
I also pondered that option but I had to take the "experts" advice and they all advised against that route. Hmmm, now I wonder what's the worse that could have happened? But I'm sure it wouldn't have been a good thing since the factory uses is a very small/weak amp to power a 2 ohm subwoofer... I think the aftermarket amp I got would have probably blown the factory one.

On the Alpine amp, there is a little switch that says "bass boost". With the volume 1/3 up and the bass-boost ON, there is too much bass and I can here the aftermarket subwoofer "bottom out." I would suspect that the factory sub, being half as heavy and so much more shallow, would do worse.

I'm kinda tempted to experiment and put the factory sub back on just to see but what if I blow up my MDX?:eek:
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