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Discussion Starter #1
I think I have read all of the threads dealing with after market speaker upgrades(a lot of reading), but still have a few questions before I take the plunge. I am not a audiophile by any means, so these questions might seem simple to most of you experts so please bear with me.

1. If the amp for the door speakers has a crossover built into it, why would you install component speakers with another crossover and keep the stock amp? Isn't this filtering frequencies that have already been filtered for the stock speakers.

2. If the crossover in the front stereo amp is tuned to the stock speakers, isn't there a good chance that better quality speakers will require different crossover frequencies and be deficient with the stock amp and its crossover?

3. How do you install component speakers in the front doors without taking the door panel completely off? From the circuit diagram in the service manual, it's obvious I would have to connect the crossover to the wires comming directly from the amp and I don't see anything like these around the speaker hole.

4. If you do put component speakers in the front doors, where do you put the crossover? If it is in the door, how do you secure it so it doesn't rattle around in a few months of heat and door closings. If not the door, where?

5. Since the front doors have both a tweeter and woofer and the back door speakers are only one-way, why wouldn't it make sense to upgrade to high sensitivity 3-way speakers in the back doors and 2-way in the front? The tweeter in the back doesn't seem to do much for the sound, even in the back seat.

6. From my perspective (and hearing dynamics), the subwoofer is the weakest component of the whole system. Its as if it is not hooked up for all the bass I get out of it. Why then isn't this replaced with all the other speakers by most folks? It seems a lot of conversions are just swapping the door speakers. I would think that this is necessary, but not sufficient in upgrading the total sound experience?

7. There are not many folks who are upgrading the door tweeters. Are they of any better quality than the door woofers? Do the 2-way after market replacements just overpower the stock tweeters that it doesn't matter if they are left as is?

8. And finally, would a subwoofer enclosure made from dense foam lined with dynamat be adequate as a "box" to help the replacement sub? It seems to need something and I don't see how a MDF box could be made to fit. At least I don't have the tools or skill to do it.

I didn't mean for this to be so long, but these questions need to be addressed before I decide what steps to take next. Any help would be greatly appreciated from you guys who know what you are doing. I am inclined to install as good quality speakers as the existing amps can handle. I am not contemplating adding or changing wiring and amps. I don't have the expertise to do it and I don't trust auto sound shops with no experience with the "X" to do it either. Just paranoid that way.

Thanks
 

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You kind of lost me on the crossover questions.
The only crossover I am familiar with is a bypass cap to for the door tweeter.
When you replace the door speakers, that door tweeter remains in the circuit.
So you effectively have an 2 tweeters in the circuit, the one in the door, and the one in the coaxial speaker. The audio effect does not seem to be significant. I have not disconnected the one in the door, as it seems an appropriate location.
The cap (crossover) for the door tweeter is right behind the door tweeter itself.

I had first thought it was disabled with the door speaker swap but it is not.

The sub is fed by it's own amplifier so additional crossovers are not present to my knowledge. Although, some circuit is being used, probably a summing ckt of sorts to feed the 'twiddler' in the roof, as suggested by TheyCallMeBruce. The twiddler seems to have questionable value, and disconnecting it might be the way to go.

To install an upgraded component system would certainly be more involved. There is not a lot of room available inside the door for a crossover, although modern systems have fairly slim profiles these days. I am sure there are those that have done it than can explain it. It would seem they would need to be externally located (like under the dash, etc. and wires routed to the drivers in the door.

I notice you never mention amplifiers. I don't think there is much to be gained by going with a more sophisticated compenent system unless you install new amplifciation.

I don't think there is a lot to be gained form a sound standpoint by going to a 3 way speaker in the rear doors either, as they don't 'work' in the best environment to provide much overall audio improvement.

Lining the existing subwoofer cavity with Dynamat including the inside of the opposing body panel could be beneficial. Beyond that, the best improvement would be the installation of a custom sub system.

That's my 2 cents.
 

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[I think I have read all of the threads dealing with after market speaker upgrades(a lot of reading), but still have a few questions before I take the plunge. I am not a audiophile by any means, so these questions might seem simple to most of you experts so please bear with me. ]

[1. If the amp for the door speakers has a crossover built into it, why would you install component speakers with another crossover and keep the stock amp? Isn't this filtering frequencies that have already been filtered for the stock speakers.]

A new set of component tweeters will replace the stock tweeter, which has a simple capacitor hot-glued to its magnet (they dare to call this a cross-over?) Therefore, the original “crossover” will be discarded along with the original tweeter.

[2. If the crossover in the front stereo amp is tuned to the stock speakers, isn't there a good chance that better quality speakers will require different crossover frequencies and be deficient with the stock amp and its crossover? ]

The “crossover” on the back of the tweeter magnet is the only frequency separation device in the audio system and it is not exactly “tuned.” They used the cheapest possible method by inserting a low frequency blocking capacitor (sort of a bass-blocker, but set really high), but this only works at 6 db/octave(capacitor only), when the industry standard is 12 db/octave (requires matching cap and inductor), and exceptional component crossovers work at 18 db/octave (requires, two caps, one inductor), and subwoofers need 24 db/octaves (2 caps, 2 inductors). The difference being a 6 db/octave doesn’t do much at all, barely audible as though it didn’t exist at all, and a 18 db/octave setup does what its supposed to, send only high frequencies to the tweeter, and only lower frequencies to the main woofer. But, it costs an extra $5.50 to buy crossovers in bulk, hence the low performance excuse for a crossover. The stock main woofer is not rigged to a crossover, so it plays music both too high and too low for its design.
As opposed to the stock system, the crossover provided with aftermarket component speakers is a separately mounted device with true-matched frequency separation elements. Crossover devices are completely unrelated to the amplifier (unless the amplifier has a built-in cross-over, as all premium amps do, but is defeatable, the Bose amp does not have this basic feature). The amps put out full tonal spectrum, the crossover divides the frequencies and sends them out to the correct speaker (the Bose components don’t actually do this, as there is no real cross-over).

[3. How do you install component speakers in the front doors without taking the door panel completely off? From the circuit diagram in the service manual, it's obvious I would have to connect the crossover to the wires comming directly from the amp and I don't see anything like these around the speaker hole.]

You must remove the door panel. The screw cover behind the inner door handle is tricky. There are slots to pry off open the cover on both sides of the cover. Only one is the pry slot, the other is the hinge. Naturally you pry open the bigger slot, but this will break the cover as its not the correct side, its actually the hinge (don’t ask how I figured this out). Pry on the small slot only, with a jeweler’s flat screwdriver.
Grill opens from the lower front edge, pulling out on the top or back will likely break the retaining tabs. Yes, there’s no way you would have known this. The cross-over you install runs off the harness that connects the main speaker. Take you speaker (you can do this without removing the panel, just the grill) to the local car audio place or franchised electronics store to get a match for a speaker harness adapter. You won’t have to splice into or cut any stock wires this way.

[4. If you do put component speakers in the front doors, where do you put the crossover? If it is in the door, how do you secure it so it doesn't rattle around in a few months of heat and door closings. If not the door, where?]

Double-stick tape the crossover to the inner door skin after cleaning the area with rubbing alcohol or prep pad. Decide if you will add sound-deadening material before you do this. If you have a ’01, you’ve done most of the work just getting the panel off so I strongly suggest it, if ’02, it should be already done at the factory but confirm that there is some rubbery asphalt sheet glued to most of the visible the sheet metal. You won’t come loose (you ever try to remove something that been foam double-sided taped?).

[5. Since the front doors have both a tweeter and woofer and the back door speakers are only one-way, why wouldn't it make sense to upgrade to high sensitivity 3-way speakers in the back doors and 2-way in the front? The tweeter in the back doesn't seem to do much for the sound, even in the back seat.]

Please refrain from making reference to 3-way tri-axials; it causes uncontrollable spasms to my nervous system, results in fits of rage. The stock MDX with quasi-components in the front, and a full range in the back doesn’t mean that this is the pattern to follow. This was a financial decision, not an audio quality decision. The back seats are used less frequently, and a percentage of time by children, whose needs are not considered, so why not save some bucks buy using the lowest quality speakers available. Can’t find anything cheaper than un-treated, un-coated, full range paper cone speakers with a plain, low density foam surround.

[6. From my perspective (and hearing dynamics), the subwoofer is the weakest component of the whole system. Its as if it is not hooked up for all the bass I get out of it. Why then isn't this replaced with all the other speakers by most folks? It seems a lot of conversions are just swapping the door speakers. I would think that this is necessary, but not sufficient in upgrading the total sound experience?]

Most people who install aftermarket component speakers will also upgrade the sub for the reasons you mentioned. The people who did not upgrade the sub did not install component speakers. Upgrading the sub is much less expensive than the upgrading to component speaks, unless you create a custom enclosure, see below.

[7. There are not many folks who are upgrading the door tweeters. Are they of any better quality than the door woofers? Do the 2-way after market replacements just overpower the stock tweeters that it doesn't matter if they are left as is?]

No, they are not better quality than the door woofers. They are not supposed to be left as is. I'm not sure if members who have replaced the woofers with co-axials disconnected the factory tweeter. If they are utilizing two tweeters simultaneously, made from different manufacturing lines, using two completely different sets of frequencies, it would cause phase collision/interference and this translates into distortion. Both the stock tweeter and the tweeter in the new co-axial should never be operated at the same time. It can be easily accessed by removing the tweeter pod and disconnecting the tweeter harness.

[8. And finally, would a subwoofer enclosure made from dense foam lined with dynamat be adequate as a "box" to help the replacement sub? It seems to need something and I don't see how a MDF box could be made to fit. At least I don't have the tools or skill to do it.]

Enclosures should not be made of dense foam. I’ve seen people line extra thick MDF boxes with a ½ inch of cement (yes, sidewalk stuff), but line foam with soft rubbery dynamat? No point in making an external MDF sub-box. I suggest, if you must use a sealed enclosure design (which does sound the best compared to free-air or vented), you would have a fiberglass enclosure built right inside your rear quarterpanel. Members have done this with good result. I was quoted $250 for this service but did not go this route. I installed a free-air with a spacer ring. Sealed subs do sound better though, but was overkill for me at the time. Maybe next year.


9. This was not a question but something no one has discussed in regards to installing component speakers in the rear doors. There is no accommodation for a separate tweeter. The reason I am partial to Boston Acoustic Pro series is that they are packaged with an integrated placement arm to hold the tweeter over the woofer cone, so that when used, it looks like a co-axial, but are really completely separate, physically and electronically. I don’t know of any other brand that provides this. If so, you will need to make a custom bracket to hold the tweeter in front of the woofer cone, but which will not touch the surround and give enough room for the woofer to move in and out without interference. Not a big deal, but an extra step I am glad I did not have to make.


[Thanks]

You’re Welcomed.
 

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TheyCallMeBruce

Note 4: Is there really room for component crossovers in the door itself? I take it these are quite flat then.
I have an '02 and while there is more padding or insulation on the inner door panel, I found no such material on the inside surface of the door's outer panel of any of the 4 doors. That's why I recommended applying some to those surfaces (as long as you are in the 'area' ).
Granted, it would even be better to remove the door panel and use it more extensively.

Note 7: I believe the wires for the door tweeter are connected at the same connector for the front door full range speaker. So the disconnect could be done there. No reason to remove door panels. Or for that matter, what is wrong with popping off the little grill and removing the door tweeter, or otherwise disconnect it at that point?

Actually. I am replacing the sub in mine with the Polk recommended by mushman. I hope for some improvement there, even with the questionable amp.
 

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Fiberglass sub enclosure

>> I was quoted $250 for this service but did not go this route. I installed a free-air with a spacer ring. Sealed subs do sound better though, but was overkill for me at the time. Maybe next year. <<


Bruce (?)

I am interested in getting a fiberglass subwoofer enclosure. Could
you tell me who/where I can get this service/product ?

TIA
--
 

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Discussion Starter #6
TheyCallMeBruce & DaleB

Thanks so much for the great advice and insights guys. Actually Bruce, I knew your reaction to coaxials, but had to ask the question anyway. Sorry for the spasms. Did not realize that the crossover was a single capacitor on the tweeter. A component system will get rid of that.

BTW Bruce, what free air sub did you install with the spacer? I am also looking at Boston Acoustics for the doors. Either that or Soundstream, but have not decided on a sub yet. Most of those I've researched are either too long (deep) or have less than 90 db sensitivity or just too cheap sounding.

DaleB, the crossover I say yesterday was very thin and would have fit into the door with good double stick tape. But, you are right, they have to be thin.

I think I'll have a local shop install the components in the doors. I think I can handle the sub. The shop installed all of the sound equipment(~$25K worth, I'm told) in Michael Dell's custom built Mercedes so they should be able to handle this. I definitely don't want to tackle the panels after your description of what is involved.

Thanks again, I'm about to take the plunge. I'll let you know how it goes.
 

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This is a great discussion and learnig tool! I had never heard of "crossovers" until joining this board. I will be going with either Polk Audio or Boston Acoustics speakers. Here is the response to my questions from the Polk Audio customer rep that goes into the crossover issue a bit. He also recommended in a phone conversation that the factory rain guard baskets be completely removed as they interefere with the speaker's ability to produce sound.

From Polk Audio:
"I would recommend using the EX3560 component speakers for the front doors and use the EX365's for the rear doors due to the limited amount of power available from the factory system. These speakers are very efficient and work well with medium powered factory systems. The driver opening is a 6 3/4 inch opening in both the front and rear doors.
You may have to use a adapter to install the rear EX365's. I would strongly recommend replacing the factory tweeters. This is one area that can be significantly improved by using a high quality aftermarket speaker system such as the EX3560.
You will need to replace the factory passive crossovers with those supplied with the EX3560's. The factory crossover are a first order crossovers that use a very gradual 6 dB per octave slope where the EX3560 uses a 12 dB per octave slope. The crossover frequncy for the EX3560 is at 4000 Hertz.
Regarding Dynamat... I would recommend installing it!! This can
significantly reduce road noise and make the system sound so much better. Plus you won't have to play the system as loud once you have applied this to the vehicle. It makes a big difference.
Another brand that you might want to consider is Cascade Audio.
This material is Latex based and is easier to apply to any rounded or irregularly shaped panels. Plus it does not crack as bad as the asphaltic based damping materials. You can reach them at 541-389-5273. "
 

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R Stevens

Those are excellent recommendations, and something well within the ability of those of us who have already done the Infinity 625i upgrade. It's the next plateau if you will.
I also strongly support the application Dynamat which can improve the outcome of any modification. Cascade Audio has been mentioned before among the numerous posts associated with audio upgrades.
The information is greatly appreciated. Yes, this forum is excellent! But it's the people like yourself, fvince, TCMBruce, etc. etc. that make it so. :) :) :)
 

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Re: TheyCallMeBruce

DaleB said:
Note 4: Is there really room for component crossovers in the door itself? I take it these are quite flat then.
I have an '02 and while there is more padding or insulation on the inner door panel, I found no such material on the inside surface of the door's outer panel of any of the 4 doors. That's why I recommended applying some to those surfaces (as long as you are in the 'area' ).
Granted, it would even be better to remove the door panel and use it more extensively.

Note 7: I believe the wires for the door tweeter are connected at the same connector for the front door full range speaker. So the disconnect could be done there. No reason to remove door panels. Or for that matter, what is wrong with popping off the little grill and removing the door tweeter, or otherwise disconnect it at that point?

Actually. I am replacing the sub in mine with the Polk recommended by mushman. I hope for some improvement there, even with the questionable amp.
This is very disappointing information. Dale, are you saying that the inner sheet metal of the door panels are not covered with sound-deadening material? The big improvement regarding sound as marketed included the application of sound-absorbing material in the door panels (shet metal, not trim panel) and roof panel, and a few smaller areas. Anybody with an '02 willing to peel down the sunroof opening trim and take a peek at the roof with a flashlight? Anyhow, the MDX has a huge door, depth-wise, and there's ample space to place a crossover most anywhere, important to tape a rain shield made from a piece of a clear plastic bag over the crossover, along the upper edge of this home-made shield.

Disconnecting the tweeter. I stand corrected. The thought actually intruded into my dreams, I sat up at 4:30 am and said, "Oh no, I was wrong, its so easy to disconnect the tweeter right at the pod! How stupid I'll sound." I've taken the panel off so many times, I've developed a one-track mind. I figured somebody would point it out, and the important thing is that the correct information gets out. I've revised my post to correct this error. Thanks for mentioning it.
 

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R Stevens - I like those Polks!

I just did some searches of those Polk systems you referenced! They are impressive.
For under 4 bills (discounted) you could have some sweet sound.
Efficient, easy to install, shallow (2 1/16) depth.
Beef up the sub and put in more damping material where you can, and end up with a very nice system.
That would have to be the about the optimum without going to new amps.
I may have to talk to Santa...well, Mrs. Santa anyway......
I need to audition those sometime.
 

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Re: TheyCallMeBruce & DaleB

fvince said:


BTW Bruce, what free air sub did you install with the spacer? I am also looking at Boston Acoustics for the doors. Either that or Soundstream, but have not decided on a sub yet. Most of those I've researched are either too long (deep) or have less than 90 db sensitivity or just too cheap sounding.

Thanks again, I'm about to take the plunge. I'll let you know how it goes.
I used a SoundStream Generator in 2 ohm version and cut a spacer out of 1" MDF, which was really a very stiff shelving piece I found for $1.99 at Home Depot. Used drawing compass and jigsaw. Pressed the spacer against the 4 mounting clips smeared with crayon to mark the spacer to car mount holes. Sprayed it w/ paint to match the interior sheet metal color. I used a SoundStream Angina sub amp (200 watts in 2 ohm) w/ x-over set at 80 Hz. Its true. Might not make sense to use a higher quality sub without also providing the necessary power to make it function as designed. If you upgrade one at a time, it will be double-work, and automotive labor is sometimes more expensive than the components.
 

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Re: Fiberglass sub enclosure

jzman said:
>> I was quoted $250 for this service but did not go this route. I installed a free-air with a spacer ring. Sealed subs do sound better though, but was overkill for me at the time. Maybe next year. <<


Bruce (?)

I am interested in getting a fiberglass subwoofer enclosure. Could
you tell me who/where I can get this service/product ?

TIA
--
Of all the custom jobs that a car audio shop might provide, building fiberglass enclosures has got the be one of the most basic. Any shop that does any kind of custom work should be able to show you pictures, or a demo car to inspect. Don't bother with franchised electronics superstores, Circuit City, Best Buy, etc. They are not into that, too risky in terms of service efficiency. In the L.A. area, Al and Ed's has completed numerous 'glass jobs, but any local competent car audio-specific shop should be up to the task. If you are really picky, you might look for a shop that has entered into (and placed at) competitions.
 

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Re: Re: TheyCallMeBruce

TheyCallMeBruce said:


This is very disappointing information. Dale, are you saying that the inner sheet metal of the door panels are not covered with sound-deadening material? The big improvement regarding sound as marketed included the application of sound-absorbing material in the door panels (shet metal, not trim panel) and roof panel, and a few smaller areas. Anybody with an '02 willing to peel down the sunroof opening trim and take a peek at the roof with a flashlight? Anyhow, the MDX has a huge door, depth-wise, and there's ample space to place a crossover most anywhere, important to tape a rain shield made from a piece of a clear plastic bag over the crossover, along the upper edge of this home-made shield.

Yes, upon removing all 4 speakers I discovered unadorned walls of metal inside of the outer skin. For as far as my hand could explore.
There is this white padding material on the inside of the inner panel, the same surface where the speaker mounts.
I plastered with Dynamat in the hope of offering some improvement. At least as far as my hand would go. I had no intention of removing the door panels.
There is similar white padding around the sub opening. I understand a lot this padding is not in the 01s?
I don't know that for a fact. The descriptions I have read suggest most of the additional sound snubbing for the current MDX went into the roof.
I think we have a couple of live wires presently doing some media mods who may be able to check the sunroof area out for you. Any volunteers?
 

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The customer rep I spoke with at Polk Audio recommended asking the following questions when looking for a quality installer:
1) Ask to see a portfolio of completed installs.
2) Have any installs won an award?
3) Are installers MACP(?) certified? (This means they completed a certain amount of formal training)
4) What is the product and installation warranty? The best shops give a lifetime installation warranty. That also means your car is returned in the same condition as before the install. The local high end installer I have been talking to provides a lifetime installation warranty plus any adjustments that might be necessary plus free replacement of OEM stuff when you sell the vehicle and want to keep the custom equip.

Bruce's comment about custom sub fiberglass enclosures is on target. The good installers do this all the time. If they can't or won't do it, then take your business elsewhere.

Dale, the Polk rep said the factory amps will have plenty of power to handle those speakers and most listeners will be completely satisfied, but something along the lines of an Alpine 55wx4 will take them to another level.

Here's a question for those who have installed external amps. Where have you been placing them (in the nav/touring model)? The headrest storage area has been used, but I'd like to keep that space available for other stuff. Under the driver's seat looks feasible for some smaller amps. Can a sub amp fit where the OEM sub amp is located?

Gotta run and install my side steps, separation net, etc. Tim is really great. Placed an order on Monday and everything was delivered Thursday AM.
 

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Folks

Thanks for replying to my question regarding the fiberglass subwoofer box. After reading just about all the posts in this forum related to this subject, I have decided to visit a local award-winning installer yesterday. Unfortunately, they were not as helpful as I wished (they were busy with lots customer in the shop). I came back with a long list of questions unanswered.

I am going to try my luck with this forum. I find people here are very courteous and helpful.

I have started a new thread to post all my questions. I hope I will come up with a nice install like yours.

TIA for your helps.
--
JZ
 
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