My speaker install, and various speaker-related questions

Hi,

I've got some vacation time coming up next week, and since I'm not going anywhere, I figured I'd try replacing the front speakers in my Leaf. In the fullness of time I may add amplification, a small sub, and fiddle with the rear speakers. But for now, I want to start small and keep things simple.

I've read the other threads on this subject, and they've been very helpful. Especially the pictures! I figured I should start another thread for my questions. I have lots of questions. Here we go:

The whole 2 Ohm vs. 4 Ohm question. What's the story there? Do the stock speakers really only present a 2 Ohm load? How do we know this? Is the "full range" speaker that is mounted in the front door 2 Ohm all by itself, or is it that the pair of front speakers (door and A-pillar tweeter), wired in parallel, present a 2 Ohm load in combination?

(BTW, I'm going to install 4 Ohm speakers. I'll let you know how that goes. I suppose I should drag out my sound-pressure meter and measure the stock volume. That way I can do a before and after comparison.)

My next question is about disconnecting the stock tweeters in the A-pillars. Where would be the best place to do the disconnecting? Right up at the actual tweeter would be an obvious place to do it, but I've haven't seen any discussion about accessing that area. Does anyone have any insight on this? Do those pillar covers pop right off?

My last question (for now!) is a nutty one, I think. Would it be possible to disconnect the rear speakers, and somehow connect both the front and rear amps to the front speakers? Kinda like how some stereo amps can be "bridged" into a more powerful mono amp? It seems doubtful, but I don't plan to use the rear speakers much, and it'd be nice to have more power up front.

This is probably a good way to explode the Leaf's head unit, but I thought I'd at least ask.

I did some more Googling, and it appears that it's a Bad Idea (tm) to bridge two channels of amplification, unless the amp in question has been designed specifically to allow that. So, that's off the table, it seems.

That's definitely correct, it would definitely not sound correct, and may damage the unit (and as shown in another thread, these things are crazy expensive at stock prices).

The specifications on the unit call for 2 ohms, but admittedly, I haven't measured the speakers. The front configuration has the tweeter wired in parallel with the full range, so in theory it could be less than 2 ohm live, but in actuality that would never happen. The impedence of speakers vary based on their frequency response and electrical characteristics; plus the cap that I'm 99% sure is on the tweeter would increase the functional impedence below the crossover frequency created by its cap - so in the real world those two speakers will still end up being around 2 ohms even in parallel.

Having said that, I've got my stock door speakers sitting on a shelf at home, so I can pretty quickly put a multimeter on it. The measured resistance won't be exactly the nominal impedence, but it'll be close enough to confirm or deny the 2 ohm assumption.

For the tweeter I can't be much help there yet, but there should be a connection that could be gotten to easily behind the a-pillar panel... If I have a few minutes extra tonight I'll check that as well.

In theory, if you have a 2 ohm speaker and a 4 ohm speaker with otherwise similar specifications (including sensitivity) at their recommended impedence, putting the 4 ohm speaker in a configuration designed for a 2 ohm will give you about a 3db drop in volume.

Quick update, I can confirm 2 ohms from 3 sources: 1) service manual, 2) stamping on the magnet of speakers, and 3) multimeter. They're definitely 2ohm

However, pulling off the a-pillar cover to disable the tweeters is not an easy thing. Apparently there is some wiring related to airbags back there maybe? For some reason, nissan installed not only the normal pop-in pins, but a second black secure latch on the a-pillar panels. So you pop them off, and they almost come loose, but a second clip holds them on solid enough that I was starting to bend the panel trying to find a way to release it. Maybe there's an easy way to get it loose, but I couldn't find it. I will, but need more light than I had this evening.

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Yep, it's the "clip anchor" I couldn't get lose. Looking at the service manual, it recommends cutting it ?? So I guess it's supposed to be replaced each time the panel is removed/replaced..? I wonder if the panel will sit snug & tight without it, since it really only serves to retain the panel after you've removed the other clips anyway.

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I used to own a custom installation shop and I did the tweeters on my LEAF, my advice unless you have quite a bit of stereo install expertise and lots of tools is to disconnect the tweeters below the A pillar if you can and put in coaxial speakers. Doing separates is quite a bit of work and any worth doing will mess with the crossover points in the LEAF unless done all four at once, not to mention the LEAF stereo will sound odd as it is not designed for these type of speakers with the low power it has. There are different resistance issues at each frequency level, etc. Best bet is to replace all four with good quality coaxial speakers and add an amp and sub later, this will be much easier and save you quite a bit of work and agony

I respectfully disagree, and was also professionally (and at one point competitively) involved with car audio. The staging improvements of using seperates would be worth the extra effort required for someone that cared about that sort of thing. I'm not sure what you mean about messing with crossover points in the leaf, any good set of seperates will have their own crossover (as compared to the factory, where the only "crossover" is a cap on the tweet). Further, the head unit is a clarion-built unit with a pretty much run-of-the-mill built-in amp; other than its preference for 2 ohms (which, as noted, the only concern is that it leads to a 3db drop in volume if you use 4 ohm, and there are lots of 2 ohm coaxials and component sets out there), it doesn't really have anything that makes it less able to take advantage of components than, say, an entry level aftermarket head unit.

I don't disagree that the best 'bang-for-the-buck' is coaxials with the stock tweeter disabled; that's a reasonably good step forward from stock (other than staging, which will suffer with ANY set of coaxials). And components are both generally more expensive, and require the installer to run additional wiring and find a mounting point for the crossover- and the gain in what most people would recognize as sound quality would admittedly be a very small step- but to anyone sensitive to sound staging, it's a major step. It just sounded like you were saying that taking that extra step would be detrimental, and that's what I gotta disagree with.

Actually... Or were you trying to discourage people from leaving the stock tweeter on with other speakers? If so, yes, I wholeheartedly agree! I'm actually DOING that right now as a temp measure while I finish up some pods, and it functions OK, but it's definitely not the right way

It sounds like removing the A-pillar "garnishes" is a bit of an adventure... one that I'd probably prefer to avoid. It would be nice if the wires leading to the tweeters could be disconnected somewhere where the access isn't too difficult. If anyone finds such a place, please share your findings!

So far my plan -- such that it is -- is to replace the front door mounted speakers with a pair of CDT Audio "braxial" speakers. They are coaxial speakers, with the tweeter mounted close to the edge of the woofer, rather than in the center.

I plan on fabricating an MDF baffle/mount to position the speakers as "correctly" as the stock door skins and grills allow. According to my reading, one wants to avoid mounting the speaker "deep" behind the door skin, and instead one should try to mount the speaker as close the the grill as possible. Based on the pictures in this forum, and observations I made by shining a flashlight through the grill, it looks like the stock speakers are set quite deeply. There's a good 2" gap between the speaker and grill. I'll be attempting to get rid of most of that when I build my mounting rings.

I also ordered an angled mounting ring that I hope can be used to point the speaker slightly up and back. Of course, that may lead to clearance issues as the magnet is moved forward and down. I may need to enlarge the hole in the sheet metal if that's the case. We'll see if I end up being that brave/motivated or not. :?

I'll also be doing a modest amount of sound deadening. The back of that whole cup-holder/map-pocket thing that's molded into the door skin looks like it could use some work. Given the complex shape, I'm wondering if squirting some expanding foam into the hollows might be the easiest way to go.

Actually now that I know, the a pillar varnish is actually very easy. It just pops off, then snip the anchor, unplug the tweet, and snap it back on. I was just wary of cutting thY clip without knowing it was the correct process.

As for the factory speakers, the mounting position is over an inch behind the.grille, but they have a very deep composite housing that actually puts the pretty close. To match it with an aftermarket speaker you'd need a 1" baffle. The good news is that there's plenty of clearance behind there, the sheet metal and door panel are really your only considerations. So you should be able to do a considerable angle, just limited to how much time you want to spend with internal door sheet metal and baffle construction.

defiancecp said:

I respectfully disagree, and was also professionally (and at one point competitively) involved with car audio. The staging improvements of using seperates would be worth the extra effort required for someone that cared about that sort of thing. I'm not sure what you mean about messing with crossover points in the leaf, any good set of seperates will have their own crossover (as compared to the factory, where the only "crossover" is a cap on the tweet). Further, the head unit is a clarion-built unit with a pretty much run-of-the-mill built-in amp; other than its preference for 2 ohms (which, as noted, the only concern is that it leads to a 3db drop in volume if you use 4 ohm, and there are lots of 2 ohm coaxials and component sets out there), it doesn't really have anything that makes it less able to take advantage of components than, say, an entry level aftermarket head unit.

I don't disagree that the best 'bang-for-the-buck' is coaxials with the stock tweeter disabled; that's a reasonably good step forward from stock (other than staging, which will suffer with ANY set of coaxials). And components are both generally more expensive, and require the installer to run additional wiring and find a mounting point for the crossover- and the gain in what most people would recognize as sound quality would admittedly be a very small step- but to anyone sensitive to sound staging, it's a major step. It just sounded like you were saying that taking that extra step would be detrimental, and that's what I gotta disagree with.

Actually... Or were you trying to discourage people from leaving the stock tweeter on with other speakers? If so, yes, I wholeheartedly agree! I'm actually DOING that right now as a temp measure while I finish up some pods, and it functions OK, but it's definitely not the right way

Click to expand...

Having factory speakers in the rear and separates in the front will mess with the loads and change the crossover points on all the speakers, good aftermarket speakers have load intensive crossovers that won't mix well with the head unit and other stock speakers. What I meant was doing the separates is far more complicated and people that do these things often take for granted how difficult and time consuming it is for others, for me it's not a big deal for others it may end up an unfinished project. The airbag retention clips on the A pillar may be a bitch for some folks and remember there are safety issues involved in that area. The LEAF stereo is a complete POS IMO, one of the worst factory audio and NAV units I have used in some time.

The front and rear speakers are on independent channels from the built-in amplifier in the head unit, so a change in one should have absolutely no impact on another (unless there is a serious fault in the design)... I agree that it's pretty sub-par, but it shouldn't be *THAT* sub-par -- Agreed on the rest, though, components and such are a lot more time consuming and there are many more barriers than just doing coaxes.

defiancecp said:

Actually now that I know, the a pillar varnish is actually very easy. It just pops off, then snip the anchor, unplug the tweet, and snap it back on. I was just wary of cutting thY clip without knowing it was the correct process.

Click to expand...

Okay, so you don't think this metal clip is "structural" in the sense that disabling it will make the garnish fall off, or anything like that?

defiancecp said:

As for the factory speakers, the mounting position is over an inch behind the.grille, but they have a very deep composite housing that actually puts the pretty close. To match it with an aftermarket speaker you'd need a 1" baffle. The good news is that there's plenty of clearance behind there, the sheet metal and door panel are really your only considerations. So you should be able to do a considerable angle, just limited to how much time you want to spend with internal door sheet metal and baffle construction.

Click to expand...

My tentative plan is to build a baffle that it about 2.5" thick. The bottom layer will be a square-ish piece of MDF, cut to fit that area immediately surrounding the speaker hole. I'll screw that to the metal, possibly using the existing mounting points. I'll also put some "butyl rope" between the door and the back of the baffle. That should serve to fill any gaps, damp vibration, and generally keep stuff stuck where it belongs.

On top of that, I'll just stack (glue and screw) a couple store-bought (eBay!) 6.5" baffle rings to get the height I'm looking for. I bought one pair of .75", and one pair of 1" thick rings, so I'm hoping that by adjusting the thickness of that bottom piece, I can get the speaker to about where I want it. I also bought a pair of angled rings that vary in thickness from .25" to .5". I can experiment with swapping those in as well. It should be relatively straight forward. (Only requiring, say, about 3 extra trips to the hardware store!)

Nope - it's a black plastic clip, and the service manual instructions for removal are to cut it. It's actually a dual function clip, it has a close part that pops into the garnish like a normal cllip, then about a 3" 'tail' with a barbed end that the end hooks into the garnish. You have to cut the tail off, there's simply no other way within reason - but it's not an issue, the main part still functions perfectly.

2.5" - Wow, that's pretty thick - I didn't measure sheet metal to door panel clearance (I just duplicated the depth of the stock ones with my baffle), so I didn't realize it had that much space!

A brief update...

It took closer to five hardware store trips, and probably close to twelve hours spread over three days, but I managed to get one speaker installed! Now that I know what I'm doing, and have assembled all the necessary tools and supplies, I can probably do the other side in about four hours. Maybe. Barring mishap.

Here's what I did, in a nutshell:

• I removed the interior door skin, according to the service manual instructions. I used the handy dandy plastic pry bar things I ordered from Amazon. They worked well. I removed the speaker as well.
• I removed the plastic sheeting that serves as a moisture barrier. It just peels right off.
• I added sound deadening sheets to the inside surfaces of the door cavity. I also plugged a few of the smaller holes with the same material.
• I used electrical sealing compound to further deaden the door cavity. Mostly behind the crash-intrusion bar, and right around the where the speaker attaches. I ended up using about three pounds of the stuff all told. It's like modeling clay that never hardens. Pretty fun to work with.
• I attached some closed cell foam (Yoga mat! Purple!) to the lower half of the door cavity with spray adhesive.
• I enlarged the "speaker hole" a bit with a jigsaw. I just rounded out the existing hole at the bottom. (The hole was sort of an oval to start with.)
• I built a speaker mounting ring/baffle out of 1/4" and 3/4" MDF. The thinner piece attached to the door using the stock speaker bolts, and the thicker ring was glued and screwed to that. Yep, I ended up only using 1" of total thickness. Pretty much like the stock mounting ring. Why? Because my new speakers have a protruding tweeter that makes the speaker itself "stick out" 1.25 inches. It's a snug fit, so the total gap must be very close to 2.25".
• My new speakers come with an "external" crossover, so that gave me lots of wire to work with. I clipped off the existing connector and soldered the crossovers to the existing wires.
• I cut two "plates" out of 1/8 inch MDF, and used them to cover and seal the two biggest openings in the interior door skin. I used self-tapping screws and more sealing compound to attach them.
• Then I attached the speaker and put everything back together. Whew.

How's it sound? Eh, about the same. It is only one speaker, which is an impedance mismatch with the stock one on the other side, and I still have both stock tweeters hooked up, meaning I have at least one tweeter too many.

I'll let you know how things sound once I get the driver's side done.

DaveNagy said:

I'll let you know how things sound once I get the driver's side done.

Click to expand...

Dave... Would love to get an update on your speaker upgrade project, and would love to hear how it sounds, perhaps at a future BayLeaf meeting? Oh, and more pictures (if you have them) would be awesome, too! Thanks!

Believe it or not, I finally got the second (left) speaker installed just yesterday! I've been sick, and busy, so getting that project completed wasn't super high on my list of priorities. Heck, if it wasn't for the fact that I have to sell the car, I may never have finished that job!

I'd have to say that it only sounds "a bit better". The bass is a bit better... not deeper or louder, but tighter and less boomy. The new tweeters sound good, and the stock tweeters up on the A-pillars should be disconnected, I think. Since I am selling the car, I'm leaving the stock tweeters connected for now. I will encourage the new owner to disable them, however.

There's still a bit of "chesty-ness" to the sound. A hump in the lower mid-range, I think. I'm guessing that this is caused by the sound getting trapped and bouncing around in the door cavity, somewhere. It's not terrible, and it would be easy to tweak via an EQ, but it's still there to a degree.