Story time...

Last week I had pulled all of my door speakers off to do some Dynamat repairs. I turned the radio on, just out of curiosity, remembering that only my subwoofer and factory tweeters were connected. The music was extremely boomy (obviously) but I noticed that almost no sound came from the tweeters, only the highest frequencies; frequencies which made the music almost non-existent from the tweeters.

Today I decided to pull of my A-pillar trim and investigate. Well, it looks like the factory tweeter is a Clarion 4-ohm tweeter and it looks all good. I then immediately noticed the cause for my investigations; the crossover capacitor was a measly 2.2uF.

At 4-ohms, a 2.2uF capacitor will make a crossover of approximately 12000Hz, which is extremely high, so high that it will not play most sounds.

The remedy: I soldered in a new 4.7uF 50V Electrolytic capacitor which lowered the effective frequency down to approximately 6000Hz. This made a world of difference. Now the music is much clearer and voices are much louder and clearer. It's amazing.

The problem: I was not sure of the safe operating frequency of the tweeters and was unable to find the specs online, so I guessed. I assumed that 6000Hz would be fine since most 3/4" tweeter drivers are capable of much lower. After testing the new setup, I heard no crackling from them and they each sound crystal clear even at really high volumes.

This was a great mod which only cost me $2.40 in capacitors at Radio Shack and 20 minutes of my time. If anybody knows of any reason why I shouldn't use a 4.7uF capacitor, please tell me before I really screw up my tweeters.

i dont think it will do any damage to your tweeters, they usually have a wide range, and bose/clarion are good components, but how long did it take you to take old ones out solder new in? and is there some room to work or is it tight, i might do the same to mine.

It took me five minutes to pull both A-pillar trims off and pull out the tweeter and mounting bracket (I pulled the tweeter and mounting bracket out as one piece, you just have to turn the plastic '+' piece 1/4 turn and the mounting bracket will pop off the A-pillar). If you haven't pulled the A-pillar trim off before, be very careful, as the plastic pieces which hold the metal clips to the pillar trim break pretty easily.



It took me at most ten minutes to un-solder the old capacitors and solder on the new ones. The factory capacitors were glued to the side of the tweeter, but some mini pliers pulled them right off. Then five more minutes to re-attach the tweeter and mounting bracket to the A-pillar.

There is PLENTY of space to work in, the new capacitors are almost exactly the same size as the old ones, so there's no clearance issues.
Modified by Pwnin O'Brien at 6:06 PM 8/16/2009

ok i might check it out after i install my new suspension and paint my wheels this week. and thanks for the tip about the clips, i took apart most of the interior but not those yet, ( just like you broke your clips i warned you about lol )

wow! kudos to you! I always found those tweeters to be pretty useless, id always put my ear to them and barely hear anything. I have quite a large selection of caps sitting around, did you mess with other values or do you thing 600HZ is good enough? Thanks so much for sharing!

Well without knowing the safe operating frequency of the tweeters, I really wanted to play it safe and only go down to 6000Hz. I was going to try a 6uF and 8uF setup to see if the tweeters could operate in those frequencies, but I didn't want to have to buy a bunch of caps. The 4.7uF really made a huge difference tho, seriously. I haven't put the A-pillar trim back on yet, but I don't think that will make too much of a difference in sound. The music sounds MUCH better from the front seats.

I guess you could experiment with different values and listen for distortion, but don't yell at me if you break your tweeters!

Before I put the A-pillar trim back on my passenger side I took a couple pictures to show the new capacitor soldered in. Sorry the second pic is a bit blurry, but you can still see the capacitor and the glue which held the old one in place.

great find man, thanks for sharing

im wondering if the setup is the same on the 01 qx4... the door speakers say bose- but do you think i have the same tweeter setup? i think i need to go pull off some trim.

I'm 98% sure that the Bose system utilizes the same Clarion tweeter. It should look exactly the same as the one in my above pictures.

Also, let me note that when removing/replacing the A-pillar trim, it is easier to pull off the weatherstripping that overlaps the edge of the trim.

You can see the black weatherstripping I'm talking about in the first picture above. The weatherstripping is to the right of the tweeter/bracket.
Modified by Pwnin O'Brien at 6:08 PM 8/16/2009

Pwnin O’Brien wrote:Also, let me note that when removing/replacing the A-pillar trim, it is easier to pull off the weatherstripping that overlaps the edge of the trim.

Great write-up Pwnin!

Billy

Ok, just so I understand you correctly, the bigger the capacitor, the lower the frequency response? Say I install a capacitor between the 2 values you quoted (2.2 vs. 4.7) , then I should be OK?(Sorry if it comes across as a dumb question, so thanks in advance.)

Buzzman wrote:Ok, just so I understand you correctly, the bigger the capacitor, the lower the frequency response? Say I install a capacitor between the 2 values you quoted (2.2 vs. 4.7) , then I should be OK?(Sorry if it comes across as a dumb question, so thanks in advance.)

No, that's not a dumb question at all. Yes, as you increase the capacitance you will be decreasing the effective frequency response of the tweeters. Now you may be able to go higher than 4.7uF, but without knowing the spec'd frequency response of the factory tweeter, I just went with the safe choice of 4.7uF.

I can say with confidence that 4.7uF works perfectly fine, so if you were to use a capacitance between 2.2uF and 4.7uF then you would be fine. Just remember, these capacitance values are for a 4-ohm tweeter, so if you decide to pull the tweeter out, ensure it is 4 ohms. If it is different, then you can still change out the capacitor, you would just have to use a different capacitances.
Modified by Pwnin O'Brien at 6:09 PM 8/16/2009

As usual, excellent information Pwnin... you got some sick mods bro. I plan on doing the lights in my door switches soon. By the way the was a well written piece about a very technical procedure. Hats off to ya!

Yes the Tweeters are clarion which sound good but once I installed the Infinity Kappa series components it sounded a lot better.. The tweeters from Infinity are a lil bigger but still fit under the factory cover.. Just got to do a lil mod on just how to hold the new tweeters in place. I will try and take a picture of them and post it up so you can see later on..

Also let me point out that most (if not all) capacitors have a 20% tolerance. This means that the capacitor will almost never have the rated capacitance. So a 4.7uF capacitor can have a capacitance as high as 5.64uF and as low as 3.76uF. After I soldered in my new capacitor (after giving it time to cool to room temperature) I measured the capacitance, it read as high as 6uF! So keep that in mind, you may get a much higher capacitance than intended.

My new 4.7uF capacitor is still functioning beautifully and the tweeters still sound amazing and I would still recommend this mod to everyone with the factory tweeter.

I've got a 3.3uF on my tweeter, is it worth changing?

Has anyone experimented with other cap values ?

slickroger wrote:I've got a 3.3uF on my tweeter, is it worth changing?

Has anyone experimented with other cap values ?

My tweeters also had 3.3µF 50v capacitors (Clarion 4ohm that came with stock Bose system). I replaced them with 4.7µF 50v 8 ohm capacitors and they sound much better and are more audible now.

Apologies for the large bump.

Finally got around to doing the tweeter mod this week.
Took me longer to find a place that sold capacitors than it did to install them.
The mod was easy. Thanks for the how-to from O'brien.
I went with the 4.7's by the way, and there is definitely a difference.
I can actually hear sound coming from the tweeters now, where before they might as well have not been there.
Sounds crisper. Thx.

Is this the right cap?

http://www.tiptopelectronics.com/home.a ... EH4.7M50AA

These are "MF" not "UF" I couldn't find a place that had 4.7UF 50V caps

sc2nr wrote:Is this the right cap?

http://www.tiptopelectronics.com/home.a ... EH4.7M50AA

These are "MF" not "UF" I couldn't find a place that had 4.7UF 50V caps

Well, the picture is not faithful to the description, but the specs indicate that it is a 4.7µF 50V cap. I assume the "M" stands for "micro", in place of "µ".

Ok so I went to the shop from the link and the guy said that there is no difference between µF and MF, doing the mod tonight!

Hey Pwnin O'Brien,

Great Find with this...

I just did this MOD took me about 90 minutes including the drive to radio shack... I actually disconnected the tweeter and brought it inside to solder it by unscrewing it and disconnecting the connectors... was actually quite simple! I had thought that the tweeters were blown as I never thought I heard anything coming from them anyway but now faded to the front and wow they do work and it sounds 100% better then it did before. Thanks for sharing the idea...


Trilo

Clarion tweeters for a Bose system? I am now a firm believer of the old addage, "No highs, just lows ... must be Bose".

I replaced mine with Rockford Fosgates as part of a component 6.5" replacement package. They came with a crossover (don't know the specs) and sound great! I had forgotten how cheap the factory tweets looked.

sc2nr wrote:Ok so I went to the shop from the link and the guy said that there is no difference between µF and MF, doing the mod tonight!

well, i hope that guy is right. because there is a BIG difference between the prefixes "M" and "µ". M = mega (i.e. megabyte), which is the equivalent to 10^6, and µ = micro, which is the equivalent to 10^-6. BIG difference. i don't know why a company would use M and µ interchangeably, but i hope that that company just really sucks at using common chemical/math/physics prefixes.

hope all goes well.

^^^
haha, hopefully the shop correctly gave him micro-farads instead of Mega!
Usually, if the textpad cannot support greek letters for "µ" (mu), then they'll use "u", not "m" nor "M". At least the shop/manufacturer had better not use "m" or "M" in place of "µ"!!! they should know better!

I'm assuming they did him good and gave him µf capacitors since he didn't come back in here saying his tweeters are blowed up.


*stop here if you don't care about the small details, the "why", and the math*
if I can recall on my electrical signals theory... essentially what Pwnin O'Brien did was reduce what's called the cutoff frequency (fc) for a high-pass filter (ie. tweeter) by increasing the capacitance.
See this Wiki linkfor a brief discussion on how the cutoff for a HPF is mathematically arrived.

so what Pwnin did was increase the "RC" (R is the resistance, or the tweeter itself, so this is constant if you're keeping your original tweeter) value from 4*2.2u to 4*4.7u, which will reduce the fc from about 18kHz to 8kHz.
The way cuttoff for HPF works is that it'll "cutoff" any frequencies below the cutoff frequency. Which is why with the 2.2uf (18kHz) you mainly hear the high frequencies. What happens when you lower the cutoff (ie. increase capacitor) is obvious, and you increase the bandwidth of frequencies detectable.

now if you so happened to decide to buy the 4.7MegaFarad capacitor, you drop your cutoff to about 8 measly Hz!!! I believe the lowest frequency the human ear can detect is 20Hz . So, now at 8Hz, you're basically allowing EVERYTHING, including the lows to pass through that little 2inch tweeter!
Not only would you be allowing all the low frequencies (ie. bass) and other noise to pass through, but I'd assume overtime it'd wear the cone down and blow the speaker.

Again, I admit I'm rusty on my electronic signals, so please cut me some slack!
BTW - I'm not tryin' to be a "know-it-all". I just like it when I understand what the mod is doing, rather than following blindly and not knowing what and why I'm doing something. Just thought this might shed some light on some stuff.

Just did this mod in under an hour and what a difference it makes. It lifts the sound up from the floor where the 6.5's are, and does a decent job of balancing the over-presence of midrange . . . it's not the perfect solution, but it sure as hell is a big change for under 3 bucks!

Pwnin O'Brien wrote:It took me five minutes to pull both A-pillar trims off and pull out the tweeter and mounting bracket (I pulled the tweeter and mounting bracket out as one piece, you just have to turn the plastic '+' piece 1/4 turn and the mounting bracket will pop off the A-pillar). If you haven't pulled the A-pillar trim off before, be very careful, as the plastic pieces which hold the metal clips to the pillar trim break pretty easily.

How do you pull Apillar trims off? I have never done this before, and don't want to break it , really needs your help! Thanks!

accurate wrote:

Pwnin O'Brien wrote:It took me five minutes to pull both A-pillar trims off and pull out the tweeter and mounting bracket (I pulled the tweeter and mounting bracket out as one piece, you just have to turn the plastic '+' piece 1/4 turn and the mounting bracket will pop off the A-pillar). If you haven't pulled the A-pillar trim off before, be very careful, as the plastic pieces which hold the metal clips to the pillar trim break pretty easily.

How do you pull Apillar trims off? I have never done this before, and don't want to break it , really needs your help! Thanks!

Just pull them off starting from the bottom. You won't break anything, the metal clips are pretty sturdy.