Hey just wanted to share the idea Spin9K (forum member) shared back some time ago.

He mentioned how he bough these discontinnued speakers from Radio Shack (tweeters) and added them to his car by installing them next to the door window speakers. I ran out and bought the speakers as soon as he shared that thread and have had them sitting in the drawer for about two months UNTIL TODAY. I installed them in about 15 minutes solder and all as per his instructions.

The sound is fantastic. Especially for $20 (reg $40) the price. I cannot express to you what a difference tweeters make in this car. Like Spin9K said, that is what is missing - the highs. Now it sounds great. The Bose system seems to reporduce bass well already. I have a fantastic sounding home system and did not want to sink a lot of money in a car system but improvement was needed. This fit the ticket well. Thanks Spin9k for your share. I finally did it.

pics please

okay here is a so so shot.

I hesitated since I hate cutting/drilling on a new car but the sound is an improvement.

I have added 2 small Kenwood tweeters to the same location, and I agree that it is like a night and day difference.

If you have the stereo cranked and you and a passenger covers the tweeters with your hands, the quality of the sound just literally disappears.

I also took the 2" Bose speakers out of their mount and used an Exacto knife to shave off the high side of the hole they mount into. Doing that has redirected the sound from pointing into the dash and directed it more towards my head. I did this at the same time as adding the little tweeters, so I can't say whether that really helped much, but I'm sure it did.

The tweeters I bought came with 5-way mounting capability, but I could not find a good flat place to mount them so I could swivel them. I had to just mount them on the outside of the plastic piece where others have.

See pics

Another pic from farther away....

Could you just replace the Bose speaker that is already there and have it sound just as good? I'm just leary about adding a speaker there. Knowing me I'd jack my car up! :D

I think that you might lose some high midrange frequencies if you just got rid of the 2" speakers and replaced them with tweeters.

I would not be afraid of "jacking" the car up. I only had to drill 2 tiny holes into the plastic to mount the ones I used. Even if you screwed it up and had to order new plastic parts for the doors....I can't imagine that they would be too expensive. Of course, knowing the way things go when it comes to parts ordering.....they probably only come with the 2" speaker mounted and would be about $200/piece or something stupid like that.

How do you folks wire this new tweeter?

Originally posted by RX-Nut
How do you folks wire this new tweeter?

In parallel to the original tweeter. Spin9k's original explanation are right here. (http://www.rx8club.com/showthread.php?s=&postid=84368#post84368)

He also has a longer set of instructions here. (http://www.rx8club.com/showthread.php?s=&postid=86413#post86413)

Looks great 91 vert!

8th1der - the problem is that the speaker in there now is a full range and the needed full range sound near your ear is important too.

It really isn't that hard to do. The trick is to figure out where you want it up there.

RX Nut

Just look at the link from mmm to the directions that Spin9k posted. They are perfect. He even mentioned how that there is a snap inside a foam piece that you push in with your fingernail. Knowing that I removed nothing and just snapped it off. Very easy. The whole job was quick. The soldering took the longest.

Originally posted by 8th1der
Could you just replace the Bose speaker that is already there and have it sound just as good? I'm just leary about adding a speaker there. Knowing me I'd jack my car up! :D

The problem with simply replacing the speaker that is already there is that the Bose tweater goes down to 2KHz and any replacement would also have to as well.

This is hard to come by. The best solution I have found is the NX30 from Image Dynamics. It has a resonant frequency of 890Hz and can easilly be crossover as low as 1600Hz. This is very rare but necessary for proper direct replacement.

The only authorized internet dealer for them is sounddomain.com.

http://www.sounddomain.com/sku/IDSNX30

Not cheap but Image Dynamics stuff is top notch. I have them on order and I plan to do a direct replacement. I will hopefully be able to do it next weekend when it comes in. At first I plan to use the electrolytic capacitor that is already there, then I will upgrade it to something that is a little higher quality than electrolytic from Madisound.

-Mr. Wigggles

great pics thanks

I personally know Eric Stevens, the founder and owner of Image Dynamics. Their tech, Matt Borgardt, used to work with me at a shop in Houston called Audio Designs right before he went to work with Eric. It was with these guys that I would travel the country and go to all the shows. Me and Matt built several show cars together. Fun times. I remember when that tweeter (NX30) came out. We had the prototypes and did much of their testing. There wasn't much of an R&D center at Image back then so Eric would sent alot of his stuff to us. Matt would run all kinds of tests of speakers of all kinds including, tweeters, mids, horns, subs, ect. We'd also modify many existing units or have custom ones built for our show cars. See, some competitors do have an advantage! We had 2 different horn mold styles that made it to show cars as well as several custom, one off woofers. The midline CD-1 horn speakers were actually a spin off of my experiments in my RX-7. I wanted a smaller horn motor than the top model but didn't want the cheap piezo drivers of the CD-1E. I ordered some small dome compression drivers from an outside company and we tested them. Immediately we sent the frequency tests to Eric and he started to develop a mid priced horn around our findings. I also have 1 of only 2 pairs of fiberglass minihorns in existence. They didn't make them in fiberglass so it took a while to convince Eric to make me a pair. I now have a mold of that horn here at home but have never used it. My fiberglass horns may end up in an RX-8 one day. For a while they were physically molded into the top of my 2nd gen RX-7 dash with 8's in the floor in the front footwell of the car. No affect on drivability. Matt taught me alot. He was the head installer and I was 2nd in the custom installation department there. Yes there were more than 2 installers! Anyways sorry for the rambling. I just thought that MrWigggles might enjoy the history.

The reason the NX30 has such a low resonant frequency is because it is a 1" dome. Most other tweeters are smaller. Many are 3/4" domes while some are as small as 1/2". I swear by a larger tweeter and so does Eric. That was the smallest size he would make that tweeter in. He actually wanted a 1 1/4" tweeter but it would be too big package wise and many people like a less obtrusive speaker. That Radio Shack tweeter in the picture looks like a Piezo-electric tweeter. Extremely low quality but it does prove a very good point. That point is that human hearing is very easily fooled. 75-80% of the music comes from the midrange. This leaves only a small spectrum to come from the subs and a small amount from the highs. Any lack of frequency is noticable though. Even a low quality tweeter can sound good in a system if it is only there for fill. If it had to play lower, say replace that Bose 2", it would sound like crap. It's not what you have, it's how you use it! This is absolutely true in audio.

I like the idea of changing the tweeters so they point more towards the driver's/passenger's ears, but I think the add-on tweeters look hideous - no offense!

Isn't there a better way than adding on those wart-like surface mount things?

yes, its called flushmount installs

Well, I just installed a pair of JL Tweeters per the instructions on this thread and yes, they do sound good, but I'm not sure about all that better.

The reason why is the sound doesn't seem as balanced (that's the best way I can describe it). Granted, there are definitely highs were there wern't before, but it seems to aparent. I have played around witht he audio settings and just can't get it perfect. I'll keep trying however.

Right now, I'm still up in the air about the install.

Here are some pics for Mikeb.....

One more...

Rotorarygod,

Thanks for the exploits. I will let you know how the NX30 sounds.

Image Dynamics and the preachings of Richard Clark really helped me see the light that car stereo is more than just booming down the road. Front imaging is both the most important and hardest thing to achieve.

I actually prefer edge driven hard dome titanium tweaters but it is hard to find them in a small package with a resonance that goes as low as the NX30. A small German company called LPG makes some but they are friggin huge.

I do like the concept of crossing the tweeters low at 2KHz like Bose has done and then use a big woofer in the front doors. They just should have used a tweeter that can go a little higher in frequency response.

We should have a beer sometime.

-Mr. Wigggles

thanks dugless
looks great and JL is a great brand

MrWiggles: A beer sounds great to me. I'm a homebrewer. I didn't even notice you were in Houston. Where at? I'll have to break out the old photo albums sometime and show you some of our cars as well as my old RX-7 install pics. I still have the McIntosh amp from that car.

BTW: Don't get me started about Richard Clark. I've met him and chatted with him many times. He may know his stuff but he is a really big a$$hole! Many of us live to see him fail. He tries alot of experimental stuff and then makes claims before he porves them. When he fails we laugh at him. A great example was several years ago when he made a 5 foot woofer that he claimed would top 170 db with his 60000 watts of Krell prosound style amps powering them. The record then was about 160 or so. He hyped it up, made big claims, made bets, and drew a crowd to the DB drag lanes where he lined up against Alma Gates. (Wonderful woman. Saw her again a couple of months ago). Alma slammed back a 160.??? Richard's van started to rattle violently. The meter read about 145 db. A few seconds into the run there was a big boom. The roof of the van (concrete reinforced) flexed about 6" upwards and there was a huge puff of smoke. He blew the magnet off of that huge pos. Great moment. I've got the pics somewhere. The whole convention center exploded with laughter and Clark went home with his tail between his legs. I really don't like him. David Navone isn't much better.

Everything's bigger in Texas....


PICS, PICS, PICS, right Mikeb!!!!!:D

dugless
I couldn't of said it better myself

Originally posted by mikeb
yes, its called flushmount installs

I doubt there's room for another pair of speakers flush mounted in the little triangular panels.

why not pull out the stock tweets and flushmount new ones

What crossovers should be used with the NX30?

Also what other options does anyone see for mounting positions for another set of tweeters?

Sun stroke,

For now I plan to use the capacitor that is already there for the 2" Bose Tweeter which is also 4 ohms.

Since both speakers are 4 ohms, the first order crossover point will be the same at 2KHz.

From there I plan to do a spectrum response to see how to proceed with a 2nd order design.

Because the NX30 can go down to 2KHz faithfully (when most 1" tweeters can not), there is no reason to keep the Bose tweeter. I will be mounting the NX30 in the same location. that Bose was in.

-Mr. Wigggles

Well, I re did somethings and it sounds a lot better. I reinstalled the tweeters so they are not pointed directly at me anymore. I had the do some cosmetic stuff to hide the previous mounting holes with some vinyl but it came out OK.

Before I remounted them, I could shut my eyes and pretty much point to the tweeter, they were much too apparent.

Now the sound is much more balanced and I am happy with the install.

nice dugless and you added blind spot mirrors:D

Has anyone considered cutting a black plastic pipe in half, round off the end and use it as a sound deflector instead of installing a whole additional tweeter? I know that if I put my hand at the back of the existing tweeter, the deflection brings out the highs. So what if you just bought some plastic pipe at the same diameter as the existing tweeter, cut it to -- I dunno -- an inch or two in length. Cut that in half (to make a 'C'), then round off one end to make it look nice. Attach the other end somehow at the back of the tweeter.

Hell, that's a lot cheaper and easier, and you don't hack away at your <1 year-old car. Might at least be worth a shot.

I actually did that first. I fabricated a little deflector out of spray paint cap. it sounded good and helped but I needed a little more because of the sub.

I was thinking something very similar, but haven't got down to Home Depot or Lowe's yet to find the right kind of plastic.

Maybe I'll give a look this weekend.

I think adding plastic would look cheap IMO

Originally posted by mikeb
why not pull out the stock tweets and flushmount new ones

Well that defeats the purpose of mounting new tweeters now, doesn't it -- the main problem with the stock tweeters is not the speakers themselves, but the way they're aimed. If I yank the stocks and flush mount new ones, I haven't changed anything.

:(

duh
sorry

youre right

may i sugest
the ideal mounting position(for relocating and to add tweeters) would be at the corner of the dash facing upward against the windsheild so sound would reflect back in to the cabin at a wider angle
and also lift the sound stage above the dash.
any speaker mounted/pointed straight at your ear is as bad as wearing one sideed headphone.

I added the Image Dynamics NX30s without any problems.

First I did some listening tests:

http://www.s40concepts.net/RX8/P7070047.JPG

The results were very good. It is very easy to audition them since they are magnetic and stick right to the metal. Because Bose has HEAVY equalization in the 10KHz on up for their tweeter, I used the factory angling technique which doesn't shoot the tweeter right at the listener. This increased off-axis angle helps reduce the upper trebble. So I just mounted them right in the hole the Bose tweeters came out of with the facotry capacitor in series:

http://www.s40concepts.net/RX8/P7070050.JPG

That little piece of metal comes with the tweeters and I used it as a bracket to hold the tweeter in place. Once the tweeter pod is snapped back into place you would never know that any modification had occured except for one thing: they sound a lot better! I found it sounded much more enjoyable as a direct replacement.

But the heavy Bose equalization was still a little too much in the 10KHz+ range even with the high factory off-axis angling. So, I did a little simple acoustic dampening to reduce those frequencies. I took a black cotton t-shirt and cut two little circles out of it. I then sandwiched the cloth circles between the tweeter and the plastic grill - even better results. (Ps. reducing the treble output on the tone controls effects everything from 3KHz+ which is not desirable. I just wanted to reduce the upper trebble where the Bose equalization kicks in). Not bad for $120 and 2 hours of work.

-Mr. Wigggles

Ps. I have already ordered Dolby Prologic II decoder. If I go that route, and use seperate amplifiers and get rid of the Bose amps, the Bose equalization won't be there and I won't need in dampening. I am not sure though because the Bose system now sounds real good!

I knew that tweeter would work! :D

I wouldn't put tweeters up in the corners of the dash pointing straight up. You will only hear the one closest to you and that just doesn't sound right. Ideally you want to get your speakers the farthest away from you that you can. If you want to smoothen out the sound even more than just replacing the tweeters, install them in the a-pillars above the dash firing across the dash. Tweeters don't have to point at you to be effective. The logic for installing them in the pillars is based on distance. Measure the disatnce from your head to the door speaker. Now measure the distance from your head to the tweeter. Much closer isn't it?! Ideally you want these to be the same dostance from your ears for time alignment. The closer they are to the same distance, the less work the equalization will require to fix the peaks and valleys in frequency response. Now measure the distance from you head to the a-pillar. It may not be equal to the distance to the door speaker but it should be much closer. I can easily fabricate an a-pillar that you'd never know didn't come that way from the factory.

If you want to take it one step farther and don't want to use the Bose mids anymore, there is an easy way to make fiberglass speaker enclosures inside the doors. Go to a new home constrution site and get some scraps of blue or green foam wall insulation. Here is Houston they install this before the brick. You can also get it new at your home improvement store since it is only about $8 for a 4' X 8' sheet. You shouldn't need this much though which is why I say get scraps. This foam is very easy to cut with a knife. Cut it to the desired shape and then stack pieces together until you have the thickness desired. Use wood glue to attach each foam piece together. For any fine edges you can just use sandpaper to shape the new foam shape you've made. This will be your mold and should look like what you want the box to look like. After it all is shaped, line the entire piece of foam with masking tape. Make sure to cover it entirely as fiberglass eats foam very quickly. Take some carnauba car wax (not the liquid) and wax all the tape then start laying piberglass down in layers over the entire mold. Don't worry about cutting any holes yet. Take your time with this step. Do several thin layers of fiberglass. The key is in using as little resin as you can with as much mat as you can and still getting it all covered and smooth. If you call me I'll give you tips and if you are in Houston I'll help you build it! After you have all the layers done and you are satisfied with your work, cut out a circle in the fiberglass for the speaker. You could have also used a wooden front plate and glassed to it. Now pour some Acetone through the speaker hole. This will dissolve the foam mold. Just pour it out. Now reach in and remove the tape remnants. Add a little sound dampening to the back, and maybe a little polyfill and you have an enclosure! It sounds tough but is actually quite simple. Depending on how big you can get the enclosure and what type of mids you have, I could even possibly tell you how to port it for some great low end entension. Anyways sorry for the lesson in fiberglass 101. I just thought that it was the next natural progression. Once you start changing the sound it is hard to ever be satisfied. That's how I got to be an installer for so many years!

I like the idea of changing the tweeters so they point more towards the driver's/passenger's ears, but I think the add-on tweeters look hideous - no offense!

Much of the problem is the space. As you can see with those that have already mounted speakers, the spatial area is a tight. You need to keep the original speaker and it is not a tweeter - another problem and the reason for the addition to begin with.

I agree with the looks. I played with where to put them for some time. I really like the last pic here where the guy moved them. One thing though as far as looks, not all speakers look good at the same angle. My speakers looked horrible to me from a side angle- they have a snap mount so I had to consider that along with sound direction. Mine do not face me directly but rather more toward the steering wheel and the front area. I mounted them low to conceal the side view. The sound is good . I really like those dome-like speakers someone showed here too. In my area I was only able to find what I bought and what Spin9K recommended and I had to drive 40 miles to get those.

The sound quality is improved and that surely is the goal of everyone. A tweeter is needed. Rotarygod, they are piezos and they are cheap but as you said, that tweak of tweet is all my ears need. I hear the cymbal brushes and the crispier sounds now - all for $20!

Originally posted by RodsterinFL
Much of the problem is the space. As you can see with those that have already mounted speakers, the spatial area is a tight. You need to keep the original speaker and it is not a tweeter - another problem and the reason for the addition to begin with.


I have stated the following before

The factory 2 inch tweeter is 4 ohms nominal and has 22 microfarad capacitor in series with it. That means it is highpassed at 1800 Hz, period. So that's criteria: finding a replacement that can do 1800 Hz to 20 KHz

Finding a real tweeter that goes down that low is difficult but not impossible so you don't need to keep the factory tweeter. The NX30 can go down to 1 KHz so having NX30 crossed at 1800 Hz suits it just fine. Also since the diaphram is only 1.25" wide, it can stil go up to 20KHz, where a 2" paper cone tweeter simply can't.

If you haven't seen my install pics above, please do.

Now the NX30 isn't $20 that's for sure, but since it is a direct replacement we agree it looks a lot better. (I think it will sound better than an add-on tweeter, but there is no way to prove that without some side-by-side listening tests.)

-Mr. Wigggles

So, Mr. Wiggles --

I can't thank you enough for the advice about the NX30s. I ordered them last week and installed them last night and *holy crap* what an incredible improvement.

You can't tell I made any changes in the car until you turn on the radio... Installing them took about 40 minutes... couple snips, a little quick soldering job and you're in business.

I really can't believe what a profound difference adding these tweeters has made.

Thanks again Wiggles!

Matt

Could someone explain the Spin9k's directions, or translate them for the layman? My knowledge of circuits is rusty.

Also, what are decent 1khz 1" tweeters <50$ and where can i get them?

and does crossover refer to the point where the 2nd speakers take over, frequency wise? What happens if speakers overlap frequency ranges?

A crossover is an active or passive device designed to limit frequencies from above or below a certain frequency from reaching a speaker. So in English it means that certain frequencies are not allowed to get to a certain speaker. A tweeter wants a crossover at a higher frequency than a woofer does. A crossover can also block either high or low frequencies.

Technically all speakers will overlap in frequency since the crossover blocks frequencies at a certain rate per octave. You can't just completely stop every frequency from reaching a speaker. If a crossover has a slope of 12 db per octave, this means that if a tweeter is crossed over at 2000 hz, at 1000 hz the sound coming out of it is 12 db lower in intensity. What you are referring to when you ask what happens when speakers overlap frequencies is really dependant upon a couple of things. First of all, how loud are the frequencies that overlap in relation to each other from the other speaker? If the speakers are exactly the same distance away from your ears then this may not do anything bad. Then again maybe it will create a severe dip in output around that frequency or it may cause a big peak. There are many variables to that.

I don't even know of a decent tweeter for under $50. Most of the good tweeters out there don't want to play down to 1000 hz. This is very hard on a tweeter and the crossover slope needs to be steep. Somewhere around at least 24 db per octave.

so, can anyone provide step by step directions 'for dummies' ?

So let me summarize what I've gotten out of this thread thus far. 5 possible solutions:

1) Radio Shlock surface mount tweeters, ~$20 pair, augment pillar speakers, hooked in parallel using same crossover

2) Kenwood surface mount, price not given, hooked in parallel using same crossover. Also take the 2" Bose speakers out of their mount and used an Exacto knife to shave off the high side of the hole they mount into. Doing that directs the sound from pointing into the dash and directed it more towards your head.

3) JL Tweeters surface mount, price not given, hooked in parallel using same crossover.

4) Cutting a black plastic pipe in half, round off the end and use it as a sound deflector instead of installing a whole additional tweeter?

5) Image Dynamics NX30s, $120 pair, replace pillar speakers completely http://www.sounddomain.com/sku/IDSNX30

Sounds to me like the best solution, for my tastes anyway, is to bite the bullet and get the Image Dynamics NX30's to replace the pillar speakers completely. Just looks the neatest, while retaining the best sound compromise with the existing Bose amps and head unit.

So my question for Mr Wiggles is this: Did you do any angling of the NX30s so they point more toward the driver, much as was done in option (2) above?

Thanks...

He just did a straight replacement of the stock tweeters. They are still pointed the same.

Omicron,

Using the NX30 is a pretty straightforward exchange.

As far as angling is concerned, when you mount the tweeters, they are a pressure fit. You could put some sort of little standoff to angle the tweeter.

However, the upper frequencies (10KHz +) are pretty bright so leaving the unit the factory highly off-axis angle isn't such a bad idea. Like I said before, I used a small piece thin black t-shirt to do some additional high frequency attenuation.

Bottom-line you will probably fine something that works for you. If you don't damage the hardware that comes with the tweeter (namely the metal bracket), you can always return it to sounddomain for a full refund.

-Mr. Wigggles

Thanks MrWiggges and Rotarygod, that's helpful. Guess it's off to Sounddomain to get some NX30s! :)

BTW,

On the NX30's, they come assembled (without any disassembly instructions).

It may sound stupid but just so you know the front mounting ring screws off. It took me a awhile to figure that out.

-Mr. Wigggles

Well I put in a pair of NX30's tonight. Gawd, what a difference!! Noticed a little brightness on the high end similar to that reported by MrWiggles. I'll try his solution when I get some more time to tweak it.

I had trouble getting a pressure fit to stay put so I ended up using some black electrical tape to hold the tweeter in place. Used a Q-tip to apply the tape in the tight spots.

Now that the NX30's are in, I notice the muddyness of the front door midwoofers. The other thing that drives me nuts is the amplifier hiss I can now hear with the tweets. It's objectionable. You'd think this was a 1970's POS KMart amp. Guess I'm being too picky since the hiss will get swamped by the road noise. No high, no lows, it must be Bose ;)

"No high, no lows, it must be Bose" <== Oh, I like that! Almost as good as "Absence makes the fart go Honda." :D

So what you're saying here is that the NX30s (which I too am considering) improve the brightness of the system, but make the front doors sound muddy? If so, is there an overall improvement, or is it a wash? Thanks...

Yeah, the NX30's do three things IMO:

1) faithfully reproduce the high-mid and high frequency range with nice imaging for such a small listening space

2) faithfully reproduce the thermonic hiss in the junky Bose amp that was far less noticible with the cheap Bose tweeters.

3) caused me to notice the sloppy response of the Bose mid bass speakers.

#3 is like owning a Neon and a minivan. You trade in the Neon for an Rx8 and now somehow the minivan seems uglier and handles even worse. Kinda psychological ;)

Just a note for those who like Opera, the NX30's are great without the black T-Shirt mod. The arias ring beautifully.

Now I need to bring in the bottom end.

Originally posted by MuzzleFlash
Well I put in a pair of NX30's tonight. Gawd, what a difference!! Noticed a little brightness on the high end similar to that reported by MrWiggles. I'll try his solution when I get some more time to tweak it.

I had trouble getting a pressure fit to stay put so I ended up using some black electrical tape to hold the tweeter in place. Used a Q-tip to apply the tape in the tight spots.

Now that the NX30's are in, I notice the muddyness of the front door midwoofers. The other thing that drives me nuts is the amplifier hiss I can now hear with the tweets. It's objectionable. You'd think this was a 1970's POS KMart amp. Guess I'm being too picky since the hiss will get swamped by the road noise. No high, no lows, it must be Bose ;)

Just when I thought I found the answer to my disappointment with the Bose muddy/flat sound, Muzzleflash had to post his experience.

In the middle of cursing Bose for making a such a piss poor sound system for our 8's, I realized that if it was perfect, we wouldn't be having all this fun trying to tweek (tweet? :P) it to suit our tastes.

I'm also curious how the 1" NX30's fit easily into the 2" Bose holes? Do the NX's come with an insert for the 2" hole?

FYI,

Sound Domain has the NX30 on sale for 15% off (until when?). The price including free shipping is $101.95

http://www.sounddomain.com/sku/IDSNX30

It's times like this when I am glad I have the connections that I do. Since I used to work with Matt from ID, I can get their products at manufacturing (not dealer!) costs. This is only for me though and I can't do it for anyone else. Sorry.

While you're cursing out BOSE for making such a piss poor sound system for the RX-8, curse them out for the rest of their product line as well. BOSE is the best thing that could ever happen to good audio companies. No highs, no lows, must be BOSE!

Haven't ordered the NX30s yet, but I did add a JL e4300 amp.

The system sounds completely different now, money well spent.

if you add the speakers in parrallel then you are deminishing the imopeadance that the amp sees. This will change the output charateristics of both speakers. THis is wrong for the amp. Not to mention the blurred image of high frequencies in four directions. What a mess. Replace them all together. I was told that the stock BOSE speakers are 1 Ohm speaks also... I woudl guess the replacements are 4 Ohm speaks. That would suggest the amp sees 0.8 Ohms... Not too far off I suppose but stilll... better to have just one set of tweets.

That obviously only applies on cars with the BOSE systems. The rest o fthe people can easily swap them out.

BOSE has internal equalization built into their amps to account for the deficiencies of their speakers. By just swapping in an aftermarket speaker for the BOSE drivers, you are only feeding the new speakers 1/4 of the power that was going to the BOSE speakers and you are still equalizing the new drivers which have entirely different needs.

[i] At first I plan to use the electrolytic capacitor that is already there, then I will upgrade it to something that is a little higher quality than electrolytic from Madisound.

-Mr. Wigggles [/B]

What effect would a higher quality electrolytic capacitor have? Also, what the heck is an electrolytic capacitor?

electrolytic capacitors don't behave like ideal capacitors at high volumes (i.e. high voltages) they start to behave in a non-linear fashion and that causes distortion. If you listen at low volume it probably won't make a difference, but if you crank it then something of better quality will probably work better.

Mylar are typically the best or NP0/C0G ceramic. Any of the capacitors sold here will work great:

http://www.madisound.com/

Try not get one that is too big.

-Mr. Wigggles

Juat wait until you guys figure out how to design and build diaural series crossovers. Perfect phase alignment and only 1 resistor and one coil. No caps to mess things up.

Originally posted by MrWigggles
I added the Image Dynamics NX30s without any problems.

First I did some listening tests:

http://www.s40concepts.net/RX8/P7070047.JPG

The results were very good. It is very easy to audition them since they are magnetic and stick right to the metal. Because Bose has HEAVY equalization in the 10KHz on up for their tweeter, I used the factory angling technique which doesn't shoot the tweeter right at the listener. This increased off-axis angle helps reduce the upper trebble. So I just mounted them right in the hole the Bose tweeters came out of with the facotry capacitor in series:

http://www.s40concepts.net/RX8/P7070050.JPG

That little piece of metal comes with the tweeters and I used it as a bracket to hold the tweeter in place. Once the tweeter pod is snapped back into place you would never know that any modification had occured except for one thing: they sound a lot better! I found it sounded much more enjoyable as a direct replacement.

But the heavy Bose equalization was still a little too much in the 10KHz+ range even with the high factory off-axis angling. So, I did a little simple acoustic dampening to reduce those frequencies. I took a black cotton t-shirt and cut two little circles out of it. I then sandwiched the cloth circles between the tweeter and the plastic grill - even better results. (Ps. reducing the treble output on the tone controls effects everything from 3KHz+ which is not desirable. I just wanted to reduce the upper trebble where the Bose equalization kicks in). Not bad for $120 and 2 hours of work.

-Mr. Wigggles

Ps. I have already ordered Dolby Prologic II decoder. If I go that route, and use seperate amplifiers and get rid of the Bose amps, the Bose equalization won't be there and I won't need in dampening. I am not sure though because the Bose system now sounds real good!


Mr. Wiggles,

Can you repost the pictures? They seem to be missing from your original post. Also, I just wanted to make sure you unsoldered the Bose capacitor and resoldered to the NX's? Also, I'm intersted in how you used the piece of metal that came with the NX's to hold the tweeters in place. I purchased a pair and it would be helpful to see how you held them in place before I start experimenting myself.

Thanks

Well, I finally replaced the stock bose tweeters with NX 30's after having them sit around for a month. Wasn't sure what I was doing but finally cut the wires over the weekend so there was no going back. I made a mess of the wires and soldering, but the tweeters work and are taped into place with electrical tape.

I can't say that they sound that much different, but the highs are definitely better and noticeable with the NX's. After listening for a few days, I can only say that the sound is more enjoyable. I wanted to make sure I wasn't imagining that they sounded better. Definitely, the "flatness" of the original bose tweeters is gone.

Is the upgrade worth $100? An emphatic, YES! The improvement is subtle but definitely worth it.

Anyone who wants a relatively inexpensive and easy upgrade should try it.

2007 Thread Revival!

I know this thread is over 3 years old, but I just wanted to add that I just ordered a set of the Image Dynamic NX30 tweeters. I've been reading and searching all over the forum and came to the conclusion this was probably the best solution to the flat sounding Bose system.

I don't have a ton of expertise in car audio, but I've installed a few stereo systems in my time as a teenager. One question for the audio experts here:

Do you think I should just re-use the Bose crossovers or should I order some new ones?
The Bose crossovers have a cut off at 1800 Hz. The NX30 tweeters can go as low as 900 Hz.
Should I just order some crossovers from Crutchfield while I'm at it?