Obsessive-Compulsive Tweeter Install

[ChrisH]

I have this annoying perfectionist tendency that leads me to more do a lot more work than is strictly necessary. Here is another case.

I am upgrading my audio system. I like good soundstage imaging, and the tweeter performance is critical to that. I bought 5.25 inch component speakers for the front (1 inch tweeters). I have seen others install their tweeters pointing up into the windshield, which will muddy the imaging a bit. So, I decided to point the tweeters at the occupants. Easier said than done.

With some woodwork (using a thick dowel - really a woodon closet rod), a miter box on the 22.5 degree angle cut, some glue, flat black enamel paint, and 3M exterior mounting tape, I came up with the following (see photos below). I installed them right next to the woofer so I could run the wire into the side of the woofer frame (so I wouldn't have to cut more holes in the dash).

On the good side, the sound is great (very good imaging for a car - I have a professional audio test CD for testing the response and imaging of a sound system). My wife, who keeps wondering why I would modify a perfectly good new car, really liked how they came out. She said they match the general interior design pretty well (the mounts are rounded, similar rake angle as the windshield, and the circular look of the tweeter matches the circular air vent theme).

On the bad side, it took me a lot longer than anticipated, particularly since the woofer basket was too large for the hole in the dash and there wasn't room for a spacer, so I had to cut the aluminum hole in the dash larger using a Dremel - boy was that a lot of work. (I have Directed Audio Studio S550 speakers for the front - good speakers that I got on a close-out sale.)

I have already replaced the head unit to an Alpine 9833, and that made a big sound improvement even with the old speakers (and yes, I did play with the sound environment adjustments on the Blaujunk). But, the front speaker change made an even larger difference. Next, rear speakers, then a subwoofer, and maybe an amp.

Oh, and from the driver's position, they do not block my visibility at all.

[Trueweb]

Aside from the fact they look a little funky, that is exactly the way tweeters should be positioned for proper sound imaging.

That certainly does look like it was a lot of work, very creative solution!

[Chococar]

Nice job

[peck555]

way to go

[rob13572468]

Originally Posted by Trueweb

Aside from the fact they look a little funky, that is exactly the way tweeters should be positioned for proper sound imaging.

That certainly does look like it was a lot of work, very creative solution!

except that you want each tweeter to actually point towards the far side listener in the vehicle (i.e. driver side tweeter points towards the passenger and passenger tweeter points at the driver) that way the off axis response of the near tweeter attenuates the sound slightly to compensate for being so close while the far tweeter is on axis to compensate for being much further. the way it is currently set up, each person get blasted by the tweeter nearest them which does not sound nearly as good.

[ttowsontt]

wow great job

[ChrisH]

Originally Posted by rob13572468

except that you want each tweeter to actually point towards the far side listener in the vehicle (i.e. driver side tweeter points towards the passenger and passenger tweeter points at the driver) that way the off axis response of the near tweeter attenuates the sound slightly to compensate for being so close while the far tweeter is on axis to compensate for being much further. the way it is currently set up, each person get blasted by the tweeter nearest them which does not sound nearly as good.

Actually, I pointed both to the center for that reason. It gives a slightly larger off-axis angle on the near side tweeter as compared to the far side (to the appropriate ear) which causes the near side to be in a lower volume region of the radiation pattern, but then the near side is closer giving a higher volume. I didn't do anything systematic to determine the perfect angle for balancing the radiation pattern versus distance (and radiation pattern will vary for different model tweeters), but it seems pretty close because when I adjust the L/R balance, it sounds best right at center or maybe slightly to the right when I am in the driver's seat. Close enough in my book. I checked that for high and mid frequencies. However, the real criteria is you want the woofer and tweeters to have the same left/right volume offset so that when you adjust the balance in the head unit, both woofer and tweeter will move together to achieve balance across the frequency range. If you achieve tweeter balance by only adjusting the tweeter angle, you could end up out of balance on the woofers.

[ChrisH]

I just installed new rear speakers today. I went with JL Audio TR650-CSI (6.5 inch components). They are the lower end of the JL Audio component line. I have them in my Honda Accord, and I like the bass and midrange response on the woofers, although I am less impressed with the tweeters. However, since the rear speakers are for audio fill and to add some bass (you don't want high frequencies from the rear), I thought these would be good reasonably priced rears. So, I installed just the woofers (and left the tweeters in the box). It sounds very good, and by not having the tweeters in the rear, I am not detracting much (if at all) from the soundstage imaging and presence of the front speakers.

For the installation, the speaker is deeper than the stock hole (even with foam removed) so I did have to put in about a 1/2 inch spacer ring, and cut out a bit of the sound deadening foam to give more space for the magnet on the upper side. I also had to widen the speaker hole, which I did with a Dremel using a cutter bit. If you have a cutter bit, it is pretty easy to do. I also used some foam rubber weatherstripping on both sides of the ring to give a better air seal. My only problem left is I am getting a resonant vibration somewhere in the cockpit when playing loud low frequencies. I'll have to track that down.

By-the-way, I have listened to both the coaxial JL Audio speakers and the higher end component speakers. If all you want is the woofer for the rear, I highly recommend going with just the TR650-CSI woofer. You would be hard pressed to notice the sound difference of just the woofer relative to the higher end speaker's woofer. Also, much of the cost of the higher end ones is in the cross-over and the tweeter. Right now, I don't feel I need to explicitly block higher frequencies from the rear woofers, but if I change my mind, a simple in-line filter should be sufficient.

After testing, it sounds very nice, and I am quite pleased. If the car is off, I don't even feel I need a subwoofer. However, while driving the car, it is obvious that a sub is needed to make the low end frequencies stand out above the road, wind and engine noise.

Also, the system is plenty loud enough with very good clarity for driving at 80 mph (except for the very lowest frequencies), and the volume on my Alpine 9833 head unit is nowhere near its maximum (I don't notice any distortion). Of course, the 9833 is one of the higher power and lower THD rated head units. But, I didn't even run higher current power and ground lines to the head unit - I just have the standard radio power and ground. If I ran the Alpine head unit at even half its max power, I would probably blow the fuse, so I may do something about that in the future just to avoid blowing fuses by mistake. Hence, I don't see the need for an external amplifier (thankfully). Of course, if I got a sub, it would need an amp.

[ttowsontt]

that is a very sweet setup.....as i was driving today with the top off i was wishing for some more db's.....i looked at your setup and thought that i need a tweeking

[ChrisH]

I was just asked for more information about the tweeter install, so I decided to post it here in case anyone else is interested.

I have attached some pictures at the end of this post of the mount before installation. You should look at the pictures in the first post of this thread and at the end of this post before reading the text below.

I used standard wooden closet rod for the tweeter mounts, which is about 1.3 inches in diameter, and fit the back of the tweeter housing very nicely (one inch diameter would have been too small).

The mount stand was made from two pieces of rod. Where they join, I just glued them with wood glue. I used the 22.5 degree angle cut on my miter box for the cuts where they join, and the cut that mounts to the dash. The cut that mounts to the speaker was just a simple 90 degree cut (so the end face is round at the speaker housing). By-the-way, on the picture showing a profile of the stands, you see some horizontal lines. That is just the camera flash reflecting off the tile counter.

The tweeter housing is simply screwed into the stand with a short wood screw.

Before gluing the two rod segments together, I drilled a hole through each piece for the speaker wire, so that when glued together, there was a hole through the length of the stand. This aligned with the wire hole in the tweeter housing. I made sure that it was not at the tweeter housing screw's position (test fit with your tweeter housing before drilling).

After the glue was set, I sanded the joint to round it off so that the stand looked like a single unit. I also gently sanded the whole stand to minimize wood grain lines before painting. For painting, I used primer first, sanded the primer (again, to minimize grain lines), then painted with spray flat black enamel. I hung the stand through the wire hole (from a short tree away from the house) in order to paint it.

The wire comes out the bottom of the housing to the side. I used a Dremel tool to carve out a channel. The wire then is routed into the edge of the woofer housing next to the tweeter stand (see first post in this thread). I had cut a notch in the woofer housing and grill to allow the wire to be fed into it, which then goes down into the dash through a hole in the woofer frame.

The stand is held to the dash using two methods - a plastic tab and 3M exterior mounting tape (the thick gray stuff). You can see the tab in a few of the pictures. When mounted, the tab slips under the woofer frame to provide some mechanical support once the woofer frame is screwed down tight to the dash. The plastic tab piece also encloses the wire coming out of the stand, forcing the wire sideways. I created the tab by carving up the housing of a black VHS tape (Dremel tool again). Originally, the tab was glued to the stand (as shown in the picture of the bottom of the stand with the tab attached). That didn't work out very well (it kept coming unglued). I later used two very short flat head wood screws to attach the tab to the stand. (I used a drill bit to create a counter-sink in the tab so the screw heads were flush mounted.) I covered the bottom of the stand with the mounting tape (almost to the edge) and pressed down fairly hard to make sure it stuck. Don't just use a few little pieces - it will come undone. Cover as much of the bottom with tape as you can.

Not shown in the photos is that I also painted the speaker wire black near the stand, so that it wasn't as obvious in the small gap as it came out of the stand and into the woofer frame.

And, just to complete my audio install description in this thread, post #8 above describes my rear woofer install (DON'T PUT TWEETERS IN THE REAR!!!), and I did later add a subwoofer (JL Audio Stealthbox) and an amplifier behind the passenger seat, as described in the following posts.
Amplifier Behind the Passenger Seat?
Amplifier Behind the Passenger Seat?
The tri-mode crossover I used to power the subwoofer also filtered out the low frequencies (below 100 Hz) from the 6.5 inch rear woofers, which helped them out quite a lot (no more buzzing from the rear speakers on bass heavy music, and seemed to improve their clarity).

I also added an iPod. Mounting description and pictures are shown in the following post:
iPod radio suggestions

[SIIK2NR]

Originally Posted by Trueweb

Aside from the fact they look a little funky, that is exactly the way tweeters should be positioned for proper sound imaging.

That certainly does look like it was a lot of work, very creative solution!

Agreed. An eyesore...but probably sound great!

[ekological]

How much does it weigh?