Well, I admittedly hate the bose system in our cars. Mainly the muddy mid-bass, distorted mids and lifeless treble. But I'm pretty broke right now so a proper system is not in the cards for awhile. From info on this forum and diyma I tried out a plan that so far has only cost me $50 ($30 of which was shipping to Canada). I know fourthmeal and other audiophiles will scoff but it's all I can afford at the moment. Here's what I've done to address my biggest beefs.
Muddiness: Others have sound deadened the doors and noticed a huge improvement in mid-bass clarity, but sound-deadening costs money, even raamat. I faded the system to the front by 5 and noticed an improvement, still muddy but not nearly as bad with the rear mids turned down. It's survivable now and a free "mod". Lightly tapping the mid while it's in the door reveals a very hollow, resonant sound, so when I have more coin deadening is certainly on the list.
Treble: On having a look at the bose tweeters I found that they have cheap plastic domes, which is possibly the worst sounding tweeter material known to man. They also have a tiny 4.7 microfarad cap on them for a crossover, which on a 4-ohm tweet results in around 8.5khz. This means the mid has to do most of the work and the tweets are just there to fill things in a bit. After reading some diyma reviews I bought these:
http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=275-035
Dirt cheap, but they have a soft dome and apparently sound way better than $12 would suggest. With a couple of wraps of electrical tape around the body they are a perfect press-fit in the factory hole. I bought some 10 microfarad caps for a roughly 4khz high-pass. HUGE improvement! Cymbals sound like cymbals now, and the lower x-over makes the upper mid-range sound cleaner and more natural. Stock I had the treble at +3 to get any crispness, now it's flat and balances with the mids pretty well. On the down side 4khz with a 6db slope is pushing them a bit, if I really crank it they get a little spitty but for the low power level of the bose amp it's not too bad.
Distorty mids: WTF? As other members have stated there is no x-over at all on the mids, the poor things are trying to play the full audio range and they just can't. I bought some 0.10 millihenry inductors for the front mids, low-passing them around 3.1khz (available inductor ratings with a 2ohm mid doesn't leave many options). This really cleaned up the mids, there's a bigger gap than I'd like with the tweet x-over but at a 6db slope it blends pretty well. After doing everything to one side I opened the doors and ran back and forth to compare my ghetto rig to stock: The ghetto mid was only playing bass and mid-range decently cleanly, the stock mid was very thrashy in comparison as it tried to play the upper-mid/lower treble. The ghetto tweet filled-in the upper-mids and up nicely and sounded surprisingly natural, the stock tweet was only playing treble quietly and sounded like a good tweet with a dirty sock covering it. When I have more time I'll finish the other side, let the tweets loosen-up and give a more detailed sound review.
Sorry for the stoopid long post but I'm pretty happy with how this is turning out and wanted to share with everyone. My next project is a budget sub setup that doesn't take up any space and hardly costs anything. I'm toying with the thought of this in-place of the bose "sub":
http://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?ProductID=18290
(not great, but at least it's an 8") but I'm saving up and haven't really decided on what to do, any ideas?
Muddiness: Others have sound deadened the doors and noticed a huge improvement in mid-bass clarity, but sound-deadening costs money, even raamat. I faded the system to the front by 5 and noticed an improvement, still muddy but not nearly as bad with the rear mids turned down. It's survivable now and a free "mod". Lightly tapping the mid while it's in the door reveals a very hollow, resonant sound, so when I have more coin deadening is certainly on the list.
Treble: On having a look at the bose tweeters I found that they have cheap plastic domes, which is possibly the worst sounding tweeter material known to man. They also have a tiny 4.7 microfarad cap on them for a crossover, which on a 4-ohm tweet results in around 8.5khz. This means the mid has to do most of the work and the tweets are just there to fill things in a bit. After reading some diyma reviews I bought these:
http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=275-035
Dirt cheap, but they have a soft dome and apparently sound way better than $12 would suggest. With a couple of wraps of electrical tape around the body they are a perfect press-fit in the factory hole. I bought some 10 microfarad caps for a roughly 4khz high-pass. HUGE improvement! Cymbals sound like cymbals now, and the lower x-over makes the upper mid-range sound cleaner and more natural. Stock I had the treble at +3 to get any crispness, now it's flat and balances with the mids pretty well. On the down side 4khz with a 6db slope is pushing them a bit, if I really crank it they get a little spitty but for the low power level of the bose amp it's not too bad.
Distorty mids: WTF? As other members have stated there is no x-over at all on the mids, the poor things are trying to play the full audio range and they just can't. I bought some 0.10 millihenry inductors for the front mids, low-passing them around 3.1khz (available inductor ratings with a 2ohm mid doesn't leave many options). This really cleaned up the mids, there's a bigger gap than I'd like with the tweet x-over but at a 6db slope it blends pretty well. After doing everything to one side I opened the doors and ran back and forth to compare my ghetto rig to stock: The ghetto mid was only playing bass and mid-range decently cleanly, the stock mid was very thrashy in comparison as it tried to play the upper-mid/lower treble. The ghetto tweet filled-in the upper-mids and up nicely and sounded surprisingly natural, the stock tweet was only playing treble quietly and sounded like a good tweet with a dirty sock covering it. When I have more time I'll finish the other side, let the tweets loosen-up and give a more detailed sound review.
Sorry for the stoopid long post but I'm pretty happy with how this is turning out and wanted to share with everyone. My next project is a budget sub setup that doesn't take up any space and hardly costs anything. I'm toying with the thought of this in-place of the bose "sub":
http://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?ProductID=18290
(not great, but at least it's an 8") but I'm saving up and haven't really decided on what to do, any ideas?