averyrm

I guess what I don't understand is that a lot of what you're saying doesn't really apply to car audio:

The audio source will be digital, so pointing out that "vinyl is best" doesn't really help. A good DAC isn't a bad idea.

The Bose headunit has been shown to output a very flat signal to the amp (not so much after), so you can't ask much more of the source. You'll hear more difference from speakers than wires or a new HU.

An external amp is preferred quality-wise over an internal amp. Some of the best head units don't even have an internal amp (p99rs).

Wiring doesn't matter that much so long as it's properly sized an insulated. Check this out : Speakers; When is good enough, enough - Page 3 coat hangers sound just as good as monster cable.

An elitest attitude towards music just rubs me the wrong way. For most ears there is a better, cheaper way to enjoy it. Especially in a sub optimal environment such as a car.

Steve Dallas

I don't have a lot of time to devote to this tonight, but I will chime in with a few thoughts. Keep in mind I have been working with audio since I was a mere kiddo.

1. Speakers offer the absolute most bang for the buck upgrade, and anything you do upstream cannot be heard through lousy speakers. So start with the speakers.

2. Sound reproduction requires clean power, and at least 50% more of it than you might think. Modern technology has made this relatively cheap. Do it if it is feasible.

3. Speakers require good, inert enclosures to sound their best. This is where Damplifier and Dynamat come in. They go a long way to converting lousy enclosures into less lousy enclosures. And, the difference is very audible--at least while you are stuck at the stop light.

4. The source can be important, but many are good enough already unless you want more features. Most source units are decent--especially the preamp outs. The Bose HU sends a flat signal to the amp, as I have demonstrated. There appears to be some jitter, but that could easily be in the laptop sound card I used to take the measurements or anywhere else in the testing system. I am willing to bet the Bose HU is fine in terms of audio. Further, in a car audio environment, while motion is occurring, most listeners cannot discern better DA converters. Don't believe me? Several recent studies have proven that self-proclaimed audiophiles and professional recording studio engineers cannot discern higher bit rates or premium converters with better accuracy than 51%. In any case, the HU is the most expensive component to replace, and the law of diminishing returns (in terms of audio) is in full effect here.

5. Cables only need to be good enough in car stereo environments. Any mid grade cables will suffice as long as they are capable of carrying the required current or have sufficient shielding according to their purpose. Home stereo and recording studio environments are different, as the noise floor and other aspects of the listening environment are completely different than what you find in a car--especially a small sports car. This car is noisy when it is moving, the Fletcher-Munson curve is always in play, and the terminal acoustics are absolutely terrible. High end cables will gain you almost nothing here. It is better to focus on finding good ground points, etc.

Steve Dallas

I will vigorously disagree with you about the order of operations in upgrading a car stereo (see my previous posts), but I would rather focus on the idea that I think you have missed my point. I am not pondering adding power. I am thinking of replacing the Bose amp, which I have shown to contain strange filter networks, which are assumed to enhance the sound of the lousy Bose speakers, with a flat EQ amp of similar specs to better compliment my newly installed non-crazy speakers, which expect to be fed a flat signal. The amp to which I linked can use all the factory wiring and is smaller and lighter. The drawbacks are in the specs (THD and SNR), but those specs can't be any worse than factory. I probably won't do it, since the system already sounds a thousand times better than before, and I only drive this car once or twice a week plus track days, but it certainly is tempting to keep pushing the envelope of what can be done while keeping a factory appearance.

kickerfox

Doesn't that just contradict what you said a few posts back?

The speakers play THE most important role in ANY audio system. Going from one head unit to another or swapping amps (Bose excluded) or w/e will have less of an impact on the sound as changing speakers. These days it's easy to produce a flat source because all the DACs and audio stages are IC chips and everyone is stuck using the same crap.

It's not like the old days where every stage of your source was designed from scratch using individual components.

stvnscott - I think it's lucky for us that the Bose HU signal is as flat as it is. We used to say the non-bose guys had it made but if there's any EQ'ing going on in their HU, they're f'd. At least we have a good starting point. I've already eliminated the Bose amp. Don't fret it. You'll be happy when you do. Don't forget to plug the big hole in the deck when you remove the Bose amp. Once removed, take a look inside. $50 says it's class-d.

averyrm

Hmm, shouldn't be. Speakers = better upgrade, so I agree with you.

I'd been drinking when I'd posted at least one of those though.

djgiron

I was wondering if you had thought about some of the shallow mount subs to put in the doors? The 10"Alpine SWR-T10 has a cutout of 9-1/8" and top mount depth of 3-1/4"? There are few 8" as well (the Pioneer is a free air design). I am not sure of the cutout size in the door or the mounting depths, but to free up trunk space I was thinking I could go this route, just add a sub amp and remove the Bose "subs" completely? Would be easy to make a mounting bracket to fit the 8's if the 10's wouldn't fit. Just a thought I had. Replacing the tweeters, rear deck and adding the subs may push all the mids to the rear though depending on what the Bose "subs" are outputting. After looking back through, it appears as if the 9" Bose are handling the mids and lows . . . My idea would not work if this is the case . . . The Pioneer TS-SW841D has a freq response up to 1500Hz, however I am sure the rolloff on that will still leave a big midrange hole, I just saw them on crutchfield so I am looking for any spec sheets for them . . . The Pioneer website doesnt show the FA charasteristics and shows -5dB at 500Hz in the best case scenerio, but stops there. Wonder if that would work?

kickerfox

The problem I'm having is the lack of midbass/midrange in the front. The 9" Bose woofer/sub does a poor job reproducing mids. Bose also put a fairly large (22uf) cap on the door tweeter attempting to push that little 1.5" paper tweeter into the midrange. That combined with the center channel is where all the mids are coming from but a center channel can damage stereo imaging. To me it sounded very harsh and my first stereo mod was replacing the door tweeter caps with a 10uf.

My next step was to replace the Bose tweeter completely with a 3/4" dome. Now I needed to get the door woofer to play higher into the mids. The 8" Pyle midbass I used did a fairly good job at it, while still maintaining quite a bit of midbass punch, but it fell a little short of the upper midrange, so, I'll be replacing the tweeter again with a larger 1.25" dome tweeter. I feel then I will have a nice starting point.

Pyle PBW8S Pyle PBW8S 8" Midbass 292-2532

280wrms
1.5" voice coil
3ohm
95-5000hz
Fs 108hz
Sensitivity 96db
Depth 2.87"

djgiron

That is the rub I guess, get some mids and midbass or just bass . . . I am just hoping to not use my trunk up with a sub (I have the spare tire kit so my trunk is already smaller). Maybe I will spring for the Focal Integration ISS 200 (if there is enough depth that is), runs the full range 40-20k with an 8 and tweet component system . . . I dont need to go bumping down the street, but I like my music full and a good bit of lows.

kickerfox

Even though the Pyles are considered a midbass driver they do play quite low. If I turn off my high-pass and unhook the sub it still sounds better then the Bose system and I could live with it but I do like the deep "cinema bass" that my 8" subs provide.

I'm sure the Focals will sound great up front and don't underestimate what a good set of 6x9s can do in a rear deck. I have a feeling Bose high-passed the factory rears because the Pioneers I stuck back there give the illusion of a subwoofer being in the trunk. If you do your rears, cover/seal the deck with Dynamat and put an extra layer around the edge of the speaker opening. Don't get a 6x9 with tweeters that stick up more then ~1/2" or they hit the covers. Also, the rear tweeters are seriously lacking output. New speakers bring new life back there.

Watch your depth up front. The corner of the window is right behind the magnet. Next time I shop I'm going neodymium.

djgiron

How much clearance do you have with your Pyle's (approx is fine) if you recall?

kickerfox

Maybe 1/2"

Geran

Although I don't own a rx8 yet, i seriously plan on getting one. this post help me understand more about the car in terms of sound quality. i currently own a 1997 jeep wrangler that has an amazing sound system. It is crisp and loud, although the wind noise while driving over 25 mph drowns out almost everything. Your post helps me understand more about the bose system, and prevents me from doing my own trial and error. Thank you.

kickerfox

If you do, set aside a couple grand for a new engine.

Beefy98

So when u spend another 6 grand for the touring model the "300 watt" BOSE in it is still crap? I have the sport and the stereo is so bad it defies description.

paimon.soror

iTrader: (15)

Bose in general is overpriced garbage if you are a true audiophile. Not saying I am, but bose is to speakers what monster is to cables .... marketing genius

djgiron

Bose basically gives good midrange in everything they put out. Since most of their systems are single driver based, they usually have to roll off the lows and highs when the volume is turned up so as to not distort or "muddy" the mids and highs. It appears in this system, they have a midbass driver in the door with a tweeter. Tweets can not really handle the lower part of the midrange and a midbass driver can not handle the upper end. What they have to do is roll off the bass at louder volumes from the midbass driver in order to keep the mids clear. The saying I think goes "No high, no lows, must be Bose". So, if you don't like detailed highs or low end, it will be fine. As an example, go into a good audio store and listen to "She Talks to Angels" from the Black Crowes on a Bose system, then listen to the same song on a good set of speakers, there is a high cymbal in that song (that can be a little overpowering) which you will barely hear on the Bose and will be loud and clear on a better system. If you can find a place that sells a good set of KEFs, it will sound like someone was standing in front of the Bose blocking all the details when they switch to the KEFs it is like the person moved out of the way, the difference will be pretty shocking. Same deal in a vehicle, although with all the engine and road noise they can hide it better. This is the reason people put sound deadening materials in their cars, to make it quieter and easier to hear the nice subtleties in the music.

Steve Dallas

Yes. If I did not have a lot of prior history with Bose, I would have been SHOCKED at how much engineering went into making such a lousy sounding stereo. They would have done much better to make a high power head unit and pair it with some Pioneer or similar speakers. It would have sounded much better, and think of the weight savings considering the amp and all the wire they used.

kickerfox

For an OEM system it's not horrible (compared to most typical OEM stereo/speakers) but sold as a "premium upgrade", I agree. It falls well short of it's price tag. It seems like Bose threw 3 dozen darts at the dart board and none of them hit a bulls-eye. I do like the amount of bass they got out of the doors though but that's it.

Bose has always sucked in the home stereo market but I am somewhat impressed how good they get very inexpensive drivers, in an equally cheap box, to sound. Nothing justifies their price tag though.

Steve Dallas

Things will be changing soon. I ordered an Alpine MRV-F300 amp to replace the Bose amp and a pair of Alpine R Series component speakers for the front doors. PVC mounting brackets for the speakers and amp are also on the way. It may take me a few weeks to get to it, but all traces of Bose except for the head unit will soon be gone.

I need to decide what I am going to do about the balanced inputs to the Bose amp. Like kickerfox, I am measuring a constant 4.5VDC to ground from both conductors of each input to the Bose amp. I will probably just build a simple 4 channel direct box, but I will look at what I can buy first.

kickerfox

I used 2 capacitors (per channel) to remove the DC offset.

kickerfox

Scott - How's the audio system going?

After spending some more time listening to the Pyle 8" midbass speakers, I decided they're a little boxy sounding. Fs is probably too high. Too bad because they really do put out a lot of sound (drums are incredible) but there's one really peaky frequency ruining it. As loud as they are, I had trouble getting a tweeter to blend with it (tried 4 different sets) and I'm not going to bi-amp the system. Then it dawned on me. Why not an 8" 2-way ceiling speaker?

So I bought these.

Not in the car yet but they sound really good hooked to my home receiver. My 12w/ch tube amp was uncomfortably loud playing through them.

Steve Dallas

I haven't done anything with it yet. I have all the parts here, but my free time with the car has been consumed by a suspension replacement nightmare. That is all sorted out now, but with track season starting up in earnest, I doubt I will get back around to the stereo for several months.

Ceiling speaker eh? That's thinking outside the box. I wonder how an open air speaker will sound mounted in a door...

kickerfox

Sounds good. Have a look. There's pics here.

Steve Dallas

Don't you have an ill-advised engine swap to be working on?

kickerfox

Lies! I'm bone stock.

I'm saving up for all the plate and tubing for fabrication. The weather put me on hold as well.