Japan8

PAC unit is POS (to me). It's wired into the steering mount controls and turns them into infrared remote control beams that are aimed at your headunit. You then program the buttons to the same functions as the HU stock remote. Not such a hot solution, eh?

Isamu

That's pretty hacked up. I suppose I could live without steering wheel controls (although the mute button does come in handy).

What about this line converter Bose interface that the guy said he would use... anybody know how much the sound would degrade after going though such an interface? Any way around it (besides replacing the amps and speakers - don't want to do that yet)?

Sputnik

Does it work?

---jps

DJ Freon

As long as your radio can accept IR commands, yes it does work. We use them at my work all the time. I wouldn't call it a POS. I'd call it the only solution that works most of the time.

Japan8

Perhaps so, but I don't like it. Works MOST of the time...

DJ Freon

If there was a better solution we'd use it. There are only 1 or 2 cars on the market that it does not work on. With a resistor or two we can make it work on almost anything. Companies like Alpine used to make hardwired steering wheel control interfaces for their radios, but those have gone away. If headunits had any other way other than IR to control them (RS-232, etc) I'm sure there would be better solutions. But for now we're happy with the PAC-SWIX. I'm not arguing with you. I agree that somewhere, somehow someone should make a better solution. But I can't think of any other solution with current headunit technology. So for now, it works. And when it does work, it's 100%. Just one or two odd cars don't work with it. And I'm sure we'll figure out those cars eventually...

Sputnik

Why don't you think that you can get as good of sound quality from a carputer as you can from an actual receiver?

---jps

Isamu

Maybe it's just because I haven't done enough research, but my impression is that if I take the audio output from a carputer and plug it into the existing head unit (via the PIE adapter I suppose), it won't sound as great as if I got a new receiver.

Of course I could plug the carputer into a receiver than run that through to the speakers - but that would be the same as an actual receiver.

I may be missing something here... so please enlighten me if there are better solutions with the carputer route. =)

Japan8

Carputer will sound better...

use a Sound Blaster alugy (sp?), high quality cabling, amps and speakers. be sure to properly ground EVERYTHING. This sound setup offers fidelity beyond what a CD is capable of...

The above is doing a total HU replacement with your carputer.

The other solution... I don't know how good the PIE adapater is, however... anything that sound excellent on your mp3 players will sound good for your carputer. What are stereos, CD/DVD players and mp3 players? specialized computers which are running stripped Unix/Linux OS (in general).

bureau13

I'm skeptical. Why is that going to sound better than a CD? What source material are you going to use? I could buy it if you said it was indistinguishable from a CD...but better?

jds

Sputnik

A soundblaster isn't going to "offer fidelity beyond what a CD is capable of", because it can't improve on the source material. And most CD/DVD and MP3 players are not running OSes of any flavor. It's all firmware, which is cheaper, simpler, easier on batteries, and much more reliable.

But the PIE setup (or any similar device that uses that input into the head unit) is capable of getting the same sound quality as if you were playing a CD in the head unit itself. With a carputer, you can have a decent sound card, and output just as good of sound quality as any other device that you can hook up to that input. With a carputer, you have the choice of playing any level quality of track, from the most compressed MP3s to uncompressed CD WAV files. And with a carputer, you can add all sorts of capacity to make room for the highest quality tracks.

The weakest link in this case would be the factory head unit itself. And you really won't be able to noticeably improve on it's sound quality with anything but top of the line head units (as in more than $500 dollar units that only have pre-amp outputs and no onboard amps). The speakers and amps leave a lot of room for upgrading, but the head unit itself isn't bad.

And if you want, you can bypass a head unit altogether, and have the carputer feed the amps directly, in which case, with the right equipment, you can match even top of the line head units.

But my basic point is, unless you put together a lousy carputer setup, you can get as good of sound quality out of it (as long as you are playing high-quality source material, of course).

---jps

Japan8

You're always skeptical bureau13.

And you aren't entirely right Sputnik. Just because the source material is limited in it's fidelity, doesn't mean that your equipment offers fidelity beyond the CD level. This is more of a situation of owning a Ferrari... due to traffic and speed limits you'll never go beyond 80-90mph, but that doesn't mean the car doesn't offer perfomance beyond that level.

You guys aren't one of the types that thinks CD's are the highest fidelity format developed? You also don't believe that a MD is the same or better than a CD in quality? (I've heard someone say this) Considering that MD's use a reduced frequency range in order to squeeze 74 minutes of audio data on a smaller disk... I won't bother to go much more into this format as it is below our standard here... CD-DA.

An audio CD contains audio data stored in a formate called CD Digital Audio (CD-DA). The specifications of this format, referred to as "red book" were decided by Philips and Sony along with other details when the CD standard was developed by them in 1982. CD-DA employs a lossy compression technique in order to store audio information in the available space. It is called "lossy" because some of the available data is lost when converted to this format. Essentially the audio is encoded by sampling the source at a rate of 44.1 kHz and each sample is 16bits in size.

A "next generation" format that arose originally to replace cassettes, giving "home" recording capabilities that the CD format did not offer at the time is Digital Audio Tape (DAT). Mechanically DAT drives resemble VCR's and are able to record at sample rate of 44.1 kHz (the CD-DA standard) and 48kHz as well. DAT has actually found wide acceptance in professional and semi-professional recording environments for master recordings. become the standard archiving technology in professional and semi-professional recording environments for master recordings.

The present "next generation" format set to replace audio CD's is DVD-A. It employs lossless compression methods and provides more complexity of sound by increasing the sampling rate and the frequency range beyond what is possible for the space limitations of CDs and even DVD-Video (16-bit 48kHz). DVD Audio is 24-bit, with a sampling rate of 96 kHz.

AND... you've missed a huge point here. Signal to noise ratio. rotarygod, Xero, any audio professional will tell about it's importance... "In analog and digital communications, signal-to-noise ratio, often written S/N or SNR, is a measure of signal strength relative to background noise. The ratio is usually measured in decibels (dB)." The Sound Blaster Audigy 2 ZS Platinum Pro offers 24-bit DVD-Audio playback at 108dB SNR clarity. You aren't going to get that with " decent sound card." You aren't going to get that with the on-board sound card used by Via Technologies on it's C3 based mini-ITX motherboards. Just see what people have had to say on http://www.mp3car.com

As far as devices go, they aren't all "cheap" firmware. If that was true then your Palm Pilot would employ "firmware" and not an "OS" (use less memory and battery) and Mp3 players wouldn't have a reset button for when they freeze. Your nav system in your 8 would use firmware as well as your PS2 or Xbox. The obvious arguement here is that a Palm Pilot is used for more than just audio playback. This is true, but things aren't so simple anymore. Now these devices have to worry about decoding data and in the DVD's case regional encoding, menus, etc. Really... this is software not just raw data. Mp3 players have to connect to PCs and "dummy" as an removable drive in order to copy files across. not to mention..."Get the latest iPod software so you can take advantage of all the great new features in iTunes." Sure there are firmware updates for devices that use them... but those devices are not very versitility or complexity of devices today. A linksys DSL modem/router has firmware that can be upgraded. I have upgraded the firmware on my old NTT ISDN modem (a serious PITA). Look... I have other things to do... like sleep. Run a search, do some research. Post some stuff to prove me wrong...

Isamu

I understand that I can probably get equal audio quality as what I have now given a carputer setup with a good sound card (SB Audigy) + PIE; I totally agree with you guys on that. But as someone else described it, I want a clearer sound, not like a pillow stuffed in the speaker. So the question I guess is whether the bottleneck is the head unit, or the amps + speakers? Probably both, but which is the bigger bottleneck (or smaller if you're thinking visually)?

I'm hesitant to change the BOSE speakers (for now) since I paid for the upgrade, might as well use it some more. That leaves the head unit. Thinking about the Kenwood DDX7015. I imagine that should give better sound than the stock HU. Correct me if I'm wrong though as I'm not quite an audiophile yet.

If there was a way for a carputer to sound as good or better, and for cheaper - I'm all for that solution. =)

Japan8

Isamu... yeah your HU, especially a stock one, will be a limiting factor. But it all depends on the level of fidelity you require and how custom you want to go. According to what many have said on mp3car.com, you're looking at about $600 to get your carputer off the ground. Now if you want more power, a smaller form factor, etc. then it will start to cost you more money.

That being said...

I think you can get a sound you like with the stock HU. Pick up some nice line converters from David Navone... N774V four channel converter. Replace those stock speakers and replace that Bose amp.

The problem with losing the HU and going all computer is you lose am/fm radio. That has been difficult to work out for everyone on mp3car.com. Another is your steering wheel controls... they'll take some work to get them to work with your PC.

That aside... going all PC means you could get a nice decoder by Audiobahn and have THX in your car... :D

XeRo

Japan 8 is correct regarding the ability for "upconversions". That's one of the abilities of "better" hardware. Why do you think that the newer home theater receivers take a massive leap in price now. Denon's higher line of Home Theater receiver specifically the AVR-3805/5803A are pushing the envelope with 24bit/192KHz digi inputs...your CD cannot go beyond 16bit/44.1 KHz...a DVD-A outputs at 24bit/192KHz...the quality is much better..you can listen to music on a carputer at a much higher fidelity level due to this...you are looking to play in the most "lossless" format, i.e. WAV, SHN, WMA and where MP3 is concerned it's the worst because it is "lossy" and the fidelity mainly due to a decrease in SNR is crap..most car stereos are rated around 82dB - 96dB...and yes the 108dB offered by the Audigy Platinum cards can be "heard"..

OK..i'm about to pull an RG...i normally do not do this but..

SNR..measure of signal strength relative to background noise with the ratio measured in dB. Incoming strength and noise level usually are in microvolts. You can use the following formula but usually you won't get the achieved signal strength and max allowed noise levels from the manufacturers so you kind of have to go with what they list in their product descriptions....but this is how they get the SNR numbers..

S/N=20 log10 (Vs/Vn)

You of course want your signal strength to be greater giving you a more positive number ..the higher you get the more fidelity you achieve...make sense?

so i'm pushing for the carputer...that's where i'm leaning...but I think i will still continue to work on the faceplate just because I rather have the touchscreen incorporated in the center dash rather than where the NAV would go...

Sputnik

No, the point was that one could not improve on the source material. Akin to the fact that putting a lousy driver in a Ferrari would not make him/her a better driver. And as far as any specialized formats (by that I mean something that you won't find in quantity in a music store), I was referring to the comparison of what both a head unit and a carputer can play (comparing apples to apples). So, as far as a standard CD is concerned, the best carputer setup will not be able to improve upon the best head unit setup, so I was right in that sense. As far as the absolute best sound quality that you could ever get out of a carputer with the right equipment compared to the absolute best sound quality in a commercially available head unit, then the carputer would be better, so you were right in that sense. We were simply talking about different things there.
I didn't miss that point, it's just a moot point, realistically. The limitations would be on the amps themselves, and what they can receive (as in voltage levels and other concerns). And there are commercially available head units that are capable of producing as good of an SNR as a carputer, in a format or manner that commercially amps are capable of handling. Yes, you can install equipment in a carputer that is better than a "decent sound card", but you can also install head units that are also capable of such performance. Realistically, that's a wash.
Again, we're talking about apples and oranges. A Palm Pilot or an Ipod are much more than a basic MP3 or CD player. They have OSes, and perform many many more tasks. Something like a basic car stereo head unit, and a Sony Discman that can play CDs/MP3s/Atrac don't have OSes, they simply have firmware. Both are software driven (and so sometimes things have to be reset even if only firmware driven), the basic difference is that firmware is closed, in that you don't have add-ons. To update or add anything, you have to re-write the whole package to make any changes. An OS is open, and you can change or add software as you wish, like adding a game to your palmpilot. That kind of open architecture requires alot of extra software, and thus more memory and processing, so it is more complex, power hungry, and expensive. It is also open to alot more problems via either the more complex OS, or any of the add-on software.

---jps

Japan8

Actually...

And no commercially available head unit in the US can even approach what you can do with a car computer. If you include the JDM you get closer, but at how many times the cost?

See the above. It's not a wash.. just a waste of your money. AND... I don't doubt the existence of said HU (I know I've seen receivers of this level for the home), but they don't seem to be so widespread. Or maybe it's the shops I go to... OTOH, the sound blaster card can be bought at virtually any computer hardware store.

Right. What do you think is running on the Pioneer AVIC-N1? http://www.pioneerusa.com/pna/articl...169030,00.html looks a lot like Windows CE/automotive to me...

Do you know what Windows XPe or Windows CE is? According to you definition they are both firmware and software. They are multifunction, but closed software. You cannot add or remove from the OS. The OS is specifically tailored to the hardware it is running on and cannot be used with other hardware. To use different hardware means rebuilding the OS.

Do you know what powered the Sega Dreamcast? Windows CE. It's a purpose built machine, is it not? What about Red Hat that's been built to run on the Playstation 2? What do you really think is running on an Xbox considering the processor is x86 and it's made by Microsoft? I'd bet the farm it's Windows CE. Ever heard of Windows Automotive? Take a good look at Microsoft's website.

So what about the iPod? How about this... http://www.macdevcenter.com/pub/a/ma.../ipod_pda.html

Ever updated the software on a Palm Pilot? There're no modules in there.... it's overwrite it all or nothing... but this is certainly multi-function, somewhat programmable, and more. Everyone would say it's running an OS...

Do I need to post the specs on DVD? Sorry firmware isn't going to cut it. This isn't a VCR. There are menus on the disks, not the machine. The system has to read that info off the disk and display it... and all menus aren't going to look the same or display the same information. Chapter search? MPEG 2 decoding? The next thing you tell me that the HDD/DVD Recorder units use firmware too...

What about these...

http://www.discount-car-stereo-deals...ar-stereo.html

http://www.discount-car-stereo-deals...ar-stereo.html

Here's an interesting one...
http://www.coderworld.net/hosted/car.comput3r/

bureau13

You're right Japan8, I am always skeptical! It must be my nature.

Redbook audio does not use lossy compression...it uses a sample rate that theoretically allows an exact reproduction of all frequencies in the source audio up to 20KHz. I don't know about you, but my hearing doesn't go any higher than that. Now, there is the whole quantization error thing...so you're correct in the sense that quantization and sampling rate were chosen at least in part to fit the required amount of material onto a standard CD.

At any rate, I was thinking you were playing CD audio files or worse (e.g. MP3s, etc) on your Carputer. So since you spent a good bit of time talking about DVD-Audio, you're planning on playing that I assume? I have not personally had an opportunity to hear that format myself. I have my doubts that you or anyone else will be able to appreciate such subtle nuances, much less notice the difference in signal-to-noise ratio you pointed out, in an automotive environment...but if that stuff makes you happy by all means go for it.

jds

Japan8

Red Book Audio does employ lossy compression. What do you know of pulse-code Modulation (PCM)? You are correct in saying that once digitized the signal is not subjected to further compression, e.g. data compression. However, the analog signal may be subjected to amplitude compression. This type of A/D processing has been made obsolete by signal compression. To further simplify this and where I got the info (http://en.wikipedia.org/wiki/PCM), the PCM analog/digital (A/D) format used by the CD-DA standard employs lossy compression.

This is why Philips and Sony developed a competiting stanadrd to DVD-A. BOth arose becuase of the limitations of CD's. The Philips and Sony standard Super Audio CD (SACD)

"The Super Audio CD samples the music 2 million 822 thousand times per second. Instead of the PCM system used in current digital audio systems a Delta signal, Direct Stream digital system developed by Sony and Phillips is used. The digital stream can be recorded on a computer hard drive or a magnetic tape. Almost no signal processing, no dither, no quantitization like regular CD is used. The music is sampled, recorded, and and a final output filter utilized, and you have music.

Unlike Dolby Digital 5.1 surround sound which highly compressed the digital signal and only allows a small bass bandwidth on the subwoofer channel, the SACD offers six full range out to 100Khz channels. " (http://www.altermanaudio.com/sacd.html)

As to being able to appreciate the difference or not... while an automotive environment is hardly offers the best acoustics, there is a clearly periveable difference. Some things are not so easily quantifiable by the standard scientific means... or at least the techniques we use today. I was having this disussion with an audio professional on the list about a month ago.

"While PCM digital recordings, even the new high big, higher sampling digital masters sound wonderful, most recording engineers still prefer and think old fashioned reel to reel recorders, operating at 30 ips, is the ultimate sound recording machine. Keep in mind cassettes operate at 1 7/8 ips. Analog 30 ips half inch recordings have a frequency response to 100kHz, a signal to noise ratio of 100 db and ultra low distortion."(http://www.altermanaudio.com/sacd.html)


BTW... this wasn't about what I will or will not use, but rather it began with talking about if a car pc can offer fidelity that exceeds the CD standard.

Maybe some more later...

bureau13

Look, I'm not going to get into a debate with you here about the CD-DA standard. Its too off topic, even for me! You've done a lot of quoting, but I've never heard anyone infer from amplitude compression of the analog signal that "may" be done that CD-DA employs "lossy compression." None of your quoted links state that either. I supposed depending on your definitions, you may be able to say that, but I've never heard it stated that way, and its not what I mean by the term.

Whatever....I'll have to check out the DVD-Audio stuff some time. I'm sure I'll never see the point of putting it in a car though!

jds

Japan8

Agreed... i tend to get a bit caught up in debates, but this is rather off-topic.

Just to explain my logic, if you are compressing the amplitude as part of the D/A conversion process, then your final digital signal will have less amplitude than the original analog signal. That's loss. I didn't say it was digital compression loss like in mp3. Just that CD-DA has a loss of fidelity if compared to reel-to-reel 100kHz masters.

As I said, the point had nothing to do with putting DVD-A in a car or not. This was a straight out standards vs standards, not practical usage discussion. but whatever... stick a fork in it. done.

Faceplate manufacturing... there is a shop here that offers a service to rebuild your faceplate into 2DIN. There are pics of it in HyperRev... I'd love to see what they did about the climate controls and LED display...

Isamu

I tried to get a custom faceplate done up - it's still going but meanwhile, my installer tried to get the electronics working first. To sum up, I have my aftermarket head unit stuck in the stock HU hole held in there by a screw. My stock HU is now 2 PCB boards with wires and solder all over it. Needless to say, my AC controls do not work. The audio bypasses the bose amp and goes directly to the speakers (no aftermarket AMP yet and couldn't get it to work with the bose). In short, nothing works!

Question is, the PCB to be relocated - it's actually 2 boards right? One attaches to another? So I assume both have to be reloacted. Nothing is turning on after I plugged it in and reading from another thread, it's probably toasted. But just before I jump to that conclusion, any idea what I am missing?

This is what really happened now:
1) Took apart everything, down to naked pcb boards.
2) Soldered wires to the connectors so the 2 boards are connected where they should be.
3) Extended heater control wires so the boards can be put up into the stock NAV area.
4) Original "plug" (the big one) was plugged back in to test.
5) Nothing works!

Many points that could have screwed the boards so what is the correct and best approach in moving the heater controls out of the way? The entire unit, frame and all, doesn't seem to fit...

SinDiego

i think im going to be very interested, but i am a picky ****. and expect awsome quality in order for me to purchase. i mean i did choose this car. bu tlet me know and maybe some picks with close ups on the seems after install.