Thread: car audio optical amplifiers

Originally Posted by raverx3m

so it seems theres not that many available
alpine, and those few listed in the other thread.
if we could only have an amp witn USB input.
i think its time to retire the RCA cables.
all these companies need to get up to speed and stop calling their very limited units "digital media players"
because the only digital media they play is 3 audio formats and ipod...
try selling a portable media player like that, or even a home media server that only supports 3 formats.

People that want optical and USB input on a car receiver are in the minority. Head units don't ship with USB out, and they don't ship with optical out, because quite frankly there is no need to do it. Why would a company spend money to put features on an amplifier (or a head unit) that no one would ever use?

In order to utilize digital all the way to the amp, then there needs to be multi-channel amps. The problem is decoding this is more expensive than simple analog electronics and is pointless in 2/4 channels amps. It's easy and cheap to get a clean analog signal using differential inputs.

So what standard should be adopted?

Digital coax/toslink?

HDMI?

Networked audio?

My vote would be networked audio, but again the cost is >>> analog, and unless car audio decides to adopt this new standard in headunits, amps and processors don't count on it. Good concept for distributed sound and pro-audio, but expensive solution for car audio and not many people require > 8 channels let alone good sound to go with it, so the market is a tiny tiny sliver. No cash cow.

Why such the necessity for digital? Scared into thinking analog is bad? Don't get me wrong, I'd like to see a complete shift but I am a minority and am not willing to pay the high costs for something that doesn't have a huge benefit.

The car environment (acoustics) is going to cause much more harm to your "signal" than any electronics. If you are so worried about keeping your signal in tact, then you should be doing the audio processing on the PC (or none at all-don't wreck that "perfect" signal), then there is one D/A conversion in the soundcard as it converts and sends the signal directly to the amp. Done. What difference does it make if it's done at the amp or the source?

the reason i mentioned USB is because it allows the components to be controlled from another unit while still beeing able to send digital audio signal.
optical, is able to do both in some cases.



i mean think about it.

USB is a standard in home/PC and many other systems( dont need to invent that)
there are USB dacs available on the market already( dont need to invent that either)
car stereos use USB for external devices already

car stereo converts digital signal to analog to send it out to RCAs or internal amp.



and now we also have digital amps as well with their own sound processing.

i mean given that engineers would have to kinda work and make something new instead of rearanging faceplates like they been doing last few years.

as has been said already, there just isn't a demand for it.

i have spent some time in almost all of my local car audio shops-- all of them make a living on 'bumpin' subwoofer systems, car alarms, and cheap decks that do one or two things the factory deck didn't, or because the factory deck died.. and when a customer plays a audio track, most of the equipment is used with files that the end user downloaded from itunes at 128kb/s quality...

with the advent of music downloading, everyone is pushing the audio quality/size ratio because to most people, large audio files are useless when "this other file is 1/2 the size, and sounds the same"... so from the largest group-- the general consumer level--they don't feel high end audio interfaces are needed..

so at this time, the people that desire higher-end audio need to pay to play....

Like it or not, the automotive industry has a huge impact on the car audio business. They install thousands of miles of speaker cable, have OEM hardware created for their vehicles, etc, etc, etc, and pretty much keep the car audio industry going. The current audio system works for them, and works very well. Until they decide to go optical/usb/whatever, I don't think the rest of the industry is going to do anything.

there are high end cars that use optical cabling between the headunit and amps--when i worked at a saab dealership, the 9-3 used optical cable from the hu to the amp on the parcel shelf.. but it was never really advertised..

i believe there are also some mercedes, lexus', and land rovers that use optical signals.

i remember hearing a little about when the first car came out with it. there was a little speculation on how it would affect the industry. in the end, it really didn't affect it at all.

but in all these cases, these cars audio systems are rarely touched. and anyone who has any desire to replace components will usually rip everything out and start from scratch..

it gets back to the other point-- no one is pushing for these features. try to tell a car buyer that their new car has optical cables run for better audio clarity. they will probably just shrug, and complain about the radio not having a ipod input...

5 years ago, most cars just came with am/fm/cd radio's. at that time, there became a huge outcry that people wanted to play their mp3 files, connect their mp3 players, and better integrate their phones with their car. the OEM's responded to that, just as the aftermarket's did. and that lands us here.

the "fast-food" attitude is really taking over everything, including audio quality. more people are more willing to accept poorer audio quality sources in the effort to get the audio track faster, and less people are less willing to wait to aquire a good, high quality audio track..

i used to use itunes a lot. after starting to build a higher end audio system myself, i am starting to realize that itunes quality is no longer good enough for me. so i go out and buy the CD's so i can rip them myself, and select the audio quality i desire. but CD's are getting harder to find because of the download mentality that is becoming common place...


i think the solution here is to have everyone convince their friends and family that downloading is bad, and that they need 5.1 audio in-car using optical-digital signal paths...

Originally Posted by kegobeer

Like it or not, the automotive industry has a huge impact on the car audio business.... pretty much keep the car audio industry going.

Apparently that is why a few local shops have shut down - car sound is now so good that there is no longer the demand for aftermarket sound.
Or maybe people are DIYing - like my mate that replaced his standard (Commodore VX) door speakers (with a $28 pair that were better; the same now replace my ~$150 door speakers), and fitted his own rear 6x9s (they were more expensive - a whopping $35!). Thanks to reasonable OEM HUs, amps and distribution, it is easier for such improvements. (Same old thing - additional wiring and HU quality is little incremental cost, but the final interface like speakers cost heaps!)

But of course, my mate did it at my place.... but others use sites like mp3car & the12volt. (Not that we have a big enough impact on the audio industry wrt robbing sales - unless we influence a few audio forums and prevent mistakes LOL!)


And I just fitted a $50 HU with USB & card (CD/FM/AM) - not that I've bothered with the USB - I presume it's for USBsticks or (maybe) USB input (I never considered output) - externally I've only used the aux in (for a MiniDisk LOL!).

As to USB & fiber demand - cable is probably stuck with RCA etc, anything later is probably wireless. And optic/SPDIF - why bother (I mean from an auto POV; as an interface, I love it!).

Combining DAC and Amp in one case is attractive, but quite questionable idea. I see several issues there.
1. DACs are very sensible to power quality and EMI while Amps are power hogs with lots of EMI. It would be uneasy (and quite expensive too) to well isolate one from the other in one case.
2. You'll have to put DSP in each Amp to enable Freq filters, time shift. EQ and other effects. Audio processor in similar system would need only one DSP for all channels.
3. All Amp would need common bus to share the settings otherwise system setup would be very inconvenient.
4. High quality DACs are bloody expensive (i spend about $500 per channel pair) and you won't throw it away when you'll decide to upgrade the Amp.

Originally Posted by raverx3m

is there still no options for people that want digital signal all the way to the amplifier?

Why worry about such losers?
If they had brains, they'd overcome the last analog links as well.
An these day the DDIs do not displace any brain matter.
(Be warned - you will not find a DDI for 44kz sampling - you will have to up convert any dc frequency stuff like that.)