What would have to be done for this to work with 3d sound upscaling like CMSS3D on the Audigy2 NX or the similar feature on the M-Audio Sonica Theater? I've read that the Audigy2 NX doesn't apply its effect to line-in sources, but would digital audio over USB work with it?
I'm pretty sure the chip only provides analog out. You'd probably have to throw in your own a/d to deal with that problem (= increased cost) not to mention some extra complexity in the firmware to deal with the stream.Originally Posted by Seth
Another thing I didn't explicitly mention in the feature list (but should be implicit) is the ability of the radio/tuner to work well in the typical car environment. I'm not sure what the difference is (better shielding or compensating tuner circuitry or ???) but non-car radios almost always perform poorly in a car/mobile environment. Whatever it is that makes car radios lock onto a channel and stay there (for the most part), you need to make sure you implement that. Otherwise, no matter which features it has, it's just going to be another crap sounding solution that really isn't a suitable alternative to a factory radio.
BTW, if you keep this non-commercial, you should be OK posting about this here. In any case, you might check in with Ziplock just to make sure.
count me in and put me on the waiting list
i'll be buying a pre-made one as soon as you have them available.
most important feature is having the antenna input just like a HU has, so we can just plug the car antenna into it and have it work with that for maximum reception
digital out would be nice, but not necessary, as the radio signals are analog, so either an onboard a/d converter or converting it with your sound card should be about the same
Ok guys here are some answers:
1) The tuner chip has analog audio output only.
Solution 1--> Convert analog signal to digital with a ADC and route it through the USB.
Pro's : Digital signal (obviously)
Con's : Signal quality loss (due to the conversion)
Expensive components needed
Design complexity rises.
Solution 2--> Convert analog signal to digital with a ADC and route it through the I²C bus.
Pro's : Digital signal
Design complexity remains the same
Con's : Expensive components needed
Signal quality loss (due to the conversion)
The I²C bus has a 400Kbit/sec bandwidth (50KB/sec)
(obviously not enough for audio data transmission)
So it's not gonna happen. Sorry.
2)The ability to record in mp3 format has to do with the software not the hardware.
3) HD radio is way out of the scope of that project. Sorry.
4)The size of the device should be somewhere in the size of a credit card. Maybe a little smaller. We'll see.
5)In order to make this as simpler as it gets we won't incorporate any DAB or XM functionality. Maybe in a latter design. Remember we want this out as soon as possible.
6)Regarding reception the tuner chip used is the same used in car HU's. Hopefully it will have equally good reception. At least the datasheet's SNR is impressive.
7)If any of the admins believe that there is something wrong with this thread please contact me. This is not a commercial venture, it's a DIY project and when the device is finished the schematics will be available here for dl. Of course if someone is too lazy building it or feels unconfortable soldering SMD components then we can provide a fully assembled unit to buy. If there is something wrong with that please tell me and I'll stop posting.
That's all folks (for now)
Just a note : due to the time difference I may be sleeping when you guys post so please be patient
Thanks everyone for the ideas and feedback.
Digital audio is pretty damn important to me but i would settle without it if you could do as rando suggested about creating a unit that is par with the head units reception.
The absolute most important thing is reception par with headunits. Even if it only had FM i am sure people would buy it as long as it had reception as good as a our current headunits (actually i currently don't have a head unit but i do remember how good the radio reception was compared to my crap usb radio that i have now)
So to sum up. Reception, Reception, Reception, USB digital Audio and Stock Antenna Connector.
I am glad you are serious and it is feasible. I hope you take whatever steps that need to happen to get a project like this done.
-Jesus- King of Kings Lord of Lords
Originally Posted by rando
rando I understand what you mean regarding reception. Hopefully the TEF6700HL tuner ic will cope with in-car environment. It is already used in most of Alpine's HU models and has excellent characteristics. Datasheet here.
btw we expect the sample ic's to arrive in Thursday (fingers crossed)
I guess analog will have to suffice. In all reality the motherboard (via epia m10k) should push the analog input right out to the spdif out port but it doesn't hence the reason for running a coax spdif and an analog RCA.
Thats nice to hear that they are using this chip in some pretty big brand names but i wonder what other designs are necessary to ensure good station locking and good reception.
I don't think i have have thanked you yet. So Thank you for seeing a need in this community and offering your help
-Jesus- King of Kings Lord of Lords
The reason I have asked for USB audio is because I don't have any audio channels free... unless someone can tell me a way to have four channel audio out and a line-in on my EPIA MII-10000.
Carputer progress meter: [-----|]
Carputer gadget meter: [--|---]