DiyMobileAudio.com Car Stereo Forum banner

61 - 80 of 98 Posts

·
Premium Member
Joined
·
29 Posts
Well, I tried an ipad2, and the same thing. I'm pretty pissed at Apple right now, why the hell do you design something to NOT work? I just can't see any reason for this product if it doesn't output HDMI when you want it to. I think any cheap HDMI to VGA adapter with digital out should work, I saw some for ~30 on ebay and Amazon. Please post if anyone has any ideas or success.
 

·
Registered
Joined
·
37 Posts
Post some gut pictures of the PXA-H800! ;)


the original opamps:


replaced with a Texas Instruments OPA1642 :)
This is a BIG change and I am still puzzled why Alpine would place the NJM4580 opamps in this high-end processor :eek:



Sorry to resurrect this thread, but I've tried the above with an original ipad, and you cannot get digital audio output simultaneously with control from the factory head unit. It works great, but as soon as the ipad sees the control from the 30 pin connector, it shuts off the digital audio, and only outputs through the 30 pin connector. Any ideas guys? This was going to be so cool...:(
I am trying this also, but I have found out that the HeadUnit switches to analogue in when selecting the iPod.
I can use my iPod with controls or via optical but not both. :-(
Currently I am working on an AI-net board to tell the H800 to switch to digital in.
 

·
Premium Member
Joined
·
29 Posts
I am trying this also, but I have found out that the HeadUnit switches to analogue in when selecting the iPod.
I can use my iPod with controls or via optical but not both. :-(
Currently I am working on an AI-net board to tell the H800 to switch to digital in.
This is insane, and it seems like Apple should have made the AV adapter to output HDMI all the time. There just seems to be no reason why it should work this way. Any hackers out there could get this to work?
 

·
Registered
Joined
·
37 Posts
This is insane, and it seems like Apple should have made the AV adapter to output HDMI all the time. There just seems to be no reason why it should work this way. Any hackers out there could get this to work?
I don't think this is Apple's doing.
It seems that the processor doesn't get the signal to switch the digital input on, when selecting the iPod.
 

·
Premium Member
Joined
·
29 Posts
I don't think this is Apple's doing.
It seems that the processor doesn't get the signal to switch the digital input on, when selecting the iPod.
The Alpine works fine when the ipod, it doesn't when the ipod is connected at the same time to the head unit. The AV adapter should be able to send HDMI at the same time, for some reason Apple didn't design this to work that way.
 

·
Registered
Joined
·
37 Posts
I've tested this once more and in my car and this is how it works:
The iPod is connected through an Apple HDMI connector to both the Alpine and the HDMI-toslink converter.
This way I can control the iPod and have digital out.
I have to confirm it outputs audio, but it does output light from the toslink.
(it should have HDMI signal, because when there is no HDMI signal this stays dark)
The iPod can only send audio to one device at one time, and it does it through the HDMI. Because the processor doesn't listen to optical signals you can't hear the music.

I will try more on this, using my laptop on the optical cables to confirm.
I will see if the HDMI converter outputs sound when connected.
If so, the problem is certainly the failing of the processor to switch the optical input on.
 

·
Registered
Joined
·
8,524 Posts
I've tested this once more and in my car and this is how it works:
The iPod is connected through an Apple HDMI connector to both the Alpine and the HDMI-toslink converter.
This way I can control the iPod and have digital out.
I have to confirm it outputs audio, but it does output light from the toslink.
(it should have HDMI signal, because when there is no HDMI signal this stays dark)
The iPod can only send audio to one device at one time, and it does it through the HDMI. Because the processor doesn't listen to optical signals you can't hear the music.

I will try more on this, using my laptop on the optical cables to confirm.
I will see if the HDMI converter outputs sound when connected.
If so, the problem is certainly the failing of the processor to switch the optical input on.

Thanks for the effort Unrealistic. Can you also check that the sync between the digital devices remains in tact when the iDevice is paused or while changing tracks. This might be hard to do if testing with a CD player or something since they don't usually have a synced indicator, but an easy way to tell is if you hear a pop every time one of the above mentioned functions is used.

I know the Airport express digital output suffered from this.
 

·
Registered
Joined
·
37 Posts
Thanks for the effort Unrealistic. Can you also check that the sync between the digital devices remains in tact when the iDevice is paused or while changing tracks. This might be hard to do if testing with a CD player or something since they don't usually have a synced indicator, but an easy way to tell is if you hear a pop every time one of the above mentioned functions is used.

I know the Airport express digital output suffered from this.

I have tested the output of my converter and it does indeed give audio via the toslink at the same time as being able to control it from the head-unit.
If I can get the processor to use a optical in, I am there! :laugh:

The Airport express is compressed I read, so this would defeat the purpose?
 

·
Registered
Joined
·
8,524 Posts
I have tested the output of my converter and it does indeed give audio via the toslink at the same time as being able to control it from the head-unit.
If I can get the processor to use a optical in, I am there! :laugh:

The Airport express is compressed I read, so this would defeat the purpose?
-Great reaffirming news! Hope you get the other part working.

-Naw the APE is bit perfect. It might use a lossless transmission format though, but thats fine too since that would also be "bit perfect" on the receiving end.

Apple AirPort Express Wi-Fi Hub-D/A processor | Stereophile.com

"Some audiophiles have dissed the AirPort Express on the grounds that its digital output is not bit-accurate. However, I found that this was not the case, that the data appearing on the AE's digital output were identical in the original file. To check this, I compared a WAV file with a duplicate that I had captured on my PC from the AirPort Express's S/PDIF output. I used iTunes on my PowerBook playing a version of the file encoded with Apple Lossless Compression to feed data to the AE. The files were bit-for-bit identical, proving that the AirPort Express is transparent to the music data (as is ALC, for that matter)."

The Apple TV on the other hand, sample rate converts to 48kHz. I've heard though that it's transparent so they are probably doing a quality conversion with it.
 

·
Registered
Joined
·
4,702 Posts
Killer review. I didn't know you test processors too. Speaker testing is of course more important :D but this is really neat. What other technical tests do you have around here Erin? I want to check them out.

I would really love to see how my P99 spanks this little gtg here.
 

·
Registered
Joined
·
8,524 Posts

·
Registered
Joined
·
4,702 Posts
Thanks T3sn4f2. Indeed it kills the competition. I'm still a bit lost when it comes to headunit performance. The p99 performs audibly better than the Eclipse CD7200 I had in there before. I mean, even given the discrepancies in theses tests none of this stuff should be audible anyway. So the question is what else are we missing?

Does distortion performance change when the output voltage goes up?

Does the heatsink shielding make all the difference in a busy car dash where the ECU and other computers are going nuts?

What about when I have 31 EQ band changes made?

Erin can you test the BT sound quality? That's pretty much all I use.

To me the P99 is perfect because I can't fit a double din in this car.
 

·
Registered
Joined
·
8,524 Posts
Thanks T3sn4f2. Indeed it kills the competition. I'm still a bit lost when it comes to headunit performance. The p99 performs audibly better than the Eclipse CD7200 I had in there before. I mean, even given the discrepancies in theses tests none of this stuff should be audible anyway. So the question is what else are we missing?

Does distortion performance change when the output voltage goes up?

Does the heatsink shielding make all the difference in a busy car dash where the ECU and other computers are going nuts?

What about when I have 31 EQ band changes made?

Erin can you test the BT sound quality? That's pretty much all I use.

To me the P99 is perfect because I can't fit a double din in this car.
-These are the short falls of the RMAA software Erin and I use.

NwAvGuy: RightMark Audio Analyzer

IMHO, the differences heard in digital sources, besides noise floor performance and clipping, are due to expectation bias. I mean if this little guy can do so good, any competent device should be able to.
 

·
Registered
Joined
·
4,702 Posts
-These are the short falls of the RMAA software Erin and I use.

NwAvGuy: RightMark Audio Analyzer

IMHO, the differences heard in digital sources, besides noise floor performance and clipping, are due to expectation bias. I mean if this little guy can do so good, any competent device should be able to.
Huge imo:
"# MAXIMUM CLEAN OUTPUT LEVEL - RMAA has no concept of absolute levels. So it can't measure voltages, power outputs, etc. So you have no way of knowing, for example, how loud that portable player or headphone amp can play without obvious distortion. You also have no way of knowing what level you’re testing it at. Is it right on the edge of clipping or is the level so low it’s affected by the noise floor?

# POWER vs THD: RMAA cannot perform the classic measurement of output power versus THD. This is a standard benchmark amplifier test that’s widely performed as it’s very revealing of the amplifier’s behavior into various loads and various frequencies. RMAA has no way to do it nor am I aware of any other software that allows this sort of measurement with a sound card. "


Let me point to two instances where the Eclipse deck thought me that these are indeed much too important:

1. The eclipse would get a very nasty harsh onslaught of distortion in the right tweeter only with the engine on. Turn the engine off and it would be squeaky clean. This is one of those things where you can't test like this and get a real world performance glimpse. Unless I missed something these power supply noises are huge and untested for.

2. The tweeter channels would clip at unreal low levels. I'm not sure what was the deal but I had the amp gains really high and still no bueno. It was unworkable. I plugged in the P99 and I could get 10X the output without clipping with the same amp gain settings. If all these tests are at .001 V output then what are we really getting from this?

I don't mean to demean the results. Whatever the application it is a magnificent relative comparison among the decks. My concern is with the actual application of the results for people that watch these threads. I'm a lover of objective data but at the same time I've been stressing a lot lately over relative importance of one test versus the other. What are the most prevalent forms of distortion and how do we test for them? Big picture objective tests are the money.
 

·
Moderator
Joined
·
18,499 Posts
Discussion Starter #75
Agreed

That's why I note where the volume is on the decks and let the user use some of their own logic to figure how worthwhile the data is.

I should have provided measured preout voltage.


At the same time, what you get is a direct one to one. If the card input clips at 1v, all the tests are done at 1v. Been a while since I did the dBu conversion to voltage of this card. You guys are more than welcome to, though. I can say that no units output was driven in to clipping. I test them all with a scope and the same 1khz tone before I use RMAA.
 

·
Registered
Joined
·
37 Posts
Can you also check that the sync between the digital devices remains in tact when the iDevice is paused or while changing tracks.
I have made a recording of the sound from the toslink and I cannot hear any plops or glitches. The light stays on and the music just pauses and skips to the next track. I haven't heard it 'LIVE' because my macbook doesn't output the input through to the speakers, but using a sound recording program I can test this.

-Naw the APE is bit perfect. It might use a lossless transmission format though, but thats fine too since that would also be "bit perfect" on the receiving end.
Ok. I didn't know that.
sadly this doesn't solve my problem... :mean:
Good people are still testing this themselves.
I've read a lot of #@%! :icon_bs: but most people won't find out the truth by really testing and seeing what happens! :rockon:
 

·
Registered
Joined
·
8,524 Posts
I have made a recording of the sound from the toslink and I cannot hear any plops or glitches. The light stays on and the music just pauses and skips to the next track. I haven't heard it 'LIVE' because my macbook doesn't output the input through to the speakers, but using a sound recording program I can test this.
Sounds like it does maintain sync, you'd definitely hear an obvious sound if it lost it. You could probably reproduce it by killing the power to the hdmi-spdif extractor while playing a solid bass tone. On my PC speakers, it sounds like an amp turn on/off thump. But yeah it sounds like it won't be an issue.

Mind if I ask which extractor specifically are you using. Just in case it is it which is keeping sync going. I wanna know of one that works for sure for future reference.

Thanks again for the efforts.
 

·
Registered
Joined
·
37 Posts
Mind if I ask which extractor specifically are you using. Just in case it is it which is keeping sync going. I wanna know of one that works for sure for future reference.
It is a cheap chinese one from DealExtreme:
1080p 4-Port HDMI Input to HDMI + Optical/Coaxial Audio Output Converter (100~240V AC) - Free Shipping - DealExtreme

Thanks again for the efforts.
no problems; I am glad there are more people trying to get there Alpine / radio to do what they want! :)
 

·
Registered
Joined
·
8,524 Posts
I remember seeing that one when I was looking around. But I wondered about the power button on the remote since it would need to come one to the right configuration from just a power up cycle. How's it funtion in that sense? Can you just plug it in and start getting audio without touching anything else.

Also, here's a little tip. Digital sync sometimes needs to happen in the order of source first then on down the component line. If you ever have any issues with digital artifacts on the H800, then you might want to try turning off the extractor and H800 while leaving the ipad and av adapter enabled. Then turn on the extractor and finally the H800. If that helps then some type of delayed triggering mod would need to be in place.

And for anyone using an iPhone or ipod in a car dock that is removed each time you leave the car. I guess you would have to build a manually resetting delayed trigger to restart the devices IF you mount the pod in after turning the system. Or cycle the power with the keys since in that case the pod would remain on and the rest would cycle.
 

·
Registered
Joined
·
37 Posts
I remember seeing that one when I was looking around. But I wondered about the power button on the remote since it would need to come one to the right configuration from just a power up cycle. How's it funtion in that sense? Can you just plug it in and start getting audio without touching anything else.
I haven't used the remote yet.
It is for switching the input from 1-4, but it always starts up at nr 1.
I also bought a switched 3A 5V power supply chip from de.com and I just plug it in.
It starts up and the iPod (Touch 64G) finds it and switches to the hdmi output.
 
61 - 80 of 98 Posts
Top