A2DP quality?

Posted by: Ken.C

A2DP quality? - 10/22/10 02:02 PM

Anyone know anything about Bluetooth A2DP quality? I know it's enough for casual use, but would it be enough to use with a good setup as a primary music source?
Posted by: pmbuko

Re: A2DP quality? - 10/22/10 02:04 PM

WhyTF didn't they just call it AADP is all I want to know.
Posted by: Ken.C

Re: A2DP quality? - 10/22/10 02:06 PM

Because A2 is cooler.
Posted by: jakewash

Re: A2DP quality? - 10/22/10 02:08 PM

They are just setting up for licensing R2D2 from Lucas.
Posted by: Ken.C

Re: A2DP quality? - 10/22/10 02:11 PM

Well, so much for this thread.
Posted by: ClubNeon

Re: A2DP quality? - 10/22/10 02:14 PM

If the transmitter and receiver both support MP3 and/or AAC bitstreams, then you can expect to get that level of quality. But if they only do SBC (more likely), then you'll not even be getting MP3 quality.

(I2C, and I2S are also two horribly abbreviated specs.)
Posted by: Ken.C

Re: A2DP quality? - 10/22/10 02:18 PM

That's what I was looking for, Chris, thanks!

Hey, 1900 posts for you!
Posted by: ClubNeon

Re: A2DP quality? - 10/22/10 02:21 PM

Cool. And most of them helpful. laugh
Posted by: tomtuttle

Re: A2DP quality? - 10/22/10 02:23 PM

As usual, Chris is WAY ahead of me on this.

I've been using a Motorola T505 to stream music in my car from my Droid for a while. I don't know if it is the BT part or the broadcast to FM part, but I think the quality generally sucks.

It is a very convenient and inexpensive device, though. Amazing, really. Allows me to use the car speakers for phone conversations.
Posted by: Ken.C

Re: A2DP quality? - 10/22/10 02:24 PM

I'm sure it's the FM part.
Posted by: ClubNeon

Re: A2DP quality? - 10/22/10 02:34 PM

Yeah, it's the FM part. With A2DP it is possible to send an untouched MP3/AAC bitsteam between two devices. That's provided the transmitter has access to the original file data, and the receiver supports that codec. In most cases the audio is decoded into PCM, and then re-encoded into SBC, which all A2DP devices must support, so quality suffers. SBC is roughly based upon MPEG Audio-Layer II, or MP2, which I doubt many of you have ever seen. It's best suited to voice (just not male, German voices, as found my the Fraunhofer Institute).
Posted by: Ken.C

Re: A2DP quality? - 10/22/10 02:35 PM

I wonder if there's any support for ALAC bitstreams. Probably not.
Posted by: ClubNeon

Re: A2DP quality? - 10/22/10 02:45 PM

The protocol is extensible, so as long as the transmitter and receiver agreed on the codec it would be possible. I just don't think anyone's building devices to do it.
Posted by: Ken.C

Re: A2DP quality? - 10/22/10 02:48 PM

Blast. So much for re-ripping every single CD in my collection. Not that I've moved the ALAC versions over to storage that actually connects to my iP[ad|od|hone].
Posted by: ClubNeon

Re: A2DP quality? - 10/22/10 02:55 PM

I just checked Pioneer's BT module for their receivers. Since they support MP3 and AAC decoding in the receiver I thought they might support them natively. Nope, SBC only.

I fear that's going to almost always be the case. So you're ALACs will get decompressed into PCM and then encoded into SBC. Not as bad as turning already lossy compressed files like MP3 or AAC into a different lossy format, but as I said SBC isn't a very good codec (just really easy to implement in hardware).
Posted by: Ken.C

Re: A2DP quality? - 10/22/10 02:59 PM

Eh, it wouldn't bother me too much to downconvert the ALACs into 256K AACs or 320K MP3s (just time and storage, who cares about that!), but the trick is finding the dock connector transmitter and receiver pair that would work. From what I know, the iPhone and iPad do not properly support A2DP, and I don't normally use those for playing music in any case.
Posted by: ClubNeon

Re: A2DP quality? - 10/22/10 03:09 PM

Wow, I just now read up on Apple's support for A2DP. It's really sorry isn't it? Pioneer's module would allow for the receiver's remote to step through tracks, pause, and even show song titles on screen. But Apple didn't implement AVRCP at all. So you'd get play and stop.

So yeah a dock is your only hope. But it would have to have access to the file information on the player (digital), along with transmitting the raw files (codec support).

You know what you need, now it's a matter of finding if someone makes it.
Posted by: Ken.C

Re: A2DP quality? - 10/22/10 03:38 PM

Basically what I want is what Steve has (ie, the iPod as remote control), but I want to be sure that the audio quality is good enough to warrant using it with the M80s as my primary music source.
Posted by: ClubNeon

Re: A2DP quality? - 10/22/10 03:43 PM

I wouldn't worry about A2DP, then. Just a way to have your music collection available to play through your receiver. Be it by DLNA server to the receiver, or another device. Then find an app for the iPod that will allow it to control what's being played.
Posted by: Ken.C

Re: A2DP quality? - 10/22/10 03:44 PM

heh. I mean an old iPod, not an iOS version.
Posted by: tomtuttle

Re: A2DP quality? - 10/22/10 03:47 PM

Wouldn't you be ahead by just accessing the files on the Mac via Airport or something instead? I don't get why it has to be from the iPod and via BT.
Posted by: Ken.C

Re: A2DP quality? - 10/22/10 03:54 PM

If I do it that way, I have to have a computer turned on to listen to music. Since 2 out of 3 computers in the house are laptops, and the 3rd is my gaming PC that sucks down power like no tomorrow, the iPod is more efficient.

Currently I have the iPod sitting in a dock with an IR receiver, so I can control it with the Harmony, but I have no real control over what's playing. Less of a problem for me, but more of a problem for my wife.

Someone tell me I'm making this more complicated than it needs to be. I usually do...
Posted by: ClubNeon

Re: A2DP quality? - 10/22/10 03:59 PM

Most of the iPod docks connect by analog out, especially for the older models. In that case you'd be limited by the DAC/opamp in the iPod. With BT you're limited to the SBC.

I think it's time to step back and look at what you really want to do, and what level quality you want. If you have all your audio files on a computer in high quality, I'd see how to get them directly to the receiver from there, without involving a portable media player, which I've never equated with quality--only convenience.
Posted by: ClubNeon

Re: A2DP quality? - 10/22/10 04:03 PM

What receiver are you using? My 2 year old Pioneer even supports an external hard drive over USB, that allows me to pick what track I want to listen to using an on screen display.
Posted by: Ken.C

Re: A2DP quality? - 10/22/10 04:05 PM

A 7 year old Harman/Kardon. No USB connection whatsoever. I'm probably best served by using an Airport Express or the like and just sucking it up and leaving a laptop open when I want to listen to music.
Posted by: ClubNeon

Re: A2DP quality? - 10/22/10 04:12 PM

Too bad the Airport Extreme doesn't have audio outs.

You could use something from the Western Digital TV line-up. To either store copies of your music right at the receiver, or stream them from the network (or both).
Posted by: cb919

Re: A2DP quality? - 10/22/10 04:25 PM

Ken, why not use a NAS with a media server (like the WD solution Chris pointed out)? Or just map a network drive if you don't want to fiddle with media servers. I have a mixed WXP and Mac environment at home and it works quite well with my NAS. I use a combination of mapped drives for windows and media server for the PS3.
Posted by: Ken.C

Re: A2DP quality? - 10/22/10 04:28 PM

Again, that would require having a computer running, or the TV on if I was using the TiVo for streaming.
Posted by: cb919

Re: A2DP quality? - 10/22/10 04:35 PM

I'm an all laptop environment at home as well, that's why I went with the NAS solution as I also do not like leaving computers on all the time. The NAS does have to stay on all the time, but they suck very little power, especially if you let the hard drives go to sleep when not in use - all computers can be powered off. If you don't want to leave anything on, then the NAS will be more trouble than it's worth.
Posted by: pmbuko

Re: A2DP quality? - 10/22/10 05:04 PM

Originally Posted By: ClubNeon
So yeah a dock is your only hope.

Help me, iP[ad|od|hone] Dockenobi…
Posted by: Ken.C

Re: A2DP quality? - 10/22/10 05:06 PM

It just seems like an elegant solution, you know? I don't mind the audio quality from the analog jacks at all, so if A2DP is equivalent, well, that works...
Posted by: ClubNeon

Re: A2DP quality? - 10/22/10 07:21 PM

A2DP with SBC may actually be lower quality than the analog jacks on the iPod.

Oh, if you were planning to use a Bluetooth adapter, it would also be more than likely by connecting by analog. Then you've got two problems.
Posted by: Ken.C

Re: A2DP quality? - 10/22/10 07:26 PM

Hunh. I figured the dock connector adapters would be going digital.
Posted by: tomtuttle

Re: A2DP quality? - 10/22/10 07:30 PM

Is this fun for you?
Posted by: ClubNeon

Re: A2DP quality? - 10/22/10 07:30 PM

Many are not. Apple makes hardware designers jump through a lot of hoops to get to the digital signal. So most just pull off the analog. Most of the Bluetooth adapters take the analog signal, run it through an ADC, and then encode it with SBC to send through the air. It's then received converted back to PCM, and then passed back through a DAC.
Posted by: Ken.C

Re: A2DP quality? - 10/22/10 07:33 PM

<runs away crying>
Posted by: ClubNeon

Re: A2DP quality? - 10/22/10 07:36 PM

I win!
Posted by: Ken.C

Re: A2DP quality? - 10/22/10 07:38 PM

Just for that, I'm going to make you help me troubleshoot why my Chicago office can't communicate reliably with my California office.
Posted by: ClubNeon

Re: A2DP quality? - 10/22/10 07:39 PM

Are you using a Bluetooth adapter? laugh
Posted by: tomtuttle

Re: A2DP quality? - 10/22/10 07:39 PM

Finally.
Posted by: Ken.C

Re: A2DP quality? - 10/22/10 07:40 PM

It would probably be more reliable if I was. Even better, why my VPN connection to HQ is so poor. Let's see you fix that, smart guy!
Posted by: ClubNeon

Re: A2DP quality? - 10/22/10 07:45 PM

It's probably packet loss, or one end's upload speed is very slow.

ADSL and cable (or any asymmetrical) connections are not well suited for VPNs.

Trying pinging (more than the 4 done by default by Window ping command) the IP address of each side from the alternate and see if there is any loss, or large deviations. Running the ping while the VPN is up may also be very telling.
Posted by: ClubNeon

Re: A2DP quality? - 10/22/10 07:46 PM

ping -t <host>

That'll keep the pings going until Ctrl-C is hit.
Posted by: Ken.C

Re: A2DP quality? - 10/22/10 07:49 PM

Ah, but one end has multiple OC3s, and the other end (mine) is 10MBit guaranteed burstable to 100MBit going through 3 redundant providers.
Posted by: ClubNeon

Re: A2DP quality? - 10/22/10 07:52 PM

And what's your upload? Try http://www.speakeasy.net/speedtest/

If it's not that, I'd say it's a configuration issue with the VPN endpoints. What are you using on your end to establish the VPN? Just a session on your machine?

You probably don't know what they are using to serve the VPN on the other?
Posted by: Ken.C

Re: A2DP quality? - 10/22/10 07:56 PM

Symetrical on both ends. Downloads from MS, VMware, etc actually get pretty damn close to that 100MBit limit.

PaloAlto PA-2000 on the head end, PA-500 on this end.

Naw, seriously, I don't expect you to solve (or even really troubleshoot) this. We've been working on this problem for months. It's just really confusing and annoying.
Posted by: ClubNeon

Re: A2DP quality? - 10/22/10 08:09 PM

One more question. Is it affecting more users than just you?
Posted by: Ken.C

Re: A2DP quality? - 10/22/10 08:10 PM

Yes. My two coworkers and all of my servers. Well, all but one, which works properly uni-directionally. Weeeeeeird...
Posted by: ClubNeon

Re: A2DP quality? - 10/22/10 08:13 PM

If more than one person is affected, I'd say the problem lies at the HQ. If they are serving a large number of VPN connections they machine doing the work may not have enough CPU power the handle all the encryption work. There are encryption accelerator cards to off load the computation (but they have to be supported by the VPN software).
Posted by: Ken.C

Re: A2DP quality? - 10/22/10 08:22 PM

Well, this is a site-site VPN, so I would expect all of us to get hit. At the moment I'm working off the idea that there's something weird in between our ISP's routers and HQ.
Posted by: ClubNeon

Re: A2DP quality? - 10/22/10 08:28 PM

In the weird category. Make sure there is no ICMP filtering on either end. I don't know why so many IT "pros" think that firewalling ICMP is a good idea, especially when they can't tell me why they think it is a good idea. ICMP delivers a lot of important control messages (not just pings and traceroutes, but those are important too when things are not working correctly).

But yeah, this isn't an easy thing to trouble shoot. If I had time, and my hands on the gear to actually try things, then maybe we'd get somewhere...then again, maybe not. smile
Posted by: Ya_basta

Re: A2DP quality? - 10/23/10 08:00 AM

My head is about to explode.......
Posted by: Ken.C

Re: A2DP quality? - 10/23/10 12:09 PM

OK, just talked about it with my wife. You guys are absolutely right, I'm making this more complicated and hard to use than it needs to be (or she wants it to be). So I'm thinking Airport Express now, unless there is a different solution (at <$150) that you guys would recommend. Source will be the laptops with iTunes, which will have copies of the music library on each. We only have a few purchased songs.
Posted by: Ya_basta

Re: A2DP quality? - 10/23/10 12:43 PM

Originally Posted By: ClubNeon
If I had time, and my hands on the gear to actually try things, then maybe we'd get somewhere...then again, maybe not. smile


My ex said that once.
Posted by: 1sweetspot

Re: A2DP quality? - 10/23/10 02:59 PM

Originally Posted By: kcarlile
OK, just talked about it with my wife. You guys are absolutely right, I'm making this more complicated and hard to use than it needs to be (or she wants it to be). So I'm thinking Airport Express now, unless there is a different solution (at <$150) that you guys would recommend. Source will be the laptops with iTunes, which will have copies of the music library on each. We only have a few purchased songs.


Just a suggestion-an Xbox 360 actually makes a pretty effective way to connect to your system. You just plug your iPod into the front with the USB cable that came with it, connect the Xbox to your receiver via HDMI and you can control pretty much all functions using the Xbox controller. I think the signal stays digital the whole way doing that.
Posted by: Ken.C

Re: A2DP quality? - 10/24/10 01:44 PM

There, ordered the airport express. My wife likes the plan.