[Riku540]

I’ve been trying to figure this one out for a while. I know very well that typical wireless technology ultimately causes signal quality to suffer, but since the AirPort Express streams music through you network digitally, I was wondering if this still applies. I figured since digital streaming, such as LAN, doesn’t actually result in data loss like when using a laptop computer wirelessly, would this mean that there is no loss in audio information when it is transferred to the AirPort Express via wireless? I know that a weak LAN internet signal is present it can cause to slow data transfer; especially when streaming music or video from the internet which causes it to pause and re-buffer information. I was wondering if this concept also holds true to the AirPort Express, opposed to standard wireless technology that transmits an analog signal and deteriorates signal quality dramatically. Thank you for your help.

 

[Oliver :)]

AirTunes employs Apple Lossless and is bit-perferct, there is no loss in quality. Under heavy load network conditions you may encounter dropouts in playback, but never a decrease in signal quality. The latest AirPort firmware does a very good job regarding signal stability though. I think it would be even better if I eliminated all 11mbit devices from the network, but what would I use for a remote control then

 

[rimmer]

I do not have personal experience, but Airport is nothing but wireless network of standard 802.11, which means the same bit-equal tcp/udp transmission as lan. The problem is the bandwidth, whether the wireless network is able to stream all data in time (and how much of them). The bitrates of losing codecs are known, cd audio is 2 * 16 * 44000 = ~1,4 Mbits/second. Lossless mean about a half.

Based on version of your Airport, maximum speeds are 11 (11b) /54 (11g)Mbits/s. This is not constant in time and even degrades upon distance.

I guess Airport end terminal must do some caching to fill short time total or low-speed gaps which occur from time to time. But I am in doubt if the DAC and output circuitry is of audiophile quality. That ask yourself or anybody who uses it.


Edit: I see Oliver answered all you have to know

 

[Oliver :)]

Quote:

Originally Posted by rimmer But I am in doubt if the DAC and output circuitry is of audiophile quality.

The DAC is okay but nothing to write home about, a little blunt maybe, nevertheless very acceptable for the price. But then there is the optical out, and you may hook up *whatever you want*

(go team AQVOX!

)

 

[ken36]

What is team AQVOX?

 

[Oliver :)]

Quote:

Originally Posted by ken36 What is team AQVOX?

http://www.aqvox.de/products.html

 

[Riku540]

Well bandwidth never seems to be a problem in my house, except whenever someone turns on the microwave O_o. I already had the optical output in mind for later when I get around to upgrading some of my sources (Sill recovering from headphone and amplifier upgrades). With that said it seems like a very worthwhile investment. I also have two more questions about optical technology: Since optical is bit-perfect, do cables matter? I would imagine they wouldn’t, or if so not nearly as much as they do in analog where interconnects can end up costing $200 an up. And finally, since optical is bit-perfect, does this mean you can theoretically hook up as many devices you want without worries of quality loss (assuming everything is optical)? Thanks again for your help.

 

[Oliver :)]

Quote:

Originally Posted by Riku540 Since optical is bit-perfect, do cables matter? I would imagine they wouldn’t, or if so not nearly as much as they do in analog where interconnects can end up costing $200 an up. And finally, since optical is bit-perfect, does this mean you can theoretically hook up as many devices you want without worries of quality loss (assuming everything is optical)? Thanks again for your help.

Well, optical is just the way of data transport, Apple Lossless is bit-perfect as source material. Since the digital data transfer is "just" light with no electricity involved, you don't have to spend enourmous amounts on a cable. The "problem" is more with the connectors, you just want to make sure they are of good, sturdy quality (no need for gold-plated contacts

) and make good contact. Should you plan to run several meters of optical connection you may want to consider a cable employing real glass-fibre instead of plastic. You can split the optical signal if you want to, but it is tricky business due to connection issues / loss of signal strength, but I'm sure there are active devices that will split without loss.

 

[Riku540]

When I mean hooking up devices I don’t mean by means of splitting the connection. For example, running the optical line out from a DVD player to a CD player to a receiver to a TV; a linear connection. Normally with analog the more connections the more quality loss. What I want to know is if this is also true with optical or if the bit-by-bit information retained throughout the numerous connections.

 

[rimmer]

Quote:

Originally Posted by Riku540 For example, running the optical line out from a DVD player to a CD player to a receiver to a TV; a linear connection.

As long as you have optical input on that CDP with loop out which is not very likely to be. Still you can hook up those optical sources to multiple input DAC (e.g. a receiver).

 

[Riku540]

Again, my question is theoretical; I just want to know if it WORKS without loss of quality. Can anybody give me a straight answer please?

 

[gerG]

Yes no maybe...

You should get bit perfect data transmission. I have even managed to work around the microwave thing. The AE buffers data, so intermittent interference is not a major problem.

The other quality issue is time accuracy. Error in timing is our old demon jitter. If you are using optical digital from the AE, you may be at the mercy of the clock in the AE. Probably not the best there is, but it is not terrible, either. If you use a DAC that buffers and re-times the data stream, this issue mostly goes away, and you are very near timing perfect as well as amplitude perfect.

I have 3 AE running in my network, and I really like them.

gerG

 

[Oliver :)]

Quote:

Originally Posted by gerG The other quality issue is time accuracy. Error in timing is our old demon jitter. If you are using optical digital from the AE, you may be at the mercy of the clock in the AE. Probably not the best there is, but it is not terrible, either. If you use a DAC that buffers and re-times the data stream, this issue mostly goes away, and you are very near timing perfect as well as amplitude perfect. I have 3 AE running in my network, and I really like them. gerG

Right, you want a re-clocking DAC such as the Benchmark or AQVOX if you think jitter might be trouble. And yes, it seems one cannot have enough APX/AE stations. If I wanted to throw a lot of money at it I would buy a WLAN equipped Palm & have a Mac mini run iTunes and a VNC server and spread APX stations & active speakers etc. all over the place.

 

[ken36]

I believe I need to read this thread again and again. I don't get it yet..

 

[Elephas]

Quote:

Originally Posted by Oliver The DAC is okay but nothing to write home about, a little blunt maybe, nevertheless very acceptable for the price. But then there is the optical out, and you may hook up *whatever you want* (go team AQVOX! )

Can I be on Team Sort-of-AQVOX?

I haven't experienced any skips, pops, etc. with the AirPort Express output to the CEC DA53 DAC, which sometimes happened with the 1212m. Sound quality seems equal to the 1212m's optical outputs using foobar ASIO and WAV files.

AE stations paired with Mhdt Lab Dialogue II DACs is relatively inexpensive for decent sound quality and wireless flexibility.