Hi,

I might be able to offer a little information about this - but I need to know what a "BS2" is... I see this as a "Beosound 2" - but I'm pretty certain that this is not what you mean. :-)

Or, if this IS what you mean, then what DAC + Preamp are you using?

Hi geoffmartin,

What i meant 'BS2' is actually 'Beosound 2' :)

I am using SMSL M500 Mk2 DAC + Topping Pre-90 for this experiment ;)

Unlike Geoff, I wasn't involved in designing these speakers, but I'll give it my best guess.  I doubt if there are any differences between the RCA and PowerLink connections. These both accept analog signals, and each probably sends essential the same signal to the same internal circuits.  Any difference might be attributable to the cable being used.  That is, there are probably more bad RCA cables out there than PowerLink.  However, if either cable is decent quality, then there should be no difference.  Use whatever is more convenient.   I'm sure Geoff will correct me if my guessing is wrong.

One nice thing about PowerLink is that it carries both left and right signals so you can daisy-chain your speakers.  That is, instead of running a cable from your source to each speaker, with PL, you can run from your source to speaker 1, then from speaker 1 to speaker 2.  Sometimes this makes the cabling easier.

Also, note that the BL18s are "digital" speakers so the analog signal you send to them will be digitized and DSPd before being converted back into analog and sent to the drivers.  You can skip that initial digitization step if you use the TOSLink connection (which must be daisy chained) and send a digital signal to the speakers.  However, if you like the sound of your DAC, you may not hear this as an improvement.  Volume control can be an issue with the TOSlink connection (it depends on your whether you source device supports).

Hi Stan,

Thanks for your reply, it is very informative, one follow-up question: do you think BS2 is also a 'Digital' speaker that will do similar things(Analog to Digital conversion) on its 3.5mm mini-jack line-in socket? My experiment has delivered better sound quality a bit(crisper highs, firm brass, broader sound stage) with external DAC+Pre-amp compare to Airplay to BS2. Do you think it is due to 3.5mm line-in goes via different path(Line-in to Power-amps to Drivers) than Airplay does(Airplay to Internal DAC to Power-amps to Drivers)?

:)

Guessing here again, but I'm pretty sure the BS2 isn't "digital" in the same way as the BL18.  It has no digital input so I would assume that the line-in signal takes a different path than a digital streaming signal.  AFAIK, all of the "digital speakers" like the BL18 have a digital input option.

I'm not very familiar with Airplay so I poked around on the web and found some discussions about Airplay2 requiring some non-obvious settings to get lossless transmission (

Hi again,

All Bang & Olufsen "Beolab" and "Beosound" loudspeakers are "digital" loudspeakers; meaning that any signal that comes in is converted to a digital signal for all processing, and then converted back to analogue signals which are sent to the amplifiers for the individual drivers. This is true whether the device has a digital input, an analogue input, or no input (meaning it only has "internal" sources).

In some cases, the Power Link input and the RCA (Line / Aux) input are essentially identical with respect to technical sound performance. In some cases, there is a difference in the maximum allowable input level (and therefore the sensitivity of the device: a measure of output level as a function of input level). In the specific cases of Beolab 5, Beolab 50 and Beolab 90, the  input sensitivity of the line inputs are user-adjustable.

IF your source / preamp has a high-enough maximum output, then it can overload the line input of the loudspeaker - but this is something that has to be specifically determined for the output and the input of the products in question.

Be careful making conclusions when comparing things like an analogue connection to a wireless digital connection. There are so many individual components in each of those two signal paths that may have an effect on sound "quality" that there's no real way to know why they may be different, if they are. You certainly cannot conclude that "analogue wired is better/worse than digital/Airplay/Chromecast/Whatever" without doing an extensive amount of testing, including being able to measure the signals at points in the chain within (not between) devices. In other words, it's not possible for a normal person without a lot of test gear to do this and arrive at a reliable conclusion. In addition, an overnight firmware update may make all of your conclusions irrelevant.

Finally, be careful to not confuse the terms DAC (Digital-to-Analogue Converter) with ADC (Analogue-to-Digital Converter), which appears to be happening above... :-)

 

Hi geoffmartin,

Thanks a lot for your answer, that is a lot to digest, the diffs I noticed between Line-in and Airplay might be too objective or an effect of my brain filters :)

 

Hi Stan,

Thanks for your reply and the link provided :)

@Archm@ge: There's definitely a difference - but which is better (= which you'll prefer) is impossible to predict. And, it might be different for audio files with different sampling rates (for example...) Anything can go wrong in many different places...

Cheers
-geoff