Beolab 50, best input?

RCA, optical, usb or spdif?

Probably USB

Why?

As with all modern Beolab speakers the analog input (RCA or also XLR in Beolab 90) is digitized. So there you have it, an extra stage in your signal chain. I am not claiming that it will sound inferior, but it is an extra stage. I am still waiting for someone to test these marvelous speakers fed by a truly hi-end phono stage (new Nagra classic phono please?)

As for the digital inputs: As fas as I know, optical input is limited at 24bit/96kHz while USB and coaxial go up to 24bit/192kHz. All digital inputs are influenced by cable length with optical being more sensitive to low quality cables. So you have to taken into account many things, like your source material, playback device, cables etc.

More or less what andreas said, cleanest data and doesn’t need converting on the source device beofre being sent out. Only thing is that unamplified aka normal usb cables have a sorta length limit of 5 meters or so.

Once the data is received the speakers can do their thing with it.

I personally honestly wonder how much it matters as a lot of the changes could be done in EQ too. I bet you can come realy close with any solution if you measure the output and then EQ the speakers to that output on any of the “inferior” inputs. Bl50’s and 90’s allow for very minute changes anyway. Most of us would get more gain out of treating the room they’re in first i recon. Just my 2 cents

I’d be much more concerned about the quality of the music, that you’d want to listen to.

There are huge differences there - and most recordings are not what one should call ‘high quality’ (regardless of the bits/kHz container they are served in).

Old recordings are analog per definition. anyway.

With the amount of processing used in modern recording, the least differences should come from the different inputs of the 50/90’s.
Those speakers were made to treat every input as equal as possible. 

It will mater much more, whether the 50/90’s are set up correctly and also play in a halfway decent room soundwise, or not.

Also consider that the sound from one particular device might be different, when you use one output instead of another.

 

Spend more time enjoying the music - and less on finding theoretical differences from the different inputs of the speakers....would be my 2cents.

MM

Millemissen:

I’d be much more concerned about the quality of the music, that you’d want to listen to.

There are huge differences there - and most recordings are not what one should call ‘high quality’ (regardless of the bits/kHz container they are served in).

Old recordings are analog per definition. anyway.

With the amount of processing used in modern recording, the least differences should come from the different inputs of the 50/90’s. Those speakers were made to treat every input as equal as possible.

It will mater much more, whether the 50/90’s are set up correctly and also play in a halfway decent room soundwise, or not.

Also consider that the sound from one particular device might be different, when you use one output instead of another.

Spend more time enjoying the music - and less on finding theoretical differences from the different inputs of the speakers....would be my 2cents.

MM

There is a tv - and there is a BV.

So you mesn whatever signal you put in them they sound the same?

That is just bs.

Take a bad car stereo and put on som music. Then connect your phone to it with the same song. Do you hear the difference?

Esax:

So you mesn whatever signal you put in them they sound the same?

That is just bs.

Take a bad car stereo and put on som music. Then connect your phone to it with the same song. Do you hear the difference? Beovision 7-55 MK1 red, Beolab 10 red. Beolab 50, all black. Beolab 17 broken ice. Beolab transmitter. Apple tv4 and apple express 2.

Not sure that's the best example

I'm with you in that obviously the 50s won't sound the same regardless of what you send to it.

After all, I've bought a Linn streamer for use with my 50's, as it sounded better than just using a Core.

But I also wouldn't get too concerned with which digital input on the 50s is better or worse.

For the same set of speakers, your room and the quality of the recording are more important factors.

Esax:

Millemissen:

 

I’d be much more concerned about the quality of the music, that you’d want to listen to.

 

There are huge differences there - and most recordings are not what one should call ‘high quality’ (regardless of the bits/kHz container they are served in).

 

Old recordings are analog per definition. anyway.

 

With the amount of processing used in modern recording, the least differences should come from the different inputs of the 50/90’s. Those speakers were made to treat every input as equal as possible. 

 

It will mater much more, whether the 50/90’s are set up correctly and also play in a halfway decent room soundwise, or not.

 

Also consider that the sound from one particular device might be different, when you use one output instead of another.

 

 

Spend more time enjoying the music - and less on finding theoretical differences from the different inputs of the speakers....would be my 2cents.

 

MM

 

There is a tv - and there is a BV.

 

 

 

So you mesn whatever signal you put in them they sound the same?

 

 

That is just bs.

 

Take a bad car stereo and put on som music. Then connect your phone to it with the same song. Do you hear the difference?

Pardon me - please read my entire post and please don’t overreact.

Not talking about ‘sounding the same’ - what I said, was that it will be very hard to define, what is ‘good’ or ‘bad’ there.....

....and that there are a lot of other things in a listening chain, that might nead more attention (as eg. the quality of the recording.....again my 2Cents.

 

When it comes to different inputs (and outputs) peole seldom agree on what is ‘best’ - it often ends up in a hot discussion, a some time rather riligeous one .

It will be much easier to agree on that they sound ‘different’.

Why not do the test yourself - after all you are the one, who will listen to the results.

 

MM

Sandyb:

After all, I've bought a Linn streamer for use with my 50's, as it sounded better than just using a Core.

Maybe it is just that the Linn/the ouput of the Linn sounds different than the Core.....and you prefer that.

Which is totally ok - noone can say anything against that.

MM

Indeed it does sound different.

I'm with you in one sense....sometimes better is a bit meaningless, especially when comparing products of a broadly similar price range. 

Sometimes not though - a high end very capable product (lets say my Linn streamer / DAC) will obviously sound better than using my laptop as a streamer / DAC.    Thats not just a question of different.

I spent a reasonable amount of time comparing Linn to Naim streamers, and while both were excellent, the Naim sound is a bit more fatiguing than the Linns.  That, to me, was a good example of different (and more pleasing to me) as opposed to better per se.

Anyway, I've done my Core vs Linn afternoon of listening, and one was more capable than the other.  Not everyone has the same sensitivity, hearing wise or whether they care enough wise though.  

With my previous speakers (18s/19), the speakers themselves werent capable enough to merit exploring something like the Linn.

But that's obviously not the case with the 50s.

And lest not pretend that all streamer / DACs sound the same, or that you can't get a better outcome than using a Core.

Elsewhere though I do agree, I wouldn't over obsess about which input / cable is better or worse, specifically as room / environment and recording quality are both hugely important first off.

 

 

Millemissen:

Sandyb:

After all, I've bought a Linn streamer for use with my 50's, as it sounded better than just using a Core.

Maybe it is just that the Linn/the ouput of the Linn sounds different than the Core.....and you prefer that.

Which is totally ok - noone can say anything against that.

MM

 

Just for the record, i onviously meant all else being the same with my comment. As in same track and or player just different output/input

Esax:

RCA, optical, usb or spdif?

So - coming back to the original post:

This is a good question......however there is no answer to it.

MM

A lot of this is subjective. As indicated, the quality of the recording has a Hugh impact and by virtue of the BL50/90 the room.

I don’t subscribe to the extra links in the chain theory as B&O if full of chains.

I drive my BL90 predominantly through an AURALiC stack (inc DAC) and sample processor into XLR. Number of reasons for that but mainly best analogue signal to the BLs, I don’t like the USB too much and also to maintain compatibility (AURALiC has a history of being fussy whic DACs it feeds inc the BL90

I may be a layman in this field. But I understand so much that if you ignore the importance of the room and the quality of the music you play. So you get a better sound experience the better signal you bring in. It does not matter if you have the worst money can buy or get cheap ***. It can only get better. I am a perfectionist and always seek the best within what I have.

Getting the best available signal into the speakers is my start point which is why I use USB.

Different Dacs and streamers will alter the sound, as will an upgraded power supply, and MM is correct - the sounds are different not necessarily better.

Sure, room acoustics, what kind of listening you do and a whole raft of things also influence the sound, but if you care about getting the best possible results (and by buying the 50s you are saying you do), why settle for anything less than the ability to go to 24bit/192kHz?

 

Esax:

RCA, optical, usb or spdif?

I'm afraid that the answer is "it depends"

• What do you mean by "best"?
• What is the source material?
• What is the source device?

However, I can say that, if your source has a digital output, and ALL other aspects in ALL parts of the chain are equal, then there will be no difference between Optical, S/PDIF, and USB-Audio, since

• The bits that come into the DSP follow identical paths for these three inputs 
  (remember, however, that the Optical input will not work at sampling rates above 96 kHz)
• All signals are re-clocked via the ASRC in the Beolab 50, so jitter originating in the source is obviated as an issue

For any given source that has an analogue AND a digital output, then the answer is still "it depends". This is because some sources use sampling rate converters before the digital output that are not applied to the DAC of the same device. So, it's possible that the artefacts caused by the DAC of a device (e.g. noise and (typically) harmonic distortion) might be less audible or less annoying to you for some recordings than the artefacts caused by a poorly-implemented sampling rate converter (e.g. typically aliasing components which are not harmonic). Since this is (potentially) a sampling rate converter issue, then it's dependent on the sampling rate of the signal. I have, however, seen strange cases where, for a specific chain of devices and software, the higher the sampling rate or bit depth the worse the behaviour of the output.

Also note that some DACs have different behaviours at different sampling rates. In the "old days" this was because there were actually different DACs used for different sampling rates. These days, that's probably not the case - but looking at datasheets different DAC brand/models show that (for example) specifications change with sampling rate. Whether or not these are audible changes depends on many things.

 

So, there is no way to answer your question without know everything about the entire signal path - and measuring it. And, unfortunately, any conclusion you make today may be made obsolete tomorrow due to a firmware update in one of the devices in the chain.

Cheers
-geoff

 

While we were walking the dog, I've given this thread a little more thought, so I've one more thing to add before going to bed:

Consider the following:

• You have a source that can take a PCM file from a hard drive and simultaneously send it out a digital and an analogue output.
  • Let's say that the DAC and analogue output stages of that source have a reasonably flat magnitude response to about 90% of Nyquist and they have a 110 dB SNR (which is pretty good - but not outrageous)
  • Let's also say that the digital output (I don't care what type of digital output for the purposes of this example) just spits out the bits that are in the file - all of the bits, at the file's sampling rate, and no errors.
    (This kind of behaviour should not be assumed, but it's not terribly unusual - I've seen it in devices for less than $100, for example.)
• You connect the analogue and the digital signals from the source to the analogue and the digital inputs of the Beolab 50.
  • The analogue input of the Beolab 50 has a SNR of 122 dB (not only according to the spec of the components - I actually measured it myself!) and has a flat magnitude response.
  • The sampling rate converter of the Beolab 50 has a SNR that's higher than the ADC - something around 140 dB, which is extremely good. The magnitude response is also well-behaved.
• You turn the volume up to something reasonably loud (let's say a peak of 100 dB SPL - which won't break anything, but it might annoy the neighbours...), you tell the Beolab 50s to use the analogue input and you play a track that you ripped from a very-well-recorded CD - let's make it classical music so there's some dynamic range.
• You hear noise... Hmmm... not good. So you switch to the digital input. Same noise... Why?

The problem here is that I said "ripped from a ... CD" which means that the original signal is limited to 16 bits, which, by itself, has a 93 dB SNR. So, even if the recording engineer was REALLY careful about everything like turning off the air conditioning  and using really good mics and mic preamps, and no one screwed anything up in the mastering:

If you turn up the volume so that you hit 100 dB SPL, the noise floor from the CD itself will be 7 dB SPL, which is audible if no music is playing, and your dog isn't barking (I own an Icelandic Shepherd, which means that I don't have to worry about the noise floor of anything else in the house...)

The point is - in this example, the recording (or more accurately, the way the recording is encoded) is the weak link in the chain with respect to the signal to noise ratio.

If you then take it one step further and say that it's a CD of Aretha Franklin's greatest hit, Glenn Gould playing the Goldberg Variations, or Malvina Reynolds singing "Little Boxes", then the noise floor will come from the original analogue tape, and not the CD. However, in all of these examples, I'll be listening to the music, and not the noise floor...

Of course, the moral of the story is what has already been stated above: The recording or the way it's encoded/distributed is often one of the weaker links in the chain.

If you'd like another example that is NOT based on geeky specifications like signal to noise ratios, listen to Eric Clapton's Unplugged album using speakers that have a reasonably good output in the low frequency bands (say, below 50 Hz). You'll hear a very big bass drum in that recording: it's very low in frequency - low enough to be inaudible in most systems. That's not a bass drum: it's Mr. Clapton tapping his foot, which causes a vibration in the stage that shakes the mic stand(s) and the microphone(s). If the recording engineer or the mastering engineer had heard this, I'm pretty certain that it would have been high-pass filtered to remove it. This is one of those strange cases where having a "better" system (in this case, loudspeakers with an extended low frequency range) makes things "worse".

G'night
-g

 

We are so lucky to have you, Geoff. As if you didn’t work hard enough during your day job, you give us your time here. We are very appreciative. Thanks for all you do—in and out of the office! Happy New Year!

BTW, Geoff’s comments to me essentially say there are far too many questions about the influences of sources, other components and the recordings themselves to answer this question clearly. Also, one part of the answer is about quantifiable measurements and “more” here may be quantitatively “better” but not sound “better” as it could mean hearing more of the crappiness in a crappy recording.

My take is to use decent components, decent cables and lossless CD-quality or higher sources and sit back and enjoy. You’ll hear great sounding music and even some of the flaws innate to the recording itself.