[geoffmartin]

Archm@ge wrote:

I think it was partly due to you and your team has built Beosound2 so great, and of course the other reason was I can’t hear the diffs. ? It was a big day for money saving ?

Hmmm… no pizza for my kids this week I guess… 😉

But I’m glad to hear that you’re happy with the BS2! One significant difference in moving to a 2-channel system with two loudspeakers is the possibility of experiencing the spatial aspects of recordings. However, this would require setting things up reasonably correctly, otherwise things like phantom imaging will be lost anyway.

[geoffmartin]

wanc1 wrote:

Hey Geoff, There is a noticeable difference in the amount of bass when I switch from power link to optical from Beosound Core to Beolab 50. The power link sounds more bass heavy, while the optical sounds more balanced. What causes this difference?

The first thing I would check is to be absolutely certain that the output levels are identical in this test. Since the Power Link transmission path is setting the internal volume of the Beolab 50 to maximum, but the Optical transmission path is not, then you have to be very careful that you’re not just hearing a change in your own response as a result of output level differences.

To be honest, I’m not certain that merely setting the two volumes (on the Core and the Beolab 50) for this test to the same number will result in IDENTICAL output levels for a number of reasons. The only way to be certain of this is to put in a static test signal (e.g. a multi-tone made of sine waves with more than one frequency) and measure it with a reliable SPL meter on a tripod.

Another possible (and possibly more obvious) reason could be that your Beolab 50s are configured to use two different presets for the Power Link and Optical inputs.

[geoffmartin]

Archm@ge wrote:

Hi geoffmartin, Thanks! BTW, any diff wrt sound quality between Wired(Powerlink) and Wireless(WiSA), thanks.

Yes, but the differences are not easily explained in one sentence.

Power Link is an analogue connection, so you have the addition of the noise floor of both the DAC (Digital to Analogue Converter) of the source device and the ADC (Analogue to Digital Converter) of the input device. Typically, the noise floor of an ADC is higher than that of a DAC (a good rule of thumb as you go through life…).

Wireless Power Link is a digital connection, so the noise floor is defined by the word length of the signal that is being sent (and possibly the sampling rate converter of the transmission and/or receiving device). In the case of the word length, it’s a 24-bit signal, which puts the noise floor at about 141 dB below the maximum – which is well below the noise floor of the rest of the system. However, any low-latency wireless audio transmission can/will have errors caused by anything ranging from a cat walking between the transmitter and the receiver antennae and a police car driving by using a radar. As with most/all other low-latency wireless audio systems, WPL uses error concealment (rather than error correction – there’s no time for that…) to recover from those errors.

My last test of WPL involved putting a transmitter and a receiver 1 m apart, and sending a signal through it, checking that the bits that came out were the ones I put in. This test ran for 24 hours a day for 11 days and I got 0 bit errors in that time. However, if I waved my hand between the two antennae, I could see the error rate go up. NOTE however, that this does not mean that you can hear those errors – this is dependent on how bad the error is (which, in turn is a result of what caused it) – but they exist.

When you ask about “sound quality” there are too many aspects / dimensions to say which is better or worse, because we’re talking about which you prefer. If you never listen at a high enough volume setting to make the noise floor of the Power Link signal audible, then this is a non-issue. IF you live in a densely-populated apartment building with a lot of RF noise (e.g. microwave ovens, numerous WiFi networks, and a high crime rate with lots of police presence and ambulances) then maybe WPL is not the best solution for you…

Which means that the answer to your question is “it depends”, which is not terribly helpful, but honest.

 

[geoffmartin]

Archm@ge wrote:

When talking about ears are untrustworthy, do you think different power cable will make BS2 sound differently, since I seemed to notice some differences(better sound quality, meaning punchier Bass and brighter Highs) by switching the power cable from BS2 original to AudioQuest NRG-X2 ?

Definitely not. The only difference a fancy new power cable will make is on the weight of your wallet. 🙂 You’ll get the same effect by keeping the original power cable and turning up the volume by 1 or 2 steps.

Glitch wrote:

Isn’t the problem actually the brain? (i.e. Psychoacoustics) ? Glitch

The brain is half of the problem – so one has to be very specific about exactly which psychoacoustic effect one is talking about in order to decide whether the issue is psycho or acoustic.

[geoffmartin]

Hi,

Sorry – the only way to find out if something is bit perfect is to actually measure it, bit for bit. And, as I said before, there are so many other things going on that you can’t trust your ears…

Even a 1 dB difference in output levels will skew opinions when there are no other differences.

[geoffmartin]

frankmj wrote:

I would like to have a 7.1.4 surround setup. I do have the folowing speakers: Beolab 18 as front, Beolab 17 as Surround and Beolab 17 as Back. Why doesn’t roomsense configure the Virtual speakers: Right & Left Elevated Virtual and Right & Left Wide Virtual. I’m able to add them in the config of my Listening Position, but with no distance or Sound Pressure levels.

Hi,

The automatic setup will never recommend the Virtual outputs – so, if you want to include them, then you have to add them manually.

The Speaker Distances and Speaker Levels are adjustments to compensate for the physical locations and acoustical behaviour of the REAL outputs (including external loudspeakers) and the listening position. Since the signals of the virtual loudspeakers are actually produced by the Left and Right Front-firing REAL outputs, the Speaker Distances and Speaker Levels for those are automatically used by the virtual outputs.

Regarding a different question above about True Image – it makes “decisions” based on the Speaker Roles that are used in a Listening Position, irrespective of whether the outputs producing those Roles are “real” or “virtual”.

Hope this helps.

[geoffmartin]

@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

[geoffmartin]

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… 🙂

 

[geoffmartin]

You too!

FYI: I just read what I wrote above – I said “you can’t trust your ears” – but to be perfectly clear: I don’t trust my ears either. Ears are notoriously untrustworthy – they’ll blindly believe anything they hear! 😀

[geoffmartin]

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?

[geoffmartin]

One of the things to beware of when using multiple drivers to produce the same signal is that you need to make sure that the highest frequency they produce has a wavelength in air of (roughly) no less than 4 x the distance between the drivers.

So, for example, if your midranges are 15 cm apart, then the highest frequency they should be used for is:

344 / (0.15 * 4) = 573 Hz

The 344 is the speed of sound in air (344 m/s) and the 0.15 is the distance between the centres of the drivers in metres. Note that it’s not strange to find yourself in a position where this rule directly conflicts with the drivers’ capabilities. For example, it’s not hard to get to a place where the drivers are so far apart that they shouldn’t be used at a frequency higher than something that’s LOWER than they should be used for… (Like being 1.8 m tall, standing at the bottom of a 2 m deep pool… this also causes a problem… eventually…) This is why the (front) midranges of the 50s and 90s (and the (front) tweeters of the 90s) are clustered to keep them as close together as possible. (However, in those cases, we’re also relying on the natural directivity of the individual drivers, which, like I said above, are measured in 3D space.)

Of course, this is a rule of thumb and assumes many things (like omnidirectional radiation of the drivers at that frequency, and the assumption that you DON’T want them to cancel anywhere…)

IF you want to do something else – say, to cancel at 90º off axis for example, then you should put the drivers 1/2 of a wavelength of the frequency you want to cancel (still assuming that you have omnidirectional radiation from the drivers…)

I mad some simple animations explaining this here:
https://www.youtube.com/watch?v=1KGeBEWsahY

-g

[geoffmartin]

Hi Beobuddy,

I don’t really understand the intention.

It seems that you’re assuming that a Beolab 50 sends the same signals to the three woofers (and again the same signals to the three midranges). This is not true. The signals for each driver are designed to have a different frequency-dependent magnitude and phase response to either constructively or destructively interfere with each other at a distance of 1.5 m or more from the loudspeaker. Those filters were designed using on the three-dimensional response measurements of the individual radiations of each driver.

Or, maybe you’re just intending to convert passive loudspeakers into fully-active versions with your own filter designs, in which case I don’t understand why you need 3 pairs…

So, it’s possible that the result may be cheaper than a pair of Beolab 50s – but I suspect that the cost might be the only parameter you can use to compare them.

Good luck!
-geoff

 

[geoffmartin]

“balanced” is a dangerous word that is typically mis-used.

A cable carrying a “fully balanced” signal has a differential signal (meaning that there are two signals and a ground, and the two signals are opposite in polarity) AND their termination impedances are identical.

It is possible to have a balanced connection that does not have a differential signal. You do this by putting a resistor between ground and the wire that would normally carry the “negative” signal (XLR pin 3, for example). The resistor must be identical to the output impedance of the circuit driving the “positive” signal.

This ensures that the interference noise that is received at the other end of the cable is identical, and therefore if the input connection is balanced, the noise will be subtracted from itself, thus cancelling. This is independent of the signal. Driving the cable with as differential signal will increase the SNR by 6 dB (because of the doubling of the signal) but this is optional in an impedance balanced signal.

For example, if you look at the outputs of the original Mackie mixers, the XLR main outputs are fully balanced. (impedance matched WITH a differential signal) but the 1/4″ outputs are impedance balances without a differential signal.

[geoffmartin]

Some things to try (including some repetition from the above):

• Don’t change the crossover
• Don’t change the Re-direction Levels (as a first step, at least)
• Don’t turn off the Loudness

Find an example of a signal that you feel has too much bass. Play it and disconnect the power to your Beolab 19 and play it again.

IF, when you do this, the issue disappears (I assume that this will over-compensate and now you have too little bass), THEN
the solution is probably to reduce the Speaker Level of the Beolab 19 in the Listening Position -> Speakers menu. There’s no way to predict how much you should reduce it. Just drop the level until you’re happy with the relative balance.

However, IF, when you do this, the issue is still there, THEN
the solution is probably to reduce all Bass Redirection levels. Do this to all of them by the same amount (e.g. drop each one by 1 dB and listen again…. repeat this until you are happy with the relative balance.)

Hopefully, one of these two procedures will fix the issue for you. After this, you can use the Bass, Treble, Frequency Tilt, and Sound Enhance sliders to make fine adjustments to taste.

Hope this helps.

Cheers
-geoff

[geoffmartin]

BeoMedia wrote:

I don’t have an Apple TV connected, just running the stock apps in the LG TV. The Atmos test videos I am playing via Plex and the stock Plex app in the LG.

Note that the LG TV can only send Atmos signals to the Theatre via eARC. ARC does not have enough bandwidth to support the data required. (there’s a table at https://www.techradar.com/news/hdmi-arc-vs-earc showing this, for example).

UPDATE: That previous paragraph is incorrect. Atmos can be distributed over ARC in the Dolby Digital plus (DD+) CODEC.

I have not tried any Plex software since I tested it on my Synology NAS many years ago. However, if you are using Plex, you should verify that it can send an Atmos bitstream.

Regarding kuyttendaele’s comment – he’s correct, but this can be stated more generally. The only way to get an Atmos signal into Theatre is via HDMI. No other input will support Atmos.

[geoffmartin]

Mr10Percent wrote:

CODEC – Dolby TrueHD (Atmos is an extension to DTHD)

This is not really true – it’s kind of the opposite.

• Atmos is the method of packaging the audio channels and objects.
• TrueHD is an indication of the audio quality of those signals

This similar to saying “5.1-channel LPCM” or “2-channel MP3” where the first half tells you how many audio channels you have and the second half tells you the COmpression-DECompression (or CODEC) method that’s used to encode those audio channels.

Cheers
-g

[geoffmartin]

Hereford wrote:

@Mr10pct Yea I’m not a fan of the 2.0 to surround upmix. Speech especially sounds tinny. I prefer to run 2.0 content in Direct mode. Either to the BL9 fronts, or just the Theatre alone.

Just out of curiosity

• what is your source for the 2.0 content?
• which Sound Mode are you using when it sounds “tinny”?
• How are you doing the 2-in-2-out configuration? with a Sound Mode set to Direct in the spatial processing or by having created a 2-output Listening Position?

Thanks
-g

[geoffmartin]

Hi everyone,

A link to the Theatre’s Technical Sound Guide v.1 is now available at

https://support.bang-olufsen.com/hc/en-us/articles/4955893911569

I hope that this may also help to clear up some of the confusion that I read in this thread… (particularly the comments about an Atmos input stream and the number of output channels, the difference between channels and objects within an Atmos stream, and the behaviours of True Image vs. “Direct” vs. “Downmix” spatial processing modes.) IF, after reading the TGS, you don’t think that the questions/confusion in the thread are addressed, please reach out here and I’ll try to help – and update the TGS accordingly, where appropriate.

Of course, the TGS will go through version updates to reflect changes in future SW releases.

Cheers
-g

[geoffmartin]

Mr10Percent wrote:

However, the way the Theatre and Room-Sense works is initially, when setting up my 5.2.2, (please note, I designate my system as x.2.y because of the BL90 “subs”), the system recognised it as 7.2. Therefore, with the Theatre, you have to designate the two new channels as height channels – almost like it calibrates like DTS-X?

This is because the automatic Speaker Role detection cannot “see” the height of a real loudspeaker.

Therefore if you DO have loudspeakers that are mounted high on the walls, or on the ceiling, you’ll have to assign “height” Speaker Roles to those outputs manually as an adjustment to the automatically-chosen roles.

[geoffmartin]

beojeff wrote:

I see there’s a new app update today that adds headphone support for the Theatre and manual speaker setup. It looks like there is now a place to add third-party speakers when adding speakers. Also, there are two new speaker roles “left downmix” and “right downmix” with this annoying scrolling list at the bottom of that page that covers up part of the page.I can’t seem to figure out what those two new speaker roles are for.

These are the same as the Left Mix and Right Mix Speaker Roles on other current Beovision televisions.

These should be used (for example) if you are using a Power Link output for a Bluetooth transmitter for headphones, or running a 2-channel feed to another room.

Note that you should NOT use these instead of the Left Front and Right Front Speaker Roles for loudspeaker outputs in the Theatre or external loudspeakers in the same surround configuration.

Cheers
-g

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