lg wrote:

I have read up a little more during the holidays and one thing that struck me is that B&O active speakers always play at "maximum volume". 

I don't know how you came across that? Maybe you could provide a link to the source of that info?

The BeoLabs are usually connected to the various devices with a PowerLink cable.

The PowerLink signal is a low level line signal for the amps. The control for volume is send along with the sound signal as well as - in most cases - the trigger on/off for the amp in the speakers. 

The controlling of the volumen is done in the BeoVision, the audiosystem, the linksystem etc (i.e. in the preamps) - mostly using the remote. This means, that the amp is active, when turned on and inactive, when off. You won't hear anything, when they aren't in use.

Modern BL amps are using ICEPower with a relatively low power consumption and they generate only a little heat.

MM

Millemissen wrote:

I don't know how you came across that? Maybe you could provide a link to the source of that info?

The BeoLabs are usually connected to the various devices with a PowerLink cable.

The PowerLink signal is a low level line signal for the amps. The control for volume is send along with the sound signal as well as - in most cases - the trigger on/off for the amp in the speakers. 

The controlling of the volumen is done in the BeoVision, the audiosystem, the linksystem etc (i.e. in the preamps) - mostly using the remote. This means, that the amp is active, when turned on and inactive, when off. You won't hear anything, when they aren't in use.

Modern BL amps are using ICEPower with a relatively low power consumption and they generate only a little heat.

MM

I should have been clearer in my question: I am referring to the phono input used for non BO-sources. As far as I understand it, if you use that connector you regulate the volume on the source device and to achieve "maximum volume" on the speakers they must constantly be amplifying as much as possible, mustn't they?

Millemissen wrote:

lg wrote:

I have read up a little more during the holidays and one thing that struck me is that B&O active speakers always play at "maximum volume". 

I don't know how you came across that? Maybe you could provide a link to the source of that info?

I think I understand the point / question that lg is making / asking. Both powerlink and line inputs of a beolab are variable level inputs, so if you were to feed full 'fixed' line level signals into either input, the speakers would reproduce that at full volume. In a more conventional hifi separates type setup, this is indeed equivalent to leaving the power amp set to maximum volume and adjusting the levels of the line inputs.

Millemissen wrote:

The control for volume is send along with the sound signal

There is no separate volume control data sent over powerlink as such - it's just two channels of variable level audio plus a signal to switch the amps on and off (and in some cases a data pair in the case of speakers with a display). I don't think it was MMs intention to imply otherwise as he specifically went on to say...

Millemissen wrote:

The controlling of the volumen is done in the BeoVision, the audiosystem, the linksystem etc (i.e. in the preamps)

...which is absolutely correct, but I felt it was worth clarifying as it was otherwise open to misinterpretation.

Anyway, regarding lg's original questions:

lg wrote:

How does that actually work? Generally, playing at maximum volume has some negative side effects, such as

1. Consume a lot of energy -> heat

Without getting too techinical, and ignoring for now the efficiency differences between different amplifier designs / classes, generally speaking, the heat produced by an amplifier will be dependant on the level of the signal being produced by the amplifier (it's output). Given that an amplifier with the volume turned to 100% should (ideally) produce no output signal when there is no input signal, it should produce no more heat in this state than the same amplifier with the volume turned all the way down. The main reason for the move towards class D 'IcePower' amplifiers is the high efficiency meaning less heat generation (which reduces the need for large heatsinks and can lead to more compact speaker designs).

lg wrote:

2. A lot of noise. Even if there is no signal, if you turn up a conventional amp to max you hear a lot of noise from the electronics, 50 Hz from the power grid etc.

The volume control in a 'conventional' amp is still done at the pre-amp stage, with the power amp section (or in our case the power amp in a BeoLab) being fed with a signal which varies in amplitude according to the volume control setting.

The fact that some 'conventional' amplifiers produce mains noise at higher volumes would tend to be down to poor power supply design, or poor shielding at the pre-amp stage. Ground loops can also cause similar issues but are much more of an issue with devices where the chassis is connected to mains earth (whereas BeoLabs are all class 2 / double insulated so require no mains earth connection).

lg wrote:

3. Distortion increases with volume.

This is not strictly true, until the limits of a particular part of the design are reached. As mentioned above, volume control is usually done at the pre-amp stage anyway, so the power amp, even in a 'conventional' amplifier, would have a fixed gain - feed 0.5V in, get 10V out, feed 1V in, get 20V out and so on. The distortion will occur either when a peak in the waveform cannot be produced because it exceeds the maximum level a given component can produce, or because the power supply is unable to meet the current requirements of the amplifier at high output levels, resulting in a voltage drop from the PSU, which will again lead to distortion of the output signal.

I've already gone into more detail that I had intended! To summarise then:

A conventional separates amp will usually consist of:

pre-amp -> volume & tone controls -> power-amp -> speaker output

A modern B&O system is really no different except that the pre-amp and volume / tone control stages are in the BeoSound or BeoVision, and the power-amp and speaker parts are in the BeoLab speakers.

Kind regards,

Martin.

Thanks Martin, for the more technical explanation - always enjoy your expertice.

MM

Answering specifically the question of using a Y-Splitter to connect audio from a volume controlled source such as a headphone jack. This is not a problem if you can set the crossover of the sub to around 60Hz for the Beolab 6000. Since both the Sub and Beolab will be volume controlled if you match the wattage of the sub and Beolab 6000s - basically any 6 inch to 8 inch sub will work and set the volume of the sub close to max you will get the same experience of not better experience with a 3rd party sub than you will with the Beolab 11 or even Beolab 2 (which completely overwhelms the BL 6000). I used to have a BL 18 sub and switched to dual Cambridge Audio Minx 200 series sub (it’s around 9 inches in all directions with a nice glossy black finish). I simply have the subs placed next to the BL6000s - they look good and are small. I have the splitter RCA left to one sub and right to the other, just like I have with the BL 6000. If you connect an Apple AirPort Express, which can be had on eBay for $50, you have a complete AirPlay 2 system.

I find the BL 11 sub is a completely useless sub and not worth the $1,200 they go on eBay. My 2 cents worth. I sold mine for a BeoSound 2 speaker 🙂