HardCopy wrote:
Cheat the BS4 by selecting other speakers in the speaker connection menu. Put like BL18 or BL17 instead of the BL20 (actually I don't know if you can select other speakers when using WISA, i know you can when cabled).
This is not the correct way to do this, since it will not only change the bass management settings, but also the time alignment. Telling the BeoSystem 4 that you have a given loudspeaker gives it a lot of information not only regarding bass capabilities, but things like latency and overall sensitivity.
The correct way to do what you want to do is to set the Speaker Connections to the correct loudspeaker models, and then go to the Advanced Menus for the Bass Management. There, you can decide which channels are filtered, where the LFE channels are routed, and by how much.
Therefore, you could, for example, decide to send the Bass Management LFE channels to the BL20's and the 19 simultaneously, in whatever level relationship you choose.
We should, however, be clear about exactly what you're evaluating. A single BeoLab 20 has a greater bass capability than a BeoLab 19. This means that, averaged over a low frequency band, it can play louder. Two BeoLab 20's are certainly louder than one 19. However, it could be that you are not evaluating your system at maximum volume, and therefore, this is irrelevant for your comparison.
This raises the question of what it is that you prefer about the 19 over two 20's. There are two main differences when you switch between these two (assuming everything else is equal):
- coupling to the room (particularly room modes)
- tuning (aka sound design) - including frequency range
My guess is that the first of these two is the biggest difference (it's only a guess because I don't know your room). Very generally, one loudspeaker will couple to (or "activate") room modes more than two loudspeakers. In addition, since you can't have the 19 in exactly the same location as either of the 20's, then the coupling to room modes is also different.
As an experiment, try changing the bass management settings so that you're sending the LFE to only one BeoLab 20 instead of both of them. Also try putting the 20 in exactly the same location in the room as you currently have the 19.
If you do choose to bass manage to the 19 - it would also be interesting to try moving the bass management crossover frequency to see if, in your room, this can help as well.
Depending on your room and your loudspeaker and listener location within it, it MIGHT be that the bigger difference is the tuning difference between the 19 and the 20. Of course, they are different loudspeakers with difference magnitude and time responses - and you might just prefer one over the other at your typical listening level. Keep in mind, however, that if you turn up the level, your opinion might be different.
Of course, what we're discussing here is personal preference overlapped with room acoustics, loudspeaker location, listener location, program materials and listening levels... So, the conclusions you reach for your system (or that we reached in when we created the automatic settings) may not be applicable to others. This is why we put in so much user-control in the Advanced Menus, particularly in the Bass Management section of the BeoSystem 4.
Cheers
-geoff
