Review: Dynaudio BM Compacts & BM9S Active Monitors

12-30-2014 06:00 PM

Recently I have become aware that my beloved Rogers LS3/5a monitors, that I have had since 1977, are not as good as I thought they were. It may be their age or the design limits of the speakers, but it has become clear to me that they were not as neutral as I thought they were.
What To Replace My BBC LS3/5a Monitors With?

So I started to research what I could replace them with. For me the most critical feature in studio monitors is that they are neutral and present to my ears an accurate representation of the audio I am listening to, neither flattering, or understating what I am monitoring. The LS3/5a speakers became a standard in brodcast here in the UK along with a number of BBC designed speakers and I wanted to retain that pedigree and so when I learnt that some of the Dynaudio ranges of monitors had been chosen by the BBC Radio and Music division to become their standard monitors I decided to investigate and try some of them for myself as these Dynaudio speakers would be replacing LS3/5a speakers in the BBC. So if they had chosen some of the Dynaudio speakers then it would be worth seeing if they suited me too before considering casting the net wider.
Which Dynaudio system To Choose?

The AIR 6, AIR 20, and BM5 reference monitors had been chosen by the BBC and because I have a smaller room I ruled out the AIR20s and decided to try the BM series and the AIR6s. Dynaudio were very helpful and have let me borrow two 2.1 systems, a pair of AIR 6s with an AIR Base 12 as well as a pair of BM Compacts and a BM9S II and it is the BM system that I have chosen to consider first.
Dynaudio BM Compact & BM9S II System

The BM Compacts are very small which suits my set up very well, because since I upgraded my screens I don’t have a lot of space on the top of my studio furniture. The Compacts are just under 7 inches or 170mm wide, nearly 11 inches or 260mm high and just over 9 inches or 235mm deep and so they fit right into my studio.
There are both balanced and unbalanced inputs and a selection of adjustment options on the back panel. There is no volume control, instead there is a 3 position switch offering +4, 0 and -10dB input sensitivity and I found that even on the least sensitive option I still don’t need to turn up the volume control on my existing monitor controller very far. There are also a range of switches to adjust the frequency response of the speakers, including a high pass filter, low and high frequency shelving and a mid eq option. I normally don’t like too many adjustments when it comes to frequency controls on monitors but I found the high pass filter useful to compensate for the fact that I have the speakers within 12 inches of a wall and because they are rear ported this can increase the bass response a little so it was useful to be able to adjust for that.
IsoAcoutic Stands Included

Dynaudio have partnered with IsoAcoustic and supply the appropriate speaker stands with every pair of Dynaudio monitors. This helps to isolate the speakers from where ever the customer installs them and will help to maintain a consistent sound. In my setting they lifted the speakers up a little so that the tweeters were very close to ear height.
What Do They Sound Like?

I started by comparing them with my LS3/5a monitors and found them very similar but better. The sound was similar but more even. The imaging of my BBC monitors was always good but again the BM Compacts are even better. The transients are much clearer and more defined but not at the expense of their neutrality. Although the BM series has been around a long time at each revision, when the Mk2 and then Mk 3s came out, Dynaudio have improved the design each time. The drivers in the Mark 3s have benefited from the designs developed for their most expensive cousins, the AIR series, and this contributes to the transients being so good and the improved bass extension.
Super Low End For A Small Box

The bass extension of these very small speakers was amazing. I had expected to need to use the sub to pick up the missing low end as I had with my existing system. The BBC monitors tail off at around 100Hz and so I have an active sub that picks up where the LS3/5s tail off. With the BM Compacts, I found that I only needed the BM9 sub for the very low end and I found that the low pass filter on the sub could be fully counterclockwise at around 25Hz. Any higher would produce a bump in the low end around 80Hz.
A Fully Featured Sub

The features on the back of the BM9 sub are very comprehensive too. It can be used as a sub woofer for a 5.1 system with a dedicated input. But it doesn’t stop there. The BM9 also has stereo inputs and outputs so you can configure a proper 2.1 system with filtering for the sub and satellites so that you can set up the bass management for a 2.1 system without any additional hardware.
They Go Loud And They Go Quiet

The well designed Class D amps and new driver designs mean that these speakers can do loud very well. The bass drivers have been designed to enable a large amount of travel so they do low end and they do it loud. But making things sound good loud is relatively easy. One of the things I do regularly is to check how things sound quiet and the BM Compacts do that translation very well too.

I am very pleased with these and I am seriously considering keeping them, but may be not just yet. Firstly I need to try the AIR system and see what that is like but also this BM system I have here won’t be staying because we are going to be giving it away to a lucky winner at the end of January. Check out the Win Page in January 2015 for details of how to enter the competition to win these speakers.