By Mark Farmer
Crossovers are the heart of a sound system. With that in mind, why would anyone want to shrink and starve their speakers with bad blood flow. A good crossover will provide your sound system with the correct transition, dividing network, and flexibility, making your system pump hard and strong.
Features
The BSS FDS-310 is a single rack space unit capable of being used in a 2 way stereo, or 3 way mono configuration. Linkwitz Riley crossover filters(-24dB) are used for a smooth blend between points. A ‘Constant Directivity’ (CD) horn EQ is available through an internal jumper. What the (CD) EQ employs a +6dB slope from about 3.5kHz to keep a flat response at higher sound pressure levels. This will aid in the horn drivers reaching 20kHz.
Although the crossover is capable of attaining any frequency between 18Hz and 9kHz, all of these points are not reachable at the same time. BSS has also provided two internal switches to divide the low outputs in half. This changes the crossover knob labeled 180Hz-9kHz to 18Hz-900Hz in the 2-way Stereo configuration and lights up the division (÷) light on the front panel. My only complaint with this switch is that it is inside the unit and not available within easy reach. Most of the other single space crossovers I have encountered have this division switch more readily available.
The front panel is a well laid out European design. Depending how the unit is used, there are level output knobs available for each range. Two sweepable crossover points are available. Channel one covers the low-high and low-mid, channel two sweeps the low-high and mid-high Points.
On the far left two independent LED’s represent what mode the unit is operating in, Stereo 2-way(green), or Mono 3-way(yellow). These lights correlate to the button on the rear of the crossover. The other LED’s on the front panel correspond to signal gain on each output. A green(Signal) and red(Peak) LED are offered to alert users of amplifier overload. Channel 1 output gains are labeled Low-Full Range and High-Low Range. Channel 2 is labeled, Low-Mid Range and High-High Range. As complicated as this labeling sounds it is not. This layout is very easy to understand.
Additionally, each output has a Polarity(phase) switch, switching pins 2 and 3 on the XLR outputs and the‘ring’ and ‘tip’ of the 1/4” output jacks. A output Mute switch is another big convenience added to each Range. With the Mute switch engaged, the corresponding signal LED’s remain lit reading signal gain. Internally BSS has installed two input filters to protect your speakers from damage, an 18dB per octave @ 30kHz, and the other a 6dB per octave @ 15kHz.
In Use
I followed the users manual suggestions in getting the unit set up into 2 way Stereo. This called for removing the unit from my rack, taking the lid off, and switching the internal slide switches, then remounting it in my rack. Hooking up the piece was simple, following the manual’s complete explanation of their FDS-310 Crossover. I plugged the Stereo outputs of the console into a 31 band equalizer then in to the inputs of the BSS which made for a clean path. Since I only needed two points set, I dialed them both between 820 and 960. With the division switch already changed, this provided me with the 90Hz I needed.
A small set of internally crossed over STI Nuggets containing a 12” driver and a 1” horn gave me frequencies from 90Hz and up. Front loaded 15” subs gave me the rest from 90Hz and down.
A compact disc was played through the system and checks were made to make sure I had the correct frequenc going to the proper drivers and each output volume corresponded to the correct Stereo side. A few minutes of matching up the gains combined with a little EQ work and I was ready to go. Having become familiar with the sound of our other crossovers this was a nice improvement. The high end was clear, precise, and brought some tones out of our boxes I had never heard. Dynamics became punchy which sounded like the amplifiers were working to their full potential. Lower frequencies had more impact and a richness never heard with our other crossovers. Also, gain was not a problem on this crossover at all. The gain knobs were matched equally on both sides showing consistent engineering. I found the output mute switches very useful too.
Summary
In my opinion, if you are a first time crossover owner this is the product for you. The user manual is one of the best I have ever seen on the use of a companies product and how the piece actually operates. At a price around $749.00 retail, make this a building block of your sound system. This crossover will provide you with the flow to make your system live again.

Mark Farmer is a sound engineer with Live Technologies in Columbus, Ohio. He can be reached via the Internet at: mixthat@columbus.rr.com

Product Points

BSS FDS-310

PLUS
+Durability
+Transparent Sound Quality
+Mute switches
+Ease of operations
+Amazing User Manual
Minus
-Crossover Division
Switch(÷)is inside unit
The Score
Super introduction for a
first time crossover buyer.