Mobile Electronics Australia

If you’re shopping for a highly space efficient 4-channel amplifier with a decent slug of power on tap you’re probably looking at models from the likes of Rockford Fosgate, Alpine, JL Audio, Digital Designs and JVC. Trouble is compact and powerful models from these brand costs a sizeable amount of cash, so what if you’re on a stricter budget. Say, under $300?

If so then you’re in luck ‘coz Orion’s new Cobalt CO6004 4-channel costs just $299RRP and makes more than enough grunt for most buyers. Rated power from the CO6004 is 60WRMS x 4 into 4ohm loads, which in my view is just about perfect for every day listening when connected to two pairs of good quality speakers. The CO6004 can have either of its two pairs of channel bridged to a 4ohm load, where power is 150WRMS each bridged pair. This is some measure shy of what I’d recommend for powering subwoofers, as modern design trends have seen subwoofer efficiency plummet in recent times. You’ll need 250WRMS or more on tap in my view, and Orion can help you here with a matching Cobalt 250WRMS CO5001 mono for $299RP if funds permit.

Nope, the CO6004 is best served as a full range amplifier powering your main speakers. And that’s fine since its main design feature is that it is very slim and compact, allowing it to be installed into any tight nook or cranny you can find in your ride. The heat sink design is made from extruded aluminium and with minimal fins it has been kept very tight and smooth over the PCB board. The ends are finished with neat ABS plastic caps to further smooth its edges and conceal the wiring and controls - giving it a clean overall look. The one design highlight is a blue illuminated strip that runs the length of the heat sink, adding a nice custom touch to your installation.

Features & Specifications

Today’s modern amplifiers need to tick a number of crucial boxes when it comes to features, while certain other features tend to be a little superfluous even if they’re kind of cool. The CO6004 just gives you everything you really need and nothing that you probably don’t. For inputs you get a choice of RCA inputs or you can connect it directly to the powered speaker output of your factory source via the supplied plug-in fly lead. This second option is great for those of you with integrated source units in your dashboards. The input stage can handle voltages as low as 250mV or as high as 8VRMS, which is a great range that will suit anyone’s needs. If you’re source only offers one pair of inputs the CO6004 has a small two position switch that will parallel inputs 1 & 2 across the 3 & 4 for you as well, avoiding the need for messy and costly RCA splitter cables.

Each pair of channels has fully varied high and low pass filters that can be engaged, of you can set either pair for full range output for when you’re powering a pair of 6x9s. The filter frequencies can be set from between 50Hz and 500Hz – which is nice and wide – while the filter slope is the industry default 12dB per octave. Each pair of channels also cops 0-8dB variable bass boost – though Orion omit to mention the corner frequency in their literature. Expect around 45Hz, but then again you aren’t likely to use this feature in any case.

The opposite end of the chassis provides connection terminal strip for power and speakers, and Orion have seen fit to use nice 45-degree angles insert style connectors that make neat and secure wiring a breeze. I did note that they’ve decided to use Allen head grub screws but didn’t supply the Allen head keys. Given this I’d have preferred to see simple Phillips head grub screws. Still, the power and earth terminals took 8-awg wire straight in which is nice. Here you’ll also find two 25-amp fuses to protect the amplifier from shorts.

Internally the CO6004 is quite a neat, if basic, overall layout. Sure, it is built to a price, but with 60WRMS x 4 on tap there’s no need for expensive double sided PCB boards as there simply isn’t that much current to flow around the place. Achieving the desired small chassis size meant that the power supply and output transistors all had to be flipped vertically, and these bolt to the heat sink down each side of the chassis. A second PCB daughter board houses all the signal processing gubbins and floats above the main board to save further space, while two additional think sheets of PCB each carry three tracks from the centre of the PCB to the speaker output ends. All in all it’s neat, tidy, and well thought out for a budget based design.

Powering the CO6004 up I noted that it brings the power up gradually from silent and equally it cuts power out smoothly, though I doubt you’d notice this without a test bench set up like mine. What matters most is that there were absolutely no audible pops or bangs at any time, nor did I hear audible hisses that would reveal a higher than desirable noise floor threshold. All I got was nice, clean, distortion free power from all channels – just as it should be. Don’t push the CO6004 into clipping and you’ll be rewarded with sonic bliss just the same.

Conclusion

Orion’s smart use of space during design means that even a classic Class A/B can still be highly space efficient. Packing decent signal processing, the choice of RCA and high level inputs, and handy connection terminals - at $299RRP the Orion Cobalt CO6004 is a great purchase for anyone who is looking for an ultra compact full range amplifier and who can’t justify something exotic or expensive.