MXL 990 & 991 SDC
MXL 990 & 991 SDC
MXL 990 / 991 SMALL DIAPHRAGM CARDIOID CONDENSERS
Thursday, November 15, 2012
These low cost Chinese condenser mics are sold under a number of names and brands. Guitar Center sells the pair for $100; less on sale from time to time. They use the same 3/4” capsule and “Schoeps” type transformerless circuit in both. They are popular starting points for modification.
> They are inexpensive. You’ll spend almost as much for plumbing supplies from Home Depot to hack a chassis, and it will be a lot more work.
> They are decent in stock form.
> They have some easily and cheaply fixed faults, such as ceramic capacitors in the signal path, which yield audible improvements.
> The 990 has a lot of room inside for a true large diaphragm capsule and other doo-dads.
> There is a lot of information on the internet about these and how to modify them.
In stock form, they measure pretty well. The frequency response looks better than the mics sound. My guess is that resonances are being used to flatten the basic response, and resonance hurts the transient response. It smears the sound and the slight ringing irritates.
The two mic bodies sound much the same from bass into the upper midrange. In the higher midrange and treble, oddly they almost mirror each other, the 990 being scooped from 3k to 7k, and the 991 being hot. The basic capsule is not as screechy as a typical Chinese large capsule. The rise below 1 KHz is of course proximity effect of the cardioid pattern, and not a fault.
Yellow = 991 pencil mic, Cyan = 990 side address, Green = reference
MXL 991 / 991 Small diaphragm cardioid condenser mics