There’s a review (from another forum member) of the RCF NX 45-A that was conducted in late 2018. Here’s my review/experience of these cabinets.
RCF NX 45-A:
Power: 1400 (700 RMS) W 2-WAY CLASS-D AMPLIFIER 133 DB SPL MAX 45 – 20000 HZ FREQUENCY RANGE 90° X 50° CONSTANT DIRECTIVITY COVERAGE
Two of these cabinets were utilized for a small outdoor event (~200 ppl). The cabinets were used as mid/high with 1 x SRX728S for lows (centered). Crossover was set at 125Hz with LR-24 between high/low pass. Cabinets were pole mounted at approximately 7ft (2m) off the ground with approximately 25ft (7m) between them. Music was live sound (church/religious music –no heavy rock) that consisted of drums, guitars, keys, bass, various men/women vocals. FOH console was a Presonus 16.4.2 (first generation). FOH was approximately 50ft (15m) out.
Comparing the NX-45 with my Yamaha DSR-15 cabinets, the NX-45 cabinets had a noticeable flat response. The DSR-15 cabinets sound great, but tend to have an audible brilliance to them which has made me attenuate a few db around the ~6K and ~8k range (FOH) on some events. I did not need to attenuate any frequencies with the NX-45. The cabinets produced a good low frequency (15" woofer) that complimented the horn, even when used as a mid/high cabinet.
I was concerned with the 200 watt RMS power rating assigned for the horn… thinking it would have been undersized for the cabinet (considering its internal xover is ~650hz… compared to the DSR-15 which has a xover of 1.7KHz and more power.) I was surprised how well the horn sounded (full bodied). During the event, I checked the “limit” lights on the cabinets; no illumination. The sound system was able to maintain a very decent volume level around 120 ft (36m) out from the stage (sorry, did not have my SPL meter available).
The NX 45-A cabinets are noticeably smaller than the DSR-15 (and weigh a few pounds less), but they do produce more bass than the DSR-15. Not much of any FOH EQ adjustments were needed with the NX-45.
The cabinets were purchased as a back-up to my DSR-15; though, these will now probably be the primary cabinet.
Caveats:
1. There are no feet for the NX-45 cabinets. If they are sitting on top of a sub, the cabinet will probably slide around. Though, an easy fix is to purchase rubber feet for them, or tie the cabinet down securely.
2. The volume control for the amplifier needed to be about ¾ of the way turned up (as compared to the DSR-15, which worked well at ½ way up).
In the end, the cabinets did great. They kept up without sounding harsh.
