Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems Alternatives to Radio Shack SPL meter for MRC?

Hey all,

I vaguely recall this being covered in previous threads but my archive keyword searches weren't having much success. I recently purchased of an 861V4 to take over from the 568.2mm in our big rig. MRC is new to me and based on the many frustrated postings on this subject, I'm experiencing a sense of dread as I prepare to run MRC. I really want to approach this as ideally as possible to reduce the frustration factor.

I'm sure some of you of you have experimented (successfully?) with standalone microphones and mic preamps. If so, what are you now using and was it an improvement in any way from the RS SPL meter. I just purchased a Velodyne SMS-1 to replace the BFD (Behringer Feedback Destroyer) parametric EQ I currently use to dial in my Paradigm Servo 15 subs. The BFD worked great and is very affordable but the pro audio user interface makes set-up very cumbersome. The Velodyne PEQ on the other hand, has the user interface dialed. I was kinda wondering if I would get more consistent MRC results if I borrowed the mic from the SMS-1, purchased an appropriate mic preamp if neccessary, and used it for MRC? I would also imagine that a proper microphone tripod used with either a stand alone mic or the RS SPL meter would be an improvement over hand held use. Thoughts on this? Thanks guys.

Happy Trails!
Vince@Freewheelcycle.com

I asked Meridian what was recommended and was told by the guys in tech support that the MRC system was designed using a radio shack SPL meter so anything better than this is a waste of time.

Michael

That's exactly my experience.

I have successfully used three setups.

ECM8000 with Rolls Preamp.
GenRad 1982 ($4000.00 SPL Meter).
RS Analog Meter.

As far as successfully getting through Measurement Phase the RS Meter has been the easiest most reliable to work with. And for as far as we know Meridian has calibration curves built into the code for the RS Meter.

They have ALL failed at sometime or another but it was always my fault.
Low batteries, wrong cable, poor connection, wrong sensitivity, wrong output level.

The SNL check is a thorough check and it usually means you do have a problem (that isn't the softwares fault). I have seen rooms that are highly absorbent or bass that is totally messed up causing MRC Measurement to fail. Also a broken driver can cause it to fail. Side firing subs can be very tricky too because Calibration noise used for leveling is different than what's used for MRC.

The most difficult speakers I had trouble with were Dipoles that radiated from the sides. And Side Firing Mains (like 8000's, this usually means they DON'T agree with your room as it is setup).

MRC is not that bad if you have a reasonably good setup and reasonably sharp at diagnosing what might be at fault (and there are quite a few things that can go wrong). What MRC could be better at is making the workflow a little smoother at getting though best SNL. For example it could try all sensitivity levels and pick which gives the best SNL / Level combination. It could also do better at picking target Decays. And one huge problem I have is repeatability. Getting through the measurement phase with the RS Meter and manually picking a target decay is fairly easy. But results may vary widely (all usually positive) but it's not easy to "optimize" without really digging deep with an RTA etc.