Sunday, May 15, 2011

Noise Comparison Beta vs. MD7a

I’m fortunate to have pretty good hearing.  While I can’t hear a dog whistle, at age 40, I still find old school CRT type televisions annoying because I can hear the scan frequency.  My wife, and most adults I’ve asked, have no idea what I’m talking about. 

It comes at a price though – I’m sensitive to noise in general.  With two notable exceptions, I find most machine noise to be annoying.  Being a mechanical engineer and former auto mechanic, machine noises that sound like something is loose or malfunctioning, or just shouldn’t be, are the worst. My old tired MD7a with it’s “missing the third jug timing” was one of those. (The MD7a has the cylinder timing of a 3 cylinder, with one of the cylinders missing.) So after reading all of the forums and sales literature about how quiet the Beta is, I was very excited to find a good deal on a Beta.


So the Beta is installed and the jury has rendered a verdict.  Although I have access to it, it didn’t occur to me to take before and after noise measurements with a sound meter, so my phone will have to do.  Quantitatively, the Beta is quieter, but nothing to….well shout about.  Qualitatively, it sounds to this designer of machines for the last decade as a 2 cylinder diesel should, if a little

Beta 14
noisier than I would like. Here are some videos. That said, no effort has been made to add sound insulation (yet) in Sojourn and in fact feels like a lot of vibration is getting transmitted through the hull and reverberating in the open space in the lazarette. I’ll revisit this when I get to sound insulation on my rather lengthy to-do list.

Oh, and the two notable exceptions: A Ducati 900 Super Sport and Packard V-1650 often heard in a North American P-51 Mustang flyby.

Galloping Ghost at Reno (3 min video.) The video doesn’t do it justice.

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