David:
The Nady meter you linked appears to offer at least a couple advantages over the Radio Shack meters.
1. It has a stated range of 30-130 dB. The low end of that range is 20 dB lower than the Radio Shack meters. This could come in handy if you ever have a need to (e.g.) measure background noise in a residential HT, which is usually (and should be) lower than 50 dB (the lower limit for the Radio Shack meter).
2. It looks as if the ranges on the Nady meter are basically "high" and "low." In other words, for quiet stuff, you pick "low" and for higher amplitude stuff you pick "high." The Radio Shack meters use a (IMO) clunky range selector that only gives you access to 20 dB of range at a time. In other words, if you pick the lowest setting on the Radio Shack meter, which is the 60 dB setting, you can only measure between 50 and 70 dB. If your source goes above 70, you have to pick 70, which now gives you access to the 60-80 dB range...and so on. Now, it might be that that doesn't matter to you since the source you'll be using - presumably some test noise signal - will not be fluctuating by ±10 dB. But I have found instances where this "feature" of the Radio Shack meters is a limiting factor. (Then again, I may be asking more out of my SLMs than the typical user...)
avaserfi:
Let me clear up one misconception about SPL meters since I see so much talk about accuracy. Just because a meter displays to 0.5DBs or 0.1DBs does not mean it is accurate. Most low cost SPL meters (under $300-500) are inaccurate to an extent and cannot actually give you a precise reading within 1DB at most frequencies much less 0.1-0.5DB. So the question becomes does it matter? No, a regular Radioshack meter is more than good enough for setting loudness levels on all your speakers the 1-2DB error will be okay (it is about this at the frequencies played through most AVRs). Would you want to use an SPL meter as a linear microphone? No way thats a bad idea, but for simple level setting you are okay. Just go to Radioshack and spend $50 bucks and be happy with it.
In general, I don't disagree with you. However...
I have owned and/or operated at least five of the Radio Shack meters in my career (maybe more). Without exception, I calibrated them and found each to be within 0.5 dB right out of the box. I would be surprised if even cheap meters like the Radio Shack ones were off by as much as 2 dB. IMO, that would be a considerable amount of error for, even a cheap SLM. There are other reasons one might consider "upgrading" from a Radio Shack meter, but I don't think SPL accuracy is one of them. (Of course, we would agree on this last point, albeit for different reasons, possibly.
)
(It might also be worth noting that there are ANSI standards for SLMs; standards that designate the accuracy - among other characteristics - of different Types or Classes of SLMs. Most inexpensive SLMs do not fall into this category. They would be considered Type or Class 3 meters at best, if they conform to the ANSI standards at all.)
And, FWIW, the Grateful Dead used B&K microphones almost exclusively for many of their recordings; the same B&K microphones that, back then, were being used on almost all B&K sound level meters.
