SPL METER? ATI OR RADIO SHACK

I haven't tried the others, but the Radio Shit is the best bang for the buck, even though it could use a little correction to achieve really flat response; it's fine out of the box for audiophile use. Just one tip, get the analog meter version, not the digital readout version.

I got the Radio Shack digital version, It has been great, Unless I go int buisness needing an SPL it is good enough.
I think it was around 49.00 or so.

Behringer DEQ2496 + measuring mike (can't recall the model) will help a great deal in speaker placement and room acoustics. More money, of couse, but it is a lot more fun too.

Go with the Rat Shack digital meter [I don't know if they still make the analog meter]. Make sure that the 9V battery is fresh, since a weak battery will affect your readings.

Also, Rives make a frequency response test CD with two set of tests. One set of tests has been specifically recorded to compensate for inaccuracies in the Rat Shack meter [Note: I am not affiliated with, nor do I have any financial interest in either of these two companies!]

I think that the Rat Shack unit is really easy to use and fun, too! I showed the landscapers why they were smart to use ear protection while operating their wood chipper....peak readings of 109 dB!

I just received a mint RS analog version I bought on EBAY for around $28. The desirable analog version is:Radio Shack Analog Sound Level Meter, #33-2050. I believe there are currently several more listed on EBAY.