Many people here have posted the corrections for the radio shack SPL meter for the lower frequencies, such as under 150hz. Does this imply that above 150hz the RS SPL meter is pretty dead on? And if so, can I plot the frequency of my room throughout the audible frequency and work to flatten it out without trying to change the crossovers in my speakers? Such as through equalization? Is it possible to do any of this? Just looking for some suggestions on how/if people flatten their response in room without building custom speakers and XOs. Thanks for any/all responses I get to this fairly newb question.