REW is hardly the only option on the market, but it continually updated and added to with a wide range of features and included simulation tools, for no cost. So long as you can configure the input/outputs of your computer for your needs, it's a very flexible tool that does most all of what other systems offer short of higher end pro-audio focused packages that require quite a bit of training to get more from that what you will do with REW. If most of what you are doing is looking at below 500Hz room interaction vs placement, channel matching, and blending of subwoofers, REW has everything you would use/need. It is also useful in looking at 3D decay plots of a room (Freq vs. Level vs. Time) to aid in selecting and placing acoustic treatments. If you can make time to get a system working and keep the computer and mic/output hardware constant, REW works quite well as a portable system.
REW and most measurement systems are a bit of a deep dive and will take some hunting/study to get good use beyond the basic frequency response measurement, where you can also look at the more packaged system from Parts Express in the
Dayton Omnimic V2 and
CLIO pocket version 2.
Some are very particular about the accuracy of their measurement microphone, while for many in-room uses the exact accuracy isn't hyper critical. If using REW I would always carry a UMIK-1 around and have one on a cool shelf as a backup. Grab 2 5m USB extensions in case you every need it. The correction and calibration they come with is reasonably accurate (batch corrected). The easy of level calibration is worth keeping one around. If
Cross Spectrum ever gets them back in stock, the specific calibration file included might be worth the $110. While I rarely use the stock UMIK-1 for speaker design, it's what I start with in most rooms and the differences not very significant when you consider the differences are less than the incremental level or tilt adjustments you might make in final subjective adjustments.
Earthworks has some very nice, and is the go-to for justifiably priced, measurement grade microphones. These are more temperature stable, and the 1/4" capsule (tip) is more omnidirectional. Few need more than an M30 (3-30kHz, 140dB operating range), but even the 3-50kHz M50 is $1299. The M30BX is nice for a portable system as you don't need to worry about getting enough phantom power from USB power. This brings up the main setup hurdle with premium microphones. If the system needs to be portable, you need to select a separate microphone preamp, and deliver appropriate phantom power for the microphone you are using. Once you have it functioning, you then need a microphone calibrator to calibrate it before measuring. You also have to be more aware of various windows settings to make sure you have the signals coming through at a suitable level to not clip or have too much noise. 1/4" & 1/2" microphone calibrators can be as much or more than a microphone.
