Originally Posted by BassThatHz
What SPL meter did you use to calibrate REW with?
Also, keep in mind it will likely be a C-weighted meter so if you are measuring a 20hz sinewave you have to add about 6db to the reading, but if you are measuring 60hz you won't have to add much of anything.
Got two microphones; firstly, it's the UMIK-1 from MiniDSP
. This microphone has a usb iface and comes with a calibration file which is specific for that S/N. When I used the SPL meter in REW I were using Z-weighting
. The microphone might not even be good for sub 20 Hz. What you think?
Didn't know the differences between the different weightings until you posted the charts, so read up on it now. Looks like Z weighted might be preferred since it should be linear down to 10 Hz +/- 1.5dB.
Also got a Check Mate CM-140
which there are correction files for out there. It also has line out and is coupled with an external sound card (for the laptop), which is a basic Creative Sound Blaster X-Fi HD
I'm using UMIK-1 99 % of the time, because it's so convenient only having to plug it in through USB and REW finds and sets everything up auto. CM-140 is used for quick "portable" tests from seating positions, in corners, ...
I'll post new measurements here very soon, then I'll set both systems up and do C weighted readings. CM-140 doesn't do Z weighted, but UMIK-1 does, because MiniDSP recommend using it.
I'm also going to read up on the CEA2010 standards, bring one of the enclosures out and try to conform as much as practically possible to the standards to see how it really performs with no room gain. Could be fun, but the area is only semi rural and I need power, so it wont be 100 % open field.
The readings I made were probably far off, because in later measurements (not with sine waves) I'm not close. Will do new measurements with both mics and see if there are any differences.
What are you using to do SPL measurements? The software looks nice, and notice you're using the signal generator in REW too.
That video of the quad LMS @ 10 Hz was insane, and so were the incremental number of subs video, haha. When you hit all ten it was really big sounding, even though the playback was only done through my measly two pair of LMS-U I got the relativity of it, hahaha.
Got to ask, sorry, haha. You could obviously afford four, why not replace the other ones with more LMS-U? If not all at once, in increments, LOL.
That Fluke meter of yours is awesome, wish I could prioritize getting something like that, but would have to be 2nd hand and able to resell again at a minimum loss, because I see those are not cheap. I've actually mounted a webcam pointing at the cheap-o meter and run a live feed from the next room where the amp is at to see wth is going on when I play those sine waves. A fluke meter and one of those high precision laser measurement devices to log excursion would be awesome and make the job of optimizing the subs in any given enclosure for maximum performance a breeze (and probably a ton of fun too!).
Wonderful that you're making these videos and showing what a system like this can do. It really helps when pushing the limits in my own system.
Had a friend over who I've not seen for a few months. A couple of years ago (before he got a GF [lol]) he used to have Klipsch RF7, McIntosh MA7000 and SVS PB13Ultra. The system played very well, but when he heard this today, he immediately said he had never heard such awesome quality bass his entire life. He spent six-seven hours here, a lot listening, and he thoroughly enjoyed it. Hope to have placed a seed to get him back into it, haha. He surely looked happy, getting goose bumps etc (I did too). Nothing like a couple of guys sitting getting goose bumps together, LOL.
What gets me every time is not just the sheer quantity of bass, but the quality
. With this tight grip and excellent quality at loud SPL it is just so perfect it almost sounds unreal to be present in the room. It's impossible to convey it through words, it's much like Anders has told me, you've got to experience it to know what it's about.