Measurements For Everyone

[fuzz092888]

OK. I wasn't going to do all the speakers at once but each individually as I have in the past with just the RS spl meter and test tones, a bit of pain in the back. The two subs I will need to do together at the same time though to EQ as one. I tried to do it individually but when they were together split and mono mode the FR changed, of course. Worked nicely with both and EQ as one.

Now, another question came up after reading the link auto-eq with rew. It mentions a need for a plug in. Is that so, or that is with a different setup?

Wait so you have a miniDSP or are going to get one? If you plan on EQing with miniDSP then yes you need a plug in.

REW does not need a plug in to perform its EQ feature, but it doesn't actually implement the EQing. You have to have miniDSP or one of the other supported items like the Behringer FBQ96.

Ok, just to clarify my point - USB 1.0 which have been used in many usb dacs is limited to lower resolution of data sampling due to deficiency of bandwidth.
USB 2.0 based solution normally allow higher precision of sampling - I think 24/96 is the norm.

I'm not 100% sure this added resolution is significant for audio measuring, but if it is than it's possible going with phantom mic and usb 2.0 dac might provide better result

Again, these are speculations, not facts.

Just want to clear something else:
Due to microphone is usb based - so the measuring portion will have no dependency on PC/MAC hardware sound card, other than to feel an audio signal to the system tested.

According to this (not sure if it is entirely accurate) USB class 1 is capable of 24/96

USB audio class 1 allows for 24 bit / 96 kHz 2 channel PCM audio.
It will run on USB 1.1. as this is what fits in the 12 MB/s capacity of USB 1.1

USB audio

 

[BoredSysAdmin]

USB audio

This is interesting indeed. All the solutions based on usb 1.1 were limited to 16/48 and I (looks this way) incorrectly assumed this is due to limitation of bandwidth, but rather is seems like the cheap designs are here to blame for.

This however doesn't change the question that UMIK1 is 16/48 and the question if higher resolution sampling would or would not be beneficial for measuring accuracy.

 

[Grador]

This is interesting indeed. All the solutions based on usb 1.1 were limited to 16/48 and I (looks this way) incorrectly assumed this is due to limitation of bandwidth, but rather is seems like the cheap designs are here to blame for.

This however doesn't change the question that UMIK1 is 16/48 and the question if higher resolution sampling would or would not be beneficial for measuring accuracy.

Given that you are looking for spl not so much frequency in these measurements, I'd say absolutely not. I furthermore if you've ever seen the wacky stuff that occurs in room at higher frequencies I don't think you'd be terribly concerned either.

 

[fuzz092888]

This is interesting indeed. All the solutions based on usb 1.1 were limited to 16/48 and I (looks this way) incorrectly assumed this is due to limitation of bandwidth, but rather is seems like the cheap designs are here to blame for.

This however doesn't change the question that UMIK1 is 16/48 and the question if higher resolution sampling would or would not be beneficial for measuring accuracy.

Actually it's 24/44.1 or 48 so it does have the higher bit depth and based some other articles I've read that's the more important metric rather than sampling rate. Of course YMMV. Still, it would interesting to compare one that is 24/96 or 192 against the UMIK. I don't believe Dayton states this spec on the UMM-6.

 

[BoredSysAdmin]

Actually it's 24/44.1 or 48 so it does have the higher bit depth and based some other articles I've read that's the more important metric rather than sampling rate. Of course YMMV. Still, it would interesting to compare one that is 24/96 or 192 against the UMIK. I don't believe Dayton states this spec on the UMM-6.

thanks for correction. I wasn't actually referring to Dayton usb mic, but to 3rd party dac (or audio interface as pro audio guys call it )

 

[Grador]

Actually it's 24/44.1 or 48 so it does have the higher bit depth and based some other articles I've read that's the more important metric rather than sampling rate. Of course YMMV. Still, it would interesting to compare one that is 24/96 or 192 against the UMIK. I don't believe Dayton states this spec on the UMM-6.

For these measurements the bit depth is extremely unimportant. How much dynamic range do you really need for this? I highly doubt your measurements will ever even approach the 90+db that 16 bit offers you.

 

[fuzz092888]

For these measurements the bit depth is extremely unimportant. How much dynamic range do you really need for this? I highly doubt your measurements will ever even approach the 90+db that 16 bit offers you.

Yes, but measurements aren't the only thing REW can do and with more features always being added the extra dynamic range can be important. Especially when using things like the RTA, or the ability to measure things other than sweeps, which is a feature that is going to be added to REW sometime in the future. The extra bit depth will be vital to things such as that.

 

[Grador]

Between the noise floor of your house and the peak output of your system, the range will never be important.

 

[Grador]

I will add one cavet to that, it won't be important as long as you have gain control on the ADC

 

[fuzz092888]

Between the noise floor of your house and the peak output of your system, the range will never be important.

We will agree to disagree

 

[Grador]

We will agree to disagree

Fair enough, but out of curiosity where do you think the bounds on useful measurement are? I'd say between 30 and 120 cover anything I'd ever need.

 

[fuzz092888]

Fair enough, but out of curiosity where do you think the bounds on useful measurement are? I'd say between 30 and 120 cover anything I'd ever need.

For home theater you're probably right, I generally find my total system peaks around 115db without me pressing it harder than I should and the sweeps I run aren't usually above that either, but with the portability of the USB mic I can start playing with the RTA, SPL, and eventually measurement features of REW on some other stuff where the extra dynamic range will come into play.

For instance, I plan on quasi-anechoic measuring some EV PA speakers, while also checking SPL at 1m, 3m, 7m, and 15m. I'm looking to hit a decent SPL at 15m, while not killing anyone 1-5m.

 

[fuzz092888]

UMIK is in the mail, should have it sometime next week I think. Hopefully it doesn't too long to clear customs and then it should be a short hop up the thruway from NYC and it's all mine

 

[mtrycrafts]

UMIK is in the mail, should have it sometime next week I think. Hopefully it doesn't too long to clear customs and then it should be a short hop up the thruway from NYC and it's all mine

Then, give it a workout and let me know how to use it with a laptop
Mine is behind yours depending which flight it is on

 

[fuzz092888]

Then, give it a workout and let me know how to use it with a laptop
Mine is behind yours depending which flight it is on

I don't know about all that. Your tracking seems to indicate that you're way ahead of me. All mine says is "Left Hong Kong"

Did you ever get the cal file/serial number?

EDIT: I made a little boo boo. I didn't read the e-mail carefully enough. The cal file is actually in the e-mail (or at least it was for me). The link that they gave me (and hopefully you) should end in ".txt" This is the cal file and all you have to do is right click on the link and click "save link as" or "download link"

If you didn't get that bit then you should probably e-mail them.

 

[fuzz092888]

So I went to the post office today and picked up my UMIK-1. Apparently when miniDSP ships it to you they require a signature for delivery. Once I got home and started to unpack it, I must say I was sorely disappointed in what I saw. Not with the actual product, but with the care in which this product was packed. As you can see below there was nothing protecting the carrying case except a thin cardboard shell. Because of this my tab that is supposed to keep it shut was snapped off, the case was open a bit when I opened the box, it is cracked in multiple places, and the bottom is scuffed to no end. Definitely a much different experience than when I opened my calibrated Behringer mic.

As to the mic and accessories, I'm extremely happy with them. The mic has a nice weight to it and is fairly similar to the Behringer, albeit a bit smaller. The small stand is a nice touch and the USB cord feels substantial, if a bit short. I plugged the mic into my macbook pro and it was immediately recognized. Fired up REW and opened the MIDI audio controller and I was able to adjust the gain, add the cal file and it worked first time. There were zero issues, no drivers or software, and nothing else to do except calibrate the REW SPL meter with the new mic. Absolutely fantastic.

 

[fuzz092888]

Behringer is silver, UMIK-1 is grayish

 

[agarwalro]

How in the world did the carrying case get a whooping when the brown paper box seems relatively undamaged?

 

[fuzz092888]

Magic? Possibly gremlins though.

 

[mtrycrafts]

Mine arrived as well this AM, signature required, and as it was an express mail, the mailman came before 11 AM. My box is undamaged. Did some preliminary test runs with my laptop to see if I can connect it to the receiver and at least get a test tone out of it.

After a little trial and error was able to assign the receiver as the default on the laptop and the test tone came through just fine. Next, later today or tomorrow, connect the mic and see what is what, just have to download the correction table to the laptop as I didn't get a serial number in the email, just a link with XXXX in the link. Fuzz got a working email; guess they were in too much hurry to send mine out