Measurements For Everyone

[fuzz092888]

REW and MiniDSP teamed up awhile back so that nearly everyone could have access to a reasonably price DSP unit with active measurement and correction capabilities. Now the two have done it agin, except in the area of measurement and acoustical analysis. The free software from Home Theater Shack, REW can now be combined with a new measurement microphone from MiniDSP. This microphone is accurate from 5Hz-20KHz +- 1db with a unique correction file for each microphone. While this isn't anything new or especially revolutionary, what comes next is. This is one of the few truly plug and play microphones out there. No drivers. No software. Compatible with Mac, Windows, and Linux. Absolutely fantastic so far. How about an external sound card or 48V power supply? Nope. USB powered (5V) microphone, compatible with all major operating systems and it comes with it's own correction file to give you +-1db from 5Hz-20Khz. Certainly nothing extraordinary when matched up against all that there is to be had out there, but definitely looking like a real winner. So how does it stack up against the competition?

UMIK-1
5Hz-20KHz +-1db
USB powered
Unique calibration file included with sensitivity calibration for SPL readings with REW

Dayton EMM-6
18Hz-20Khz
Phantom power required
Unique calibration file easily downloaded
$38

Behringer ECM8000
15Hz-20Khz
Phantom Power Required
No calibration file
$55

Now both the Dayton and the Behringer are also available from cross spectrum labs where they create a unique calibration file for each microphone, albeit for an additonal fee. They can either calibrate a microphone you already own, or you can purchase a calibrated mic from them. If you choose to go that route, the Dayton measures and Behringer will then be provided with calibration files from 5Hz-25Khz, although no word on the +- of those frequency responses. You can also get calibration files for 45 degrees and 90 degrees in addition to the 0 degree standard calibration file with an upgrade. The Dayton mic from Cross Spectrum Labs is $75 + shipping or $90 + shipping for the upgrades. The Behringer is $90 + shipping or $105 + shipping for the additional cal files.

So to answer the question you've been dying to know the answer to.....the UMIK-1 is $75 + shipping which is typically $20 for a total of $95. Not exactly the breath taking deal you thought? Well consider your alternatives. With either of the other two microphones you're still left without a power supply or external sound card which could add $100+ dollars to your total costs. If you bought a preassembled hardware+software kit like the Dayton offering or maybe the XTZ measurement kit you're looking at over $300.

Given the current competition I think the UMIK-1 has really carved a spot out for itself with both seasoned measurement experts and, maybe even more importantly, those who wish to get into measurements for the first time. With the simplicity of the unit, combined with fact that you don't need anything else to actually use it except REW, which is free, makes it extremely appealing for first timers. The extremely flat frequency response, plug and play simplicity, and competitive pricing make it one of the best deals around currently.

Hopefully when I receive mine I can give additional impressions and observations.

 

[fuzz092888]

 

[cpp]

Pretty cool stuff fuzz.

How does it work?

Integration between REW and minDSP consists of 5 steps:

1) Setup your miniDSP system with some basic settings
2) Measure your audio system using impulse response or FFT measurements to optimize your system
3) Export the Auto/Manual EQ settings to the biquad section of miniDSP Advanced
4) Finally, enjoy your processed system without the need of any PC

Things you need to make it happen
One miniDSP DSP hardware platform (kit/2x4/balanced/2x8/8x8)
One miniDSP plug-in with the Advanced feature for custom biquad.
1 x measurement microphone + sound card to perform your audio measurements
1 x PC/Mac running the latest version of Room EQ Wizard (REW) V5 available for download here.
A basic understanding of the biquad filter programming as already highlighted in this application note.
Finally, this application will not cover the wealth of features provided by REW. The REW Help file does a great job at it so a careful reading of the user manual is strongly recommended.

Auto-EQ tuning with REW | miniDSP

 

[josko]

In what way does this microphone outperform the Radio Shack SL meter when used with REW?
I kinow the RS SL meter is only good to 3500 Hz, but how much calibration can be done above that frequency?
(I'm wondering if there's a reason to upgrade my SL meter to this mike. Would I also need to swap out my BFD for a miniDSP?)

 

[AcuDefTechGuy]

I've never measured my speakers before. I'm sure some guys are itching to see how they all measure lining up the way they do in my room.

So the ONLY 2 hardware I need to measure my speakers are

1) my Laptop
2) this Microphone ?

And the ONLY software I need is this REW (which I've never used either)?

And I will get these on-axis frequency responses?

What about off-axis FR?

Where do I place the microphone?

Man, I'm a total noob on this.

 

[Steve81]

And I will get these on-axis frequency responses?

What about off-axis FR?

Where do I place the microphone?

Usually you place the mic at the listening position. This isn't really about getting on or off axis FR ala Stereophile (though you can if you want); it's about measuring whats happening at your listening position so you can try to correct any big problems.

 

[cpp]

I've never measured my speakers before. I'm sure some guys are itching to see how they all measure lining up the way they do in my room.

So the ONLY 2 hardware I need to measure my speakers are

1) my Laptop
2) this Microphone ?

And the ONLY software I need is this REW (which I've never used either)?

And I will get these on-axis frequency responses?

What about off-axis FR?

Where do I place the microphone?

Man, I'm a total noob on this.

Here's a basic tutorial on REW
Room EQ Wizard: REW Room Measurement Tutorial - YouTube

 

[fuzz092888]

Pretty cool stuff fuzz.

How does it work?

Integration between REW and minDSP consists of 5 steps:

1) Setup your miniDSP system with some basic settings
2) Measure your audio system using impulse response or FFT measurements to optimize your system
3) Export the Auto/Manual EQ settings to the biquad section of miniDSP Advanced
4) Finally, enjoy your processed system without the need of any PC

Things you need to make it happen
One miniDSP DSP hardware platform (kit/2x4/balanced/2x8/8x8)
One miniDSP plug-in with the Advanced feature for custom biquad.
1 x measurement microphone + sound card to perform your audio measurements
1 x PC/Mac running the latest version of Room EQ Wizard (REW) V5 available for download here.
A basic understanding of the biquad filter programming as already highlighted in this application note.
Finally, this application will not cover the wealth of features provided by REW. The REW Help file does a great job at it so a careful reading of the user manual is strongly recommended.

Auto-EQ tuning with REW | miniDSP

Thanks, but this is for MiniDSP and REW. I'm was strictly talking about measuring, not EQing.

 

[fuzz092888]

I've never measured my speakers before. I'm sure some guys are itching to see how they all measure lining up the way they do in my room.

So the ONLY 2 hardware I need to measure my speakers are

1) my Laptop
2) this Microphone ?

And the ONLY software I need is this REW (which I've never used either)?

And I will get these on-axis frequency responses?

What about off-axis FR?

Where do I place the microphone?

Man, I'm a total noob on this.

Yes, now that this microphone is available all you need is REW, the mic, and a laptop. You can also get a boom stand as well.

You can take quasi-anechoic measurements above 200Hz on axis and off axis with this "kit" as well and as stated above, get room response curves at the LP or multiple LP's.

 

[AcuDefTechGuy]

Usually you place the mic at the listening position. This isn't really about getting on or off axis FR ala Stereophile (though you can if you want); it's about measuring whats happening at your listening position so you can try to correct any big problems.

I see. All I want is to measure the FR of my Salon2, 802D2, KEF, TAD, Orion, etc.

All my speakers are connected to my HTPC. I thought the REW/mic could just measure the FR of my speakers.

 

[fuzz092888]

In what way does this microphone outperform the Radio Shack SL meter when used with REW?
I kinow the RS SL meter is only good to 3500 Hz, but how much calibration can be done above that frequency?
(I'm wondering if there's a reason to upgrade my SL meter to this mike. Would I also need to swap out my BFD for a miniDSP?)

The radioshack SPL meter has serious limitations even with calibration files since most cal files are not unique to each meter. You can probably get someone to make you a unique cal file, but its limitations are made abundantly clear when put up against a calibrated Datyon, Behringer, and now probably UMIK-1.

The issue with the BFD and this mic is that you wouldn't be able to hook up the mic directly to the BFD. You'd have to have a MIDI interface because the Mic can only be plugged into USB. Then you could utilize the mic and REW in conjunction with the BFD since I believe REW makes BFD files for room correction.

TO EVERYONE:

In case I wasn't clear this mic is compatible (or so miniDSP says) with anything you can plug a USB mic into. Any software or hardware that will accept a USB microphone should be compatible with this mic.

 

[fuzz092888]

I see. All I want is to measure the FR of my Salon2, 802D2, KEF, TAD, Orion, etc.

All my speakers are connected to my HTPC. I thought the REW/mic could just measure the FR of my speakers.

It can, but you are either measuring quasi-anechoic (not taking the room into account) or you are measuring at the LP (or any LP) to see what the FR is while taking the room into account. With with quasi-anechoic you generally are 1 meter away aimed at the tweeter and can go off axis from there. If you are at the "sweetspot" you are probably some degree off axis anyways unless the speakers are crossing directly at the measurement spot.

In other words, as far as I can tell, the REW/mic combo will do exactly what you want it to do.

 

[AcuDefTechGuy]

Yes, now that this microphone is available all you need is REW, the mic, and a laptop. You can also get a boom stand as well.

You can take quasi-anechoic measurements above 200Hz on axis and off axis with this "kit" as well and as stated above, get room response curves at the LP or multiple LP's.

But if I'm using a laptop, I would have to connect my speakers to the laptop to measure?

Since my speakers are connected to my HTPC, I guess I install the REW on my HTPC, hook the Mic to the USB of my HTPC, place the Mic on a boom stand at 6 ft away from the speakers in the sweet spot (middle of room) tweeter level?

The REW/HTPC will generate the sine waves through my speakers (Salon2, B&W 802D2) from 200Hz-20kHz. The Mic will measure the FR?

 

[fuzz092888]

But if I'm using a laptop, I would have to connect my speakers to the laptop to measure?

Since my speakers are connected to my HTPC, I guess I install the REW on my HTPC, hook the Mic to the USB of my HTPC, place the Mic on a boom stand at 6 ft away from the speakers in the sweet spot (middle of room) tweeter level?

The REW/HTPC will generate the sine waves through my speakers (Salon2, B&W 802D2) from 200Hz-20kHz. The Mic will measure the FR?

Aren't the HTPC's connected to a receiver? You can certainly do it the way you just mentioned or you can simply get a headphone jack to RCA L/R and plug that into the front L/R of any receiver and do it that way as well to generate the tones.

 

[AcuDefTechGuy]

Aren't the HTPC's connected to a receiver? You can certainly do it the way you just mentioned or you can simply get a headphone jack to RCA L/R and plug that into the front L/R of any receiver and do it that way as well to generate the tones.

Yes, my HTPC is connected to the Denon AVP-A1HD pre-pro.

If I measured using the laptop, I would need a headphone jack-RCA adapter to connect the headphone output of the laptop to the front of the AVR?

So measuring from the listening position will measure each speaker separately taking room acoustics into account?

Quasi will measure each speaker separately not factoring in room.

Or do they measure both speakers playing in stereo?

 

[BoredSysAdmin]

I wonder how Umik1 compares vs Dayton Audio UMM-6 ??
They has basically same looks, features and very close in price... Both provide cal files as well.

UMM6 looks to have a bit worse sensitivity on lower end - Frequency response: 18-20,000 Hz (Calibrated) or is it Umik specs are a bit too enthusiastic ?

 

[fuzz092888]

I wonder how Umik1 compares vs Dayton Audio UMM-6 ??
They has basically same looks, features and very close in price... Both provide cal files as well.

UMM6 looks to have a bit worse sensitivity on lower end - Frequency response: 18-20,000 Hz (Calibrated) or is it Umik specs are a bit too enthusiastic ?

So far it is unclear, but as far as I can tell the major things the UMIK has over the Dayton are

1)No phantom power source needed
2)An SPL calibration in addition the FR calibration (not sure the Dayton has this)
3)Claimed universal compatibility with any USB compatible hardware/software

The graph seems to indicate that the UMIK has what it claims, but I guess we'll have to wait for third party measurements to know for sure.

 

[fuzz092888]

Yes, my HTPC is connected to the Denon AVP-A1HD pre-pro.

If I measured using the laptop, I would need a headphone jack-RCA adapter to connect the headphone output of the laptop to the front of the AVR?

So measuring from the listening position will measure each speaker separately taking room acoustics into account?

Quasi will measure each speaker separately not factoring in room.

Or do they measure both speakers playing in stereo?

Yes

Measure each speaker individually and then average the results into a single measurement.

Yes

No

When you do the quasi you are measuring the individual speaker without room effects to see how accurate that speaker is. So basically you'll measurements kind of like Dennis has on the Philharmonic website.

 

[Grador]

So far it is unclear, but as far as I can tell the major things the UMIK has over the Dayton are

1)No phantom power source needed
.

The UMM-6 appears to be a USB powered as well.

 

[fuzz092888]

The UMM-6 appears to be a USB powered as well.

Oops, I was thinking of the other dayton mic.

The dayton mic sure looks interesting, but given the specs of the dayton mic and assuming the UMIK-1 specs are accurate, I would still call the UMIK a better value, tentatively of course. Plus the UMIK-1 has the SPL cal file as well and it is unclear whether the Dayton mic will be the same.

It is also unclear as to whether the Dayton is a class 1 USB device, meaning no drivers and software. I would assume so, but it remains to be seen for sure.