V2?

[ErinH]

http://www.parts-express.com/pe/show...number=390-792

What are the differences between v1 and v2?

I assume v2 comes with the cd that has more tracks and a text cal file. Is that it?

[critofur]

I hope it finally measures voltage across the speaker terminals so we can measure sensitivity!

The other feature I would want would be 24 bit / 96 Khz measurement.

[Johnnycat]

I hope it finally measures voltage across the speaker terminals so we can measure sensitivity!

How is it going to do that, it is the omnimic system not the Dayton Audio Test System (390-806)

[Jeff B.]

http://www.parts-express.com/pe/show...number=390-792

What are the differences between v1 and v2?

I assume v2 comes with the cd that has more tracks and a text cal file. Is that it?

Version 2 has been out for a while now. I don't have it ( I still have version 1), but physically the difference is that V2 has a regular USB port rather than the mini-USB. All other differences, like the software updates that use the Calibration file, and the expanded CD can be downloaded even if you have a version 1 mic. If you need it calibrated and a file generated you can send it in and they will do that for free. So, in the end, you will have V2 for everything except the cable connector.

[Deward Hastings]

physically the difference is that V2 has a regular USB port rather than the mini-USB.

Mine (which I presume to be a V1) has a micro-B USB connector (on the mic end, it's a "regular" A connector at the computer end). I suspect that V2 has the mini-B connector . . . (the "regular" B connector is rather large).

[critofur]

I guess the combination of OmniMic + WT3 is a good balance of completentess + easy to use - perhaps if someone would post a simple guide on how to measure/set your amp so that your FR measurements can be calibrated in terms of absolute sensitivity?

How is it going to do that, it is the omnimic system not the Dayton Audio Test System (390-806)

Well, for anything to be a "complete" measurement system, obviously that portion is needed!

It's always been so tedious/difficult/expensive to put together a COMPLETE speaker measurement system. It's always been either A) very difficult, B) very expensive, or C) incomplete.

One could build a cheap DIY mic, put together a little jig, and use free software such as Speaker Workshop - but - that's quite a steep learning curve and I felt like very time I got one part working, another part wasn't...

I'd love to see something like the OmniMic, but that was actually complete (and would be nice to be able to work up to 24 bit/96 Khz (USB 3?). I suppose the higher bit rate / sampling rate is less critical than being able to measure absolute sensitivity (which requires measuring the frequency response at the time as measuring the voltage).

[dcibel]

perhaps if someone would post a simple guide on how to measure/set your amp so that your FR measurements can be calibrated in terms of absolute sensitivity?

From the Omnimic manual: (trueRMS meter recommended)

Loudspeaker sensitivity is normally expressed as the SPL level that is sensed at 1 meter from the loudspeaker when it is driven from a voltage of 2.83Vrms. When you are using a CD as the signal source with OmniMic, the nominal level of the swept sine signals can be determined (or set) by use of the 50Hz reference tones that are at the end of the Version 3 OmniMic Test Signal CD or DVD.

To use these, you may want to disconnect the speaker of the channel being tested (the output voltage of quality amplifier should not be affected by whether a speaker is being driven). Then attach a Digital Voltmeter (also known as a "DVM") to read AC Voltage across the amplifier terminals. Be sure to configure the voltmeter for AC Volts and that the probes connect to the meter's Voltage (and not its Current!) reading terminals.

Turn any equalizer or tone controls off. You can then play the 50Hz reference tone tracks and measure or set the voltage level from the amplifier. Next, reconnect the loudspeaker, set OmniMic at the 1 meter distance from the loudspeaker and play the desired sweep track of the test CD. Use the OmniMic software in its Frequency Response measurement mode for Sine Sweep, and the plot should then be a reading of SPL sensitivity.

Some loudspeakers reference to a 1 watt level rather than to a voltage level. 2.83Vrms is equivalent to 1 Watt into an 8 ohm (resistive) loudspeaker. For a 4 ohm loudspeaker at 1 Watts, the voltage to use would be 2.0Vrms, for a 16 ohm speaker use 4.0Vrms.

So there you have it. Set amp to 2.83Vrms, measure at 1m. I want to add that absolute sensitivity has never been of much concern when considering crossover design. For design purposes, relative sensitivity is all you need, which is as simple as not changing the volume knob on your amp, and measuring your drivers at the same distance.

[exojam]

The V2 system is also coming with the below two items according to Dayton.

1) Heavy-duty carry case
2) Tripod included

James

[critofur]

...For design purposes, relative sensitivity is all you need, which is as simple as not changing the volume knob on your amp, and measuring your drivers at the same distance.

Yeah, been doing that way for years - but it'd be nice to have a USB device with a little amp built in that came with the WT3 funtionality / measured voltage while you take FR measurements...

I wouldn't call something "all-in-one" without those features...

[bwaslo]

The problem with that would be that to get 2.83Vrms across 4 ohms would be 4V peak across 4 ohms.... 1A required, and that's if you had 100% amp efficiency. USB can only do 0.5A max. You'd need a power amp with another power supply, which you presumably already have outside the measurement system.

The rather simple procedure in OM requires you only have to add a cheap multimeter to set up the system so the sweep runs at 2.83Vrms (or whatever you want). That's why the level tone on the CD is in the 50-60Hz region, any AC meter can measure that reasonably accurately (example: http://www.parts-express.com/pe/show...number=399-002)

[dcibel]

That's a good price tag!

[critofur]

The problem with that would be that to get 2.83Vrms across 4 ohms would be 4V peak across 4 ohms.... 1A required, and that's if you had 100% amp efficiency. USB can only do 0.5A max. You'd need a power amp with another power supply, which you presumably already have outside the measurement system.

The rather simple procedure in OM requires you only have to add a cheap multimeter to set up the system so the sweep runs at 2.83Vrms (or whatever you want). That's why the level tone on the CD is in the 50-60Hz region, any AC meter can measure that reasonably accurately (example: http://www.parts-express.com/pe/show...number=399-002)

How about making a box with a 15 or 25 watt stereo amp + WT3 functionality that can also measure the voltage while measuring FR. One software package could include the Omnimic + WT3 functions, and, eventually, you could add in crossover simulation capacity.

It would be sold without a Mic (with the suggestion that you add a mic at the time of purchase if you don't already have one) so that both those with Omni-mics and Dayton measurement mics would need only this, and a PC.

I've got a wallin jig, I've got a WT3, I've got an "All-in-one" box w/AMP, I own SoundEasy, and various other programs. But still, it's such a hassle to set things up and get them working that when I have a few minutes to measure a speaker I can't. I mean, I can use the WT3 of course, and sometimes I can do a frequency measurement - but it's not usable with previous measurements of other drivers because the actual sensitivity is unknown and I don't have any way of easily setting the exact same volume accross the board (Amp, PC out, mic pre, PC in, etc.).

I suppose there is the option of playing the amp into a resistor with a DMM hooked up and setting the volume such that the DMM reads a pre-determined value?

Plug-and-go would just be sooo appealing. An easily portable little box that I plugin to power, or run from batteries maybe? Plug in my mic, connect the box to USB, and run the software off a thumb drive - that way I can use any PC, anywhere? How about a digital volume control on it? Or a feature that lets you auto-set the voltage to whatever you want? You hook it up to your speaker and you tell it: I want 1 volt RMS measured at 60 hz (sin wave), or, 2.83 volts with white noise etc?

EDIT: how about a version of the WT3 that can remain hooked up to the speaker while it's being driven with an amp? That combined with the Omni mic would be the next best option. That would let [an updated version of] your software "auto set" the volume level before taking the full measurement?

[bwaslo]

..and you're willing to spend how many k$ for that?

Really, it's not all that hard. Set up OM with the laptop soundcard's gain and an aux power amp set at a known gain setting (mark volume knobs, or write down the gain value in the soundcard's windows mixer). Then recheck/set the gain settings and the voltage level is always the same.

The only possible problem is ground loops between the laptop and the power amp (can make a lot of racket sometimes). Power the laptop off it's battery fixes that.

[ErinH]

How about making a box with a 15 or 25 watt stereo amp + WT3 functionality that can also measure the voltage while measuring FR. One software package could include the Omnimic + WT3 functions, and, eventually, you could add in crossover simulation capacity.

It would be sold without a Mic (with the suggestion that you add a mic at the time of purchase if you don't already have one) so that both those with Omni-mics and Dayton measurement mics would need only this, and a PC.

I've got a wallin jig, I've got a WT3, I've got an "All-in-one" box w/AMP, I own SoundEasy, and various other programs. But still, it's such a hassle to set things up and get them working that when I have a few minutes to measure a speaker I can't. I mean, I can use the WT3 of course, and sometimes I can do a frequency measurement - but it's not usable with previous measurements of other drivers because the actual sensitivity is unknown and I don't have any way of easily setting the exact same volume accross the board (Amp, PC out, mic pre, PC in, etc.).

I suppose there is the option of playing the amp into a resistor with a DMM hooked up and setting the volume such that the DMM reads a pre-determined value?

Plug-and-go would just be sooo appealing. An easily portable little box that I plugin to power, or run from batteries maybe? Plug in my mic, connect the box to USB, and run the software off a thumb drive - that way I can use any PC, anywhere? How about a digital volume control on it? Or a feature that lets you auto-set the voltage to whatever you want? You hook it up to your speaker and you tell it: I want 1 volt RMS measured at 60 hz (sin wave), or, 2.83 volts with white noise etc?

EDIT: how about a version of the WT3 that can remain hooked up to the speaker while it's being driven with an amp? That combined with the Omni mic would be the next best option. That would let [an updated version of] your software "auto set" the volume level before taking the full measurement?

Sounds like you might want S&L's Woofer Tester Pro. $999.
http://www.woofertester.com/wtproproduct.htm

[critofur]

"An exceptional value at

$999.95"

?!? Insane!

"Exceptional value" would be $99 - knock off a digit... But yes, I guess that IS what I want, just at a reasonable price instead.

Sounds like you might want S&L's Woofer Tester Pro. $999.
http://www.woofertester.com/wtproproduct.htm

No, I want something for a couple hundred $$$

I bought a WT3
I bought a Dayton Measurement Mic
I bought cheap little amp
I bought a phantom power source
I got a "Wallin Jig"
I bought a Berhinger 1024 USB WHICH DOES NOT EVEN LET ME USE the RCA inputs at the same time as the USB soundcard?!@?!?? (WTF??)
I bought a "All-in-one" jig
I bought Sound Easy
I made a "simple jig"
I bought other stuff...

I don't want to have to use all those different bits and pieces, I want something without the headaches (and not so expensive as all that stuff!)

I want something affordable and *easy*, and with which you do not need anything else besides a mic and a PC.

If it costs too much to add an AMP, ok then.

At least give me ONE BOX which I can simply plug in which has:

Mic input, sound output, automatic level setting and lets me measure:

1. FR sweep
2. Sensitivity
3. Impedance sweep



Why would that have to cost more than $200??? If it HAS to not come with a mic and an amp to be $200 or less, then ok. But it'd be nice if it came with a 15 watt amp and a $2 mic capsule + a few $ in chips to make it work...

If you basically take a WT3, add a $25 amp too it, and a mic preamp, then that would do it, no? Maybe a couple more resistors? (voltage divider network). I guess it would need some kind of switch, to switch between measuring impedence and FR sweeps?