Measurements For Everyone

[cpp]

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

Hey Fuzz all I was getting at is the mic is good enough to work for all measurements

 

[fuzz092888]

Hey Fuzz all I was getting at is the mic is good enough to work for all measurements

No no, I understand, I just didn't want to have the impression that the miniDSP mic was only for miniDSP products. When you posted that I wasn't sure I had made myself clear about that bit.

You are absolutely correct about it being good enough for all kinds of applications.

 

[Grador]

AcuDefTechGuy,

Fuzz pretty much covered everything I'm going to say but I figured I'd try and put it all in one single post and add a few things of my own.

Since your room is not anechoic it's difficult to get a measurement of the speakers independent response. Frankly I'd imagine you'd be more interested in your in-room response at the listening position anyway but I love having as much info as I can get my hands on so I'd want speaker measurements as well. You can attempt to get the speakers intrinsic FR by placing the microphone very close to the speaker, this doesn't completely remove the room from the equation, but puts the reflections far further away than the direct sound of the speaker making them far less of a factor. You will be very hard pressed to get good on and off axis FR measurements in room as the further off axis you go the more the room response will play into the measurements.

I would not recommend using your laptop if you are going to be using the internal sound card. I have never seen a laptop who's sound card had a very clean or flat output, so the fluctuations of the card will be measured in addition to that of the speakers response. If the card's fluctuations are large [and they may be] the measurements could end up telling you more about your sound card than the speaker, and the worst part is that you wouldn't even necessarily know where to attribute the response characteristics.

If you have a good output method from your HTPC, then installing REW onto it is your best option.

As for measuring one speaker or in stereo, REW defaults to stereo but there is nothing stopping you from setting the balance on your receiver, or simply unplugging one of your speakers.

 

[BoredSysAdmin]

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.

1) Was already corrected
2) Not 100% how spl cal is differed from fr cal...
3) How else could it possibly work - there's really no other way to do it, unless bundling it with heavy software package
Usb Class 1 is not really a benefit, more like cheaper way to go by it using older tech. Usb 2.0 has been here for ages and could allow more precise data to be captures. So, I'm just not 100% sure that this is the holy grail, but certainly a very interesting product

It is premature to argue which one is better value or not. All I was pointing what two very similar product with almost identical specs, packaging and price - they both more than likely to have a single source (in China if I have to guess)

 

[fuzz092888]

1) Was already corrected
2) Not 100% how spl cal is differed from fr cal...
3) How else could it possibly work - there's really no other way to do it, unless bundling it with heavy software package
Usb Class 1 is not really a benefit, more like cheaper way to go by it using older tech. Usb 2 has been here for ages and could allow more precise data to be captures. So, I'm just not yes, 100% this is the holy grail, but certanatly
a very interesting product

It is premature to argue which one is better value or not. All I was pointing what two very similar product with almost identical specs, packaging and price - they both more than likely to have a single source (in China if I have to guess)

I'm not entirely sure either about the difference in cal, but supposedly there is a difference. REW is going to be adding an SPL cal file option sometime and the UMIK-1 will have it.

As to your 3) my understanding of it was this (although it may be different now):

All major OS (Win, OSX, Linux) has native support for a USB audio class 1.
OSX and Linux also support USB audio class 2 from mid-2010 on.
On Win you need a third party driver.

This would go against their "absolutely nothing to add" sales pitch if they used USB 2.

All I was saying is that based on current information the UMIK seems like a little bit better value with a few IF's and WE'LL SEE's. When other or more information becomes available that may change. I don't think anyone said it was the "holy grail" Unless this is some sort of Monty Python skit

 

[fuzz092888]

AcuDefTechGuy,

Fuzz pretty much covered everything I'm going to say but I figured I'd try and put it all in one single post and add a few things of my own.

Since your room is not anechoic it's difficult to get a measurement of the speakers independent response. Frankly I'd imagine you'd be more interested in your in-room response at the listening position anyway but I love having as much info as I can get my hands on so I'd want speaker measurements as well. You can attempt to get the speakers intrinsic FR by placing the microphone very close to the speaker, this doesn't completely remove the room from the equation, but puts the reflections far further away than the direct sound of the speaker making them far less of a factor. You will be very hard pressed to get good on and off axis FR measurements in room as the further off axis you go the more the room response will play into the measurements.

I would not recommend using your laptop if you are going to be using the internal sound card. I have never seen a laptop who's sound card had a very clean or flat output, so the fluctuations of the card will be measured in addition to that of the speakers response. If the card's fluctuations are large [and they may be] the measurements could end up telling you more about your sound card than the speaker, and the worst part is that you wouldn't even necessarily know where to attribute the response characteristics.

If you have a good output method from your HTPC, then installing REW onto it is your best option.

As for measuring one speaker or in stereo, REW defaults to stereo but there is nothing stopping you from setting the balance on your receiver, or simply unplugging one of your speakers.

The only thing I disagree with here is that a laptop cannot have a stock soundcard that would be adequate for the measurements you intend to take. A macbook pro has a perfectly adequate sound card, especially after REW calibration, from the REW board itself. I think that most soundcards will be good enough for your purposes after you run the soundcard calibration.

From the sounds of it you're just trying to get a general picture of how your speakers perform, which does not speak to the need for hyper accurate +-0.5db measurements. Which means a stock soundcard should get you close enough after cal. Other than that I agree with everything Grador said.

 

[Grador]

I do not believe the device class is referring to the interface standard, it seems to be driver. USB class 1 audio devices seem to be universally accepted while Linux only added class 2 two years ago.

Also i think in this case the sound card calibration my not be the best of ideas. If i remember correctly this is done by looping the output into your input and measuring. If your input is off point, this also calibrates the input to some extent which is very useful if you're going to be using it to measure. If you aren't using the soundcard input to measure you are now at the mercy of your sound cards input for accuracy. I have no clue how good these are, they may be fine, they may not be.

 

[fuzz092888]

I do not believe the device class is referring to the interface standard, it seems to be driver. USB class 1 audio devices seem to be universally accepted while Linux only added class 2 two years ago.

Is that what I said or is that what he said?

I think he was talking about the speeds and I was talking about something else?

 

[Grador]

^^I edited on you after while you quoted, might want to check it out

Is that what I said or is that what he said?

I think he was talking about the speeds and I was talking about something else?

It's what you said, but BSA seemed to think you were talking about USB interface.

 

[fuzz092888]

I do not believe the device class is referring to the interface standard, it seems to be driver. USB class 1 audio devices seem to be universally accepted while Linux only added class 2 two years ago.

Also i think in this case the sound card calibration my not be the best of ideas. If i remember correctly this is done by looping the output into your input and measuring. If your input is off point, this also calibrates the input to some extent which is very useful if you're going to be using it to measure. If you aren't using the soundcard input to measure you are now at the mercy of your sound cards input for accuracy. I have no clue how good these are, they may be fine, they may not be.

^^I edited on you after while you quoted, might want to check it out


It's what you said, but BSA seemed to think you were talking about USB interface.

Hmm good point. I'm not entirely sure either, I'm just going off what I've found and asked on the HTS REW forum. The REW developers or mods of whatever they are who answer told me that the stock macbook pro soundcard should fine, and that for windows based laptops it just depends on what soundcard it already has in it and that the easiest way to know for sure if the soundcard will be good enough would be to either google it or come back on the forum and ask. That's probably a question that is going to become more relevant with the UMIK and Dayton coming out (the whole USB mic, but using the stock input for calibrating thing). Would be interesting to hear what they have to say about that.

 

[Grador]

Hmm good point. I'm not entirely sure either, I'm just going off what I've found and asked on the HTS REW forum. The REW developers or mods of whatever they are who answer told me that the stock macbook pro soundcard should fine, and that for windows based laptops it just depends on what soundcard it already has in it and that the easiest way to know for sure if the soundcard will be good enough would be to either google it or come back on the forum and ask. That's probably a question that is going to become more relevant with the UMIK and Dayton coming out (the whole USB mic, but using the stock input for calibrating thing). Would be interesting to hear what they have to say about that.

For me I just know that plugging my headphones into different laptops provides a fairly different experience, though for measurements purposes most modern laptops have HDMI, so I think most people are covered with that.

 

[AcuDefTechGuy]

AcuDefTechGuy,

Fuzz pretty much covered everything I'm going to say but I figured I'd try and put it all in one single post and add a few things of my own.

Since your room is not anechoic it's difficult to get a measurement of the speakers independent response. Frankly I'd imagine you'd be more interested in your in-room response at the listening position anyway but I love having as much info as I can get my hands on so I'd want speaker measurements as well. You can attempt to get the speakers intrinsic FR by placing the microphone very close to the speaker, this doesn't completely remove the room from the equation, but puts the reflections far further away than the direct sound of the speaker making them far less of a factor. You will be very hard pressed to get good on and off axis FR measurements in room as the further off axis you go the more the room response will play into the measurements.

I would not recommend using your laptop if you are going to be using the internal sound card. I have never seen a laptop who's sound card had a very clean or flat output, so the fluctuations of the card will be measured in addition to that of the speakers response. If the card's fluctuations are large [and they may be] the measurements could end up telling you more about your sound card than the speaker, and the worst part is that you wouldn't even necessarily know where to attribute the response characteristics.

If you have a good output method from your HTPC, then installing REW onto it is your best option.

As for measuring one speaker or in stereo, REW defaults to stereo but there is nothing stopping you from setting the balance on your receiver, or simply unplugging one of your speakers.

If I were to measure, I would use my HTPC.

So, if I were to place the mic at the listening position and run REW as default with stereo speakers, what would it really measure?

The FR of what I'm actually listening?

So measuring both speakers at the same time is okay?

 

[Grador]

If I were to measure, I would use my HTPC.

So, if I were to place the mic at the listening position and run REW as default with stereo speakers, what would it really measure?

The FR of what I'm actually listening?

So measuring both speakers at the same time is okay?

Correct, measuring at the listening position would be showing you FR of what you are listening to. Measuring both together is fine, but measuring them together and then individually can be fairly enlightening as well.

 

[AcuDefTechGuy]

Correct, measuring at the listening position would be showing you FR of what you are listening to. Measuring both together is fine, but measuring them together and then individually can be fairly enlightening as well.

But will measuring at the LP be considered "off-axis"?

Especially when measuring a single speaker at the LP?

My speakers are all toed in about 30-45 degrees. I really don't want to move them around or even unplug them. Feeling kind of lazy.

If I were to measure, I would just put the mic in the middle of the room - sweet spot at the LP- and measure both speakers at the same time. Would the measurement tell me anything useful?

 

[cpp]

But will measuring at the LP be considered "off-axis"?

Especially when measuring a single speaker at the LP?

My speakers are all toed in about 30-45 degrees. I really don't want to move them around or even unplug them. Feeling kind of lazy.

If I were to measure, I would just put the mic in the middle of the room - sweet spot at the LP- and measure both speakers at the same time. Would the measurement tell me anything useful?

Heck I thought off-axis was taking a measurement 15 or 30 degrees from the speakers face (2 or 3 meters)

SoundStage! Measurements - How we test loudspeakers...

 

[Irvrobinson]

But will measuring at the LP be considered "off-axis"?

Especially when measuring a single speaker at the LP?

My speakers are all toed in about 30-45 degrees. I really don't want to move them around or even unplug them. Feeling kind of lazy.

If I were to measure, I would just put the mic in the middle of the room - sweet spot at the LP- and measure both speakers at the same time. Would the measurement tell me anything useful?

You're making too much of this. You place at mic at your listening position at ear height. Using test tone sweeps you see the frequency response you actually hear.

Your problem is, now that I think about it, is that you have so many sets of speakers. Each will likely require a separate optimization strategy, and you're always moving them around. I am wondering what benefit you could possibly get. If you leave your subs in a single position you could optimize their response, but only if you have flexibility in placing them, or if you can equalize them.

 

[cpp]

You're making too much of this. You place at mic at your listening position at ear height. Using test tone sweeps you see the frequency response you actually hear.

Your problem is, now that I think about it, is that you have so many sets of speakers. Each will likely require a separate optimization strategy, and you're always moving them around. I am wondering what benefit you could possibly get. If you leave your subs in a single position you could optimize their response, but only if you have flexibility in placing them, or if you can equalize them.

I'm with you on this Irv. His speakers (all) are so tight together and his room is rather cramped that making a measurement might not even provide a worthy measurement. I say set back and enjoy ADTG what you have and save the money for the "new house build"

 

[Grador]

But will measuring at the LP be considered "off-axis"?

Especially when measuring a single speaker at the LP?

My speakers are all toed in about 30-45 degrees. I really don't want to move them around or even unplug them. Feeling kind of lazy.

If I were to measure, I would just put the mic in the middle of the room - sweet spot at the LP- and measure both speakers at the same time. Would the measurement tell me anything useful?

You are over thinking this a little bit.

It's neither an on or off axis measurement really it's an "in room measurement" and it is useful with both speakers running. You can think of it as the response of a sound in the center of the sound stage as your speakers are able to do in your room. This is the sound that reaches your ears in your setup.

Doing additional measurements of the speakers separately will then allow you to see how they are interacting with each other, but doing stereo measurements give you a good idea of room response.

Furthermore, for you, the stereo in room measurements could be used as direct comparison between all your speakers as they are all listened to at the same listening position.

 

[cpp]

Furthermore, for you, the stereo in room measurements could be used as direct comparison between all your speakers .

The key words there are as they are all listened to at the same listening position talk about moving some heavy speakers

 

[AcuDefTechGuy]

Sit back and enjoy what you have.....

Yeah.

Why can't the Audyssey RC measure my speakers like this and plot the response graph? Or do they ?

I've run Audyssey several times in the past and I recall the response graphs, but I never thought much about it.

I think the Audyssey OFF looked very similar to the ON & FLAT graphs.