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Discussion Starter · #3 ·
Do you mean "narrow IR window" settings?

Mic distance needs to be close but far enough away for transducer integration - 0.5 m for small 2-way, 1 m for 3-way or small floor standing, 2 m for large multi-way floor standing - on tweeter axis or, if really close, on axis midway between tweeter and midrange driver.

In REW > IR Windows > Right Window: try values between 2 ms and 5 ms, then click on Apply Windows.

REW smoothing 1/24 oct or 1/48 oct.
Thank you very much.

I am trying to get a near field measurement for my Energy Veritas 2.3i floor standers. The 2.4i were the biggest in the range.
I am trying to determine what the manufacturer intended them to sound like characteristics etc.

For this size speaker which would you recommend distance wise etc?

For the REW settings i am trying to setup the program to give me the near field results without room interference etc. I don't want to take the speakers outside.

Currently the IR window left and right is set to Tukey 0.25, is this ok?

Thanks again
 

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Discussion Starter · #5 ·
Unfortunately, no one can tell you what gate settings to use in your room.....you need to take a measurement with the speaker and mic in your desired position and look at the impulse to see where the first reflection happens. When you click on the IR Windows button, don't worry about the "Left" and "Right" window setting at the top. Leave that where it's set. What you need to change is the "Left Window (ms)" and "Right Window (ms)". In order to set those right you need to make a measurement.

In my picture is an impulse from my speaker, which is on a stand and the mic is about 6 feet from the speaker. You can see I have the first reflection marked. It will be the first major blip after the initial impulse from the speaker flattens out. This is a reflection from the room, and you don't want that. In my case shown, I set the left window to about .5ms before the initial rise of the impulse and the right window to a little less than 3ms. This will set the gate and window out the room influence. The only caveat here is that since we are truncating the impulse of the speaker we can't see all the information. A 3ms gate will give you info from about 300hz up. IMO the data below 1Khz is questionable because the frequency resolution is quite low to see the detail of what's actually going on, but it will give you a good idea of the basic trend. You can't set the gate long enough to get LF data without the room swamping the response.
Thank you

How did you determine the 6 feet for measurements, the same as above posts?

Did you position the mic between the tweeter and mid range?

Thanks again
 

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Discussion Starter · #9 ·
In your case positioning between the mid and tweet 1 meter from the speaker should do it if you're trying to see how well it matches up to the manufacturer's anechoic response. 1 meter distance is typical.
Thank you

I can't find the manufacturer's anechoic response, i have emailed Energy but because of changes they haven't got records of this. Any ideas would be appreciated.

I will give this a go and post the results.

Thanks again
 

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Discussion Starter · #10 ·
The direct sound of speaker is single most important in playback. Equalizing for room gain and peaks/dips for listening setup then follow, if really needed/desired.

Thank you

Interesting, i have heard that equalizing for the direct sound can be preferred.

Also seen that equalizing using the Anechoic response as a target can give the listener the true response the manufacturer intended, or close as possible.
 

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Discussion Starter · #16 ·

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Discussion Starter · #18 ·
A familiar question; what are your perceptions of your speakers that you would like to change?
Thank you

Basically the high above 5 kHz falls off at listening position.

I review above mdat files; importing to one, adjusting all windows to 12ms Blackmann-Harris 7, smoothing 1/6 octave, and adjusting levels to get overlay:

View attachment 42568
Those dips and peaks are pretty much followed the same, seen in the listening position graphs, other than the 5 khz drop off.

Can you please show your adjustments in the IR window and Impulse graph to get this result.

Speaker as measured could be described as having flat response ±3dB over significant portion of spectrum. A trained eye sees ripple due to diffraction across width of front baffle. Location of peaks/dips >1kHz will likely shift as measurement point is moved off axis. Some of response is inherent to driver spacing, crossover points, and crossover slopes.
They are bi wired would this make a difference.
Does bi wiring bypass the crossover?

Very little that can be done, even with very powerful processing techniques. Bass in 100Hz region could be broadly boosted; but also needs to take in considerations of subwoofer. If peaks/dips >1kHz remain fairly constant as microphone is moved off axis, some EQ is possible with equalizer with very narrow bands of control. Results are not likely to be dramatic, even if feasible.
Currently i am running 2 x REL Strata 5s high level.

These measurements were taken with the Dspeaker Antimode Dual Core 2.0 disabled (with a push of a button).

Thanks again
 

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Discussion Starter · #20 ·
Ok,

What convinces you that you are having a problem >5k,
Thank you

With REW test sweeps for each speaker and then combined.

and what have you done to change this?
Used Treble Tone Tilt and PEQ.

And what happened when you attempted to change this?
It improved bringing up the treble, but still remains. I tried not to use too much boost.

You seek measurement techniques, yet something tells you where the problem is? Or has previous measurement convinced you that a problem exists in one place, yet experiments in this place yield no fruit?
Correct in the latter comment.

As I recall, three-way speaker with dome mid and dome tweeter. These, once again in conjunction with baffle width, and these driver's distances from top edge too, and in conjunction with likely high crossover point between them lead to ripple, and comb filtering. Additionally comb filtering exists when both speaker are running, and none of this noted in literature to cause any audible effect with normal program material. Sure, sweeps, or continuous noise reveals all this with measurements, and just slowly moving about listening space
I first thought my ears where either blocked or decreasing in the higher frequencies until i started to use REW, and realized my ears were not bad after all.

The main reason for the near field measurements were to see the characteristics of the speakers, and see if this was a characteristic of the Veritas.

When i get home i will post a mdat file of my Veritas in the listening position.

Thanks again
 

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Discussion Starter · #23 ·
Blackman type windows are smooth and highly symmetrical. They introduce very little ripple in FR display relative to other types. "7" refers to number of terms in formula. This has smooth performance over very large dynamic range, four terms is really quite sufficient for 16bit data on CD; even exceptional speaker and measurement circumstance is typically <12bits of useful dynamic range.


In near field measurements, ratio of direct to reflected sound is very high. For Blackman-Harris 7 12ms window, weighting is 50% at 3ms, and falls off rapidly. Combination leads to very good overview. Exact shape of curve going down to 60Hz may be overly smooth, but likely captures realistic -6dB point of speaker with minimal interaction of floor and walls. This low frequency curve fall off as microphone moves closer due to relative spacing of dual woofers and port.

In summary: You don't like the low end of your speakers, so you got two subs, and apparently you are not happy with the high end either. I'd seriously consider a nice pair of active two-ways with sealed cabinets so they integrate well with subs.
Thanks

The low end is ok on there own, combined with with the 2 x REL Stratas 5s and i am happy with the low end.
With the high end looking at the nearfield measurements what are the characteristics of the speakers in your opinion e.g. lacking, bright etc. Wonder if it is my ears or room, has quite a bit of soft furnishes?

So i would use Blackman Harris 7 with 12 ms for all my future nearfield measurements?

Thanks again
 

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Discussion Starter · #25 ·
12ms is good for general overview; shorter windows more fully limit room interactions, and require little if any additional smoothing when concentrating on HF performance; even 1ms for working above 1kHz.

Try running some near field measures (<1m) at small angles off axis, vertical and horizontal and see how peaks and dips shift. Also do at listening position. Sometimes small changes to speaker location, and toe-in can bring significant changes to perceptions at listening location. Even though speakers are floor standers, sometimes feet or small stands that add small amount of tilt can be used for focusing alignment at listening position too.

I used to have floor standing speakers with four drivers that where very difficult to get right. Getting a friend to tweak toe-in while listening always worked better than using a tape measure and repeatedly getting up to bump a speaker a fraction of an inch this way or that.
Thank you very much

I originally looked at 2.7 ms.

The speakers are currently sitting on there spikes which tilt the speakers back slightly.

Toe in effect which frequencies?

Thanks again
 
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