Measurements of Phase Plugged and EnABLed FE167E

[Bob Brines]

I have done a bunch of measurements of stock, phase plugged and EnABLed FE167E's. There is way too much into to post here, so I am giving this link to a web page:

http://www.geocities.com/rbrines1/Pa...ABL/EnABL.html

Have fun!

Bob

[Nelson Pass]

That's really interesting, many thanks.

[InclinedPlane]

I'm missing the point of why the smoothing of 1/3 octave is necessary and how the omitted data is 'trash'. Ha maybe I'm just sick of all the super-smoothie plots you get from Fostex and everyone else. For once, I'd like to see the real deal. But you're taking the initiative and doing the work so I applaud that. Would measuring them outside offer a cleaner plot compared to in the garage?
I just can't see how the driver could be within 5db 1K to 20K.

[Jim Griffin]

Inclined Plane,

I think Bob's 5 dB criterion is within plus or minus 5 dB so it is a 10 dB window.

My initial view of these plots convince me that Enabling doesn't significantly improve the performance unless your criteria is to have lower output (sensitivity) level and more rolloff once you go off axis. Phase plugging shows imrovements in certain frequency ranges but overall it is not a clear winner. No doubt that a listener will hear sound differences between these modifications.

Bottom line for me is that a 'standard' unit is flatter and better off axis vs. either modification. Save your money and time and if you want a better driver purchase a better one.

Jim

[ttan98]

Originally posted by Jim Griffin
Inclined Plane,

I think Bob's 5 dB criterion is within plus or minus 5 dB so it is a 10 dB window.

My initial view of these plots convince me that Enabling doesn't significantly improve the performance unless your criteria is to have lower output (sensitivity) level and more rolloff once you go off axis. Phase plugging shows imrovements in certain frequency ranges but overall it is not a clear winner. No doubt that a listener will hear sound differences between these modifications.

Bottom line for me is that a 'standard' unit is flatter and better off axis vs. either modification. Save your money and time and if you want a better driver purchase a better one.

Jim

Based the FR curves I then to agree with you.

There are many users of Enabled tool swear that the technique improves the sound reproduction. I am not one of them and probably won't be.

Cheers.

[planet10]

It looks like the FR differences are from the phase plug installation... from the difference curves, both the phase plugged drivers track fairly tightly. Certainly within sample-to-sample variation.

y initial view of these plots convince me that Enabling doesn't significantly improve the performance unless your criteria is to have lower output (sensitivity) level and more rolloff once you go off axis

Jim, that is only a valid statement if a FR measure as Bob made actually tells you everything about a driver's performance. Certainly that is a very short-sighted view... i view this as akin to saying you know everything about the ocean by looking only at the surface.

It is very important to know what the driver is doing 10, 20, 30, 40 dB down from this signal in its precense. I've yet to see any measures that tell us anything about this.

dave

[BudP]

Well. frequency response curves are a nice way to imagine what a speaker might sound like. Unfortunately, they do not provide an indication of information content. As an example, a ribbon tweeter will have much the same frequency response as other tweeters, but in reality, the information content is off the scale in comparison to any other form of driver. Even comparisons of off axis frequency response do not provide any better clue as to the information content that you, as a listener, can make, sense of.

A very famous designer of some very famous speakers (think Bozak) once commented that no driver he had every encountered allowed coherent information content below -40db down from the reference signal. Everything below that floor was unintelligible. This is where EnABL does it's immediately apparent work. After you get over hearing sound that is clearly audible and comprehensible as far down in dynamic range as your electronic equipment can provide, the next thing that becomes apparent is that all of the rest of the information you are hearing is complete. Piano notes are exactly like they are in real time, same strike, same carry through and the same decay as you find in reality. Transients have internal tones, decay structure and sound like the original event, rather than a whack or a smack without any further descriptors available.

EnABL does this without really affecting the frequency response of the driver, unless we use it to subdue those resonance nodes that are so prominent in CSD plots of full range drivers.

Looking at published data is not in any way going to inform you of what EnABL provides, period. You will have to experience it for yourself before you have any idea of what the rest of us are talking about.

You might look here to get a clearer presentation of what I am providing here, which I am fairly sure will raise your hackles due to it's absolutist tone.

http://www.diyaudio.com/forums/showt...33#post1883833

Bud

[Scottmoose]

Very interesting set of plots Bob -many thanks.

One general observation WRT the FR plots is that I wouldn't draw too many conclusions about EnABL per se from these. I gather the 167eN does not just have the EnABL pattern applied to a plugged stock driver, but several other mods too, so it's really a comparison in the frequency domain between stock, stage 1 & stage 2 general mods.

On that basis, both the plugged and fully modded units appear on-axis to be somewhat smoother in detail, although the general trend of the stock unit may end up slightly flatter. I'd expect both to sound smoother & better controlled than the stock driver, purely on this basis -can't speak for the rest of course.

[Bob Brines]

Originally posted by InclinedPlane
I'm missing the point of why the smoothing of 1/3 octave is necessary and how the omitted data is 'trash'. Ha maybe I'm just sick of all the super-smoothie plots you get from Fostex and everyone else. For once, I'd like to see the real deal. But you're taking the initiative and doing the work so I applaud that. Would measuring them outside offer a cleaner plot compared to in the garage?
I just can't see how the driver could be within 5db 1K to 20K.

Indeed you are missing the point.

If I didn't smooth these spaghetti charts, they would be unreadable.

Do you really want to see all of the cabinet defraction effects and the reflections within my garage?

We are looking at the DIFFERENCES between three different cone treatments. The actual performance of the stock driver is irrelevant.

The measurements were done with a 2k FFT. That in itself smooths the data, and I didn't feel the need to take the time to increase the data points.

Finally, you brain is going to smooth what you hear to something like 1/3 octave (actual number debatable). Unless narrow spikes are very large, you won't here them.

But since you ask,




Bob

[Scottmoose]

Right, in general terms, the unsmoothed data isn't especially practical to work with. If you want really raw, see attached Clio measurement.

This was of a 167 MLTL I did a few years back. 1m, on axis, room heavily damped for the measurements. Driver had a phase plug; otherwise stock.