Raw 1m Measurements of a Gedlee NS15?

[solderdude]

It will only be relevant to that room, that speaker, that placement on the microphone position used.
How do you plan to implement the interaction in that room to yours ?

 

[Bjorn]

Hello again and thank you so much for sharing these. There is a lot of philosophy going into this loudspeaker but what matters most is how things play out in the room.
If you can share the mdat files with me that would be awesome. I sent you a PM about it.

I emailed it this morning.

It's a speaker with classic collapsing polar. But a much larger Os waveguide, improved compression driver, and with a horn loaded midbass could have be interesting.

 

[Bjorn]

It will only be relevant to that room, that speaker, that placement on the microphone position used.
How do you plan to implement the interaction in that room to yours ?

While there's a lot of truth to that, in room measurements can also reveal flaws in speaker designs. A really well designed speaker, will generally achieve a very even response in rooms, especially above the Schroeder. Sure, a really poor or super small room can break even the best speaker design but that's more the exception.

 

[solderdude]

Yes, it could but you would have to understand what aspects of the room (or placement) would cause this and would probably have to have done a lot of measurements to recognize those issues.

 

[al2002]

If there are any questions or you want to look at other measurements, let me know.

I went from Gradient Revolution to Abbey. In retrospect I would say that wasn't overall better. The Abbey sounded more dynamic, but coherence was better with the Gradient. The Gradient also measured flatter in the room, but I should have added some shelving to the Gradients that were a bit too flat (didn't fall enough towards he treble).

Funny to look back on this. Here's the Gradient with Adam Classic Column Mk3 on the inside and a XTZ speaker used a surround in the back.
View attachment 336748

Talk about extensive treatment in a small space!
View attachment 336749

And treatment got thicker and thicker over time!

View attachment 336750

View attachment 336751

Very nice!

Can you post some measurements of the Gradient speakers? Thanks.

 

[Bjorn]

Very nice!

Can you post some measurements of the Gradient speakers? Thanks.

Sure. Here are some different in room measurements at listening positions of Gradient Revolution MKII. 1/24 octave smoothing.

 

[DRNNOO]

I thought of something, do you remember if this is the picture correlating to the measurements?

 

[Bjorn]

I thought of something, do you remember if this is the picture correlating to the measurements?

They were measured in two rooms and with various placements in both rooms. That picture is from a small room, the other is quite big.
They didn't measure particular even at neither places below the frequency of the waveguide.

 

[No. 5]

Not even close. A outdoor measurement at 1m, is standard practice anyway. Professionals use Anechoic chamber but everyone else just goes outdoors.

For reference, if anyone is interested, the data provided on the GedLee website is made by best fit calculation of radiation modes, like Klippel's NFS but in 2 dimensions rather than 3.

 

[ctrl]

For reference, if anyone is interested, the data provided on the GedLee website is made by best fit calculation of radiation modes, like Klippel's NFS but in 2 dimensions rather than 3.

The measurements from GedLee's website are not comparable to the NFS measurements in terms of resolution and accuracy.

Like all measurements in small rooms, reflections are suppressed using gate/windowing.
This leads to a decrease in resolution below around 2kHz and severe smoothing (1/1 oct) around the lower cut-off frequency (usually in the 200-300Hz range) of the gated measurements.
If I have understood correctly, the frequency response and radiation are simulated/calculated below this cut-off frequency.

There are only measurements for horizontal radiation. The sound power response and DI shown also only refer to the horizontal plane and are not comparable with the CTA-2034 diagrams, which always consider horizontal and vertical planes in relation to SP, ER, PIR and DI together.

The calculation of the DI is also not comparable, as in the CTA-2034 results the DI refers to the difference between listening window and sound power response (hor + ver data). Whereas Dr. Geddes uses the difference between horizontal sound power and a specific hor off-axis frequency response (20° for the NS15) as DI.

So please keep that in mind when comparing the measurement data and diagrams of the NS15 and other data and diagrams based on NFS measurements.

 

[No. 5]

The measurements from GedLee's website are not comparable to the NFS measurements in terms of resolution and accuracy.

I didn't say they were. Only pointing out a similarity with regard to data processing.

But if we're getting into details, it can be argued that horizontal polar plots of monopole sources would be comparable at frequencies where both are using IR windowing, since both are capable of better than 2 degree angular resolution... assuming that the sound source didn't have too wide and complex of dispersion since Dr. Geddes method makes specific assumptions about the sound field.

That being said, I do agree that readers should keep in mind the differences in data acquisition and presentation that you brought up when comparing data, as they are certainly relevant.

 

[DRNNOO]

If there are any questions or you want to look at other measurements, let me know.

Axi2050 and Radian950be on K402 would make my day

 

[Bjorn]

Axi2050 and Radian950be on K402 would make my day

Nah, you're happy with the AXi2050 and prioritize different than I do. No need to spoil that. I'm keeping those measurements to myself.

Besides, a 2" exit simply doesn't rival a smaller exit in high frequency distortion, which JBL showed us decades ago. So why chase something that will be great?

 

[DRNNOO]

So why chase something that will be great?

Measurements tell a story... The more you know... To increase my knowledge base... Compare and Contrast... Learning.
I am happy with the Axi, I'm just another science nerd. Pleeaassssaagh lol! I know you gave a worded description of the 2 situations But I would love to see the measurements tell the story as well. Probably the most interesting aspect is that the measurements are on the same horn in the same room from the same mic. Its rare that we get to see usefully objective comparisons! At this level of performance I don't think anyone is losing but in the name of science and truth, please share with me your mbats