Measuring data for D2 (2430k) on M2 waveguide wanted [Archive]

sebackman

08-03-2016, 04:34 AM

Dear all,

Much info on varoius M2 data has been shared here. However I cannot find a good raw measure ( no/limited smoothing, no dsp, with or without the passive network) of the D2 on the M2.

Can someone please measure the driver/horn and post here. There are many here using active setup and this could be easily done by bypassing all eq points and change xo to 5-600Hz with 24-36db slope HP.

Since the measure signal do not need to be strong this will absolutely not effect the driver in any form.

I would like to compare the raw D2/M2 curve with the JBL factory eq points to figure out how to adapt them to my DYI's.

i did equalize a flat curve on my setup, but it did not really sound as expected. I just bought a pair of LSR305's for sanity check but this would be better.

If possible please PM or publish the measuring points or a wav file along with a curve.

kind regards and thank you
//RoB

srm51555

08-03-2016, 07:57 AM

Rob,

If nobody who already might have the info pops up with the data you are looking for and this can be taken with Holm or REW then I will be happy to take the data for you.

Thanks,
Scott

sebackman

08-06-2016, 02:02 AM

Hi Scott,

That would be brilliant. I have not seen any feedback beside yours so far.

I you please can do some measurements that would be much apprecierad.

Kalle said he can do them when he gets back from vaccation so that could well work as a "sanity check". It is always good to have several inputs to verify.

Kind regards andf thank you
//RoB

johanwholst

08-09-2016, 03:01 PM

Dear All

Kalle sent me some fresh measurements of unequalized D2 in the M2 waveguide.
For fun I compared it with raw measurements of the 2450 with truextent

73018

They have the same Level at approx 17k where 2450Be drops like a rock. Approx 10dB from midband. Same amount of compensation is needed for both drivers, but way less EQ to get a smooth response from 2450Be.

Last week I compared them both sonically in my M2 clones, and we much preferred the Be diaphragm.

We even got to measure and listen to 476Be in the M2 waveguide :)

Did a quick measurement for EQ settings....

73019

Excellent output to 18k and not much compensation needed. Less than 2450be and D2.
Sounds VERY good in the M2 WG but I will stick to my 2450be.

JeffW

08-09-2016, 04:02 PM

2450SL-Be, right?

This:

http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=49826&stc=1&d=1297242237

Not this:

http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=57984&d=1358675349

johanwholst

08-10-2016, 01:29 AM

Yes 2450sl with truextent

pos

08-10-2016, 03:16 AM

Interesting measurements and opinions, thanks!

So the target curves were identical when comparing the 2450SL-Be and the D2430K?
How would you describe the difference?

Sounds VERY good in the M2 WG but I will stick to my 2450be.
Do you mean that the two were similar enough?

johanwholst

08-10-2016, 04:41 AM

Yes, my humble opinion is that sonically, 2450sl/be and 476be is comparable. I EQed them to the same target curve apart from the slight more UHF with 476be.

To our ears, D2 sounds more polished and sterile than the drivers with Be diaphragm. To use a Hifi cliché, I would describe the Be as more organic. Everything just sounded more real and they gave the music more precence. Thats probably what is called high fidelity...

But my goodness, D2 is an excellent driver, and maybe it is a bit "owners bias" kicking in here

Cappelen

08-10-2016, 09:19 AM

I have posted this one before.
This D2 is from a vertec, not the M2 labeled version.

I use a 2435 modified with aquaplass and ferrofluid that sounds better to my ears. Also measures smoother, but drops fast in the UHF.

srm51555

08-10-2016, 10:30 AM

Dear All

Kalle sent me some fresh measurements of unequalized D2 in the M2 waveguide.
For fun I compared it with raw measurements of the 2450 with truextent

They have the same Level at approx 17k where 2450Be drops like a rock. Approx 10dB from midband. Same amount of compensation is needed for both drivers, but way less EQ to get a smooth response from 2450Be.

Last week I compared them both sonically in my M2 clones, and we much preferred the Be diaphragm.

We even got to measure and listen to 476Be in the M2 waveguide :)

Did a quick measurement for EQ settings....

Excellent output to 18k and not much compensation needed. Less than 2450be and D2.
Sounds VERY good in the M2 WG but I will stick to my 2450be.

Thank you Johan and Kalle for the results. It's good to hear the 2450be's are not too far off from the 476be's. I should be posting my results tonight for comparison if everything goes ok.

When you ran the initial sweep for DSP setting calculations for the 2450be, did you have the D2's DSP setting already on for a baseline and adjusted where needed or did you start clean.

Thanks,
Scott

johanwholst

08-10-2016, 12:25 PM

Scott: I Eqed 2450sl-Be with a fresh start. It is quite different EQ needed than D2. Roughly, its possible to get away with a shelf and a couple of notches.

It remains to do better off-axis measurements, but I am very happy with my preliminary result with correcting based solely on on-axis measurements.

srm51555

08-10-2016, 07:05 PM

Below is what I took after turning off the DSP settings in AA. I also received about the same plot when I turned the settings back on. I assume this is not normal and really can't find out what I'm doing wrong, any suggestions? Thanks, Scott

73047

Note: mic distance was centered and 1 meter away from the waveguide.

Kalle

08-11-2016, 04:18 AM

Scott: That looks strange. Try clicking on the "Freq. Axis button" (if using REW to the left of limits) to get the same window as the others for easier comparison. Are you using REW? Original filters? What HP filter in DSP? I used LR36 @600hz for the non EQ measurement.

This is my measurements 103cm from floor and 100cm from WG. DIY passive filters. Crown CTs 4200 with BSS. 3,7ms gating. Calibrated U-mic.

http://i68.tinypic.com/315lkdx.png

Does it look legit?

Regards Karl

srm51555

08-11-2016, 06:35 AM

Scott: That looks strange. Try clicking on the "Freq. Axix button" (if using REW to the left of limits) to get the same window as the others for easier comparison. Are you using REW? Original filters? What HP filter in DSP? I used LR36 @600hz for the non EQ measurement.

Hi Karl,

I'm using REW. All filters were disabled in the Crown dci unit through AA. Original passive filter was also used. I think something is not correctly set up in my REW because every time I perform a sweep I get an input sensitivity error explaining that it isn't loud enough. I calibrated SPL within REW to 90db with an external meter but received the same results. Looking at the manual my gain might be set too high on the mic input of the Scarlet 2i4. It's currently set at the half way point on the dial. Whatever the problem is I will eventually resolve it because with my M2 project I believe it's essential for even greater results. I'll try again tonight and hopefully be able to provided some meaningful data.

Thanks,
Scott

srm51555

08-11-2016, 06:39 PM

Ok, I took another shot at it tonight and below is what I got. Doesn't look exactly like Karl posted but it's getting better. Both look to have the slight hump at 3K. Microphone height was 98cm and the distance from the waveguide was 100cm. Filter was set at LR36 and crossover point was set to 600.

73061

Kalle

08-13-2016, 11:49 PM

Still thinks it looks strange. It rolls of very fast. Any ideas?

Regards Karl

sebackman

08-15-2016, 11:33 PM

Thank you both!

There seem to be more of a difference than expexted. Can you please check that any imposed delay in the dsp is turned off, no limters are active and if possible please use LR24 XO at 5-600Hz cut off to protect the driver. MTM/LR 36 filters may sometimes disturb the measuring algorithms. LR24 turns phase 360 degrees so that may help.

As both of you are using REW I expected the curves to be rather similar.

I don't know REW but if that is tricky to set up, maybe Holmimpulse could be an alternative.

Is there anyway to obtaing non equalised D2/M2 curves from JBL? They must have them...

kind regards and thank you
//RoB

srm51555

08-17-2016, 05:46 AM

I set the Crown dci back to factory setting just in case turning off the filters wasn't enough and took another sweep with only LR36 crossover point added. This measurement was sent over to Karl for comparison to his.

Special Note: when resetting the Crown dci it will deliver a loud test tone during reset. Almost had to change my pants. I assume since it has a BSS processor inside this may be the case for all units.

Thanks,
Scott

zeljkor

08-20-2016, 05:29 AM

Hi,
today I have measured my D2 on M2 horn. Serial capacitor of 47uF was added since I do not want to test my luck with DC component. Calibrated B&K mic was used.

Zeljko

srm51555

08-26-2016, 06:15 PM

sebackman

08-26-2016, 10:27 PM

Excellent !

That is what I was looking for. I will try to figure out a target curve for 2450sl and 2451be and post my findings here.

thank you
//RoB

Kalle

08-30-2016, 11:27 AM

I had some missed steps with soundcard calibration when taking my measurements. Karl's sweep is in Blue and my sweep is in Red. The sudden drop off at 17khz also appears on the soundcard cal file. Smoothing is at 1/6

73355

For me it would be extremely interesting to se your measurements and comparisation to mine curve with EQ. Can you do that? I will do new measurements on mine with a diffrent soundcard to se if there is any differences.

Regards
Karl

srm51555

08-31-2016, 05:20 AM

For me it would be extremely interesting to se your measurements and comparisation to mine curve with EQ. Can you do that? I will do new measurements on mine with a diffrent soundcard to se if there is any differences.

Regards
Karl

Sure no problem, I'm hoping to have some time this weekend to do it.

Are you using a BSS Processor or MiniDSP or Other?

Thanks,
Scott

Kalle

09-01-2016, 09:42 PM

Sure no problem, I'm hoping to have some time this weekend to do it.

Are you using a BSS Processor or MiniDSP or Other?

Thanks,
Scott

Fantastic:)

I use Crown CTs4200 with BSS DSP. I will do my measurements again with a analog soundcard to se if there is any difference. Maybe the reciver (and possible delay) interfere with the EQed measurement.

Regards
Karl

srm51555

09-03-2016, 06:26 PM

Below shows Karl's measurement(Gold) with DSP and my measurement(Blue) with DSP.

73479

Zvuchniak

09-05-2016, 02:30 AM

.
Why they measure so bad ? Are your DSP settings as they should be ? Shouldn't they look more like this ?

73526

pos

09-05-2016, 06:57 AM

These measurements are flat +/- 2dB or so, quite similar to the on-axis measurement (the black one) in the spinorama.

The main difference is the rising response in the spinorama, mandatory for the flat "listening window average" curve (the green one).
It looks like JBL gave up on that one, probably for the better...

Another difference, that shows up constantly in nearly all real world M2 measurements I have seen, is that dip around 6.5kHz, and bump around 10kHz (although this one could be the only remaining sign of the HF boost of the original spinorama, resulting in a "listing window" curve that will be flat up to 10kHz)

Zvuchniak

09-05-2016, 11:32 AM

bubbleboy76

09-05-2016, 01:30 PM

Let's hope a former JBL-employee with a grudge or a former JBL-fan with a grudge can post the real unechoic data! ;)

srm51555

09-06-2016, 05:54 AM

Has anyone taken listening position measurements with the D2 they could post? I'm currently running another system for maintenance purposes.

Thanks,
Scott

pos

09-06-2016, 11:14 AM

I kinda disagree.

From JBL measurements you can easily see that SPL is virtually the same in the region 1-2KHz and 5-10KHz with maybe 1dB rise in SPL at 10KHz. That's not to say that from 2KHz to 5KHz it measures bad - it retains the same SPL with minor glitches in response.

Karls measurements clearly show great SPL difference. Very flat from 1-5KHz (that is expected) and then rise in level, +3dB hump from about 7.5KHz to at least 12KHz. I'm not concerned with the 6.5KHz dip... That hump looks awful and is worrying. Shouldn't that be dealth with DSP ? I'd really like to see gated measurements with gate set to at least 3ms which would make them valid to about 350Hz.

Cheers
That "hump" might look awful to you, but it is nothing compared to what happens in the 8kHz-20kHz in the on-axis curve from the spinorama.

Anyway, the on axis curve is only a (minor) part of the whole picture here, and the EQed curve was the listening window average.

Here are my gated measurements (correct settings in red, you can ignore the blue curve), 0° and 20°
http://www.audioheritage.org/vbulletin/showthread.php?33972-JBL-Master-Reference-Monitor&p=393721&viewfull=1#post393721

You can clearly see that the bump around 8-9kHz results in a flat curve at ~30° off axis (which is probably a good approximation of the listening window curve...)

Zvuchniak

09-07-2016, 11:50 AM

8-20KHz on axis from spinorama does not look bad at all. It has gradual tilt starting from 8KHz to +3dB at 20KHz. I just don't see that as bad untill i hear it sounding bad.

You are totally right about on axis being just one part of the energy that is transmited into the room, but i was aiming at another thing. Measurements that are being made differs (a lot) from JBL measurements - yet they have the same DSP settings. There are few possibilities why.

JBL lying ? Possible but in that class of loudspeakers - very hardly.
Difference in drivers ? Isn't it possible that D2 ring radiators differ so much from one another that JBL pairs them up for M2 monitors and generates DSP curves for that particular pair of drivers ? That would explain the difference between two measurements provided by srm51555, and the difference between your measurements with theirs.

Your on axis measurements shows (6.5KHz dip excluded) +/-0.75dB variation from 1KHz-10KHz. Your drivers measures way better than the ones shown in smr51555 post because there is no bump.

7354073541

That "hump" might look awful to you, but it is nothing compared to what happens in the 8kHz-20kHz in the on-axis curve from the spinorama.

Anyway, the on axis curve is only a (minor) part of the whole picture here, and the EQed curve was the listening window average.

Here are my gated measurements (correct settings in red, you can ignore the blue curve), 0° and 20°
http://www.audioheritage.org/vbulletin/showthread.php?33972-JBL-Master-Reference-Monitor&p=393721&viewfull=1#post393721

You can clearly see that the bump around 8-9kHz results in a flat curve at ~30° off axis (which is probably a good approximation of the listening window curve...)

srm51555

09-07-2016, 12:53 PM

Isn't it possible that D2 ring radiators differ so much from one another that JBL pairs them up for M2 monitors and generates DSP curves for that particular pair of drivers ? That would explain the difference between two measurements provided by srm51555, and the difference between your measurements with theirs.

I'm using the Crown DCI 4300 which has an analog DSP, I know Karl is using a BSS DSP but it may be digital, maybe this could explain the slight difference is measurements. As for Thomas's measurements not sure why its better in the 8-10 range.

Zvuchniak

09-08-2016, 04:39 AM

Maybe...

I have no material or emotional involvement in this, i'm just trying to say that you should take JBL dsp curves like a good starting point for your speakers and adjust it yourself so that it suits your drivers. Do not hold on to it like it's a holy grail. Temper with it a little bit and then measure on and off axis.

Thomas's measurements do not look bad on axis nor off axis. Why wouldn't yours be like that with a little fiddling.

pos

09-08-2016, 10:39 AM

All 7 D2430K drivers I have measured measured pretty much the same.
5 came from ebay and were the VTX ones, and 2 were new and branded as M2 drivers.
Some ebay ones had serious distortion problems, but response curves were all very close.

The differences we see here are probably only measurement artifacts (mic response curve, distance, angle, smoothing, gating, etc.)

srm51555

09-27-2016, 06:09 PM

Will someone please post their room response with stock DSP M2 settings without any room EQ. I'm trying to figure out if my room measurements taken are correct or not. Final measurements would help a lot also if available.

Below shows a quick stereo measurement with 1/6 smoothing. The mic was placed at ear level by listening position and positioned at 90 degrees.

73810

Thanks,
Scott

timc

10-14-2016, 02:32 AM

Got my M2 waveguides two days ago.

Hopfully i can do a proper anechoic measurement in about two weeks. The room is booked for the next 10 days.

I will do raw measurements without EQ. 5 degrees intervalls to 180 degrees without any box or baffle around the horn. Driver will be 2435 with Aquaplas (done by Guido)

If i find anything new i will post the results.

-Tim

Zvuchniak

11-09-2016, 11:19 PM

Hi Tim,

Did you measure your driver/waveguide combo ?

I'd really like to see your measurements because D2 proves almost impossible to get.

Cheers

sebackman

11-21-2016, 12:26 PM

Dear all,

A little late to the party but for the record.

Attached is two D2 drivers on M2's. Measured indoor on workshop bench. Calibrated Earthworks mic, LSPCad MLS, 65 cm out, 4ms window, 33mfd in series, simple EQ as XO, two channel measurement (ie sound card, amp, EQ, tara), no smoothing, 65k samples, M-Audio Pro sound card.

Measurement files available for those who may be interested. PM me.

74636

Kind regards
//RoB

sebackman

11-21-2016, 02:11 PM

Just looked at my data and saw that timing differs 2cm between D2 and 245x. That means that you need to reduce the delay with 2cm = 58 micro seconds from 270,8 to 212.8 when using an old 4" driver. Also worth noting is that the sound outlet is slightly larger on the D2 compared to the 245x.

Kind regards
//RoB

sebackman

11-24-2016, 11:56 AM

Dear all,

This is an average of 2pcs D2's (as per above) and an average of 3pcs 2451/475nd drivers on the same M2. No smoothing.

Pretty interesting as you clearly can see the waveguide notches albeit with some shift in frequency which may be due to driver geometry (the D2 is acoustically deeper). This may look worse than it is so please mind the scales here.

Kind regards
//RoB

74661

Easier to look at.

74662

ivica

11-24-2016, 12:06 PM

bubbleboy76

11-25-2016, 05:13 AM

Kalle

11-26-2016, 12:02 AM

Hi!

Nice work as always Robert:) Very interesting to compare with the SL-drivers.
Any measurements with EQ?

Regards
Karl

Dear all,

A little late to the party but for the record.

Attached is two D2 drivers on M2's. Measured indoor on workshop bench. Calibrated Earthworks mic, LSPCad MLS, 65 cm out, 4ms window, 33mfd in series, simple EQ as XO, two channel measurement (ie sound card, amp, EQ, tara), no smoothing, 65k samples, M-Audio Pro sound card.

Measurement files available for those who may be interested. PM me.

74636

Kind regards
//RoB

globulegl

02-22-2017, 04:58 AM

What is the difference between d2430h and d2430k. Lower frequency response for the d2430k?

Don C

02-22-2017, 10:22 AM

That last letter usually indicates the impedance.

johanwholst

02-22-2017, 12:03 PM

My guess would be that they are the same driver, but the -H has its voice coils connected in parallel instead of in series as used in M2. Parallel connections of the coils would give ~8 ohm impedance, or -H as JBL likes to call it

JeffW

02-22-2017, 01:08 PM

That appears to be the consensus in at least one other identical post he made about it:

My guess is that these are the same drivers, but wired differently: D2430K as used in the M2 and VTX F12 have their two 10/16 ohm diaphragms wired in series for 20/32 ohm load (hence the letter K, as it seem they skipped letter I and went directly to J for 16 ohm for some strange reasons), whereas the D2430H as found in the VTX M20 would be a 5/8 ohm version with the two 10/16 ohm diaphragms wired in parallel (hence the letter H) for increased sensitivity.
If that is the case going from one to the other would just be a matter of using a different wiring schema, and I'd bet the D2430H has a D2430K foilcal.

ivica

11-14-2018, 11:21 AM

Hi,
today I have measured my D2 on M2 horn. Serial capacitor of 47uF was added since I do not want to test my luck with DC component. Calibrated B&K mic was used.

Zeljko

Hi Zeljko,

It seems to that , even passive network can be applied to Your D2&M2 combo, using RLC network with Q ( =XL/R) about 0.5 with resonant frequency fo=3.6kHz, reducing sound level about 10dB on that frequency, so "only" proper serial resistor has to be calculated.

Regards
Ivica