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JBL Dynamics Project - L200 box, 2216ND/Smith Horn/2405 Slots

hjames said:
The sound is great! There is an upper mid spot I heard (during the Hallelujah chorus on the first Roches album) that is a bit harsh - I’ll have to pin that down at some point, but overall, swapping tweeters was a huge improvement!
Click to expand...

This is what I was alluding to before. This may be source-related and the Heils simply allowed you you hear it more clearly.

Ever heard of "digital glare"? This may simply be a case of that phenonom. I can certainly hear it in my system on many recordings as a "congestion" especially before the system has had sufficient time to fully warm up.
 
Macaroonie said:
I would download a signal generator and run a sweep test.

Tone Generator Software – Sound Frequency & White Noise Generator (PC or Mac)

Easily generate sine waves, sound frequencies or signals to create test tones or noise waveforms. Align radio levels, calibrate sound equipment and more.
www.nch.com.au
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I got the Dayton Calibrated iMic last week and have Spectrum Analyzer software loaded on Emma's iPad.
I also have sig gen software on my iPhone I can stream to the system.
Just gotta do it - we've been busy this week with house cleaning & projects for the holidays ...
and I haven't even started baking holiday treats yet!
Dayton_iMM-6_CalibratedMic_3107.jpeg
 
I did a setup a mic stand for the Dayton miniMic on the coffee table, and ran some pink Noise through the system yesterday.
Not sure I got what I want, witness that rolloff above 10k, so I'll try again later when I find time ...

Dayton_iMic-PinkNoise_3198.jpeg
 
Mr Boochie said:
Nice graphics. What distance did you have the mic from the speakers?

Thanks!
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about 4 foot - I'll do a pic of the setup next time, but, think I need a better Sig gen ...
and verify that its using the external mic ...

The graphics are "Octave RTA" from the Apple App store ... running on Emma's iPad.

The Pink Noise I use is from a Delos Test CD I loaded as a playlist into iTunes (lossless) last spring
Very cool since it was done with JBL guru John Eargle ... (RIP)

delosmusic.com

The Music Surround Spectacular - The Tests

An audiophile's dream collection assembled by Delos' acclaimed acoustical guru John Eargle and Stereo Review's David Ranada.Specially priced 2-disc setDISC 1 is a 70-minute Dolby Surround music sampler supervised and annotated by acclaimed audio guru John Eargle. Each of the 23 tracks was...
delosmusic.com delosmusic.com

Screenshot 2023-12-12 at 11.17.23 AM.png
 
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hjames said:
about 4 foot - I'll do a pic of the setup next time, but, think I need a better Sig gen ...
and verify that its using the external mic ...

The graphics are "Octave RTA" from the Apple App store ... running on Emma's iPad.

The Pink Noise I use is from a Delos Test CD I loaded as a playlist into iTunes (lossless) last spring
Very cool since it was done with JBL guru John Eargle ... (RIP)

delosmusic.com

The Music Surround Spectacular - The Tests

An audiophile's dream collection assembled by Delos' acclaimed acoustical guru John Eargle and Stereo Review's David Ranada.Specially priced 2-disc setDISC 1 is a 70-minute Dolby Surround music sampler supervised and annotated by acclaimed audio guru John Eargle. Each of the 23 tracks was...
delosmusic.com delosmusic.com

View attachment 3059498
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Is this one channel, or the pair? If the pair, try each channel individually, if nothing else, just for grins.

Your roll off at 10kHZ is not that bad, and unless your mic is in just the right position on axis, HF roll-off is to be expected.
 
I would run your full spectrum test again with the slot moved towards the front of the Smith Horn. You may be seeing cancellation caused by local reflections.
AFAIK the x/o hands over at 8.5K and you spectral shows fall off above approx 10K. In other words pretty much all of the range from the slot.
 
Not real happy with the mic stand I fabbed up yesterday -

iMic_Stand-Ver1_3205.jpeg

So I ordered a "hands-free" vise for $9 that I should have tomorrow. I already have one for assembly work,
so I'll remove the magnifying glass from the new one, strip it down to a minimum, and all the swivels will
let me use it to clamp the iMic however I want.

61r+DzMeSOL._AC_SY300_SX300_.jpg
 
I use camera tripods.
AKG_with_sound_panel.jpg


The bottom of the mic holder can take various thread sizes, including standard tripod (1/4-inch by 20 thread pitch).
 
I do have a couple of camera tripods, and the tripod base in the first picture is a folding microphone stand for interviews ...
the trick is I just need a clamp for that Dayton iMic, which I can hack off the mini-vise.
Or maybe this configuration with the camera swivel near the top will do -
it's more stable than it was with the (floppy) orange handheld adapter in the middle.

iMic_Stand-Vert2_3206.jpeg
 
Bigyank said:
@hjames try reaching out to @duaneage if you need crossover help. He has a lot of experience in this area.
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Ive built several Pass crosovers for people. One used 200 dollar caps. In that instance the room was unstable and added bad resonance which defeated what was being attempted.
The Pass network inverts phase and imparts a sound Nelson found better. Doesnt mean its definitive.

I travel to DC regularly and can offer help with measuring and testing. I think i could offer assistance. Let me know in a PM. Sometimes a different set of ears and approach helps.
 
Got the config improved - not sure the iPad is actually seeing the Dayton mic ...
The sig Gen only outputs to the phone speaker or headphone jack - I can work around that with a few cables ...
The tripod gave me these results a few mins ago - using the Delos pink noise in stereo.
So I need to play around with this gear, find the height and distance that gives me a better overall image of the sound -
I can see position is so critical.
I don't have a mic stand with a boom (I'm not a FOH engineer with an inventory, just a hobbyist). ;)

iMicStand-SetupTest_3210.jpeg
MicStand-TestImage_3211.jpeg
 
I don't have a good mic stand, but I can set it up on a camera tripod just as easily ...
These brief tests show me the mic is too close to the speakers to get the sound of all drivers blended,
plus I found I need a 4 conductor 1/8 cable for the accessory iMic to work with the iPad lightning connector port.
So I just ordered the cable & it'll arrive Tuesday.
Also - the crossover box has arrived!
CameraStand-iMic_3213.jpeg
 
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Riley Casey said:
Down 3db at 16khz is pretty damned good but then I haven't been able to hear anything at 16k for a long time. That 6db bump at 250 would to me annoyingly tubby if it translates.
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Based on the position of the mic, at this time I would not worry so much about this bump. Floor bounce will typically create a null through this area and the 5 dB bump may work to advantage. This is something more to think about when the mic is positioned in the "sweet spot."
 
hjames said:
I don't have a good mic stand, but I can set it up on a camera tripod just as easily ...
These brief tests show me the mic is too close to the speakers to get the sound of all drivers blended,
...
Click to expand...
Measuring speakers is one of the worlds ultimate rabbit holes. Having a mic stand that is easy to move is valuable since as you've already discovered th sound is different everywhere. Our ears have years of experience at making sense of it all, the little mic and computer less so. The most valuable measurement will be an average of many positions keeping in mind that the 'nearfield' is mostly a measurement of the speaker while the 'farfield' a measurement of the speaker and the room. Fun stuff.
 
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