I searched the diyAudio site for any reference to the 1 inch screw on JBL PTB99HF-1 Waveguide. 6 inches square. 90 x 90 degrees.
I came up empty.
Anyone use it in a project. Listen to it or have anything to say.
I am thinking of possibly applying it as the top end in a bookshelf.
I have a pair plus a pair of JBL 2408H-2 compression drivers to test drive.
I will post some measurements if there is an interest.
Thanks DT
I came up empty.
Anyone use it in a project. Listen to it or have anything to say.
I am thinking of possibly applying it as the top end in a bookshelf.
I have a pair plus a pair of JBL 2408H-2 compression drivers to test drive.
I will post some measurements if there is an interest.
Thanks DT
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Hello,
Using the AP tools on my bench I measured the PTBHF99-1, JBL2408H-2. This is what I got for impedance, phase and TS/P. More measurements to follow.
I did not see any wild resonance stuff in the higher frequencies, good news. Sometimes there is breakup that shows up as high frequency resonance.
Note: these are raw data curves. The saw-tooth appearance happens with Compression Drivers and Waveguides/Horns. My suspicion is that some of the output bonces around on the hard surfaces on the longer reflected path out of the waveguide.
Disclaimer:
I am a retired ME. I own more electronic tools than I should. I measure stuff for fun. If I claim to measure or hear stuff, Your Mileage May Vary.
Using the AP tools on my bench I measured the PTBHF99-1, JBL2408H-2. This is what I got for impedance, phase and TS/P. More measurements to follow.
I did not see any wild resonance stuff in the higher frequencies, good news. Sometimes there is breakup that shows up as high frequency resonance.
Note: these are raw data curves. The saw-tooth appearance happens with Compression Drivers and Waveguides/Horns. My suspicion is that some of the output bonces around on the hard surfaces on the longer reflected path out of the waveguide.
Disclaimer:
I am a retired ME. I own more electronic tools than I should. I measure stuff for fun. If I claim to measure or hear stuff, Your Mileage May Vary.
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See the attached PTBHF99-1 on JBL2408H-2 plots, typical waveguide/horn roll-off that will require some EQ plus some padding.
If I recall the input voltage was0.5 volts The microphone was ~ 5 inches from the plane of the waveguide flange.
loud output.
low distortion.
Perhaps crossover at 2.5kHz or higher.
Thanks DT
If I recall the input voltage was0.5 volts The microphone was ~ 5 inches from the plane of the waveguide flange.
loud output.
low distortion.
Perhaps crossover at 2.5kHz or higher.
Thanks DT
Attachments
Hello,
A few days ago I bought a pair of JBL AC16 speakers. This speaker uses the waveguide JBL2408H-2. This speaker (AC16) to my ears does not do well with speaking voices speaking in DVD movies. It does better with bass in the movies. Over all too much bass.
Back in the days of Zilch (RIP) there was a Econowave that used the JBL2408H-2.
Thanks DT
A few days ago I bought a pair of JBL AC16 speakers. This speaker uses the waveguide JBL2408H-2. This speaker (AC16) to my ears does not do well with speaking voices speaking in DVD movies. It does better with bass in the movies. Over all too much bass.
Back in the days of Zilch (RIP) there was a Econowave that used the JBL2408H-2.
Thanks DT
After looking at the data sheet, the 2414 is the Compression Driver and the JBL PTB99HF-1 is the screw on waveguide.
Yes the 2414xx are "traditional" mylar dome diaphrgams, with a really tiny motor structure.
The 2407/BMS 4540nd, annaular diaphragm is what the 2408H,H-1 and H-2 has been derived from.
Different phase plugs in them all.
The 2407/BMS 4540nd, annaular diaphragm is what the 2408H,H-1 and H-2 has been derived from.
Different phase plugs in them all.
Hello All,
Back to that pair of JBL AC16 speakers that I purchased. One of the pair had a rumbling grumbling coming from the low end of the frequency bandwidth I bought a new JBL 226J driver from the usual JBL sources.
I took the driver out of the enclosure and ran a separate pair of speaker wires in through one of the reflex ports bypassing the crossover network.
I ran some frequency and distortion sweeps of both the old damaged driver and the new replacement driver
Plus with the APx500 software I made wave files of both the damager driver and the new driver.
You know all that contention about A X B testing needing to double blind to be valid take a listen to the attached audio files. The test sweeps and applied 1 volt applied to the drivers was automated and identical.
Thoughts?
The wave files will not post here on diyAUDIO, ideas on how to post audio files? They are short only 10 seconds each.
See attachments:
Back to that pair of JBL AC16 speakers that I purchased. One of the pair had a rumbling grumbling coming from the low end of the frequency bandwidth I bought a new JBL 226J driver from the usual JBL sources.
I took the driver out of the enclosure and ran a separate pair of speaker wires in through one of the reflex ports bypassing the crossover network.
I ran some frequency and distortion sweeps of both the old damaged driver and the new replacement driver
Plus with the APx500 software I made wave files of both the damager driver and the new driver.
You know all that contention about A X B testing needing to double blind to be valid take a listen to the attached audio files. The test sweeps and applied 1 volt applied to the drivers was automated and identical.
Thoughts?
The wave files will not post here on diyAUDIO, ideas on how to post audio files? They are short only 10 seconds each.
See attachments:
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@DualTriode
You will have to put the audio files in a zipped folder and attach that in the normal way 🙂
The maximum file size is 10Mb.
You can upload a large image provided that the file size is under 10Mb.
Large images will be resized so that they are less than 2028 x 2048.
There is a limit of 20 images per post.
You can attach files of these types: zip, txt, pdf, png, jpg, jpeg, jpe, gif.
You will have to put the audio files in a zipped folder and attach that in the normal way 🙂
The maximum file size is 10Mb.
You can upload a large image provided that the file size is under 10Mb.
Large images will be resized so that they are less than 2028 x 2048.
There is a limit of 20 images per post.
You can attach files of these types: zip, txt, pdf, png, jpg, jpeg, jpe, gif.
Hello,
Okay
I have Zipped the two .WAV audio files of the old broken JBL 226J woofer and the new JBL 226J woofer.
You can hear the painful difference between them.
Tell us what you can hear.
DT
Thanks for the information @wooly.
see the attached .zip files: VC Voice Coil Rub Buzz (for search)
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