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PostPosted: May 27th, 2020, 10:16 am 
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Location: Parkville, Maryland
Pelliott321 wrote:
The tweeter does roll off naturally starting at 1k and looks like 3db down around 750 pHz.
The cap is 33uf and impedance 8 ohms. That calcs out to 600hz 3db down.
So it looks like the cap is slightly below the natural roof off.
I still thinks this I quite a stretch of definitions.
The two other drivers are 15inch each has a different slope
One rolls off at around 200 the rolls off at 600hz


That may limit excursion, but it still leaves a power-handling issue with the voice-coil getting current that in terms of sound reproduction is not doing much if anything other than converting waste energy into heat.

If reliability means anything to this guy maybe a 1.5-mH shunt coil across the tweeter taking it to 2nd-order with some safety.

Otherwise, even with that, assuming the main woofer natural roll-off is at 6-db octave from 600-Hz. with the tweeter staring at 1-kHz. I would think there is a dip in the lower mid-range giving the speaker system a dark, "smothered" character.

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PostPosted: May 27th, 2020, 10:21 am 
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Joined: January 15th, 2015, 7:19 am
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Actually I have been working with Walt on this tweeter.
My big problem with the speaker even after almost 200 hrs of break-in is the tweeter is still calling attention to itself.
We looked a lots of things and added a 400 ohm resistor in parallel to reduce electrical resonances. We have added second order low pass to roll of above 22k the nasties with cone break up at the top.
These have helped quite a bit. But I will remove them and listen as a reality check to see if the changes I heard are due to mods or break in.
Since this driver is a 1.3 inch hard dome designed for handling the freq range of 575Hz on up, i am curious how much effect this non crossover 33 if metalized poly cap has on the musicality This is 90% of the sound.


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PostPosted: May 27th, 2020, 10:27 am 
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No this is the flattest measured speaker I have had in my system.
The two woofers are rolled of differently. One rolls off above 200Hz the other rolls off at around 600Hz.
After the taming of the tweeter this is a very balanced speaker.
But there is something that makes one focus on the tweeter while music is playing.
What I heard at CAF and at Florida was magical. The speakers just disappeared.
Not happening here.


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PostPosted: May 27th, 2020, 10:52 am 
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Location: Baltimore MD
I have RTA Pink noise graphs of each driver and overall which I will put up later today.
This speaker measures very well. Don’t get me wrong, the speaker sounds really good, very deep image but no wider than the center of the tweeter.


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PostPosted: May 27th, 2020, 11:06 am 
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Joined: February 28th, 2013, 3:31 pm
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Roscoe Primrose wrote:
Jim G wrote:
I can't speak to the values involved. I only know that in the Gallo speakers the capacitor doesn't create a rolloff or cause a phase shift, it only attenuates the tweeter level across it's entire frequency range.


Either someone is lying to you, or it's not merely a capacitor.

Roscoe,

That's my understanding of the system. A capacitor wired in series with a purely capacitive tweeter. Dhar and I measured one at his house last winter and it appeared to be accurate. We measured with a 5uf cap then a 4 and the frequency response was identical but 1.5db down on the 4. They overlayed perfectly. Shrug shoulder emoji


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PostPosted: May 27th, 2020, 11:20 am 
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Pelliott321 wrote:
...But there is something that makes one focus on the tweeter while music is playing.
What I heard at CAF and at Florida was magical. The speakers just disappeared.
Not happening here.

I hate to steer this off course from the tweeter discussion, but this could be caused by a multitude of issues not having anything to do with the speaker itself. Getting speakers to disappear can be tricky.


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PostPosted: May 27th, 2020, 11:24 am 
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Jim G wrote:
Roscoe,

That's my understanding of the system. A capacitor wired in series with a purely capacitive tweeter. Dhar and I measured one at his house last winter and it appeared to be accurate. We measured with a 5uf cap then a 4 and the frequency response was identical but 1.5db down on the 4. They overlayed perfectly. Shrug shoulder emoji

That's only the frequency response of the tweeter, to be clear, not the system.


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PostPosted: May 27th, 2020, 8:03 pm 
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Joined: July 17th, 2016, 6:24 am
Posts: 806
Pelliott321 wrote:
Actually I have been working with Walt on this tweeter.
My big problem with the speaker even after almost 200 hrs of break-in is the tweeter is still calling attention to itself.
We looked a lots of things and added a 400 ohm resistor in parallel to reduce electrical resonances. We have added second order low pass to roll of above 22k the nasties with cone break up at the top.
These have helped quite a bit. But I will remove them and listen as a reality check to see if the changes I heard are due to mods or break in.
Since this driver is a 1.3 inch hard dome designed for handling the freq range of 575Hz on up, i am curious how much effect this non crossover 33 if metalized poly cap has on the musicality This is 90% of the sound.


Driver perform best if their FR is limited to a decade. If the tweeter is starting at 600Hz, try low passing at 6000Hz and see how much better it sounds. Is this going to be your reference system?

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PostPosted: May 28th, 2020, 8:25 am 
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Location: Baltimore MD
If. I understand you correctly if I low pass at 6k. Dose this mean the drop off is above 6k, then there will be no highs


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PostPosted: May 28th, 2020, 9:38 am 
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Location: Baltimore MD
Room set up
Attachment:
room_measure1_Xsm_web.jpg
room_measure1_Xsm_web.jpg [ 171.13 KiB | Viewed 474 times ]


Pink noise realRTA
Attachment:
M3_full_new_web.jpg
M3_full_new_web.jpg [ 60.21 KiB | Viewed 474 times ]


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