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| Re: Definimax 4012HO - End of Life [message #90519 is a reply to message #90517] |
Tue, 25 June 2019 10:04   |
Symphonimind
Messages: 33
Registered: May 2018
Location: Singapore
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Baron |
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Wayne Parham wrote on Tue, 25 June 2019 09:36The Delta 12 Pro works in the three π cabinet, having an EBS alignment like the other drivers I've chosen. I chose the Definimax 4012HO because of its shorting ring. My upgrade driver has always been one with a shorting ring. But you're right that the Delta 12 Pro driver could be considered as an upgrade too.
Thank you a lot for your consideration. I have tested many Eminence drivers (luckily, I live near a Eminence distributor) and this is my list of best performing 12" EMI woofer:
1. DELTA PRO 12A: Best Bang for Buck. High power handling, really good LF transient and mid reproduction. The frequency response is almost ruler flat for a PA driver.
2. 4012HO: Excellent Performer. Yeah, shorting ring does magic to reduce THD, I love every bits of it. However, now, it is belong to the past. I am happy that I owned 1 pair in my beloved 3Pi.
3. 3012HO: Excellent High Output woofer. It has low THD (if 3rd harmonic is lower, it will be one of the best 12"s ever made) and really smooth frequency response. It also has lighter MMS than 4012HO, together with relatively high BL motor, high Xmax (6.2mm), extremely high sensitivity (>100dB). This is really unique driver. I have succeed with it in my 2x12 bass cabinet. Sadly, it does not have shorting rings. Thus, I think Delta Pro 12A is better mid-priced option because it is much cheaper and also perform really well.
So, as I understand, will we have next 2 woofers in 3Pi Plan's driver list (one is Delta Pro 12A for mid-priced upgrade over Delta 12LFA, the other one is a high-end 12" woofer)?
I can't wait for the day you add Delta Pro 12A into the list. Many friends of mine also like that option a lot because it fits their bill.
And the last question:
How about an upgrade HF driver option with PSD2013 compression driver? BC DE250 is only a little bit higher priced, however, PSD2013 is much easier to grab in many places over the world.
Thank you Wayne.
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| Re: Definimax 4012HO - End of Life [message #90816 is a reply to message #90815] |
Tue, 03 September 2019 16:02 |
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Wayne Parham
Messages: 18793
Registered: January 2001
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Illuminati (33rd Degree) |
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I'm not ready to make an announcement, but I can give a status update.
I have a pair of Eminence Delta Pro 12A woofers and a pair of B&C 12PLB100 woofers here to test with.
Both look like they will work very well from modeling and from free-air measurements.
But when I went to install the 12PLB100 into my cabinet to test with a couple weekends ago, I realized it wouldn't fit. So I put off testing for a couple weeks. I had lots of projects going (and still do) so the fail-to-fit problem pushed me to work on something else.
The cabinet I'm using has been routed for flush fit of a driver with 12-3/8" basket diameter, which is what the Eminence drivers have. The 12PLB100 has outside diameter of 12-1/2" so I need to have the cabinet routed to fit.
I could also use another test cabinet I have in storage to test with. So one way or the other, my plans are to test this coming weekend.
I could have tested the Delta Pro 12 first. And I may still do that. But I really want to focus on the B&C driver 'cause it has a shorting ring.
Then again, the Delta Pro 12 will be a great driver too. I think you were right to suggest it, and it was your prompting that made me reconsider it. It will be a lot like the Omega 15A option in the four π loudspeaker.
I am optimistic about both the 12PLB100 and the Delta Pro 12 because they both have the right characteristics. There are three basic requirements over and above the obvious desire for good build quality.
The first and the second are inter-related, being that the electro-mechanical parameters must provide specific sensitivity and EBS alignment in this cabinet. Typically, drivers built with the motor strength and suspension stiffness to get the alignment we're after also provide the sensitivity we need for this kind of speaker. But some drivers don't work in this design, and produce an underdamped curve.
What we need is an EBS alignment that provides extended bass without any peaks, and it dove-tails perfectly with the flanking sub approach. Between baffle step and the cabinet alignment, using the flanking subs act as a 2.5-way system that offers flat amplitude response with deep bass extension. It also smoothes the self-interference notches and higher-frequency room modes.
So this alignment is a perfect natural mating for flanking subs and multiple subs. But it also sounds great without subs, because even though the response below 100Hz falls off, it is only slight and there is still usable response way down to 30Hz.
In addition to the electro-mechanical properties, we have a requirement of the cone to be well damped, so that it is smooth above 1kHz. Many drivers - even some that are of high quality - do not have cones with sufficient internal damping to prevent cone flex and they get ragged above 650Hz. This can't be determined by electro-mechanical specifications or models, but it can be seen in free-air response measurements, even without the cabinet.
Both drivers satisfy each of these requirements and should prove to sound very good in the three π model loudspeaker. All that remains is to put them in the cabinet and measure them. They may perform perfectly using the same crossover components as the Definimax did. Or they may require minor changes in component values in the low-pass filter or sometimes just a nudge of the Zobel capacitor.
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