Home » Sponsored » Pi Speakers » Definimax 4012HO - End of Life
Re: Definimax 4012HO - End of Life [message #90821 is a reply to message #90816] Tue, 03 September 2019 23:11 Go to previous messageGo to next message
Symphonimind is currently offline  Symphonimind
Messages: 16
Registered: May 2018
Location: Singapore
Chancellor
Thank you very much for consideration regarding my suggestion with Delta Pro 12A as low cost alternative choice for 3Pi. I am looking forward to hearing from you with appropriate changes in crossover and guidances.

Best regards,
Edward.
Re: Definimax 4012HO - End of Life [message #90826 is a reply to message #90415] Wed, 04 September 2019 15:43 Go to previous messageGo to next message
Mudshark is currently offline  Mudshark
Messages: 12
Registered: May 2019
Chancellor
Thanks for the detailed reply, Wayne.

As I was itching to get going, over the summer I built the Three Pi with the Delta 12LFA as a stop gap and whilst it's very nice I can't help feeling that there are further improvements to be had.

It's easy enough to find the centre again for re-routing the rebate (already had to do it once after realising the rebate was slightly too tight after I'd already removed the centre cutout) so I don't mind a larger diameter driver if it has better performance.

Thanks to Symphonimind for suggesting the Delta Pro 12A which I'm sure is an substantial improvement. I don't mind paying a bit more for the B&C if it's significantly better. If there's any way you can help in quantifying the difference in sound quality between the two to help in making a choice it would be much appreciated.
Re: Definimax 4012HO - End of Life [message #90828 is a reply to message #90826] Wed, 04 September 2019 21:55 Go to previous messageGo to next message
Symphonimind is currently offline  Symphonimind
Messages: 16
Registered: May 2018
Location: Singapore
Chancellor
Dear Mudshark,
Thank you for sharing your experience with 3Pi Delta12LFA version. Which compression driver did you select? Is it PSD2002?
Re: Definimax 4012HO - End of Life [message #90829 is a reply to message #90415] Thu, 05 September 2019 06:15 Go to previous messageGo to next message
Mabob is currently offline  Mabob
Messages: 9
Registered: December 2017
Location: Finland
Esquire
Hello

Following this one very closely. Both speakers are widely available in Europe and
quite inexpensive. Even the B&C which can be a expensive brand, can be found below 200€ here.

This would give me the perfect upgrade path, by using existing Delta 12LFA for flanking subs and moving on to 6Pi cornerhorns in the future.

Thanks Wayne for keeping up the great work!
Re: Definimax 4012HO - End of Life [message #90830 is a reply to message #90828] Thu, 05 September 2019 08:24 Go to previous messageGo to next message
Mudshark is currently offline  Mudshark
Messages: 12
Registered: May 2019
Chancellor
@ Symphonimind:

I'm using the B&C DE250 (£83 (€91) ea in the UK including VAT ($83 without tax). I always knew I'd want to upgrade the compression driver so I went straight for the top option. The PSD2002 is £62 here so not much of a price difference in the context of a €800 build.

I found the top end to be a little laid back with the default xover options so I'm using 22R/15R for R1/R2 (C1 omitted) which adds a bit more sparkle and gives a flat response through the xover region with a slight rising response starting at 10 kHz which I can't hear anyway as my hearing pretty much stops at 11 kHz.

I found that the H290C waveguide rings like a bell when you hold it by the flange and rap it with your knuckle so I damped the two larger sides with triangles of 5mm Dedshete and it's now completely inert, so that's my DE250 setup.

Re: Definimax 4012HO - End of Life [message #90841 is a reply to message #90830] Fri, 06 September 2019 22:16 Go to previous messageGo to next message
Symphonimind is currently offline  Symphonimind
Messages: 16
Registered: May 2018
Location: Singapore
Chancellor
Mudshark wrote on Thu, 05 September 2019 08:24
@ Symphonimind:

I'm using the B&C DE250 (£83 (€91) ea in the UK including VAT ($83 without tax). I always knew I'd want to upgrade the compression driver so I went straight for the top option. The PSD2002 is £62 here so not much of a price difference in the context of a €800 build.

I found the top end to be a little laid back with the default xover options so I'm using 22R/15R for R1/R2 (C1 omitted) which adds a bit more sparkle and gives a flat response through the xover region with a slight rising response starting at 10 kHz which I can't hear anyway as my hearing pretty much stops at 11 kHz.

I found that the H290C waveguide rings like a bell when you hold it by the flange and rap it with your knuckle so I damped the two larger sides with triangles of 5mm Dedshete and it's now completely inert, so that's my DE250 setup.


Thank you a lot. I will try to damp my existing 3Pi (De250+4012HO) to see if it can make the mid and high smoother.

Edward.
Re: Definimax 4012HO - End of Life [message #90842 is a reply to message #90826] Sat, 07 September 2019 09:41 Go to previous messageGo to next message
Wayne Parham is currently offline  Wayne Parham
Messages: 17534
Registered: January 2001
Illuminati (33rd Degree)

Mudshark wrote on Wed, 04 September 2019 15:43
Thanks to Symphonimind for suggesting the Delta Pro 12A which I'm sure is an substantial improvement. I don't mind paying a bit more for the B&C if it's significantly better. If there's any way you can help in quantifying the difference in sound quality between the two to help in making a choice it would be much appreciated.

See the following link:
This shows what shorting rings do and what you can expect from them.


Mudshark wrote on Thu, 05 September 2019 08:24
I found that the H290C waveguide rings like a bell when you hold it by the flange and rap it with your knuckle so I damped the two larger sides with triangles of 5mm Dedshete and it's now completely inert, so that's my DE250 setup.

Of course there is never any harm covering the waveguide with damping material, but the bell mode of the H290C is well below the passband of the device, being approximately 420Hz. And the amplitude is very low when the waveguide is mounted in the cabinet.

It's kind of like standing waves in a small subwoofer cabinet - They line up at high frequencies, above those which are presented to the cabinet. So but it never hurts to add fiberglass insulation inside a subwoofer and it also sure can't hurt to cover a waveguide with plumbers putter or other damping material to reduce the bell mode even lower than it already is.

http://www.pispeakers.com/Measurements/H290C_unmounted_bell_mode.jpg
Unmounted H290C 420Hz Bell Mode

What I've found is the amplitude of the 420Hz mode of the H290C drops considerably when it is mounted on the baffle. It sort of sounds like the frequency drops too, because it sounds so muffled. But in fact, the frequency is about the same. Mounted or unmounted, the bell mode is approximately 420Hz. But the amplitude drops considerably when mounted.

So the excitation frequencies are over an octave above the bell mode. Of course, it "lives" in the same cabinet as the midwoofer, which does generate 420Hz signals. So it is good that the bell mode amplitude is low when mounted. And I don't see any anomalies in the loudspeaker's response chart around 420Hz, so the bell mode is undetectable and inaudible. But your damping material will decrease bell mode amplitude even further.
Re: Definimax 4012HO - End of Life [message #90843 is a reply to message #90415] Sat, 07 September 2019 17:15 Go to previous messageGo to next message
Wayne Parham is currently offline  Wayne Parham
Messages: 17534
Registered: January 2001
Illuminati (33rd Degree)

I spent a few hours today evaluating the Delta Pro 12 and found it to be a good drop-in candidate. So those of you that were interested in this driver - You can pull the trigger.

I was going to measure the 12PLB100 first, but the interest here for the Delta Pro 12 pushed me to measure it first. That and the fact that I didn't have to run the router to get it to fit.

The frequency response looks almost exactly like the Definimax 4012HO using the same crossover components. The Delta Pro 12 almost looks like it is a Definimax minus the shorting ring. The cones are a little different, but response is smooth between 600Hz and 1.2kHz, so the cone is well damped. The basket is the same and the magnet looks the same from the outside, although it's different internally. Still, all-in-all, I'd say the Delta Pro 12 is very much like a Definimax 4012HO sans Faraday ring. So for those that are wanting the Delta Pro 12, use the crossover components shown on the schematic for the Definimax.

I used the ICD in the WTPro system to evaluate the driver with various crossover topologies. Then I ran it with the same physical crossover used for the Definimax 4012HO. The main thing I was looking for was clean on-axis response and vertical nulls in the right positions, which are approximately +/-25°. In those respects, the Delta Pro 12 looks almost exactly like the Definimax 4012HO.

You can see what I was looking for in the thread called "Crossover optimization for DI-matched two-way speakers." There's a link to a video in that thread that shows the exact process I was doing today.

I'll do the same thing tomorrow to learn if the 12PLB100 will work, and if so, what crossover components it will need. Then I'll modify the crossover schematic to list the new drivers and the crossover components required. I'll post here when I do, so stay tuned.
Re: Definimax 4012HO - End of Life [message #90844 is a reply to message #90842] Sat, 07 September 2019 17:39 Go to previous messageGo to next message
Mudshark is currently offline  Mudshark
Messages: 12
Registered: May 2019
Chancellor
Thanks, Wayne, you anticipated my next question.
Re: Definimax 4012HO - End of Life [message #90845 is a reply to message #90844] Sat, 07 September 2019 17:48 Go to previous messageGo to previous message
Wayne Parham is currently offline  Wayne Parham
Messages: 17534
Registered: January 2001
Illuminati (33rd Degree)

Excellent!

I'm excited about these new driver choices. They give people the kind of good quality choices that are what this loudspeaker design really needs.
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