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Re: Definimax 4012HO - End of Life [message #90842 is a reply to message #90826]

Sat, 07 September 2019 09:41

Wayne Parham
Messages: 18791
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:

Magnet structures

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 putty 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.

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[Message index]

		Definimax 4012HO - End of Life By: Mudshark on Mon, 10 June 2019 13:59
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Tue, 11 June 2019 09:05
		Re: Definimax 4012HO - End of Life By: Mudshark on Wed, 12 June 2019 11:41
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Wed, 12 June 2019 12:11
		Re: Definimax 4012HO - End of Life By: rkeman on Sat, 15 June 2019 20:24
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Sun, 16 June 2019 09:59
		Re: Definimax 4012HO - End of Life By: johnnycamp5 on Tue, 18 June 2019 14:40
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Tue, 18 June 2019 14:54
		Re: Definimax 4012HO - End of Life By: Mudshark on Thu, 20 June 2019 19:15
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Fri, 21 June 2019 16:19
		Re: Definimax 4012HO - End of Life By: Mudshark on Wed, 12 June 2019 13:34
		Re: Definimax 4012HO - End of Life By: Symphonimind on Tue, 25 June 2019 09:08
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Tue, 25 June 2019 09:36
		Re: Definimax 4012HO - End of Life By: Symphonimind on Tue, 25 June 2019 10:04
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Tue, 25 June 2019 14:01
		Re: Definimax 4012HO - End of Life By: Symphonimind on Tue, 25 June 2019 20:53
		Re: Definimax 4012HO - End of Life By: johnnycamp5 on Tue, 25 June 2019 18:58
		Re: Definimax 4012HO - End of Life By: Mudshark on Wed, 26 June 2019 03:18
		Re: Definimax 4012HO - End of Life By: Mudshark on Tue, 03 September 2019 12:07
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Tue, 03 September 2019 16:02
		Re: Definimax 4012HO - End of Life By: Symphonimind on Tue, 03 September 2019 23:11
		Re: Definimax 4012HO - End of Life By: Mudshark on Wed, 04 September 2019 15:43
		Re: Definimax 4012HO - End of Life By: Symphonimind on Wed, 04 September 2019 21:55
		Re: Definimax 4012HO - End of Life By: Mudshark on Thu, 05 September 2019 08:24
		Re: Definimax 4012HO - End of Life By: Symphonimind on Fri, 06 September 2019 22:16
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Sat, 07 September 2019 09:41
		Re: Definimax 4012HO - End of Life By: Mudshark on Sat, 07 September 2019 17:39
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Sat, 07 September 2019 17:48
		Re: Definimax 4012HO - End of Life By: Mabob on Thu, 05 September 2019 06:15
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Sat, 07 September 2019 17:15
		Re: Definimax 4012HO - End of Life By: Mudshark on Sat, 07 September 2019 17:59
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Sun, 08 September 2019 17:55
		Re: Definimax 4012HO - End of Life By: Mudshark on Mon, 09 September 2019 10:30
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Mon, 09 September 2019 11:20
		Re: Definimax 4012HO - End of Life By: Symphonimind on Fri, 27 September 2019 08:06
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Fri, 27 September 2019 09:22
		Re: Definimax 4012HO - End of Life By: Symphonimind on Fri, 27 September 2019 10:26
		Re: Definimax 4012HO - End of Life By: Mabob on Mon, 07 October 2019 08:01
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Mon, 07 October 2019 09:07
		Re: Definimax 4012HO - End of Life By: Symphonimind on Wed, 09 October 2019 06:20
		Re: Definimax 4012HO - End of Life By: Mabob on Fri, 11 October 2019 11:42
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Fri, 11 October 2019 13:16
		Re: Definimax 4012HO - End of Life By: paulp1960 on Sun, 13 October 2019 10:16
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Mon, 14 October 2019 11:08
		Re: Definimax 4012HO - End of Life By: paulp1960 on Tue, 15 October 2019 06:33
		Re: Definimax 4012HO - End of Life By: Symphonimind on Thu, 12 December 2019 04:35
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Thu, 12 December 2019 09:30
		Re: Definimax 4012HO - End of Life By: Symphonimind on Fri, 13 December 2019 00:39
		Re: Definimax 4012HO - End of Life By: Symphonimind on Fri, 20 December 2019 00:23
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Fri, 20 December 2019 09:09
		Re: Definimax 4012HO - End of Life By: Symphonimind on Fri, 20 December 2019 09:16
		Re: Definimax 4012HO - End of Life By: DaveFred on Fri, 01 May 2020 09:30
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Fri, 01 May 2020 11:10
		Re: Definimax 4012HO - End of Life By: Symphonimind on Sun, 03 May 2020 23:21
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Mon, 04 May 2020 12:47
		Re: Definimax 4012HO - End of Life By: Symphonimind on Tue, 05 May 2020 22:58
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Wed, 06 May 2020 09:52
		Re: Definimax 4012HO - End of Life By: johnnycamp5 on Wed, 06 May 2020 11:30
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Wed, 06 May 2020 11:39
		Re: Definimax 4012HO - End of Life By: Symphonimind on Thu, 07 May 2020 06:49
		Re: Definimax 4012HO - End of Life By: Symphonimind on Tue, 12 May 2020 21:36
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Wed, 13 May 2020 11:01
		Re: Definimax 4012HO - End of Life By: Symphonimind on Wed, 13 May 2020 23:33
		Re: Definimax 4012HO - End of Life By: DaveFred on Wed, 06 May 2020 13:44
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Wed, 06 May 2020 16:39
		Re: Definimax 4012HO - End of Life By: Scott L2 on Mon, 15 January 2024 06:48
		Re: Definimax 4012HO - End of Life By: johnnycamp5 on Mon, 15 January 2024 09:04
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Mon, 15 January 2024 10:37
		Re: Definimax 4012HO - End of Life By: Scott L2 on Mon, 15 January 2024 14:03
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Mon, 15 January 2024 15:34
		Re: Definimax 4012HO - End of Life By: rvsixer on Sat, 25 July 2020 11:14
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Sun, 26 July 2020 11:01
		Re: Definimax 4012HO - End of Life By: rvsixer on Sun, 26 July 2020 13:30
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Mon, 27 July 2020 10:24
		Re: Definimax 4012HO - End of Life By: rvsixer on Thu, 28 January 2021 14:26
		Re: Definimax 4012HO - End of Life By: Wayne Parham on Thu, 28 January 2021 15:17

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