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32 Search Results Found |
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Forum: Pi Speakers «»
Posted on: Sat, 30 August 2003 13:44 «»
By: Wayne Parham
Re: Diaphragm Mass
I think Adire combines an underhung voice coil with something very similar to the symmetrical field geometry design, don't they? Wasn't that the thrust of their "XBL2" design approach? It seemed to me that they were also using a flux stabilization ring, ...
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Forum: Pi Speakers «»
Posted on: Wed, 06 August 2003 22:35 «»
By: Wayne Parham
Qms, Qes and Qts
Qms is a figure of merit for the mechanical damping of the speaker, Qes is the figure for the electrical damping and Qts is their combined total. If the diaphragm is heavy and the motor is weak, then Qts will be high. When the cone is made very heavy to ...
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Forum: Pi Speakers «»
Posted on: Wed, 16 July 2003 09:01 «»
By: Wayne Parham
Re: Damping
It's all about stored energy and inertia. Think about the energy required to stop a motorcycle in comparison to that required to stop a semi tractor trailor truck. More energy is required to accelerate or decelerate the heavier load.Do a search here and ...
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Forum: Pi Speakers «»
Posted on: Sat, 05 July 2003 06:31 «»
By: Wayne Parham
Re: Motors
You've got the deal about Q. And you've made the connection how back-EMF and amplifier characteristics come into play too. But there are a handful of applications where a high Q motors are well suited. Use as dipoles or in infinite baffles or very large...
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Forum: Pi Speakers «»
Posted on: Tue, 12 November 2002 14:42 «»
By: Wayne Parham
Impedance at resonance
Definitely, that's true. Bi-amping and connecting the drivers directly improves motor damping from the amp, and also provides other benefits.But then again, the reactive components in a passive crossover and the reactive nature of the driver itself intera...
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Forum: Pi Speakers «»
Posted on: Thu, 04 July 2002 00:11 «»
By: dbeardsl
arg..
The piezo's don't need to be crossed over, I need a method of limiting back-EMF from the woofer. I tried your suggestion anyway, but it'd didn't change anything.. except make the tweeter output 6db quieter and rolling of the highs just a bit as expected. ...
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Forum: Pi Speakers «»
Posted on: Mon, 01 July 2002 22:33 «»
By: Wayne Parham
Re: Piezo chirping
I've run into this before. If the amplifier can't damp the system well enough, back EMF causes the tweeters to oscillate - making that chirping sound. I've found it to be the case with woofers having high inductance voice coils, even on amplifiers with...
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Forum: Pi Speakers «»
Posted on: Fri, 14 June 2002 08:42 «»
By: Wayne Parham
Piezo stuff
For acoustic damping material, use R13 fiberglass insulation. I don't know if you have this designation in Sweden, but you can just find some that's 5-6cm thick. Put it on the bottom, back and the side nearest the port.About the piezo, I don't recommend ...
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Forum: Pi Speakers «»
Posted on: Mon, 22 April 2002 14:08 «»
By: Wayne Parham
Re: Theater series Four Pi
One thing that is very important for good sound on low-power SET amp is how the woofer acts at resonance. All speakers have an impedance peak when driven at their resonant frequency. This condition is also associated with back-EMF and amplifiers with low...
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Forum: Pi Speakers «»
Posted on: Thu, 24 January 2002 16:51 «»
By: Wayne Parham
Back-EMF solutions for piezos
I have never had success adding passive components around the piezo's to reduce chirping caused by back-EMF from a woofer. If the woofer makes enough back-EMF to cause the tweeter to chirp, you can't use the two together on the same output circuit.
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