BillFitzmaurice.info

I'd just like to mention something regarding surround speakers that wasn't mentioned before. The best way to make sure the side speakers do not intrude on those seated near them is by getting them up high and pointing them such that coverage is even. Time delay can't be dealt with, but our brains do...

Height off the ground for the subs will diminish the loading. . With a 100 Hz crossover the subs need to be within 2.8 feet of the ground for full loading. So if the trailer isn't too high there's no problem. But four feet up would certainly be detrimental. Are you saying there wouldn't be any meas...

Height off the ground for the subs will diminish the loading. Consider placing the subs on the ground, it will make a large difference.. try it once you've made your subs! 2 feet is actually a lot and enough to drop 1/2pi loading to probably 1/3pi. You'll lose your last precious octave. Best bass wo...

http://82.95.237.142/mhsoft/diffusor.asp#calcul

Calculate and build your own. With sufficient depth, you can even break-up low frequencies.

danderson, Try the params I gave for this horn: http://billfitzmaurice.com/phpBB2/viewtopic.php?f=7&t=6877&st=0&sk=t&sd=a&start=15#p67819 just to see if you're getting in the zone. Should be dropping off at 22Hz. For driver configuration use 2s x 8p (16) and Ang: 1.0xPi I like th...

hate to be so dum but what is matrix? :oops: I know why you're here, Neo. I know what you've been doing... why you hardly sleep, why you live alone, and why night after night, you sit by your computer. You're looking for him. I know because I was once looking for the same thing. And when he found m...

Yeah.. I'm a bit confused by the question. The sub signal is mono from my crossover, yet the tops are split for right/left. I use 3 channels from 2 PLX2402 amps for driving the 6 subs for 500W peak each, but soft limit to around 300W. The amps aren't run bridge-mono as the 1.9ohm Zmin load would be ...

Lots of good java visual aids here: http://www.falstad.com/mathphysics.html

Why should you place all your subs in a single stack?: http://www.falstad.com/wavebox/

Concepts with room modes: http://www.falstad.com/modebox/ http://www.falstad.com/ripple/

I am also beginning to wonder about the potential positive effect of re-tubing the preamp stage, but I am quickly learning that is a very cluttered debate. Tung Sol, JJ, EH, oh my god it goes on and on. Yup! It makes for some good evening fun after dinner. I had good luck with a J/J ECC803S for the...

So how do we come to a conclusion about "rated impedance" vs amplifier loading? I like the EPDR technique on loudspeakers, but there is no corresponding amp spec for safe-operating-area intrusion. We could probably start on the loudspeaker side and translate actual impedance graphs to the ...

The speaker is supposed to be operated in its linear range for testing. IEC 60268-5 states this: 16.2.2 Method of measurement 16.2.2.1 The loudspeaker shall be brought under normal measuring conditions in accordance with 3.2.2, conditions a), b) and d). 16.2.2.2 A constant voltage or current shall b...

The real problem lies in the speakers specs! I agree. The complexity of the load can not be simply stated with a single number. I just found this article that has a nice intro describing impedance of a loudspeaker. I like how the author takes the minutia of 4.97Ω and correctly turns that into the I...

Sydney wrote:Thanks for that IEC ref. David.

No prob. But what the IEC spec doesn't say is a "correct" method to determine what it should be. Do we assume it to be an average of the passband? Why isn't phase angle of the load an attribute as well as that effects the work the amp has to do?

But in practical use the minimum impedance is not a factor, there will be a range of frequencies in it's bandwidth and the actual impedance will be an average. Is it? What's the math on that? Is that banded pink noise in the intended frequency range monitoring RMS current and coming to a Znom=Vrms/...

I have lots of thoughts on this topic, but I'll limit myself to just this for the moment (cause I'm at work). The IEC document 60268-5 defines "rated impedance" for loudspeakers in section 16.1 as The value of a pure resistance which is to be substituted for the loudspeaker when defining t...