Craig Sawyers

Yeah - I know what they meant. But if you knew nothing about a subject (which they clearly did not) you'd get someone who knew to check it; well I certainly would. And if they meant approximately, then either write the word, or an abbreviation like approx. Then there is no ambiguity. But then again, I'm just your regular pedantic asshole

That is what we used to use at Wharfedale. Actually it was speckle interferometry, which is what you have to use to map the resonances in rough surfaces. In the mid/late 1980's. Dunno what if anything they use now.

Plus *or minus* 20km??

A good way of subjectively seeing if anything is moving is the Beethoven trick. Put a stick (of a sort that will not damage the finish on the speaker) between the speaker and the pinna of your ear. You'll hear if anything moves.

The whole vibration thing is interesting. Suppose you put a mass on something that is springy, and the other end is coupled to something rigid, like a floor. What is the resonance frequency? It is dead easy to calculate - if the spring compresses by delta x metres, the resonance frequency is (1/2pi) x root(g/delta x). You do not need to know the mass and spring constant - just the deflection. So suppose the speaker compresses (say) sorbothane feet by 2mm, the resonant frequency is (1/2pi) x root(9.81/2E-3) = 11Hz. So at frequencies higher than 11Hz the speaker stays (vertically) stationary, and at frequencies lower than 11Hz, the speaker bounces up and down. Of course if it is actually sorbothane, there is high loss, so there is not a resonant peak, but the basic motion remains. Of course it is more complex than that, because the cones have substantial mass, so there will be a tendency for the speakers to rock like a pendulum as well as the cones move back and forth. In this case it depends on where the C of G of the speakers lie, where the drivers are (particularly the bass driver), and how far apart the springy bits (sorbothane for example) are. That in general will be a low frequency, certainly lower than the vertical 11Hz. Try rocking the speaker and see what happens - probably 1 to 2Hz. If you use spikes there is a gotcha. The spikes need to be very, very seriously locked in place. Because of the cone motion, particularly at low frequency, and tendency to pendulum rock, it the spikes are not locked absolutely solid, the speaker can rock on the spikes. Most easily diagnosed with swept sine. Got the badge on that one - testing a homebrew sub I wondered what the god awful noises were as I swept a sine wave - sounded like the worst sort of distortion. Loose spikes.

A rapid lithium battery induced disassembly incident at NASA. Oops.

About 50F here in the UK, and looking to cool down during November with night frosts and snow on high ground. Texas (30N) is on the same latitude as Egypt, Saudi Arabia and Kuwait. The UK (51-53N) corresponds to Southern Alaska. Factoid No:47b

RIP Bobby Vee, age 73. Early Alzheimer's. Far far too early.

Just catching up after a few days away, and am just reeling. Go for her jugular Steve - bring her as low as low can go. PS we get our cats from https://www.bluecross.org.uk/oxfordshire-burford-rehoming-centre , and fortunately these are the good guys. They give you a verbal third degree to make sure that you are the kind of person who can be trusted with a cat or dog from them.

Haven't heard anything since that post; but yes like you I'd be up for a bunch (provided they are genuine new old stock).

I'm just not sure where the silicon is in relation to the package. It *may* be much closer to one face than the other.

Happy Birthday!

Dog goes into the telegraph office (this is an old joke), puts his paws on the counter and goes "woof woof woof woof woof woof woof". The lady behind the counter says "You can have one more woof for the same money" The dog replies "That would be ridiculous, it wouldn't make sense with another woof"

That is the sort of faultless logic I use. "Hey - I've got all this free stuff. Let's use that fact that to spend lots of money to get the best value from the free stuff". Been there so many times.....

You can also get the Neutrik RCA's in an XLR housing, which looks kind of cool.

Hey man - have an absolutely great one!

The Naim Statement. About the same price as the boulder above, but at least you get a preamp (the middle slice).

Ooh - shiny

He doesn't say what the measurement bandwidth was. Which really makes it a very loose specification. The only hint is the very sharp mains harmonics in the noise plot, which are way sub-Hz in width. To get to -158dBV (-155.8dBu) from -107dBu on a 20kHz B/W you would need a measurement bandwidth of 0.25Hz, Shockingly badly specified.

The most significant issue with the THAT 1200 series of receivers is noise, -107dBu. It is dominated by the rather large values of noise-generating resistors inside (7k typical). With a good discrete design, or clever use of opamps you can get to -120dBu, which challenges measurement (<1uV in a 20kHz bandwidth).

Cooler is a relative term with the T2 Clone

I have mine on two separate shelves - in a stack it gets pretty toasty!

Have a spiffing day!

Have a truly superb day!

Have a great day, sir!