Travis In Austin

Who has a photo of PMK'S first speaker design? Headphones with paper tubes affixed to them?

So sorry to hear this, my prayers are with you and your family. Travis

PWK collected all kinds of old horns, including WE. Including the one I posted above. Can't say for sure, but I think he would all for you experimenting with that horn.

I can only imagine. Just want to throw that out there.

Wow, he lives and breathes

Maybe

Getting a vision of yellow and blue is gone

For the last couple of days I've had this feeling that something has been missing around here, but I can't quite put my finger on it.. Anybody else have that same feeling?

So was there enough people on the list @Chief bonehead for you to explain to them how you test headphones in your anechoic chamber?

@dtel's wife They are getting ready to lynch you over in that Pilgrimage thread if you don't get a list, you better hide here for awhile. Even @Chief bonehead was clammering for a list, that guy never never needs a list. Maybe he is trying to figure out if there will be enough folks who will be interested is seeing how he tests headphones in the chamber?

Luan, @HDBRbuilder you never cease to amaze me. In California in the 60s and 70s redwood was the same price, or close, as pine. So everone built their decks, swing sets, dog houses, FENCES, out of redwood heartwood. Those days are long gone. Figured it must have been some type of wood that that was close to price as birch, but never heard of Luan before.

Things apparently much different in 1954 then the system in place by the 1970s.

Read this article from a peer reviewed engineering journal, they did exactly what you are proposing to see if the know correction factors were accurate, and whether temprature or atmospheric pressure had more of an effect. You will need to know what the barometric pressure is at the time you run your acceleration tests as it has even more of an effect than temprature which is inversely proportional to the square root of temperature (absolute, which for centigrade would be in Kelvin) a10v25n3.pdf

That answered my questions, thank you. My first sub had both line level connection (from LFE) and speaker wire terminals, but wasn't passive. The Mac HT processor I had at that time had both an LFE Out, and speaker terminals for Sub. This was way before HDMI.

I've been admiring Quiet Hollow and his posts for years, somehow I'm not convinced that his question is all that serious; is it more a comment about videos from the recent CES shows of systems like the Delgados/F3s, etc with iPhone? Then he pulled out the GL 1 card, so now I'm really not sure, he has been quiet. (I know he is "Quiet", he has not been responding). What really gets me is TV makers trying to spiff up a picture on a new tech display, like 4K, that they know you are seeing on 1080, or worse. Every ad has a disclaimer at the bottom that says "picture is simulated." I guess if someone has that great Cannon video camera, always wanted one, they can go into a B&O store and video that, and then maybe go into a theater Chief Bonehead has set up, (synching the camera audio into a Nagra at the highest Rez) with a water cooled laser 4K projector, full blown Atmos system with 5 of his Gradures across the front, etc. I guess the question is, what are you trying to compare? Somehow I'm expecting the sound of a shoe to drop in one or both of those videos.

That is what I guess I am asking. What is his ideal Xover point. If it is two high isn't CL going to be taking away from the sound of his H woofers?

So do the sub experts or the OP mind if I ask a more fundamental question? CL is running Heresys right? He want to optimize Sub to go with it. Do you start with figuring out what is the best crossover point for Heresy for sub? Let's say that is 60 Hz, I have no idea, just throwing a number. That is determined by where FR drops off by 3db from flat, or thereabouts? Assuming it is 60, there's a knob or some adjustments on the back of that Sub from some number to some number, and hopefully it is rated at 60 HZ. His his sub powered? I saw someone say it won't take line level, does that mean it is unpowered? It says it is 500 Watts, 1100 peak, so I'm assuming not. Is his question whether he should power his sub with the internal amp, or the Mac Amp? Or what signal to send to the Sub? What signal could go to the Sub that bypasses the Mac? That newer Mac is going to have THD at max output, from 20 to 20 at what .006 or so? Can you really hear Mac sound from a Sub being used to cover 20 to 60 Hz.? I know you can hear Mac sound, it's about all I have, but can you here it through a powered sub, or even one that is unpowered? I guess I don't understand what his connection options are with that Sub, which the Sub experts know.

I don't know, they are pricey, but supposed to be the best sounding product in that class, which is like a Waveradio by [Name which shall not mentioned]. KGI loaned us one for the KGI/Museum Booth at the Watermelon Festival. I heard it sounded great for the size, etc.

@mungkiman. Near as I can tell it was only a concept, using the speaker technology used in their Stadium product. I think working prototypes were made, but it never launched. At least in that form. There was a long thread about it from CES 2015.

It's the Second Law of thermodynamics. The maximum efficiency of any heat engine decreases as the heat of the air the engine exhausts into rises. Specifically

Isn't it a matter of thermodynamics?