thetubeguy1954 said:
If you really can pull that off, you're better than superman. You're doing this double-blind, right?
Jan Didden
nigelwright7557 said:
If you wish, I can send you some zero ohm wire..
But I'm afraid the wire would be the cheapest part.....😱
[/QUOTE]
jneutron said:
You cant have zero ohm wire at 25 degrees C.
It would have to be reduced in temperature to absolute zero so it became super conducting.
nigelwright7557 said:
Um, nigel? That's why I said the wire would be the cheapest part..😉
And it does not require absolute zero. For american superconductor's G-2 product, liquid nitrogen suffices, it boils at 77K and is cheaper than beer, 32 cents per liter.
Niobium titanium is the other choice, but it requires liquid helium, 4.22 K, and it is really expensive, last I checked it was 60 dollars per liter..
The insulated vacuum jacketed line is the expensive part, as well as the warm to cold transitions.
Cheers, John
Yes
We have versions with both designs
Don't really get your question, are you asking about the circuit or the materials they are made of? We use low carbon steel and Grade5 equivalent ceramic on the models you see there. The market for better materials is extremely small for the added cost and low gain of better materials. In fact our magnets are better than most of the current stuff being sold now (an inferior grade of ceramic that is about 20% cheaper)
Read the report on the motor design here, you can see what I did to the pole piece and my thoughts on inductance in a bass driver:
http://www.aespeakers.com/Lambda001-1.php
Never tested for that to be honest?
nickmckinney said:
"Linear magnetic flux levels across the entire VC movement range."
Seems pointless if the speaker has a resonant frequency !
I have specs for speakers that show wildly fluctuating impedances and sound levels across the frequency spectrum.
I use a Fane Collosus 18inch 600WRMS and the frequency response has more curves than Pamela Anderson !
nigelwright7557 said:
In my overhung design we came out to about 16mm linear peak one way with a 10 mm overhand of coil, the curve is nice and shallow falling rather than a cliff dive. My other criteria was to have the voice coil always keep the same core material no matter where the xmax had it located. That way you can inject whatever LF you want and mix in whatever HF at the same time and get about the same HF out. Many drivers I tested you could see their inductance change 5X with xmax position and to me I thought it was such a simple fix, just extend the pole and short it with the copper. Once the prototypes were working I saw I could thicken the copper up some more as the motor strength came out pretty good so we went to a full 0.025" thick (which is really thick) pressed tight to the pole. The end result is a bass driver with a 38mm 4 layer winding length on the coil and a minuscule 0.3mH of inductance. The first person that ever heard them full range was surprised that you could hear cymbal shots on a bass driver (as well was I, I wasn't expecting a 4Khz response)
I rebuilt a lot of those Fane drivers, I can't really say publicly my thoughts on their sound quality 🙄
nickmckinney said:
I must admit I havent used this Fane in anger yet as its too big to get into the car for disco work. However, it has some serious bass in the house.
My first disco in the late 1970's used 4 off 50WRMS 12 inch Fane drivers with twin cones and they sounded great, lasted for many years despite lots of abuse and sounded very loud for the power rating, so their sensitivity must have been really good.
nickmckinney said:
I'm fighting two aspects.
1. Eddies within the steel, they simply dissipate, shifting the phase angle slightly between the current and the magnetic field, and dropping the TF a tad...
2. Eddies due to structure, complete conductive loops that enclose the magnetic flux...they store energy and release it back, they are major contributers to phase shift.
Cheers, John
nigelwright7557 said:
Sheesh, I used 8 speakerlab K's and 4 SWTPC tigersauruses..
You must have had a small car..😀
Cheers, John
jneutron said:
Laminations were considered and rejected for cost. Its hard enough selling these drivers as is. If someone is willing to pay we are willing to make them, we do custom runs of everything.
We have tested with 1008, 1010, and A36 steels and found around 2% variance in motor strength and in the final product we couldn't find a difference to be honest. We have used American supplied steel, Chinese supplied steel, and now its a combination of both. Some things the Chinese can do that the Americans can't anymore without extremely large purchases.
As for the inductance I have measured it at all possible voice coil locations and found it tracked near the same no matter where it was located. We are shorting by about 10X with that copper sleeve (3.0mH on a steel core down to around 0.3mH with the copper sleeve inside the voice coil)
jneutron said:
I have good sized car but tend to use large enclosures !
The Fane is in a folded horn enclosure, rear facing with two large vents to the front from the rear.
I intend getting a van or an estate car next so I can take all my speakers with me on gigs.
A few questions for audiophiles:
Would it be possible to make differences between interconnects audible by recording a CD-player output via these interconnects and by reproducing the recorded signals on another audio system?
If you think this is possible, would 24 bit/ 96 kHz recording quality be sufficiënt? And what kind of reproducing system would be good enough to identify the differences between the recorded signals by listening?
Would it be possible to make differences between interconnects audible by recording a CD-player output via these interconnects and by reproducing the recorded signals on another audio system?
If you think this is possible, would 24 bit/ 96 kHz recording quality be sufficiënt? And what kind of reproducing system would be good enough to identify the differences between the recorded signals by listening?
nigelwright7557 said:
The speakerlab K was a Klipsh folded corner horn.
I used 8 because I wanted stereo for gigs and the K's require 1/4 (1/8th?) space...I would put 4 together in a back to back style so they would radiate 360 degrees and be happy. I'd do this twice for roller disco type stuff outdoors and maintain stereo..
nigelwright7557 said:
I'm done with the mobile stuff. Gettin too old. Now, I give it to the kids when they want to use it...
Cheers, John
ps...never, and I repeat NEVER, make a klipsh folded corner horn using particle board. Not unless you have a death wish for your aching back...
John another motor design I did is called the "Apollo"
Its basically the same motor except I tapered the top plate and added a 6" round disc of aluminum right to the edge of the gap. Then I added another ring of aluminum outside the voice coil to fill the area between the top and back plates and inside the magnet. These drivers also have a 4" tall by 2" diameter solid plug of aluminum on top of the pole piece and sticking out of the front of the driver (the regular "TD" series has this plug only) This is alot of aluminum😀 The upper plate effectively turned the aluminum basket into a heat sink. The solid plug is very good at drawing the heat from the copper sleeve and pole out of the front of the driver.
From what I learned copper and aluminum all around the gap can be your best friend to fight the problems in the steel and the electro magnetic effects of the voice coil. They also are good for heatsinking as all drivers are 0.5~5% efficient at best which means 95-99% of the amps output is delivered as heat right at the voice coil.
Its basically the same motor except I tapered the top plate and added a 6" round disc of aluminum right to the edge of the gap. Then I added another ring of aluminum outside the voice coil to fill the area between the top and back plates and inside the magnet. These drivers also have a 4" tall by 2" diameter solid plug of aluminum on top of the pole piece and sticking out of the front of the driver (the regular "TD" series has this plug only) This is alot of aluminum😀 The upper plate effectively turned the aluminum basket into a heat sink. The solid plug is very good at drawing the heat from the copper sleeve and pole out of the front of the driver.
From what I learned copper and aluminum all around the gap can be your best friend to fight the problems in the steel and the electro magnetic effects of the voice coil. They also are good for heatsinking as all drivers are 0.5~5% efficient at best which means 95-99% of the amps output is delivered as heat right at the voice coil.
ravon said:
My gut feeling is no. A prev post discussed how the ear-brain can with ease locate sounds based on an ear/ear difference of 2*10-6 seconds even if buried in a complex and much louder signal. I suspect that no digital system can reproduce this level of performance, you would need an analog computer.
So as soon as the digital signal becomes analog, further signal degradation may be extremely subtle, yet still audible.
Objectivists will immediately respond that 24/96 resolves beyond thresholds of detectability. Yet the above-mentioned time difference is not consciously detectable (hmm, slight time delay there) but manifests itself as the brain simply locating the sound in the soundfield. Tuned by millions of years of evolution survival presumably.
HOWEVER ... I have still to do the DBT. Got the Charlize rewired, now. System very sweet and hyper-detailed, so I'm feeling confident. But all this subjectivist bluster may well be shattered with the planned 20 A/B tests ...
nickmckinney said:
Strangely enough, the basic effort of mine is to alleviate the problems in the steel without stuffing conductive material into the fray. I have to make 400 gauss at 1 Khz, the gap is 4 inches tall by 6 inches long by about 6 inches wide. I have to eliminate all conductive plates for cooling the magnet wire, as they eddy some of the field away, as well as choosing conductor cross section to reduce eddy losses in the wire itself.
Then of course, the end user puts two 1 cm thick aluminum plates in the gap, so the 1Khz field must penetrate through..😱
Doesn't the added conductive material act to damp the velocity?
I enjoy the fact that a lot of what I do does pertain to audio indirectly..
Cheers, John
Why not just starting to develop test signals and look how your ears and system react to these, changing a thing here and there?jneutron said:
Here is what I've used to test phantom imaging qualities to a certain, somewhat isolated extent (the reason for test signals, after all):
Noise stacks, that is sequences of bandlimited noise impulses, rising in frequency and with various ITD/ILD relationships.
- Bandwidth on the the order of 1..3 octaves, moderate filter slopes (24dB Butterworth). Bandwidth is an important parameter, so play with that, starting with full range spans. Overlap impulses freq band by half a bandwidth from one impulse to the next when stepping bands.
- Envelopes; fade-in raised cosine (2..4 periods of the lowest involved frequency) for click free start, fade-out exponential decay on the order of 1/4th second, somewhat adapted to overall frequency region (lower freqs with longer fade-outs).
- Sequences of these impulses raising in freq with short pauses between them, giving about 1/2 second impulse grid, forming the "stack".
- now the hard part (regarding the effort involved): apply some ITD/ILD relationships to make stereo samples from these mono noise stacks, for example use the mappings for localization direction for the ORTF stereo microphone (see the Sengpiel site for tables/graphs for these). Now you have close to what such a microphone would pick up from a point source in free field, at sufficient distance (to factor out path length mismatches bewteen mics, or factor those correctly if you want to model near field conditions -- with the 1/r-law here;-). Of course you can systematically generate any reasonable ITD/ILD ratios and map them to known real-life stereo mic setups afterwards and even to non-existing ones (and don't forget to include inverted polarities as the can apply whith some mic setups, like Blumlein etc). Include way off-axis points if you want to simulate revererant off-axis sound incidients also. I propose writing some little C-programs or the like that generate these stereo files from a variety of mono noise impulses applying the standard microphone equations, to minimize efforts ("by hand" it will get too tedious).
Now you have a huge set of test signals, hopefully spanning the whole ITD/ILD map (including as well part of the trading regions preferably). Make a lot of CDs with nice compilations that make fun to listen and have noise stack sequence setups that allow relaxed listening (try the proper arangements before burning a lot of CD's, with a proper audio editor program).
Then finally have big fun and gain knowledge from listening to that. I just went to all that when experimanting with trinaural etc speaker setups, and this was quite revealing. It also is very revealing to experiment with speaker toe-in etc, acoustic treatmants etc. On a qualitative level one can even make 2D phantom imaging graphs, with the position (in percent of speaker base), size/focus (indicated by line/bar width) and frequency range (going from low to high in the vertical axis), as well as remarks about other aspects (like distance sensation etc).
Will this testing be sensitive enough to image quality changes from different speaker cables, amps etc (assuming that those "exist" physically significant in audible quantities, not conditioned by human factors)? I doubt that, but still it gives you some hints how precise your stereo imaging works, basically.
- Klaus
Alan Hope said:
The Tripath TA-2020 chip which is in your Charlize has a switching frequency of several hundreds of kHz, that's a signal with a period in the 10*10^-6 second range. That switching frequency is not filtered out 100% so it's available on the output of your Charlize and it's right in your face when you listen to music.
If you're right there must be a lot of nasty audible modulation products available in the output of that Charlize. I don't understand how you will ever be satisified by the sound of such an amplifier if you are able to hear differences of 2*10^-6 seconds. 😀
Perhaps it's time for a doublecheck of that gut feeling before we discuss the resolution of a 24/96 recording compared to a 16/44.1 recording as we find it on CD's 😉
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