Phones are all over the map. I would bet that almost all record at 48 kHz and even if they go higher, probably roll off near 20k.
The Axicom IM series appear to be a good relay also and sealed with SF6 inside.
Yes they do look good, bifurcated etc. and same form factor as the small one I showed.
Scott,
The Teledynes have pretty much been a standard for decades. The hermetic seals do add a bit to the cost though.
Interestingly enough on small sealed power relays there is almost always a small bump of plastic on the top. You are supposed to break this off after soldering and cleaning bath. It is designed to let air circulate to let the ionized air inside to not reduce the breakdown voltage.
Any slew effects on the electronics or driver could cause the offset. I have seen mechanical shifts with level on a driver.
Yes, but only a speaker that has a DC path to the amp. A tweeter crossover cap prevents it.
Jn
I have to say that Bonsai seems to be overly concerned about my CTC Blowtorch preamp and its reliability. My personal unit, that I have had for about 20 years has never been opened, yet it runs, day after day, week after week, year after year. We do recommend that people 'wipe' the switch by using it once in a while, but I have never personally had any audible problem my unit. Fortunately, the preamp box is nearly totally sealed, and it runs at a constant temp, 24hrs/day, so there is no big cause for air circulation to the outside. I love my Shallco switches, but I have tried just about everything else.
For example, I first used Teledyne TO-5 relays for servo control when I was at the Ampex research department, 50 years ago. Yes, they are cute, tiny, and reliable. In fact, I selected them for the Dennesen JC-80 preamp about 11 years later. Still, I doubt they are the very best choice. Generally with Parasound, we use standard gold on silver contact relays, and sometimes relays especially designed for very low levels, like the ones Ed wants to use. They are OK, but I will stick with my Shallco switches. I just might measure a Shallco switch that has been sitting around more than 10 years in just a drawer, just for the heck of it. It should be tarnished by now. '-)
For example, I first used Teledyne TO-5 relays for servo control when I was at the Ampex research department, 50 years ago. Yes, they are cute, tiny, and reliable. In fact, I selected them for the Dennesen JC-80 preamp about 11 years later. Still, I doubt they are the very best choice. Generally with Parasound, we use standard gold on silver contact relays, and sometimes relays especially designed for very low levels, like the ones Ed wants to use. They are OK, but I will stick with my Shallco switches. I just might measure a Shallco switch that has been sitting around more than 10 years in just a drawer, just for the heck of it. It should be tarnished by now. '-)
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Since air is nonlinear and the pressures in a driver/enclosure can be considerable the compression itself could push a cone out.
If the suspension has an issue it can happen. Surrounds are notorious for having issues. Spiders also are not made from springs, they usually are more like phenolic impregnated fibers and often in nonsymmetrical shapes.
Not too sure about tweeters. With a laser you could test one. There are many of the same issues except for smaller parts.
I have seen temporary/dynamic cone offset with ported speakers and high levels of low f sustained tonal bass mixed with high levels of low f transient bass.
I don't know if this is a nonlinear/directional flow characteristic of the port causing box internal pressure offset and consequent cone displacement or if it is driver characteristic or amplifier characteristic...or what ?.
Dan.
As mentioned driving speakers face to face in anti-phase at high operating levels will exercise drivers without causing significant radiated sound.
However by definition the the above recommended Pink Noise does not contain significant continuous or transient peak power in the high frequencies, so therefore does not exercise tweeters to the same extent as the the woofers are exercised.
M-Noise is very different to standard PN -
and contains full amplitude HF transients but at low reputation rate and therefore satisfying PN 1/f energy density specification.
So, for running in loudspeakers the tweeters can also be exercised to full amplitude but without getting cooked or broken (smoked or fatigued)....very useful also for running in electronics.
In the past few days since 'discovering' this novel test waveform I have explored other uses for it and have used it to discriminate ferrite filter and my filter caused system changes that are revealed by music signal but not reliably revealed by static waveforms or standard PN.
Music mostly follows PN power spectral characteristic but can contain high level HF transient power/information that pure PN by definition does not.
M-Noise is a significant step in bridging the gap between conventional measurements and subjective findings.
Dan.
Yes, that's odd. If you do buy it, be sure to get it on Jasmine. A friend bought it when it came out, pretty damn good
The 1938 Benny Goodman broadcast that never was
You´re not alone.
As you´ve mentioned it above, i thought an example where some components above 20 kHz will produce IMDs _in_the audible range, and the example was a NOS player.
Some people obviously prefer the sound of these NOS-devices - of course there exists a variety of implementations - but given the reality of sampling, i´d assume suppose that there will be a strong dependence on the recorded content at the upper end of the 20 kHz audio bandwidth and of course it depends on the linearity of the electronics and speakers.
As i´ve posted on other occasions, Pioneer introduced in the beginning of the 90s the so-called "Legato link" which offered sounds above 20 kHz (with decreasing level) from CD playback. They argued with listening experiments where listeners preferred this extended sound. As usual, no details were given so nobody knows if it was real evidence. (*)
Technical information also was sparse, i always thought it was use of attenuated mirror images but had never examined it.
Or just a small misunderstanding, but nobody was harmed....
(*) The referral to listening tests was quite common even in patent applications from japanese companies, but iirc Scott Wurcer onces argued that it could only be a result of the japanese company culture where the ideas of the boss were often not questioned. Is a plausible explanation too. Anyway the "Legato link idea" wasn´t afair not a big success.
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Maybe the same listeners that preferred the NS-10.
When I went to Japan to help peddle our first DAC's in 1988/1990 the social protocols were very evident seating order and who spoke and when was always observed. We did one long meeting through very difficult back and forth interpretation, a young underling engineer was assigned to show us out at the end, he spoke perfect English.
I spent long meeting with NTT (Nippon tele...) debating the workings of a new mobile standard for Japan. They outnumbered us by 1:5. 30% where asleep 90% of the meeting time (10h?) - then all of a sudden it was he subject for one of the sleepers - he woke up immediately - made a long harp of something while, often a girl, made a perfect more or less simultaneous interpretation of what was quite advanced technical topic - amazing performance of all involved. The system worked even if it required some heroic trouble shooting, climbing Tokyo roofs in the middle of the night a few days before launch. Great times
//
even if it required some heroic trouble shooting, climbing Tokyo roofs in the middle of the night a few days before launch. Great times //
Dan,
I thought white noise had constant spectral power density and pink noise had a -10 dB per decade power spectral density characteristic (yes, I am mixing up my decades and octaves - sorry for that). So, relative to HF, you are getting more power into the bottom octaves with pink noise.
Pink noise - Wikipedia
I don't think you need to drive speakers hard to run them in. That said, I remember reading a paper many years ago (maybe posted up here on DIY Audio) where the 'speakers should be run in' thing was tested by measuring them before and after run-in and IIRC the conclusion was there was no difference. But YMMV of course.
I thought white noise had constant spectral power density and pink noise had a -10 dB per decade power spectral density characteristic (yes, I am mixing up my decades and octaves - sorry for that). So, relative to HF, you are getting more power into the bottom octaves with pink noise.
Pink noise - Wikipedia
I don't think you need to drive speakers hard to run them in. That said, I remember reading a paper many years ago (maybe posted up here on DIY Audio) where the 'speakers should be run in' thing was tested by measuring them before and after run-in and IIRC the conclusion was there was no difference. But YMMV of course.
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Lived in Japan for 5, Taiwan for nearly 4 and China for nearly a year.
Loved it - what an adventure. Once you settle in an immerse yourself in the culture there's a lot to enjoy.
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