Friday, November 30, 2012

Mac Mini Setup, Phase 2

Over in my other blog, Brick Pool House, I described setting up my new Mac Mini starting on Black Friday.  It went smoothly.  But I did not hook it up to my video system because I needed an appropriate Mini DisplayPort adapter(s).

One reason I had not bought a Mini earlier, say 2-3 years ago, was because I was worried about connecting to my video system as easily as I had the PowerBook which had S-Video output.

On Wednesday and Thursday I bought various parts at Radio Shack and Best Buy.

On Thursday night I hooked up a MiniDisplayPort to HDMI adapter "cable" from Belkin, which I bought at Best Buy.  What Belkin has done is package a short cabled adapter with a 7 foot HDMI cable for $44.  You could buy the separate parts but they would end up costing more.  Plus I figured these pieces were made to go together (they are, and the inline HDMI connection fits snugly).  I only worried that the actual "converter" circuitry might not be as good as the more expensive separate options.  But I figured it was probably about the same, and this looked neat.

Well at first I plugged in the display port adapter and plugged the HDMI into my 5 way HDMI switch (which feeds a HDMI splitter which goes to TV's in 3 different rooms) it did not work.  I fiddled with it on Thursday night for more than an hour and could not get it working.  I unplugged and replugged the HDMI cable.  I turned off the kitchen TV (an older model which has 1080i, but not 1080p) and tried the Bedroom TV (a Samsung from 2008) instead.  I rebooted the Mac.  Frustratingly, the Display Preferences showed only one device, the DVI monitor, and not anything else.   However, the status light on the HDMI switch did light up.  I changed the refresh rate for the (only one shown) display to 60Hz.  I also tried changing the display preferences down to 1024x768 (very similar to 720p) and even 640x480.

I did not re-plug the Mini DisplayPort plug itself, because that was tricky.  By the end of the night, I had removed the Mini DisplayPort plug, but been unable to plug it in in the dim light, and beginning to wonder if the Thunderbolt indication meant this wasn't really a Mini DisplayPort.

All night long I was dreading the possibility that this newfangled DisplayPort thing would not work a video switch.  Apple does indeed say you should not plug any other adapters into a Mini DisplayPort adapter.  They say you should ONLY plug an approved monitor into the adapter.  This would go way beyond the normal HDCP copy restriction if you couldn't even use HDMI switches and splitters.  But maybe that's what I was not stuck with.  Perhaps I could get the old PowerBook going again with a new Hard Drive.  This was the kind of thing I was thinking, and dreading.

In the morning I checked online, and in fact the Thunderbolt plug can work like a Mini DisplayPort plug if a Mini DisplayPort adapter is plugged into it.  Looking at one set of troubleshooting instructions from Mac, I noticed that as their last step, they had you remove and reinsert the Mini DisplayPort plug after shutdown and then restart.  The instructions were a bit ambiguous as if to suggest you should try re-inserting the plug several times even.

This time I was able to re-insert the plug, and it still didn't work right off, but after a bit more fiddling, it started working, and I got good images on both kitchen and bedroom TV's at once.  The second monitor now does show up in Display Preferences and I adjusted them for side-by-side.  I set the main monitor for "best display."  For some reason, the video system only gets 640x480.  I can only choose that.  I shut off the kitchen TV again, and on my Bedroom TV I could select either 640x480 or PAL, but no HDTV like 1080p.

It must be that my switch and splitter are sending some kind of least-common-denominator display information back up the line.  All of my TV's are capable of 720p and 1080i, but my Kitchen TV only does 1080i and not 1080p.  Perhaps the DisplayPort can't do 1080i (update: I now know that it can do 1080i from the adjustments with the Monoprice DisplayPort->Component adapter) and can't do 720p either but only 480p or 1080p.  That seems very limited, but it would explain what I am now seeing.  I have turned off the kitchen TV but maybe I need to disconnect it from the HDMI splitter to get a higher resolution.  Anyway, I'm actually glad it does support 480p, which is more appropriate for some things.  But what I'd like to do is be able to switch among these resolutions (and even 1080i, if that is possible, to get best image on my kitchen TV).

Wednesday, November 28, 2012

More fun with Kenwood L-1000T

Just a few weeks ago I hooked up my Kenwood L-1000T (aka Kenwood in this post) to my whole house Sonos audio system using a Behringer DEQ 2496 digital equalizer to correct the European 50uS deemphasis to the USA 75uS standard.  In the digital domain I can do the conversion quite well, even with the limited choice of cutoff frequencies.  I use a 6dB per octave shelving at 2212Hz.  Right now I can't remember the dB of adjustment but I think it was between 2 and 3dB (calculated in an earlier post).

Well of course I couldn't even enjoy the Kenwood over Sonos without this change (or something having a similar effect, like actually changing the parts in the Kenwood), so even though I had hooked up the Kenwood to Sonos back in July, I hadn't really used it much for the Kenwood.

What I mostly use this for is listening to radio in the bedroom.  The bedroom currently does not have any tuners hooked up (though, ironically, I have the stack of second best tuners that the Kenwood defeated now resting in the bedroom because the computer room has been overstuffed with junk).

When I used the Sonos system to listen to FM, which wasn't that often, I usually listened to the Marantz 2130 in the kitchen as it has the correct EQ and actually sounds very nice.  Sonos lets me pipe a line-input signal from any room to any other room, it goes through a moderate quality 44.1Khz 16 bit uncompressed codec with digital level adjustment so you can optimize the dynamic range.

This was a revelation.  The Kenwood always sounded great, but now I could actually stand listening to it for hours, and using my KT-6040 remote control, I spent one evening scanning radio stations.

On Tuesday night I found how the Kenwood L-1000T with correct EQ really blows away the Marantz 2130 over Sonos.  The Marantz sounds veiled and muddy by comparison.  (It doesn't sound that way at all in the kitchen, possibly because of different room acoustics and near field listening, but also possibly this test is unfair, I have fully optimized the Sonos level for the Kenwood a few days ago, currently max tuner output gets to -3dB digital maximum, but the Marantz level in the Kitchen has not been optimized, and was about 20dB lower, causing huge loss of digital resolution (though I raised the volume level to compensate, it can't restore the resolution lost over 16bit depth conversion and transmission).  Possibly the Marantz level actually depends on the volume level I set on the amplifier in the kitchen, actually a Yahama receiver.

But I also came to notice on Tuesday night this week that the signal from San Antonio City College was mono.  I noticed this because I happened to pipe the Kenwood output to the kitchen system, and look at the stereo separation on the L-R scope mode of the Marantz.

So I took a careful look at the display of the Kenwood tuner.  It was showing only one (tiny) bar of signal strength, yet the RF selection was Direct.  Obviously this was causing a weak signal and limiting stereo separation.

For some time now, I had been convinced that the 6040 remote doesn't control the station control settings on the Kenwood.  But somehow I had pre-programmed Preset 2 for Direct mode.  Either I had actually set the Direct mode somehow, or at some earlier time the signal strength may have been stronger when I was setting the presets.

I was able to un-set the Direct mode by this procedure:

a) Disable setup mode using small button to the right of tuning knob.
b) Change the tuning by the minimum amount in either direction.
c) Change the tuning back to the correct center tune.

This forces the Kenwood to determine the best settings for this station, and when I do this now, it correctly choses High Sensitivity mode.

Now the fact that the presets had been programmed with direct mode suggests that possibly I had been able to control the RF mode previously, and I had deliberately chosen direct thinking it would give the best sound quality.  Or, more likely, I had set direct mode for KPAC, a much stronger station, and had failed to unset it for the remaining stations that I programmed.

Taking the remote in hand again, I struggled and with much fiddling with angle and direction was able to get the Kenwood to change RF mode once.  I think the capability is actually there, I just lost it when I stuffed the Kenwood into the corner it now occupies, which gives no good way to aim the remote at it (the Kenwood is immediately behind the transformer of my Acoustat speaker).  I can try to control it from the side that I have open and it sometimes works.  I can also use the Remote Extender system which I use to control the preset station selection from the bedroom.  That also has a receiver over the living room mantel so I can point the remote at that rather than at the tuner.  It works, mostly, for setting presets, but may not have enough IR resolution for the advanced settings like the RF mode.  The remote extender has a transmitter I place just to the side of the L-1000T and it works, at least it works well enough to change presets.

It may also be the batteries in the 6040 remote have gotten weak.

I need to experiment with this more, it was already well past my bedtime when I made the above discoveries, and I decided to stop because I know these kinds of explorations can last all night and typically end on some frustrating note.  But I will be back at it soon.

In the meantime, I used my mis-tuning method to get the Kenwood back to receiving the city college station in High Sensitivity mode.  But if I change the preset, this gets messed up, so I really have to find some way to fix it.  I could also memorize the preset with the High Sensitivity mode.  But I also forgot how to program presets, I alway find this confusing and counter-intuitive on Kenwood digital tuners and I need to read the instructions again.

But another flaw is that I can't, or at least was unable, set the IF bandwidth.  When I change the RF mode back to High Sensitivity using the method above, it also resets the IF bandwidth to Narrow.  It really doesn't need to do that I think, as Wide works fine on Direct mode, it should also work OK on Narrow.  But as yet I haven't figured out a way to change that.  Perhaps the remote will do this, and perhaps it won't.

Here's a discussion of HDMI/HDCP handshaking.

There are endless blogs of people describing issues and frustrations with Apple's Mini DisplayPort.  Many people have suffered with the disappointment that they cannot use their cherished display with their cherished Mac.  And for many of those people, the problem did not go away the next day.

After you look at the discussion of HDMI/HDCP handshaking, it's not surprising that this technology is so finnicky.  HDMI/HDCP want to make sure you're not doing anything that isn't allowed (recording!).  And it seems, even a slight seeming irregularity will shut them down.  Also, all HDMI/HDCP units have an internal state, which may need to be reset by powering down the unit for 10 seconds.  You try powering down everything, making all the connections, then powering up switches, then displays, then sources.  If that doesn't work, try powering down everything and then powering up switches, sources, and displays.  Some configurations work better with powering source first, others with powering display first.

Oh Boy.

Thursday, November 1, 2012

Playing with the Kurzweil

A month or so ago I pulled out my mint (barely used) Kurzweil K2661.  Over in the corner where it has had a nice custom made table to sit on for the last 4 years, it has mostly just sat, because it's just no fun to stand in that corner and play.  So I pulled it out right in front of the Queen Anne chair at the back of the living room.  That makes for a great place to play.  It is lined up with the L-R of the speakers.  Obviously one does not get the incredible image one gets up front.  But one does get a nice distant image that I find good enough, and the back of the room, and the Queen Anne chair, is much more suited to playing than in front.  And the beauty of this arrangement, with playing chair in the back and listening chair up front, is that both are independent and always available to be their best.  I can leave the Kurzweil out for the whole month until my end-of-the-month party, when I can temporarily put it back on the custom made table in the corner.  The rest of the time, it can be out in the room.

That's exactly what I did for the party in October, I put the Kurzweil away on the morning of the party and back after the party, so it was unavailable for the minimum time.  And when I set it up this time, I skipped all the wiring mistakes I made the first time, and got the wires entirely out-of-the-way instead of taking-up-the-whole-room.  There is one passage, around to the couch in back, that has become a bit tricky mainly because of the Kurzweil itself.  But now I make the front path to the couch around the listening chair entirely clear of wires.

Since I purchased the music workstation in 2006, I suspect I've used it less than 400 hours, mostly just random playing, barely learning how to program or do anything (though I know it's all can do anything, well almost, play all parts you've recorded at once, just like a full band, with accurate (to varying degrees) renditions of every kind of instrument or synthesizer, and every aspect of every Program (instrument) can be edited, or new ones can be created from factory samples or new loaded samples.  The Kurzweil gives you a nice collection of samples and raw sounds and an all-inclusive (just about) set of all the possible transforming operations that could be done with them, and then you can hookup as many of one to the other and to controllers in as many ways you can imagine in fairly long channels.  Thus, it makes you the instrument designer, and you can make it do anything anyhow.  It's a kind of soft instrument made of user programmable DSPs, which uses actual DSP hardware to realize how it is programmed.  A true analog instrument with as many capabilities as this would fill a building.  (DSP = Digital Signal Processors)

Last month I finally figured out Record Mode, or at least I recorded myself a few times, and it actually worked.  I've been watching the video tutorial that I downloaded from Kurzweil or somewhere when I bought my unit.  It's good, but it doesn't start with creating Programs and so even though I've now watched half of it I still haven't gotten to the programming part.  I watched him record a sequence, and after that I got it to work.

Here is one of the better tutorials I've seen on creating a Kurzweil Program.