This past week I had the chance to listen to the Pono music player at dreamforce. I happened to have a classic iPod with me with ALAC files of a couple of songs that were in the demo units. I also had Shure in-ear-monitors I bought a few years ago with me.
The quick review: The music player sounds really solid, BUT... it was clear to me that we are listening to modern remasters. Doing direct comparisons is really impossible. That being said, I mostly really liked the remastering and the overall combination of player + new masters I was listening to with the exception of Miles Davis Kind of Blue. Great noise and clarity but the stereo field seemed exaggerated.
Full disclaimer: I only listened for a few minutes, and there was this model-gorgeous blonde listening to music across the table from me, so I may have been distracted.
Thursday, October 16, 2014
Wednesday, January 8, 2014
Add HEPA filtration to any CPAP for $20
In a previous post I had written about my attempts to modify the Resmed S8 to add HEPA filtration. The purpose was to help my allergies and asthma, and maybe by reducing my allergen load I might even improve the quality of rest I get when I sleep. I've also written how dissapointed I've been in that Resmed and other's don't offer this as a standard feature, and that the filters they DO offer are so chintzy. Those little inserts are designed to protect the CPAP, not you.
In the past I had thought of elaborate schemes to do this, going so far as to order industrial HEPA medium (i.e. filter) for the woodworking industry, cutting it to fit, I've thought about making special molds or filter holders to fit the wonky air entrance of the S8, making a custom CPAP filter box, you name it. All those solutions were expensive, time consuming and most looked ugly. I have finally found a good compromise which is ridiculously easy to make, very inexpensive and at least after my first night, worked flawlessly.
You'll see a picture of my prototype below.
You will need the following supplies:
In the past I had thought of elaborate schemes to do this, going so far as to order industrial HEPA medium (i.e. filter) for the woodworking industry, cutting it to fit, I've thought about making special molds or filter holders to fit the wonky air entrance of the S8, making a custom CPAP filter box, you name it. All those solutions were expensive, time consuming and most looked ugly. I have finally found a good compromise which is ridiculously easy to make, very inexpensive and at least after my first night, worked flawlessly.
You'll see a picture of my prototype below.
You will need the following supplies:
- A CPAP machine, such as the S8, but almost any will do.
- Wide tape, such as packing, duct or Gorilla.
- Kenmore Q Vacbag Style Q
- Scissors
The idea is simple. The Kenmore Q bags filter down to the same size of particles as HEPA requires. This is very good for anything short of laboratory grade clean room filtration.
Instructions
Because some packing tape can off-gas it's a good idea to do this several hours before you go to sleep.
- Cut the bag open at one side or the back. Just enough to allow you to slip your existing CPAP machine into the bag.
- Detach the hose and thread it through the intake of the bag. Then attach it to y our CPAP.
- Remove any existing air intake filters.
- Put CPAP in bag, pulling out as much of the air hose as needed to snugly fit the bag's opening up to the CPAP itself.
- Make sure the power cord is attached. It's probably easiest to move it to one side or the other of the slot you cut.
- Close the slot you cut out with the tape. Try to get as air-tight a fit as you can.
- Check that the CPAP air intake is not pressed up to the media. You want to have that be loose fitting, with room so that as much of the bag's surface area is used as possible.
- Optionally, tape the hole around the hose itself, where the bag's cardboard insert is closed.
For best results, keep the bag as loose as possible so there are as many paths of air available.
Congratulations, you now have a very efficient, and inexpensive, HEPA filtration system attached to your CPAP machine. May you have many allergen free nights of rest.
Discussion
In terms of efficiency, etc. the bag is incredibly well suited to this task. Though the filter is of a much tighter weave than the OEM part we compensate for this by having about 100x or more surface area.
You should notice is that the bag does not crumple when you turn the CPAP on. In fact, the bag doesn't do anything. This is a VERY good sign that the bag is barely in the way of the airflow. Imagine for instance if the bag were a trash bag instead. Because the bag has no air flow, as soon as you turn the CPAP on the bag would collapse, like a vacuum seal food infomercial. The same is true by the way in the woodworking / industrial application of the media. If the media inflates very firmly it means it's clogged up and restricting airflow.
You should notice is that the bag does not crumple when you turn the CPAP on. In fact, the bag doesn't do anything. This is a VERY good sign that the bag is barely in the way of the airflow. Imagine for instance if the bag were a trash bag instead. Because the bag has no air flow, as soon as you turn the CPAP on the bag would collapse, like a vacuum seal food infomercial. The same is true by the way in the woodworking / industrial application of the media. If the media inflates very firmly it means it's clogged up and restricting airflow.
Isn't this like perpetual motion?
No, not really. We are taking advantage of the fact that while the bag is good for a vacuum cleaner it is overkill for our needs. Think about how much air a vacuum has to suck per second, versus how much air you can intake in a second. No comparison. The bag is designed for much higher air flow than the CPAP could possibly need but has much better filtration than CPAP vendors offer. The vacuum bag will not only will keep dust, dust mites, molds, etc. from the air you breathe, but will reduce the power consumed by the CPAP and ensure that enough air flows around the unit naturally to keep the machine at normal operating temperatures. All in all, a win win for you, the CPAP and the environment. :)Is this worth doing?
Maybe. We do know that allergies, like colds, activate our auto-immune system which takes energy and stresses our bodies so the idea that reducing allergic response could lead to more energy and less stress is completely medically and scientifically sound. I also believe that the bags filter many more allergens from the air than the S8 foamy filters can. However, whether adding a HEPA bag to your CPAP will make a difference to your situation may require experimentation but at $20 per experiment I think it's worth trying.
Here's my suggestion, if you know you suffer from allergies, and you are condemned to a life of sleeping with CPAP, try it for a week. See how you feel and how alert it makes you. Blog your experience either way.
Saturday, December 21, 2013
Winner - Prettiest and Worst Website of 2013
After very little time, thought or deliberation the winner of my personal award for "Prettiest and Worst" website of 2013 goes to danger!awesome.
The website is the worst for wasting as much bandwidth as it does saying nothing. It's essentially a worthless placeholder with a lot of forethought. Unless you already know who and what danger!awesome is or does, this site is useless. It's like a very expensive fashion watch that can't actually tell time and as such is to me a great example of the very worst kind of web marketing tripe.
The website is the worst for wasting as much bandwidth as it does saying nothing. It's essentially a worthless placeholder with a lot of forethought. Unless you already know who and what danger!awesome is or does, this site is useless. It's like a very expensive fashion watch that can't actually tell time and as such is to me a great example of the very worst kind of web marketing tripe.
Friday, December 20, 2013
At Long last, an affordable Audio Analyzer from QuantAsylum! Uncork the casks and let the feast begin!
An audio analyzer is a high precision tool used to measure the performance of a variety of components involved in sound recording and reproduction. Pretty much everything except for speakers. Think of it as a combination precision signal generator and spectrum analyzer that let's you at the very least do noise and distortion tests to a high degree of certainty.
Despite the proliferation of cheap components which could be used to build audio analyzers in recent years an "affordable" unit was still in the neighbourhood of $5,000 or more. Easily more. Keep in mind that the audio analyzer market is not the same as the audiophile gear market. Audio analyzers are not meant to appeal to those with more money than sense audiophiles or use diamond transistors and tubes recently "appropriated" from the radar of a Mig-23. I'm comparing prices and performance from real gear from Audio Precision or Hewlett Packard here. Even the cheap imports were still far too expensive for the 21st century small manufacturer or repair shop, not to mention a hobbyist.
Some alternatives that have come close have appeared from the PC oscilloscope vendors. Companies who leverage a PC to use as a test bed, but from my point of view, they were not yet a serious challenge. While they may have offered wider frequency ranges in the Gigahertz ranges, and a great combination of digital and analog measurements and signal generation their use of bit limited analog to digital converters made them of little use or interest to the likes of me or any audio repair shop either. I've yet to see one in the range for instance provide distortion measurements directly.
Within the last week however I became aware of the QuantAsylum QA400 Audio Analyzer. Finally, a piece of kit in line if not less expensive than a PC oscilloscope with the technical chops to rival the serious offerings from Audio Precision and others. It's exactly what it should be. An external 24 bit/192Ksps DAC and ADC with software to use it. At $199, most audio designers without deep pockets would be ecstatic. Given that it also throws in serious automation capabilities this device is a steal. This company from a city in Washington state with an unpronounceable and indecipherable name ( Snoqualmie ) has broken the barriers!
I hope to see them featured in places like PartsExpress and PartsConnexion soon, not to mention a Linux port as well.
Despite the proliferation of cheap components which could be used to build audio analyzers in recent years an "affordable" unit was still in the neighbourhood of $5,000 or more. Easily more. Keep in mind that the audio analyzer market is not the same as the audiophile gear market. Audio analyzers are not meant to appeal to those with more money than sense audiophiles or use diamond transistors and tubes recently "appropriated" from the radar of a Mig-23. I'm comparing prices and performance from real gear from Audio Precision or Hewlett Packard here. Even the cheap imports were still far too expensive for the 21st century small manufacturer or repair shop, not to mention a hobbyist.
Some alternatives that have come close have appeared from the PC oscilloscope vendors. Companies who leverage a PC to use as a test bed, but from my point of view, they were not yet a serious challenge. While they may have offered wider frequency ranges in the Gigahertz ranges, and a great combination of digital and analog measurements and signal generation their use of bit limited analog to digital converters made them of little use or interest to the likes of me or any audio repair shop either. I've yet to see one in the range for instance provide distortion measurements directly.
Within the last week however I became aware of the QuantAsylum QA400 Audio Analyzer. Finally, a piece of kit in line if not less expensive than a PC oscilloscope with the technical chops to rival the serious offerings from Audio Precision and others. It's exactly what it should be. An external 24 bit/192Ksps DAC and ADC with software to use it. At $199, most audio designers without deep pockets would be ecstatic. Given that it also throws in serious automation capabilities this device is a steal. This company from a city in Washington state with an unpronounceable and indecipherable name ( Snoqualmie ) has broken the barriers!
I hope to see them featured in places like PartsExpress and PartsConnexion soon, not to mention a Linux port as well.
Optical S/PDIF is the only reliable way to get high quality sound from a PC.
If you are using a PC for music or movies, you should avoid taking the audio from an HDMI, USB or coaxial output. The reason for this is that PC's tend to create ground loops when connected to other pieces of equipment. This is readily audible with analog connections, but insipid in digital.
The issue with digital is that you'll get a ground loop introduced into the signal which can cause very high amounts of jitter and you'll be listening to just OK sound which you won't notice until you get something better.
There are some exceptions though. Unfortunately magazines like Stereophile won't test these options. They deliberately use test in a way that negates the benefits, so you can't tell from a review if your DAC has good isolation or not.
Using an optical connection between your PC and audio system guarantees that you won't be listening to a DAC under the worst possible conditions.
There have been some that argue that coaxial S/PDIF connections are better, but those arguments were made assuming dedicated CD transports and DAC's which have far less ground loop and noise issues than PC's.
So, until something better and reliable comes along, I'd suggest to always use optical.
The issue with digital is that you'll get a ground loop introduced into the signal which can cause very high amounts of jitter and you'll be listening to just OK sound which you won't notice until you get something better.
There are some exceptions though. Unfortunately magazines like Stereophile won't test these options. They deliberately use test in a way that negates the benefits, so you can't tell from a review if your DAC has good isolation or not.
Using an optical connection between your PC and audio system guarantees that you won't be listening to a DAC under the worst possible conditions.
There have been some that argue that coaxial S/PDIF connections are better, but those arguments were made assuming dedicated CD transports and DAC's which have far less ground loop and noise issues than PC's.
So, until something better and reliable comes along, I'd suggest to always use optical.
The best Linux for your Home Theater system is Xubuntu
For me Xubuntu kicked the pants off of Fedora 19, and Ubuntu. First, it does everything I need it to do relatively easily. Secondly it's a relatively lightweight installation compared to the default Ubuntu. Thirdly, the UI itself is really CPU light, giving you extra horsepower for watching movies and playing games. Lastly, SteamOS is built on Debian, with official out of the store support for Ubuntu/Xubuntu.
In case you dont' know, Xubuntu is Ubuntu - (bunch of fat apps and an ugly default UI) + Xfde. From a binary perspective, Xubuntu IS Ubuntu in a different, leaner packaging. Anything you can do in Ubuntu you can do in Xubuntu using the native Ubuntu installs.
A lot of people may be wondering why I'm not recommending XBMCubuntu which is in fact a distro specifically designed to give the home theater experience. The answer is simply that I found XBMC really not ready for the casual user. If you want something to install, to just work, and not be Windows, Xubuntu is a much better idea in my mind. Below you will find some examples and installation instructions.
Xubuntu installed Squeezebox server with no issues at all.
[Update January 6, 2014] There is an issue with the default gstreamer settings which causes repeated audio stuttering. It has an easy fix. Type the following in a command line terminal:
gsettings set org.gnome.totem network-buffer-threshold 4.0
Congratulations, you can now watch everything on AnimeCrave in high quality.
Now comes the patient part. I'm not sure if this is related to other software updates, so you may want to go to your command line and try:
sudo apt-get update
sudo apt-get upgrade
After that, restart the "Software Updates" app, and click "Additional Drivers" where you will see cool things like proprietry nVidia and Broadcom (Wi-Fi) drivers show up if they are compatible with your hardware. You may need to wait 1-2 minutes for this screen to correctly populate, or even try it a couple of times.
Fortunately, it's relatively easy to find. From the main system menu, or from the Application finder (the magnifying glass icon in the bottom of your screen) select "PulseAudio Volume Control. " This is where you will need to enable your fancy digital audio outputs, whether it's via HDMI or an S/PDIF connector on the back of your motherboard. You may have to dig around a little bit.
In case you dont' know, Xubuntu is Ubuntu - (bunch of fat apps and an ugly default UI) + Xfde. From a binary perspective, Xubuntu IS Ubuntu in a different, leaner packaging. Anything you can do in Ubuntu you can do in Xubuntu using the native Ubuntu installs.
A lot of people may be wondering why I'm not recommending XBMCubuntu which is in fact a distro specifically designed to give the home theater experience. The answer is simply that I found XBMC really not ready for the casual user. If you want something to install, to just work, and not be Windows, Xubuntu is a much better idea in my mind. Below you will find some examples and installation instructions.
Squeezebox Server
Due to missing and impossible to resolve conflicts in the Perl graphics libraries, Fedora can no longer install squeezebox server. It has to do with a native image compression library and that there is no way to resolve it without going backwards and some serious hackery.Xubuntu installed Squeezebox server with no issues at all.
AnimeCrave.com
Perhaps the best source of legal anime on the web, AnimeCrave uses some Windows specific codecs which are hard to reliably implement in Fedora. On the other hand on Xubuntu they are installable reliably from the Software Center. Search for "totem." Click on "Videos." Scroll down to the list of "Optional add-ons". Select them all. Click on the "Install" button near the top when it's done updating.[Update January 6, 2014] There is an issue with the default gstreamer settings which causes repeated audio stuttering. It has an easy fix. Type the following in a command line terminal:
gsettings set org.gnome.totem network-buffer-threshold 4.0
Someday Linux will just work. Until then we are faced with these silly quirks.
Congratulations, you can now watch everything on AnimeCrave in high quality.
Steam
Installs directly from the Ubuntu Software Center though you will need an UbuntuOne and Steam account.Netflix and Amazon
http://www.compholio.com/netflix-desktop/Video and Network Drivers
This part is really easy but it takes a little patience, because the application takes a while to update itself. In the system menu select "Settings Manager" then under "Hardware" select "Additional Drivers". Click on Ubuntu Software tab. Turn on all of the checkboxes. Click "Other Software" tab. Turn on "Canonical Partners" but you can leave off "Canonical Partners (source code)" unless you want to do some compiling on your own.Now comes the patient part. I'm not sure if this is related to other software updates, so you may want to go to your command line and try:
sudo apt-get update
sudo apt-get upgrade
After that, restart the "Software Updates" app, and click "Additional Drivers" where you will see cool things like proprietry nVidia and Broadcom (Wi-Fi) drivers show up if they are compatible with your hardware. You may need to wait 1-2 minutes for this screen to correctly populate, or even try it a couple of times.
Audio Devices
This is the one place where Xubuntu sucks. The audio device management should be integrated into it's otherwise great Settings Manager application but it's not. If, like me, you are using S/PDIF outputs to feed your home theatre processor, it won't be on by default. Now, you'd think you'd go into "Settings Manger" scroll down to "Hardware" and find a "Sound" app. But noooooooo. << sigh >>Fortunately, it's relatively easy to find. From the main system menu, or from the Application finder (the magnifying glass icon in the bottom of your screen) select "PulseAudio Volume Control. " This is where you will need to enable your fancy digital audio outputs, whether it's via HDMI or an S/PDIF connector on the back of your motherboard. You may have to dig around a little bit.
Thursday, December 5, 2013
Flatware Cleanliness Test
Have you ever gone to a "high end" restaurant only to be served with dirty flatware? Isn't it a huge disappointment? I have. Last time it was a high-end Chinese-like chain restaurant. The chopsticks I received had particles of food on them you could scratch off with a fingernail. Ugh!!
I've also been to places where several sets of flatware looked clean but were still dirty. Maybe I was pickier than most, but I could feel the greasiness on my fingers. How could others not notice?
So, here's a test, and if you are a kitchen manager I highly encourage you to try it. Take two identical pieces of flatware. Take a paper towel to one of them and rub it as clean as you can. With clean, dry hands feel both of them. If the one you did not clean off feels slick, but the one you cleaned feels tacky you still have plenty of oil and grease left on the flatware. Clean flatware should not feel slick.
I should add of course, this is not meant to be a substitute for adhering to industry best practices and regulations, or biochemical analysis and regular inspections. It is meant to help diners, washers and kitchen pro's see something they might have missed otherwise.
I've also been to places where several sets of flatware looked clean but were still dirty. Maybe I was pickier than most, but I could feel the greasiness on my fingers. How could others not notice?
So, here's a test, and if you are a kitchen manager I highly encourage you to try it. Take two identical pieces of flatware. Take a paper towel to one of them and rub it as clean as you can. With clean, dry hands feel both of them. If the one you did not clean off feels slick, but the one you cleaned feels tacky you still have plenty of oil and grease left on the flatware. Clean flatware should not feel slick.
I should add of course, this is not meant to be a substitute for adhering to industry best practices and regulations, or biochemical analysis and regular inspections. It is meant to help diners, washers and kitchen pro's see something they might have missed otherwise.
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