Comparing some Headsets

I was looking for a good and affordable headsets for to-be-mine Sandisk Sansa e280 (darn, 2 more days have to wait till it is delivered) MP3 player (will put a review on it later).

Upon searching on google, I landed on a site http://www.headphone.com that compares the 'really' technical comparisons (not just a sounds-like-a-geek-but-a-stupid reviews). The web gives a frequency response graphs, harmonic distortion graphs, isolation and impendances for the tested headsets (unfortunately, they did not test on Bose headsets).

Here I try to compare between Sennheiser's PX100, Sony CD3000, Apple's Ipod earbuds and KOSS KSC55:

Frequency Response


Harmonic Distortion Products



Isolation



Impedance



So How to pickup the best headset? The rules of thumb are:

1. Pick the headset with the flattest and widest frequency response
2. With the lowest and flatest spikes in harmonic distortions
3. Isolation; This is a measure of a headphone’s ability to isolate the listener from outside noise. The deepest notch for the noise frequency usually good ones.

Recompiling my Linux

Somehow, my Xserver just hung everytime I browse some sites, especially the ones with script. That was one of the reasons I almost rebuilt all my Linux components from scratch. From kernel, XWindow, QT, KDE, DBUS, Apache and many others.

Compiling those libraries and applications are not always staright forward. Many of them are dependent each other (causing circular/loop dependencies). Others are out-of-date or too old hence would not compile with the latest GCC/kernel. I had to hand-fix them manually. You know it was not easy at all to fix these broken codes, but luckily I enjoyed it and learned a lot by doing it. Google is still my best tool to search missing components or how-tos.

Now, my machine had been running (almost) the latest libraries available at the time I wrote this blog. I also always enabled optimization with -mtune=pentium3 -msse. Also, if possible and available, I turned on POSIX threads as well. The kernel recognized my dual-processor chips as well, so I ran folding@home application and it showed (by 'top' tool) that the application uses one of the processor to do its very extensive biological chemistry computation.

I am still having problem making PHP run from Apache. Somehow it could not recognize/interpret PHP commands and just showed error. I will try again later if I have time. Oh, by the way, I could make the perl cgi work. It was just a configuration issue (fault from my side!).

I think I will take easy and relax now to concentrate more on my work, study and research (and perhaps pursuing my professional certifications). See you again in year 2007! (hopefully I still work on the same job).

Blue-Ray and HD-ROM War?

The drum has been beaten. Blue-ray capable game console from Sony called PlayStation 3 has been released to US market Nov 16. The high performance game console is equipped with Blue-Ray developed by Sony alliance. Will the same story of Betamax v.s VHS format be repeated? I don't think so.

First, the physical dimension of both discs are about the same. Secondly, it is digital era, whilst in Betamax-VHS war, there was only analog. In digital, signals are easire to manipulate, so there is not much difference in the encoding. Besides, some companies even have developed with Blue-Ray and HD-ROM capable drives.

The market will decide which one will win. But, unlike in Betamax-VHS case, the loser will not really lose and vice versa.

My New Linux Server

After awhile using my really-old PC (AMD K6-III) for running my personal web server, I finally replaced it with much better PC. I got this PC from trash bin/dumpster at my office (yep, it may sound crazy to some of you for a company to trash a still-good PC).

The PC is a Dell-branded "Dell Workstation 540T", a dual processor Pentium3 (Coppermine) workstation with 1 GB of RAM and a 32 GB SCSI HD. I scrapped and dismantled other PCs just to get other 2 SCSI HDs (about 15 GB each). I also moved ATPI HD (15 GB) and CD-RW (50x) from my old AMD-PC. So the total storage is 3 SCSI HDs (with total space about 80 GB space), 1 old DVD-ROM (it came with the Dell PC) and 1 CD-RW.

In the beginning of SUSE Linux installation (version 10.1), it ran in single-processor mode only. That was because the original SUSE from CD did not support SMP. After initial installation, I downloaded and compiled the latest stable Linux kernel (2.6.18.2) and enabled SMP as well as many other optimizations. I rebooted it, and...it recognized my second processor (the "top" tool showed "cpu0" and "cpu1", also the "pinguin" logo showed double telling me it was running dual processor).

The latest SUSE is really cool. A lot of improvements and fixes have been made and the GUI much stable. I also downloaded the NVIDIA driver and installed it (yes, the VGA card is NVIDIA Quadro5). Everything was running smoothly, except my apache server was somehow not able to read the folder (it showed "access denied"). After spending a few days to trace the root cause, I found out that the directory access was not granted to the folder. I then modified httpd.conf to allow apache to access the /srv/www/ folder.

I also recompiled many libraries (especially anything related to multimedia) with full optimizations. I rebuild XINE with DVDCSS enabled. Also installed MPG321, LAME, TWOLAME, etc.

After everything was done, I then configured GNUMP3D and ran it. It ran perfectly at port 8888, so now I can see all my MP3 file on the server. GNUMP3D is really cool, it displayed the files in a nice format (configurable) and when I click a file, my web browser spawn and play it automatically.

OK, enough for now. Will post it later.

Software Engineer's songs

My brother forwarded these songs to me. I've read them before somewhere, but still smiled when read it.

YESTERDAY
By : Beatles

Yesterday,
All those backups seemed a waste of pay
Now my database has gone away
Oh I believe in yesterday... ..

Suddenly,
There's not half the files there used to be
And there's a milestone hanging over me
The system crashed so suddenly
I pushed something wrong What it was I could not say Now all my data's gone and I long for yesterday-ay- ay-ay

Yesterday,
The need for back-ups seemed so far away
I knew my data was all here to stay Now I believe in yesterday



IMAGINE
by : John Lennon

Imagine there's no Windows
It's easy if you try
No fatal errors or new bugs
To kill your hard drives
Imagine Mr. Bill Gates
Leaving us in peace!

Imagine never ending hard disks
It isn't hard to do
Nothing to del or wipe off
And no floppy too
Imagine Mr. Bill Gates
Sharing all his money

You may say I'm a hacker
But I'm not the only one
I hope someday you'll join us
And your games will fit in RAM

Imagine 1-Giga RAM
I wonder if you can
No need for left-shifts or setups
And no booting again and again

Imagine all the systems
Working all life-time!

You may say I'm a hacker
But I'm not the only one

Maybe someday I'll be a cracker
And then I'll make Windows run.....



LET IT BE
By : Beatles

When I find my code in tons of trouble
Friends and colleagues come to me
Speaking words of wisdom: Write in C

As the deadline fast approaches
And bugs are all that I can see
Somewhere, someone whispers: Write in C

Write in C, Write in C
Write in C, oh, Write in C

LOGO's dead and buried
Write in C

I used to write a lot of FORTRAN
For science it worked flawlessly
Try using it for graphics!
Write in C

If you've just spent nearly 30 hours
Debugging some assembly
Soon you will be glad to Write in C
Write in C, Write in C

Write in C, yeah, Write in C
BASIC's not the answer
Write in C

Write in C, Write in C
Write in C, oh, Write in C
Pascal won't quite cut it
Write in C

The Future of Router

Nowadays, internet routers are much smarter than they were years ago. More and more features are added to this boxes in such that packets can be delivered faster and managing them easier. What do you think a router will be in next decade?

Currently, with Resilient Packet Ring, traffic can be rerouted to other paths in milliseconds response, close to SONET ADM. Processor used in the router box is also much better than we saw a few days ago. Probably they are already a dual-core RISC processor or something like that.