dinsdag 16 augustus 2011

The smoby trike adventure part 2 – Finding the solution

In my last post on the smoby trike I bought for my son, I shared what horribly loud it was and what to do with it. It also talked about finding the root cause of the noise and what to do about it. The main noise factors are indeed the bucket and the wheels. So how do we get the noise down? Well let’s put our thinking caps on first: Sound, what is sound? Vibrations in the air. Our ears pick these up and they turn it into a signal that our brain recognizes as sounds. To put it simple:
Air (vibration) –> Ears –> Bain (Sound)
So these are our options, we can tweak our ears, our brain or the air. Sounds tempting to do something about our brain doesn’t it :)? But to do something about the vibrating air before it reaches our ears and is the more pragmatic and practical goal for some household hacking on the trike.
Let’s use another tool to generate some ideas about reducing the noise. It’s called a morphological scheme. Here’s how it works: you take a goal (make air vibrate less) and doodle what could help reach that goal with no concern for reality or feasibility. Here’s mine:
morphological scheme smoby trike
Now this is just to get the creative juices running to see broaden your scope. I can imagine my handwriting being illegible on the picture so here’s what I thought of: foam , tape, clay, noise cancellation, wheels, skids, box.
Now we have multiple solutions and tighten our scope and start to define our limits. For example
1. Price - Under 10 euro solution
2. Effect – It has to work
3. Endurance – has to withstand daily use

The solution?

Noise cancelation would be a cool idea to experiment with, you know add speakers in the wheels that try to cancel out the sound waves that are being generated. But alas to expensive/time consuming. Building a noise isolating box around the tricycle would work but make the trike rather unusable. And spraying foam around the wheels would help just until the wheels have turned one circle, and all the foam is left on the road, I think the same goes for clay. Changing the current wheels with skids or another will increase the complexity and cost. So I’m left with… Tape. The wrap up will be in a next post.

vrijdag 12 augustus 2011

My personal acoustic guitar buying guide, Introduction


I recently purchased my third guitar over a time period of 7 years.
Guitars 400px
I started out with a classical nylon stringed Yamaha c-70 I got for my birthday. This got me learning guitar, thank you yamaha. After 4 years I switched over to a steel string Epiphone EJ-200 super Jumbo model. I just loved the sound and the looks. Getting the EJ really improved my playing because every song I played sounded new to my ears compared to my old guitar. After another 3 years it was time for a new guitar. Although I loved me EJ and I got attached to it, the sound couldn’t compare with an all solid guitar and because I could get a good price for it… I traded it in for an Eastman AC320CE which is a dreadnaught model. It did not have the flair of the EJ and I don’t like the looks of a dreadnaught much, but the sound was unbeatable. And that is first and most important thing about buying a guitar. Use your ears, they don’t lie and only they can tell you what the best sound for you is. And what is the point in buying an instrument that you don’t like the sound of?
I’ll end this section with a quote from Justin referring to scales over at justinguitar.com (amazing site by the way!):
If it sounds good, it is good
If it sounds bad, it is bad

The pointers

1. Use your ears
Your ears are two very complex high quality receivers. They will tell you more than a brand or price tag. Before I bought my EJ all guitars would tend to sound alike. So I went to the store multiple times and let my ears get used to the different sounds that guitars have. And by doing that I developed a liking for certain sounds and without a doubt the EJ-200 had the right sound for the right price for me.
That’s it for now. In my next post I’ll be looking into form factor and woods

woensdag 10 augustus 2011

The speed of sound on the dell E5410

I'm amazed.

Here I am with my Dell Latitude E5410 laptop with an intel i5 processor and 4 gigs of ram running windows 7. And here comes the amazing part, Windows Media player/Itunes has a hard time playing mp3's fluently. Almost at random it stutters in playback and this off course really annoying. Almost random because it does sometimes seem to correlate with dragging your windows across the screen. But still with a wopping duo-2.5 ghz at your disposal I'd think the CPU should be able to handle this...

A work around that has some succes is to increase the cpu priority setting in the taskmanager manually to realtime. This is less than ideal since you have to do this everytime you restart the program. See screenshot: image

Any thoughts anyone?