Category Archives: Uncategorized

Of Watts and Volume

There is an equation for watts to decibels, given a sensitivity of x decibels, (1w/1m)!  Wattage must double for each increase of 3db.  See here and here for more info.  So that sensitivity (SPL) score is a pretty crucial starting point for a speaker.  Not that adding more amplifier watts is not impossible, just moderately costly.  But then again, in the case of an amplified PA speaker with 700 watts peak (and 350 RMS) then you’ve a lot of power.  By my calculations, taking a 98db SPL woofer up north of 122db, and a 110db SPL tweeter up past 134db – past the threshold of pain!  Also, I’ve read that perceptively, humans believe +10db makes one sound twice as loud as another.

BUT distance from the speaker matters!  On a ratio of 1/d^2, the sound gets softer the further away you are!  If pumping 350 watts through that woofer gets us 122db, standing 52 feet away from it, it will sound just like it we only pumped in 1 watt at 1 meter = 98db.  That’s still plenty loud.

It makes sense to me now why stage monitors are always like 100-150 watts.  Even with all the noise on stage, you’re pretty close which means they’re pretty loud.

Here’s what that speaker system sounds like as the watts are increased:

Watts Woofer Tweeter
1 98 110
2 101 113
4 104 116
8 107 119
16 110 122
32 113 125
64 116 128
128 119 131
256 122 134
512 125 137
1024 128 140
2048 131 143

 

Contrast that with another system with a higher SPL:

Meters Woofer Tweeter
1 122 134
2 116 128
4 110 122
8 104 116
16 98 110
32 92 104

 

For reference, here is a reference table for decibels:

Source Intensity Level (db)
Threshold of Hearing (TOH) 0
Rustling Leaves 10
Whisper 20
 Quiet bedroom at night 30
 Quiet library 40
 Average home 50
Normal Conversation 60
Busy Street Traffic 70
Vacuum Cleaner 70
Busy road 80
 Diesel truck, 10 m away 90
Large Orchestra 98
Walkman at Maximum Level 100
Front Rows of Rock Concert 110
 Chainsaw, 1 m distance 110
 Threshold of discomfort 120
 Threshold of pain 130
Jet aircraft, 50 m away 140
Instant Perforation of Eardrum 160

Technical Leads in Scrum

I just read a great article on Effective Technical Leadership that outlines with a fair amount detail, the role of a great development technical lead. Since then, for the last few minutes I’ve been trying to figure out how a technical lead would fit into the scrum variant that we run, as we currently don’t have tech leads.

Simon Jones Leaps high at Lineout - Westcliff RFC

# How does this fit with scrum masters, off-team architects and team managers?
# Would you need a tech lead for each functional development team (UI, services tier, back-end), or one tech lead for each scrum team?
# Does an off-team architect become a technical lead if you assign him to a team?
# Do scrum masters have the time and technical chops to be a tech lead?

I realize that team titles past PO, scrum master and team member are no less than subversive to scrum, as the whole team needs to own the process and the results, but it is clear that there is room within the team for these responsibilities. Additionally, several of these positions are, in a healthy way, at odds with each other. Simply merging two scrum master and tech lead would result in only one individual responsible for both the results and the approach, which is a lot of weight to not be spread around the team. Perhaps technical leadership lies outside of scrum, but within agile’s self-organization principle, to be cultivated by the organization’s managers.

I’m going to stew on this for a few weeks. I was inspired by the content of the article, but I don’t know how to formalize it in my organization.

Scouting is Still About Religion

I appreciate a recent article from the Washington Post that discusses the changes to BSA policy and the Mormon faith. As a scout leader of eight years who is moving out of the area of my current service, this change has cause me to reflect on my involvement with Scouting and the policies of large organizations.

One key line in the new resolution that the scouting body approved is worth citing: “…any sexual conduct, whether homosexual or heterosexual, by youth of scouting age is contrary to the virtues of scouting.” That is it, in a nutshell. For the Church of Jesus Christ of Latter-day Saints, this was never about whether the BSA or local scout leaders should try to discern or categorize ill-defined and emerging sexual awareness of pre-pubescent boys and early pubescent young men

“…Some may not see the sacred gatekeeping role scouting plays. They may see only fundraising and not a foundation. Others may brand scouting activities as merely outdoor recreation, but it can and must be shown that BSA is not a camping club; it is a character university centered on duty to God. I quote again from Robert Baden-Powell: ‘The whole of [scouting] is based on religion, that is, on the realization and service of God.’

I am satisfied that a renewed focus on the BSA’s foundational principle – Duty to God – is sufficient for the continued support of the LDS Church and my continued participation, should new opportunities arise.

Response to FCC 12-581

http://transition.fcc.gov/Daily_Releases/Daily_Business/2013/db0401/DA-13-581A1.pdf

I do not support a loosening of restrictions on offensive content, including but not limited to language and nudity, based on concepts of deliberate placement, isolation or repetition. Offensive language is just that, regardless of its density throughout a program. Individual nudity is not accepted in public, sexual or otherwise, nor should it be allowed on public broadcast. Public broadcast is a common asset and should be appropriate for the general public and if it is allowed to become unsuitable for significant portions of society, particularly families and those who understand the negative outcomes of repeated exposure to vulgar content, it will become devalued as a medium for education, entertainment, marketing and news as viewership decreases. If any change is to be considered, let it be to tighten restrictions to include offensive material that has crept into acceptance over the past years!

The argument that the enforcement of established standards has become excessively expensive is surprisingly shallow and does not address the root cause: despite clear restrictions, media organizations continue to broadcast material that is offensive to the public. At least two other solutions should be considered as well: additional federal funding as granted from expressed public interest and higher fines to further discourage offenses and to subsidize enforcement.

All ranges of appropriate and inappropriate programming are already available via Internet, cable and satellite media providers. Those wishing to experience more offensive programming should continue to turn to these, leaving public broadcast wholly appropriate for all ages and sensitivities.

Lastly, I suggest that any changes to the FCC’s policies be submitted to a more formal public review. Furthermore, please evaluate establishing differing standards based on state or regional standards as well as different bands of public broadcast with varying levels of objectionable material.

Weaving

We do so well at diving deeply into product features and functionality. We can map so many of the possible outcomes and approaches along a single line of thinking, and then we stop because we’ve either hit bedrock or because it’s time to dive down the next feature. Sometimes it’s a sister feature and sometimes totally unrelated. When we’re tired of diving down features we step back and look at all our features. We wonder which feature sets should be done first, and how many could be done at the same time.

We sometimes ignore a more sensible approach: a single focus that weaves its way through each of the feature sets we’re interested in.

Holistic focus on limited feature sets instead of shallow focus on entire features.

Movie Review: Hanna

I watched Hanna last night an was left with the pressing need to immediately watch something else, as if to remove a bitter taste from my mouth after eating bad food! The story was engaging but the characters were creepy – all of them. I found that I didn’t care what happened to anyone because they were all so uncomfortable. Maybe if another director took a crack at it, one that had a normal childhood or something, I’d like it better, but as it is I didn’t care for it.

2 stars out of 5.

Nimbile Software Development

Years ago while working at a young start up it dawned on me, like hundreds others, that I needed a name for our particular brand of agile software development.  Ours was a different style, unique, personal, successful – not like all the others, right?  But I wanted it to last because I loved it.  I wanted it to last forever, but it didn’t.  And since then I have always tried to replicate that success to varying degrees of success.  Here are some of the key aspects:

  • Where Agile focuses on the need to move quickly and change easily, Nimbile emphasizes the ability to do such, but not necessary the need to.  Point being: too frequent or unnecessary change is unhelpful at best and at worst crippling.
  • Positive, fun and productive work environment.  Yes all those things are necessary.  I do not believe that the ends justify the means, I believe that the end, however cast is a product of the means and carries with it the essence of those who made it.
  • Believe that what you are doing is good for your customers, the company, the employees and in any small degree, the world.
  • Do the right thing at the right time.  Don’t wait to change when you need to and stick to what is working.
  • Dream, test, measure, execute.  Then repeat.  If you didn’t know what you were doing and if you don’t know that it’s working then you’re just wandering.  That’s nice, but I need to run a business here.
  • Almost everything else good that is Agile and nothing of the bad of all the other methods(tm).  That’s right.  That makes this an airtight claim to being _the best_ methodology ever!

I want to take time to flush this out more, and in particular share experiences from each of the subsequent companies that I’ve worked for.  Hopefully this will allow me to refine the definition of Nimbile and show how it works and what you need to make it work.

Nutty Putty a No-go

Nutty Putty - that's the way in?We took the boys caving at Nutty Putty cave the other night. 45 minutes around the lake, another 30 minutes down a bumpy dirt road and then a 10 minute hike up a hill – this got us to the proximity of the cave. Our guide couldn’t find it right off, we had to spread out and look for it. When we did we all piled in, but I was the only one that came back out. The initial opening was alright, but the opening at the bottom of that opening was tiny. Tiny, like for badgers

Wanted: My Next Sci-Fi Show

So I’ve been watching a lot of new shows lately. I found Hulu.com and like a new shiny toy I’ve been giving it a lot of undeserved attention. One of my favorite shows is Stargate Atlantis and I’ve watched every episode on the site. After that I started watching Kings, which I might continue to after they make some more episodes. I dabbled in Heroes, Battlestar Galactica, the Dresden Files, the Legend of the Seeker and sister-show Stargate SG-1.

I found a real gem in Firefly, which only had 14 episodes before it was cancelled. It took me one and a half episodes to figure out that it was supposed to be sci-fi show in a western motif.

What I’m finding is that I’m having a hard time finding new good shows to watch. And the ones that I have found seem to have been cancelled or had just a limited run. Why is that? Are my tastes so rare that

Today, I’m watching Eureka, which is about a town of geniuses. If this doesn’t work, then I’m pitching a new idea to the big wigs at the TV studios… are you ready? Check this out:

So you know all the sci-fi shows where they run into alien technology or they all the sudden have a great new technology: ships, guns, transporters? Think of all the stuff in the Star Trek series, the Stargate series, the X-files, right? Where do they take that stuff? That’s what my show would be about – the geeks in the basement labs that get to play with the new tech and make major jumps in innovation and invention.

Sound good? I’ll let you know how it goes.

How Goulash Reminds Me That I Love My Mom

A co-worker of mine just warmed some Hungarian goulash in the microwave for lunch. I stopped moving and played a little movie in my head, hand still on the cupboard door. It went a little something like this:

“Mom, I have to do a presentation in class on Hungary. Is Hungary in our encyclopedias or was that after they were printed?”
“I don’t know much about Hungary, but I can make Hungarian goulash…”
“That’d be great, Mom! You can bring it to my class and give everyone a bowl. I wanted to give a report on Germany – East or West, but some other kid got it! So I had to go with Hungary… speaking of, when’s that soup gonna be ready?!”

Little did I realize then that a bowl of goulash for all thirty kids in my 5th grade class was a tall order. I think I even had the audacity to ask for bread sticks – you know, the Hungarian kind. I also didn’t think through the fact that my mom had a job, and would have to tote our giant Crockpot to work to keep it warm for the morning before bringing it to my class at some unusual time, say 1:26 PM. Then there was the spill. I can imagine now the frustration of spilling a tomato-based soup in the car! She was running late and the heavy pot slipped out of her fingers! What a mess that must have been! But my Mom did it, and it’s a testament to her love, dedication and motherly-ness. It’s time to thank her now, because I am sure that I didn’t then. Thanks Mom, and happy Mother’s Day!