Well, this is awkward…

(posted several weeks after writing, life is good again: new shared flat, back on a three day/week working schedule, …)

Over easter I spent some “me time” actually playing a computer game. Haven’t done that for quite a while, Wasteland 2 was the pick. Post Apocalyptic RPG (Role Playing Game), four Charakters which you can create by yourself. So I did the obvious and called them Hannibal, B.A, Templeton and Murdock. Some adjustments had to be made (no Planes / Helicopter to fly, no cars to drive) and the latter two became female body types, it’s 2015 after all. A couple of hours into the game I passed a fellow Team, the members named Peppard, Tureaud, Benedict and Schultz. Well, this was awkward…

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Zwenkauer Lake, not connected to the post but nice anyways..

It’s interesting that I always resort to A-Team quotes wenn life is shitty. The realtionship mentioned in the last post actually ended in a rough patch. Luckily we identified the underlying conflict under our struggels and didn’t end fighting about unimportant stuff. But yeah, seems we both are not willing to change drastically enough so that stuff would work out. That one really helps with transition. Besides that I have to move out of my shared flat on short notice and started a new work project which doesn’t actually lighten up my mood at all for reasons which probably fall under a non-disclosure agreement. So life has been kinda shitty on these sides but I also have set things in motion which might turn out truely awesome. But these will need some more patience before I officially announce anything.

Back to the A-Team. When I was young I was an addict. I used to cry when I missed an episode (these were the days were there was no Internet available for streaming and my parents didn’t have a VCR). Life back then was pretty dismal. My parents were fighting every day, I was fat, nobody liked me (or at least that was what I thought) and I got bullied a lot. So these guys (as well as McGyver) became some sort of role model. Not because of being unable to hit people while shredding through a gazillion bullets without reloading. Because they don’t get bullied? Yep, thats one part. Much more important is probably that they were abandoned by society (as I sort of was by my parents) and that they look out for each other / became a family. They work together and care for each other.

B.A. doesn’t want to fly but if the shit hits the fan he lets the others drug him so they can escape/rescue somebody/whatever. He can’t change instantly, they can’t change him but they work out weird ways to make it work. Same for Murdock, certified lunatic for sure but they endure his character because they love him. And if they have to count on him he pulls himself together. Face’s Ego makes his company unbearable but deep down he is a really nice and decent guy. Hannibal on himself would probably be a drunkard, not knowing what to do with all his brains. Don’t get me wrong: I strongly believe in change and think everybody should work on themselves every day. But some stuff takes time, in rare cases even more time than a lifespan.

Hannibal is another strong reason for identifying: He always has a plan. Or several. They seldomly (ever?) come out as expected but he excels in improvising. Even if he ends up in a dead end, he pulls himself back together and doens’t stop plotting before he knows how get everything back to normal. I really like that, still today. Back in the day I just wanted to have a plan to get out of my misery and (hello McGyver) be able to fix the relationship of my parents. That one didn’t work out but I still like to have a good gameplan and to watch it coming together. Besides that I enjoy fixing stuff, even though I completely gave up on fixing humans I’m quite good in fixing anything technical.

Too much to blog about / Two year anniversary

Give me a minute, I'm good. 
Give me an hour, I'm great. 
Give me six months, I'm unbeatable. 
-- Col. John Smith

Well, it has been some time. Dunno why I lost the motivation to blog. Guess stuff was either too personal for the interwebs or too boring. So what happend in between?

Around march last year I started hanging out more in Leipzig. Met really decent folks, spent time with them, got to know the city better. Shortly afterwards I started a new work project at some large cooperation close to Hannover. Luckily it didn’t last too long because it was not exactly what I was longing for. Somewhere around that time I decided to actually move to Leipzig and fell deeply in love, not only with the city. The rest of the year was split up between wrapping stuff up in Hannover and starting new stuff in Leipzig.

At the beginning of this year things got out of hand. I co-founded a venture with a group of people wanting to share an old industrial building for workshops and other projects, started a new work project at a local company and a relationship went through a rough patch. And I got sick. And sprained an ankle. And two fingers. And I have to search for a new home in Leipzig since almost everybody is moving out of my current home (for reasons…) which I was told me one day after I lugged in my last stuff. Two stressful month all in all. But now it’s improving almost every day.

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The new Job got the nicest view out of the window so far. I was to slow taking the picture, it was a double rainbow, there is a faint reminder on the left

Yeah, so thats it, one year in fast forward. It was a good year after all but it surely had its ups and downs.

I guess I’ll start settling in over the summer, try to cut back to a three day a week work schedule and enjoy the finer things in life. Either just chilling in the sun or sweating while refurbishing a freaking huge industrial building. Or finally make the missing licenses for boats. Or start a house project. Hmm, seems I have one gift at least: I seldomly get bored, theres always stuff to do or adventures to experience. Life is good. But the older I get the more I try to max out the good things. That doesn’t always work out as expected. But I’m learning to accept that and to just enjoy trying.

Sailing

I guess I’ll start cruising some day. As in sailing, not gay lifestyle. At least I’m not planning on the latter. Anyways, I started watching tons of videos on youtube about the topic and even started reading books (yay!). Seems like quite a project, the last time I have been sailing was about 20 years ago on summer holidays. I always liked boats and the water but seldomly got the chance to enjoy these. A couple of years back my girlfriend and I chartered a ten meter motor yacht and really enjoyed it. The only problem is an ecological, ships which are large enough to life abroad have the fuel economy of a tank or worse. The 160hp volvo penta of the thing burned something like one liter per km (roughly two miles per gallon). So both my consciousness as well as my wallet rule out that option. So sailing it is.

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Mecklenburger Seenplatte in 2012. Since we were aboard all the time I don’t have a decent shot of the boat…

The other problem with boats are that they are expensive. Let’s say we do it like with we do with cars and buy something old and reliable/upper class which needs some fixing, maybe a 16m “Amel Super Maramu” like the sv delos (little tacky but still awesome youtube channel btw.). Some call them “the mercedes of it’s class” so it seems like a decent choice for 25+ years old thing. For my 25 year old merc coupe I paid 1800€ and put in another 1000€ in parts and easily 40h of work. Definitely not the best buy of my life. The Super Maramu from the same era is advertised for prices somewhere between 170.000€ and 250.000€ and the ads look like there are quite some expensive repairs waiting for the new owner. So it’s no wonder that most people who are doing this seem to be retired high income folks who sold their house&fancy stuff to shell out a serious amount of money for getting a boat fitted out and sailing it around the world. These people are also telling you that it costs about 1/10 of the original price of the vessel per year to keep it running if you don’t do anything by yourself. Let’s say 25.000€ per year which is probably not enough. So to be on the safe side you should plan on something in the vicinity of a million to go cruising for a couple of years if you just buy something, and put it in a shipyard every time it needs tender & care. Well, as most people I don’t have this kind of money.

Amel Super Maramu, Source: http://sailboatdata.com/viewrecord.asp?class_id=5880

Enter the shoestring budget sailor. Most sail the world until the budget run out and then work shitty jobs to earn money fast and to return to cruising. Some even manage to earn money on their way, like for example fabulous caption fatty goodlander who writes books about his lifestyle and how to achieve it. I bought “Buy, Outfit, and Sail” from him and can really recommend it. The funny thing from a hacker/tinkerer point of view is that there’s not too much new information in it. In short: If you want to buy a boat cheap look for something that’s severly (but repairable) damaged with an owner who has to sale on short notice. Then you fix it yourself investing plenty of time, sweat and tears tapping as many brains of professionals for advice as possible. Extreme example from the author: bought salvaging rights for a sunken vessel for 3000USD and ended up spending 10.000USD (+ labour) to end up with a vessel worth of 100.000USD. Only buy quality stuff, if possible slightly used and thus greatly reduced in price. Dive every interesting dumpster you pass by. If you can’t afford it build it yourself. Focus on what you really need. Do not make any compromises in safety.

So yeah, my basic lifestyle with electronics and cars applies to boats as well. Nice! But still this seems like a longterm and expensive project. I guess it will be in two phases, get a small cheap boat to sail on lakes, rivers and near shore to see how it feels like and learn prober sailing and then get a decent sized vessel (around 10m) and spend some time repairing, outfitting and taking small trips before crossing the atlantic over to the carribian. So it seems five years from now would be a realistic time to start, even the season seems about right, spending my 40th birthday in the middle of the ocean and being in the Caribbean around Christmas. Seems like a plan indeed.

So if you’re hooked up by now I’d recommend watching sv delos if you like it a little fancy or “hold fast” if you prefer punkrock. I enjoyed both big time, maybe because I’m kind of a punk driving mercs :-)

One year anniversary!

I started blogging over a year ago and forgot the anniversary. I did post the first posts on 17.03.2013 and wrote them a couple of days before. What was I doing at the same time this year? I hiked the Bodenstein and Harz Mountains and visited Leipzig for almost two weeks to meet old friends and make new ones. So I actually did quite an anniversary celebration without even realizing. Not too bad at all.

more bass knowledge

German wikipedia provided something interesting. The resonance effect is working best from 0,75*fb to 2*fb (resonance frequency of the enclosure). Subwoofer normally operate from approx. 20Hz to 80Hz.

The previous owner tuned the enlosure to 27Hz, to work nicely from 20Hz to 54Hz. It would have been interesting to adjust the crossover (80Hz, 4th order in my case) to 54Hz and to run it as a deep bass addon with my living room stereo. But since I’m running it with small satellite speakers on my desk 27Hz – 72Hz seems like a good choice…

more knowledge on bass / speakers

Friends pointed out to me that they don’t understand my writings about building/optimizing speakers and don’t even know what to google for. Sorry, guys, I was just writing down what I was doing and not thinking about that.

The Variables (Fs, fb, ….) are so called Thiele-Small Parameters, named after two aussie guys doing research on the matter. Wikipedia provides links to sites explaining the stuff in both german and english.

Don’t let the math scare you away, you don’t need it. To build a woofer you just have to look up these values and put them in some online calculator which is spewing out build dimensions. Just make sure to get a second opinion on the results, be it through research, online forums or just asking folks…

more bass #3

“Yeah Science, Bitch”  -- Jesse Pinkman

I did some research. The concept of tuning a vented box very low is called EBS (Extended Bass Shelf). This site explains it pretty good, the basic idea is getting more bass on low frequencies. You basically take an enclosure 160-180% the size of a “maximum flat” setup and then tune it close to Fs (Free Air Resonance of the speaker). As I already found out the previous owner did tune the enclosure to about that frequency. But how about enclosure size? The manual suggests “maximum flat” enclosures from 64 to 92 litres, suggesting an EBS setup between 102 and 165 litres. The enclosure has around 80 litres not accounting for the speaker and the vents. Well, I guess I found a problem here.

I tried some more online calculators and plenty of them tune close to Fs without even mentioning it. So it’s more than understandable to end up with this setup. But as always, you gotta trust your senses: If it sounds shitty there has to be a reason… Ah, and trust the engineers. If you deviate far from their suggested path you better know what you are doing…

So to wrap this up and continue other important work I’ll go the humble approach. I’ll measure the actual resonance frequency of the enclosure and tune it to something between 36-39Hz for the suggested “maximum flat” response.

Measuring shouldn’t be to difficult, the impedance of the speaker drops at the resonance frequency, so the current spikes ( I = U/R ). So just rig an ampere meter to the speaker, a frequency generator to the amplifier and play with the frequency knob until you reach maximum current. Well, my ampere meter doesn’t like low frequencies at all making it impossible to get a reading. Using a shunt (resistor in series) and measuring voltage I pinpointed the resonance frequency at 35,7Hz. That’s way lower than the expected 43Hz. Good news: That’s the lower end of my target frequency. Bad news: I’ve got to redo the math…

Some site suggests if the distance of the ports to any wall is less than their diameter the tuning gets lower. That’s definitely the case here…  The increase of Volume by damping depends strongly on the material, ranging from 0-20%. If I run the numbers with an estimated volume of 115 litres everything checks out and the estimated resonance frequency with the long vents would be around 24Hz. I guess I have to measure that as well :-( Hmmm, 27Hz, not too bad for an estimate…

Hmm, maybe I should give the 31Hz a shot. 18,5 cm for the vents… Let’s say 20 for good measure… After some try and error 21cm turn out to lead to 30.something Hz. Good enough. Yeah, there is more ooompfff on low frequencies, you don’t hear some but feel it in your guts. I had to adjust the woofer level back to +6db on the amp. But it seems to be a trade-off with quality. Most of the time there’s not enough bass and then suddenly it’s killing you when the frequency drops low enough. For example with “Clint Eastwood / Gorilaz”, some low rumbling for the whole song and then the break with a couple of low beats is just plain awful. Somebody suggested that EBS setups often have cancellation issues on the two octaves above the resonance frequency (so 30-120Hz). Yeah, that might be the issue here.

To cut a long story short: EBS doesn’t work out with this enclosure, even if you do it right. I guess that’s 2:0 for the engineers… Disclaimer: I’m working low volume settings (neighbours…) and the placement of the sub is bad. Maybe it’s getting better with optimal placement and if you crank up the amplifier. Maybe not. At least now the sound setup at my desk is ok. Time to actually do some work…

more bass #2

The new subwoofer has bass, I’ll give it that. But sounds like a trumpeting elephant somehow. Well, it’s probably not the speaker itself. The broken crossover / connection panel is already removed. Hmm, let’s have a look at the mods of the previous owner.

He reduced the volume by adding an enclosure for the connection panel, added some foam isolation and adjusted the length of the vents. Alright, the enclosure lowers the volume (obviously), the insulation increases the (virtual) volume of the enclosure (not so obvious). Measuring inside the box is difficult, I’d estimate the volume about 70 litres so with the insulation it’s probably somewhere between 70 and 80 litres. The original vents have 75mm diameter and are 120mm long. The previous owner extended them to 350mm / 360mm using pipes from the hardware store and claims to have calculated everything with some software.

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The vents should be the same length. They are extremely close to the rear wall of the box but I couldn’t find proof that this is an issue. Let’s start with the obvious: Some designer made this enclosure and even if it’s a cheapo they probably put some thought in it. The vents adjust the resonance frequency of the box. Changing them by a factor of three means either the engineer who build it was way off or the one doing the modification. I used an online calculator to run the numbers. With the extensions the resonance frequency (fb) of the enclosure is around 29Hz, without approx. 43Hz. The manual of the speaker comes with 12 suggested enclosure dimensions ranging from 36 to 50Hz fb. The interwebs suggest it makes some sense to go for a “bass shelf” by tuning fb to Fs (30,83Hz) or even lower. One formula I found suggests 31Hz being ideal for this setup.

The manufacturer of the speaker and the manufacturer of the enclosure obviously don’t think so. I removed the extensions and the setup is quite close to the “Standard Tight Bass” box design of the speaker manufacturer. Afterwards I had to reduce the amp setting from +7 to +3 (probably db) and it sounds pretty tight.

I guess I’ll rig up a setup to actually measure the resonance frequency to check my estimates and tune the box to “optimal sound quality / flat response”.