Building Speakers
I built my first set of speakers when I was 15 years old. I bought two full-range 5” speakers from Radio Shack and 6” wide shelving ¾” vinyl covered particle board from the hardware store. This saved a lot of cutting and saw dust in my parents’ apartment in St Catherines Ontario. Not a lot of bass mind you and the high frequencies didn’t come out crystal clear but still it was OK and a lot of fun to build them.
It was an easy build. No other parts to integrate. No additional tweeter to hook up, no large woofer to integrate and no “crossover” to make sure that the different frequencies go to their proper places. One single little speaker struggling to do it all. Hooked up to my 16 watt per channel Realistic receiver and I enjoyed Fleetwood Mac off the FM radio and Rush “2112 Overture” off my turntable. Now those were the days I tell my kids. I had to carry groceries in large brown paper bags not those easy to carry plastic ones you have to day. Had to carry these through a foot of snow UP HILL for over a half a mile till your arms felt like they were going to fall off. Yes, those were the days! Anyway, back to speakers.
Built my first 2 way speakers when I was 18 years old. Oh yes, back to Radio Shack. This time two 8” woofers in a sealed box with one small compression tweeter that play louder than the two woofers. As good as the tweeter sounded I could never really get the sound right. The crossover I used was only one small capacitor to the tweeter blocking the medium and low frequencies from getting to it and damaging it. But nothing to stop the high frequencies from getting to the woofer it was a guessing game of trying to get it right. And then the tweeter was too loud. Too cheap to put a volume on it I just turn down the treble on my Integrated Amplifier. OK but nothing spectacular I’m telling you.
My first really, really loud pair of speaker was built when I was 19 years old. Electro Voice SP 15A 15” woofer midrange. 103 db with 1 watt at 1 meter they claimed (now we know this is probably a slight exaggeration). These speakers were the size of refrigerators when I finished building the boxes for them. They were a "bass reflex" or "ported design" which means there is a hole in the speaker with a tube placed in it that has a particular length and diameter to “tune” the back bass inside the speaker and let it come out to help out on the overall bass performance.
My room was lined with curtains all the way around, even the door! My stereo was placed in a refrigerator with the door still on that I tore out the insides and built shelves to place my Amplifier, Cassette Deck and Turntable in. I tell my kids, “These were the days way before CD’s”.
I tried every possible position to place my turntable. I put it on cement blocks. I hung it from the ceiling! Nothing worked! The bass was so unbelievably loud that it would actually work its way backs up vibrating the turntable and so then the Stanton Stylus (needle of the turntable) and cause feed back when I played LPs!!! If I was going to listen to my music loud I had to first record it on my cassette deck. When listing to Rush 2112 you could close your eyes and be sucked into the black hole of the vibrations of the double kick bass drums I kid you not! Not just a musical experience but also a physical experience. “Lord, please forgive me for torturing my parents.”
But I still couldn’t get the sound right. I could not afford the high volume tweeters and crossover that were supposed to go with it.
Over the last few years I’ve been experimenting with horns! Large horns! When done right there is nothing like it. The detail in the "presence" is unbelievable. But getting it right is not easy. Each horn carries only so many octaves so you have to divide up the bass midrange and high frequencies and cross them all over correctly.
The most interesting part of speaker building is trying to judge the individual parts. A tweeter that carries the high frequencies will sound way to loud if you do not have enough mid-bass. You cannot by ear, match a midrange to a tweeter.
Without an overall context of the sound you cannot discern the individual parts and their performance. You simply cannot tell what the tweeter is doing unless you have a full spectrum of sound to base it on. No matter how long you play with it and toy with it and change its crossover or turn it up or down it will never sound anywhere near right unless you have an overall picture of sound by which to work from.
Speaker building is not the only thing for which the same concept can be applied. You really don’t know the true place and position of that tree or its bark or it place unless you place it conceptually in the forest that it is a part of.
Fulfillment works the same way. Fulfillment in the context of ongoing history is the same way. We struggle with that which really cannot be accurately discerned for its particularities unless those particulars are placed in the whole.
The whole is that God is love, he loves us, and he is sovereign. He knows where he has brought us and he knows where he is taking us. I do not see that everything is set in stone and there are no possibilities of participation. I do think however that our trust in Him to carry us forward is well founded.
We as believers need to see a larger world than the world of believers. We are all in this together. The sooner we see the bigger picture the sooner we can place ourselves in the larger context of who we are.
The world of believers is like a tweeter who can’t hear the mid-bass. We have grown accustomed to the screeching high frequencies and thought that this is how the music is supposed to sound. The mid-bass looks up and says, “Hey there, center of the universe screeching tweeters, you are too loud and vocal.” God stands back and listens to His creation playing his favorite tune.
There is still room for improvement. There are some new tunes coming out that will require some changes to faithfully produce all those new dynamics and nuances. And the old system just can't handle the surround sound like it should. Maybe a slight change in the crossover frequency. It’s a bit low. Those tweeters are trying to cover too much range. No wait, maybe just a little more mid-bass. A subwoofer would be nice! That will really shake things up!
By Barry Dupont
