Years ago when I was a keen but inexperienced amateur in sound, I thought it would be a good idea to build a couple of 4 x 12 loudspeaker cabinets for my guitar. 'Stacks', as they were called, consisting of an amp plus two big cabs, were popular in those days. Highly impractical, but if it helped a guitarist look one-twentieth as cool as Jimi Hendrix it was the right thing to do.
So I bought eight twelve-inch drive units and a truck load of wood and started construction.
The first cabinet went together nice and easily. I covered the cab with a lovely imitation leather material. Well it was considered quite nice at the time. The result looked great. If I had put a Marshall badge on the cab, no-one would have questioned it.
Of course I was eager to try the cabinet out so I plugged it into my amplifier and strapped on my guitar. From the first notes of 'Smoke on the Water' I realized that all was not well. It sounded terrible - the cab I mean, not my playing.
This was a tremendous disappointment. The speakers were a reputable brand and the rest was just wood. What could have gone wrong?
I pondered this question long and hard and eventually decided that there was something about cabinet construction that I just didn't know, and sources of information were few in those days.
So I decided to cut my losses and sell the two cabs, the first as it was and the second I would build.
So I advertised the cabs as a pair and soon enough a likely buyer came around. He was the concert manager for a local working men's club. He wanted to hear the cabs in the club and offered to take them there in his van. I was perfectly honest about having built the one cab myself and that the other wasn't finished yet, but he was OK with that.
So we took the first cab to the club and plugged it into their system. It sounded terrible like I expected, but the guy seemed very happy with it. Perhaps the rock-bottom price I was asking made a difference.
So we did the deal on the basis that I would finish the other cabinet. I took the first cab home in the meantime.
Building a second loudspeaker cabinet is nowhere near as much fun as the first, especially when you know it's not going to sound very good. But I built it carefully and wired the speakers up. Of course I had to test it...
It sounded GREAT!
This cabinet was truly the dog's bollocks (UK English for 'very good indeed'). It was EXACTLY what I had wanted when I set out on the project.
So something must have been wrong with the first cab. I looked inside and spotted the problem, the speakers were wired in pairs, and the two pairs were out of phase with each other. One pair was pushing air out as the other was sucking it back in.
Now of course, with the benefit of experience, I would recognize this straight away. But then... well you learn from your mistakes.
So I put the first cab right, set up my stack and had a blast. People could probably have heard me ten blocks away.
Then I rang the guy who had agreed to buy then, he came over with his van and took them away. He left me with a wad of cash that wasn't even as much as I had paid for the parts, and all the work I had put in went unrewarded.
Still, at least I know I got it right in the end, and I suppose I had the satisfaction that my cabinets were doing good service for the 'turns' down at the club.
Every sound engineer should build a pair of loudspeakers at least once in their life!Come on the FREE COURSE TOUR