Sunday, January 5, 2014

Bird Songs Revisited

Muffler guy replaced the two-chamber "turbo" mufflers on Nell with OEM mufflers, resized for 2" inlet and outlet. Maybe I'm getting old, but in the end I just didn't want anything louder than the turbo mufflers. Glass packs may sound cool for a while, but they aren't polite to the neighbors and are annoying on long trips. The OEM mufflers are the largest that will fit under the frame. They aren't really quiet, but they have mellow tone without any metallic ringing and are a little quieter than the mufflers they replaced. With the muffler leak gone, I could now hear another exhaust leak at the driver's side manifold flange. This to went away after loosening the flange and applying a liberal coating of high-temp gasket sealant.

You would think that making the exhaust quieter would make the stereo sound better... unfortunately, not so. Wind noise drowns out everything on the highway except for passing trucks. The motorcycle stereo that I installed doesn't really cut though the wind noise over 50 mph. It's really not quite adequate on the freeway with the top off. At this speed it reminds me of music, but is only enjoyable if I have heard the song before and can mentally fill in the gaps! I've been suffering with this for the last 10 months, and finally decided to do something about it.

The motorcycle amplifier is pretty wimpy... It was clearly cutting out long before the speakers were distorting. It would also be easy and inexpensive to replace. I needed to know if the speakers could handle more power, so I took them apart and examined the drivers. I have built many sets of loudspeakers in my day, and have even been published in Speaker Builder magazine, so I have a pretty good idea about what to look for. The drivers in the motorcycle speaker pods have massive magnets and fairly stiff rubber surrounds, so I figure they can handle a LOT more power. I stuffed the backs of the speaker pods with some left over miraflex and sealed them up. I then got an inexpensive 50 watt/channel stereo amp... which is 5 times larger than the old one! Yeah, I know it has "200w" printed on it. Don't believe it. The old one said 600w on the box! Hogwash. There really isn't a reliable standard for advertised power of car amps.





I rearranged things under the dash to fit. I retained the 50w mono block I got to drive the 6x9 dash speaker. It has a switchable low pass filter, so I can use the dash speaker as a subwoofer or a center channel. Oh, it says "200w" too! This shot shows the new amp on top, the old mono block underneath, and the back side of the dashboard with the dual potentiometer/pull switch I got from an old tape deck that I will use as a volume control.



I also did some things to dress up the front of the dash. I got a set of used bezels and knobs to make the fog light switch and volume control fit in.





The little knob between the gauges has been there for a while. It is the pull switch for the electric radiator fan.

After hooking everything up and carefully testing it, I must admit that it sounds pretty good! It isn't "killer" loud, but it is loud enough that I can clearly hear rock and roll from my iPod over the wind noise at 70mph. That is definitely good enough!


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