Need help from audio experts!

[48Rob]

Thanks for the explanation Bruce!

Sounds like I can move forward now

The only other issue to solve is chrome or black...so many decisions

Rob

[asianflava]

Thanks for the advice on the capacitors.
I have capacitors on the door speakers in my truck, had to install them after putting big speakers behind the seat.
The door speakers kept trying to kick out bass to keep up with the rear speakers, and sounded horrible.
Now they only produce mid range and higher sound.

This is the same concept you're trying to show me for the 4" speakers, right?

Exactly!

That is a cool chart I linked to. Back when I was installing, a lot of this was like a black art. Now, it's as easy as a few mouse clicks away. When it was slow at the shop, we'd make sub enclosures strictly based on Thiele Small calculations just to see how they'd come out.

I think you'll be OK with the setup.

[Trackstriper]

Capacitor thoughts-

If you want to have just the mids and highs from your motorcycle speakers, use the caps. With your truck you had some bass working with the rear speakers and maybe having the door speakers pushing bass at the same time was too much, or they were undergoing high distortion for one of several reasons.

My only concern with adding the capacitors is that you might clip out a lot of musical information, including voice. If we assume a 4 ohm speaker impedance, a 100uf capacitor will drop your electrical output power to the speaker by 50% at 400Hz (3db down at this "crossover" point). One octave lower (6db farther down)...200Hz... you have would have 1/4 of that 50% power or about 12% of what you have at say 800-1000Hz. For reference, middle "C" on the piano is about 260Hz. You might set a lower crossover point, maybe 200Hz so as no to lose music. See Rocky's charts. This would take a 200uf capacitor (or two 100's wired parallel...they add this way). I'm not knocking Rocky's previous information because it can save some amplifier power from being wasted, but it just sounds like the frequency is too high unless you have some additional low frequency speakers, which you don't.

It would be true on a bike that you most likely won't hear the low lows anyway (very little from a 4" driver), but try not to lose the music. Ever try to listen to real music from the speaker of your cell phone? You can play with the capacitors if you have them, let your ears decide. You can even get creative if you wish and use a DPDT switch and be able to switch the capacitors in and out. Maybe have them in line when you are riding and maybe need slightly more volume, then be able to bypass them if you want to listen to music while the bike is parked. Or KISS...red wire to red wire........

Bruce

[PaulC]

96 Drifter. The last of the carby model. Only done 15000miles. It's my all time favourite.

[asianflava]

My only concern with adding the capacitors is that you might clip out a lot of musical information, including voice. If we assume a 4 ohm speaker impedance, a 100uf capacitor will drop your electrical output power to the speaker by 50% at 400Hz (3db down at this "crossover" point). One octave lower (6db farther down)...200Hz... you have would have 1/4 of that 50% power or about 12% of what you have at say 800-1000Hz. For reference, middle "C" on the piano is about 260Hz. You might set a lower crossover point, maybe 200Hz so as no to lose music. See Rocky's charts. This would take a 200uf capacitor (or two 100's wired parallel...they add this way). I'm not knocking Rocky's previous information because it can save some amplifier power from being wasted, but it just sounds like the frequency is too high unless you have some additional low frequency speakers, which you don't.

Yeah, 400hz is kinda high since those are the only speakers being used. That's why I said to try different sized caps to see which one he liked.

It is suprising how varied people's tastes are. For instance, I've always had soft dome tweeters. Metallic or hard dome tweeters just sound really harsh to me. Then there is the other side, people who listen to my system says that it lacks sizzle.

It's been a while but I think a cap in series is a fist order or 6db/octave crossover. A cap with an inductor in parallel is a second order or 12db/octave. Somebody correct me if I'm wrong because I'm just shooting off the top of my head and I'm being too lazy to look it up.

But yes I agree with Bruce, 400hz might be too high of a crossover point. Play around with it if you have the time though. It's part of the fun.

[Trackstriper]

If you think you need more bottom end, you can remove the cap or try a different size.

Your memory regarding crossovers serves you a lot better than my reading comprehension serves me! I find as I get older I may read something but miss some of the information that was presented.