4uf vs. 4.7uf Capacitors

Hey guys,

This seems like a dumb question, but I'd like to verify just to make sure I'm not making incorrect assumptions. So today I realized one of my Mach One tweeters was silent. First thing I thought was that it somehow got fried. With some further investigating I realized the tweeter was fine, but the capacitor on the crossover must've gotten cooked, because when I bypassed it, the tweeter opened back up.

I've done the Tier 1 mods to my Machs, so the value of my tweeter cap is 4uf. My local radioshack doesn't stock 4uf, but they do stock 4.7uf. I'd normally just order them, but I literally only need 1, and the shipping is like way more then the part. I'd rather not pay a bunch in shipping for a part that's around, or less then $1. So my question is, even though there's only .7 difference in the values, will that make a huge difference in what it does? I mean, .7 doesn't seem like much to me, but I feel like I could be missing something. lol If I picked up the 4.7, I'd replace the cap in both speakers, as to keep the values symmetrical. But yeah, is there any major reason I should avoid the 4.7's as a replacement?

Thanks guys!

If you're paying less than $1 for a crossover cap, I'd suggest that you use a better cap. And the likelyhood of that 'better cap' being at Radio Shack is nil.

I can't speak to the quality of Radio Shack parts, but the last time I looked up electrolytic capacitor tolerances they were quite large. Typical values for electrolytic caps is -50% to +100%. Unless you measure them you don't know what you had or what you're buying.

Make sure they are non polar or bipolar (or film or oil type)!
.7 is 17 percent off (neglecting variations). The main disadvantages are that it lowers the xover point and increases the amount of power the tweeter has to handle. Depending on the accuracy and complexity of crossover, may throw balances off (but it could sound better but not likely). My choice would be to get two caps that add up to 4 and connect them in parallel - film types if you can find them ( 2 2uF, or 2.2uF and 1.8uF, or 3.3uF and .68uF .... or 4 1uFs. you get the picture. YMMV

A 4.7uf capacitor is really meant more as a 5uf replacement than a 4. "sregor" pretty much covered it, as your tweeter crossover point will likely drop down about 1khz if doing this. Very important using NP's in speaker crossover's, as polar's will cause distortion. As mentioned, nothing wrong paralleling two 2uf NP's to get the value your looking for.

Get four 1uF caps and put them in parallel. That will get you a 4uF value and better performance than a single cap.

Standard electrolytic caps have a tolerance of 10% however, so the value can never be exact. You may very well use a 4,7uF cap and not hear a difference.

I realize your trying to source parts locally and avoid shipping etc. However, bite the bullet and do the job right. Get TWO of THESE and do both speakers.

OverLoad said:

I realize your trying to source parts locally and avoid shipping etc. However, bite the bullet and do the job right. Get TWO of THESE and do both speakers.

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It's funny you say that. Today I remembered I needed to pick up some replacement tweeters while I was at it, so I placed an order for those, plus some Dayton caps for my speakers.

Thanks for all the recommendations guys. At least now I know what I can do in a pinch.

Also, on a side note, if you place an order for parts express through Amazon, the shipping is way cheaper. When I tallied up the order on PE, it was like $13 for shipping. So while snooping around on Amazon, I put together the same order through PE, and payed $5 for shipping. lol