Woofer as midrange?

[audiophileboss]

I want to build a pair of speakers. But I ordered the wrong size of something by mistake. No returns, and the size I wanted is unavailible anywhere. Could I use the woofers as midranges

[Grainger49]

The quick answer is, yes.  But it depends on the response of the driver that you bought.  Most woofers carry up into the midrange band.  Then they roll off.  So depending on the frequency range you need to cover the drivers you have may or may not cover it.

[audiophileboss]

Frequency range on these is 300-5000

[Grainger49]

If you have a graph it will help you more than a raw spec.  If they do indeed carry up to 5k Hz then you can easily crossover to a tweeter, first order, with 4uF caps (if the tweeters are 8 Ohms).

[richardl]

Frequency range on these is 300-5000

If this is true, they are midranges, not woofers.   You are fine. 

The problem with using 8" drivers and above for midranges is that their dispersion is terrible above a certain frequency and they cannot match the tweeter.