I am new in this, I'm planning to do a DIY Center Speaker for my Yamaha A-2070, if I have a mid-range driver with 80-100 watts @ 8 Ohms, how many watts will I need for my Tweeter in a two way set up, will it be the same as the Midrange driver or less.
Things work better if the center speaker's sound qualities are similar to the front left & right speakers. Please tell us what speakers you have.
For movies and TV, a center speaker's main job is dialog. It must reproduce human voices clearly. Exaggerated bass, preferred by many in music, does bad things to male voices. At higher frequencies (upper mid-range or lower treble), the human voice can be muted or unclear if a speaker's response drops. This could easily be in the range where a mid-range driver is crossed over to a tweeter. Very often a poorly designed crossover can create such drops.
A good center channel speaker should also be able to spread those upper mid-range frequencies widely. They should be dispersed in a wide pattern as opposed to being beamed in a narrow pattern. If a center speaker has a narrower dispersion pattern than the left & right speakers, there will be a 'hole in the middle' of the sound across the front. This is especially noticed if there is motion panning across the front three speakers.
Isn't this about the point where TLS Guy comes in with his post about matched speaker design: matching tweeters to drivers to crossovers? Any other approach is doomed to failure. TLS Guy may be on vacation and I miss his consistent and informative approaches to queries like this.
I'm not TLS Guy, but I've been known to deliver similar messages about DIY to eager newbies. I don't want to discourage Francis JEncar's enthusiasm, but I also want his efforts to have good results. And good results take a lot more than a circle saw, a Parts Express catalog, and some enthusiasm.
The power rating of a driver, such as the 80-100 watts at 8 ohms that you mentioned, doesn't mean much. More often than not, it refers to the power level at which the driver suffers thermal failure. Usually the glue attaching the voice coil to the cone breaks down with enough heat. It tells you nothing about the sound quality of the driver.
It would be better to know how loud (in decibels, db) a driver is when driven by 1 watt, when the measurement is taken 1 meter away – this is called driver sensitivity. It is nice, but not absolutely necessary to have a mid-range and tweeter with similar sensitivities. And again, knowing the sensitivity tells you nothing about the sound quality of the driver.
But you did say you are new at this, and your question is clearly a new guy's question. So I won't go further into DIY speaker design principles until we hear back from you.
You might be better off with a DIY kit, as Mr. Boat suggested. But to choose a kit you have to know what front left & right speakers you have and have an idea what their sound qualities are.
