Tweeter selection

[newaudiofile]

Hei guys.
I'm building my first speakers. A pair of three-way speakers.

The woofer is 8 ohm, 80 watts.
Midrange is 8 ohm, 130 watts.
I have found some tweeters that i want to use.
The problem is that the wattage on them are not so much.
The first two are 15 watts: Dayton ND20FB-4 Rear-Mount 3/4", Dayton ND20FA-6 3/4",
The next two have about 50-70 watts and twice as expensiveGoldwood GT-525 1", Tang Band 25-302SH 1".
Of course since this is my first build i dont want to spend so much.
Suppose i was to use the 15 watts, is that advicesable?
Or will it be under too much stress should i be playing loud music.

Another questions is how is the wattage of a speaker calculated. Not the driver.
Is it the sum of individual drivers in the box or what?

 

[WmAx]

Hei guys.
I'm building my first speakers. A pair of three-way speakers.

The woofer is 8 ohm, 80 watts.
Midrange is 8 ohm, 130 watts.
I have found some tweeters that i want to use.
The problem is that the wattage on them are not so much.
The first two are 15 watts: Dayton ND20FB-4 Rear-Mount 3/4", Dayton ND20FA-6 3/4",
The next two have about 50-70 watts and twice as expensiveGoldwood GT-525 1", Tang Band 25-302SH 1".
Of course since this is my first build i dont want to spend so much.
Suppose i was to use the 15 watts, is that advicesable?
Or will it be under too much stress should i be playing loud music.

Another questions is how is the wattage of a speaker calculated. Not the driver.
Is it the sum of individual drivers in the box or what?

The tweeter receives much less power as compared to the other drivers. Music has a ratio of energy that is pretty much common among all genres, give or take a few dBs, with the main deviation being in the low bass. For treble over about 4kHz, you can count on the the power being on average, about 8-10dB less as compared to the mid-bass spectrum of music. This means that a 10 watt tweeter is appropriate to match with a 60-100 watt mid-bass, assuming both have an identical in-box sensitivity. In reality, the sensitivity of the tweeter is usually higher than the mid-bass, this requiring even less power ability from the tweeter. The real key to a tweeter handling power is designing the crossover such as to prevent the tweeter from exceeding it's mechanical limits of excursion and using an amplifier with enough power that it will not operate into clipping/distortion very often. Clipping an amplifier surges high amounts of treble energy into the tweeter, thus increasing the chance of driver failure by a substantial amount. The Dayton tweeters you listed above are very nice, actually, despite the super low price. But they should be crossed with a steep rate xover no lower than about 3.5-4kHz in order to have low distortion and high SPL ability.

-Chris

 

[newaudiofile]

Thanks Chris,
I really do like the first tweeter. I think it will make my design look good too. I have also been been planning on crossing it at 3500 Hz, with a second-order crossover butterworth circuit. Assuming my midrange can handle up to that frequecy.What do you think? Is that steep enough?

My midrange drivers are from my current centre speaker. i have to open it and calculate the two-way crossover design.