10 Watts into a Tweeter - How Loud is that?

[jcapodieci]

Attached is a ribbon tweeter with a short term capacity of 10 Watts but exceptional characteristics. I'm always bothered that whenever tweeter specs are published the assumed operating range isn't clear. I hope that 10 Watts is the power applied in a range from 3KHz to 20KHz. If so, that should be plenty for a 20x40 ft room. All comments will be well received.
Jerry

http://www.troelsgravesen.dk/download/Raidu_planar.pdf

[Cinemadesigner X]

Re: 10 Watts into a Tweeter - How Loud is that?

30dB + tweeter sensitivity

for operating range you can use -3 point of the tweeter lf with a 12db crossover rolloff as a general reference on the speakers lower bandwidth...unless the manufacturer specifies otherwise

[Dirk]

Re: 10 Watts into a Tweeter - How Loud is that?

If you plan on crossing around 3khz, that's plenty of power handling, especially if that's RMS. You'll only be asking it to play about 2-1/2 octaves.

[Paul O]

Re: 10 Watts into a Tweeter - How Loud is that?

With a 90db sensitivity(usually that means [email protected]/1m), the maximum output this driver can achieve is about [email protected] Sound levels drops at a rate of 6db for every doubling of distance away from the driver, so that means the maximum SPL it will generate at the back of the room will be below 80db. Maximum SPL at 4m away will be 87db, probably fine for easy listening but it's certainly not party levels.

[curt_c]

Re: 10 Watts into a Tweeter - How Loud is that?

30dB + tweeter sensitivity

for operating range you can use -3 point of the tweeter lf with a 12db crossover rolloff as a general reference on the speakers lower bandwidth...unless the manufacturer specifies otherwise

Sorry, but I believe you math is off a bit, nor can you assume a tweeters natural roll off is an acceptable operating range. Besides the HP transfer function, excursion and distortion constaints at the target SPL will determine the allowable passband.

See Paul's post for a more accurate response for max SPL.

C

[JRT]

Re: 10 Watts into a Tweeter - How Loud is that?

Attached is a ribbon tweeter with a short term capacity of 10 Watts but exceptional characteristics. I'm always bothered that whenever tweeter specs are published the assumed operating range isn't clear. I hope that 10 Watts is the power applied in a range from 3KHz to 20KHz. If so, that should be plenty for a 20x40 ft room. All comments will be well received.
Jerry

http://www.troelsgravesen.dk/download/Raidu_planar.pdf

Relative to 1_Watt, 10_Watts provides +10_dB. So using the nominal 8_Ohm impedance and 90_dB sensitivty at 2.83_V (which across 8_Ohm load equals 1_Watt) at 1_meter, output would be 100_dB at 10_Watts at 1_meter.

At 4 meters that would be 88_dB.

If nominal system output level at -20_dBFS signal level is set to ~82_dB from each of a stereo pair separately at the listening position at 1_kHz, then 88_dB corresponds to -14dBFS, leaving 14_dB remaining to full scale.

Put another way, an 88_dB limit is providing only 6_dB crest factor above 82_dB nominal, 1_bit out of 16 in a CD WAV file.

IMO, that is grossly inadequate.

You can reduce the nominal level to provide more dynamic range, but reducing level also imposes significant distortion in your perception, hearing being a nonlinear process (see equal loudness contours).

[Cinemadesigner X]

Re: 10 Watts into a Tweeter - How Loud is that?

yep my math is wrong, that's what I get for posting at work

[billfitzmaurice]

Re: 10 Watts into a Tweeter - How Loud is that?

I believe everyone is overlooking the matter of power density, which falls at an average of 3dB per octave with increasing frequency. Rating a tweeter for actual power, rather than system power, is rather arcane ( the venerable EV T35 was rated 5 watts actual program, for instance) but is probably true in this case. A tweeter crossed at 3kHz at 12dB is probably adequate for a 100 watt system. Confirmation by the manufacturer would be prudent.

[curt_c]

Re: 10 Watts into a Tweeter - How Loud is that?

Attached is a ribbon tweeter with a short term capacity of 10 Watts but exceptional characteristics. I'm always bothered that whenever tweeter specs are published the assumed operating range isn't clear. I hope that 10 Watts is the power applied in a range from 3KHz to 20KHz. If so, that should be plenty for a 20x40 ft room. All comments will be well received.
Jerry

http://www.troelsgravesen.dk/download/Raidu_planar.pdf

http://sound.westhost.com/tweeters.htm#a2

C

[Hi Fi Guy]

Re: 10 Watts into a Tweeter - How Loud is that?

The distribution of power during the playback of real music is not equal at all bands. It is concentrated between 350Hz and 700Hz. Furthermore, most of the high power excursions are very brief. Most drivers can withstand many times their continous rating for brief (20ms or less) peaks.

The distribution of power for real music falls rapidly over 1000hz and even more rapidly over 3kHz. Furthermore, the tones in that region tend to be very brief. The ear is more sensitive to highs, so fragile tweeters are often quite sufficient for most loud situations.

The crossover slope is very critical. It must be sharp enough so that energy from the below-700Hz range does not get through.

Also, tweeters tend to be quite efficient -- frequently very, very efficient -- so they are padded down reducing the power needed for loud passages. The average power that actually reaches a tweeter during the reproduction of real music is actually very small.

[marlboro]

Re: 10 Watts into a Tweeter - How Loud is that?

No matter how you look at it tweeters aren't loud. They cover a range of hearing that if they were loud it would damage your ears quickly.

In my array, I have 64 tweeters(32 per channel), running on 60 watts per channel. When providing support for the mid rnages and the woofers, I would never perceive them as loud in any way. I doubt they need more than 10 watts total.

Marlboro