gorgon53,
I expect there are examples of successful 2-way and 3-way speaker systems that use 6dB/octave crossovers.
There might be some on diyAudio.
But if not, I bet there are some successful commercial designs.
If there is such a thing as a good full range single driver speaker, then 2 and 3 way with 6 dB crossovers limiting the signal frequencies that reach each driver should be possible too.
6 dB/octave crossover; suppose the signal is 1 Watt:
- 3dB at crossover (0.500 Watt) 500 milliwatts
-9 dB one octave away (0.125 Watt) 125 milliwatts
-15dB two octaves away (0.0316 Watts) 31.6 milliwatts
-21dB three octaves away (0.00794 Watts) 7.94 milliwatts
Part of the issue of any driver is how much power it can take before distortion, even if the signal frequencies are in the drivers rated frequency range.
I am not an expert about speakers.
Just my opinions
I expect there are examples of successful 2-way and 3-way speaker systems that use 6dB/octave crossovers.
There might be some on diyAudio.
But if not, I bet there are some successful commercial designs.
If there is such a thing as a good full range single driver speaker, then 2 and 3 way with 6 dB crossovers limiting the signal frequencies that reach each driver should be possible too.
6 dB/octave crossover; suppose the signal is 1 Watt:
- 3dB at crossover (0.500 Watt) 500 milliwatts
-9 dB one octave away (0.125 Watt) 125 milliwatts
-15dB two octaves away (0.0316 Watts) 31.6 milliwatts
-21dB three octaves away (0.00794 Watts) 7.94 milliwatts
Part of the issue of any driver is how much power it can take before distortion, even if the signal frequencies are in the drivers rated frequency range.
I am not an expert about speakers.
Just my opinions
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Hi, I am no expert either when it comes to speakers, but you do not have to be an expert to understand that the amplitude of the membran movement INCREASES as the frequency goes down. Thinck about that, do you really want to keep the membran movement at max amplitude all the way down to the lowest frequency? And, do you really want all the IM distortion that follows from it?
I have lots of speakers.
One is a 2-way speaker with no inductor for the woofer, and a 2uF cap for the 8 Ohm tweeter.
2uF is 8 Ohms at 10,000Hz.
The capacitor is the only part that reduces the drive to the tweeter, there is no series resistor.
10k -3dB; 5k -9dB; 2.5k -15dB; 1.25k -21dB; 625Hz -27dB
-27 dB is 1/500 power; 25 Watts x 1/500 = is 50milliwatts.
Most of the time, I listen near field (2 to 2.5 feet from speaker to ear), at less than 1 Watt total power to the speaker.
A 625Hz music tone from a solo instrument: 1 Watt / 500 is 2milliwatts to the tweeter.
My hearing is not what it used to be. But I have not noticed any intermoduation of bass and upper bass affecting the sound of the tweeter.
The tweeter has a closed back.
That seems similar to an acoustic suspension woofer in a closed box.
At frequencies below the resonance, the cone excursion actually becomes less (it does not increase).
Perhaps you are thinking of a woofer that is in a port loaded enclosure.
Below the port frequency, the cone excursion actually increases (the cone becomes un-loaded below the port resonance).
One is a 2-way speaker with no inductor for the woofer, and a 2uF cap for the 8 Ohm tweeter.
2uF is 8 Ohms at 10,000Hz.
The capacitor is the only part that reduces the drive to the tweeter, there is no series resistor.
10k -3dB; 5k -9dB; 2.5k -15dB; 1.25k -21dB; 625Hz -27dB
-27 dB is 1/500 power; 25 Watts x 1/500 = is 50milliwatts.
Most of the time, I listen near field (2 to 2.5 feet from speaker to ear), at less than 1 Watt total power to the speaker.
A 625Hz music tone from a solo instrument: 1 Watt / 500 is 2milliwatts to the tweeter.
My hearing is not what it used to be. But I have not noticed any intermoduation of bass and upper bass affecting the sound of the tweeter.
The tweeter has a closed back.
That seems similar to an acoustic suspension woofer in a closed box.
At frequencies below the resonance, the cone excursion actually becomes less (it does not increase).
Perhaps you are thinking of a woofer that is in a port loaded enclosure.
Below the port frequency, the cone excursion actually increases (the cone becomes un-loaded below the port resonance).
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Hi, as to your tweeter fed from an amp trough the cap. I assume the resonace frequency of that speaker is far below the electrical x over and out of reach for any electrical damping from the amplifier. If so, the speaker damping relies on mechanical damping. The closed back provides an additional 6db/octave attenuation, but membran amplitude will be smaller only below that speaker resonance because then your slope will be 12db/octave. In the range from resonce to actual crossover frequency your speakermembran amplitude will stay unnecessary high with all the good and evil associated with that. As to not hearing IM distortion, propable neither would I, but that does not do away with the fact that with a higher order filter there would even be less of it. Ported enclosure, no, actually this how many db/octave thingy got may attention many years ago after demolishing a compression driver that was mounted to really big horn. Closer inspection showed the damage was done do to not using high enough attenuation. 500Hz 12db/octave crossover was not enough despite 220Hz horn cutoff and driver resonance around 400Hz. Well, I should have known better, I heard something is not right long before, but did not expect to rip the membran apart. Lesson learned, a new membran now combined with a active 24db Linkwitz Riley filter/amp combo solved the problem.
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Wow - and you only shredded one set of diaphragms? I'm impressed. I have a whole shoebox full of LE85 diaphragms to prove my willful ignorance! 😉
If a really low power amplifier (2 Watts for example) shreds tweeter diaphragms, perhaps there is something wrong with the Hi Fi / Stereo system, or how it is used.
1. Playing the amplifier into constant clipping.
2. Playing continuous sine waves at full power, and playing sweeps at or near the driver resonance, or at frequencies where the driver does not have an acoustic load, but still has significant signal power applied.
3. Playing too loud for near field listening.
4. Unusual modern art recordings, not usual music; highly compressed music.
5. Playing at sound levels so that ears that are bad because of playing music loud enough to destroy hearing.
6. Other possible causes of diaphragm shreding?
Not all Hi Fi / Stereo systems are played the same way.
Just my opinions
1. Playing the amplifier into constant clipping.
2. Playing continuous sine waves at full power, and playing sweeps at or near the driver resonance, or at frequencies where the driver does not have an acoustic load, but still has significant signal power applied.
3. Playing too loud for near field listening.
4. Unusual modern art recordings, not usual music; highly compressed music.
5. Playing at sound levels so that ears that are bad because of playing music loud enough to destroy hearing.
6. Other possible causes of diaphragm shreding?
Not all Hi Fi / Stereo systems are played the same way.
Just my opinions
I believe the important issue overlooked in this discussions is distortion caused by speaker crossover components. The steeper the crossover slope, the more capacitors and inductors. These components are not benign, they introduce coloration. If I avoid using even a single coupling capacitor in my amplifier, the pileup of capacitors in a crossover is like blasphemy. I am not even touching on the subject of rollercoaster phase shifts.
Burning tweeters? Never had this problem. It is likely due to pub level sound pressures vith very inefficient tweeters. Like 6A3sUMMER, I listen to my music at comfortable 70-80 dB levels. My tweeters are 93 dB efficient and crossed well above their 200 Hz bottom end.
Burning tweeters? Never had this problem. It is likely due to pub level sound pressures vith very inefficient tweeters. Like 6A3sUMMER, I listen to my music at comfortable 70-80 dB levels. My tweeters are 93 dB efficient and crossed well above their 200 Hz bottom end.
Blowed mine, a jbl 1" compression driver outdoors, and yes at high level. Aluminium membran surround broke do to too large membran movement propably, did not happen again after changing Xo from 12 to 24db/octave. An other choice would have been to rise the Xo frequecy but i did not do that because easy implemented active Linkwitz/Riley took care of the problem and the really heavy woover membran is better to cross at as low a frequency as possible.
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Yes, but if the speaker is designed as a unit, the end result take into account the extra parts - at least that's what most Canadian speaker companies do. My Energy speakers were tested in collab with the National Research Council of Canada in their anechoic chamber.
Here's some data: https://www.soundandvision.com/cont...ur-rc-70-surround-speaker-system-measurements