League For High Efficiency Loudspeakers

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#163
billshurv said:
It's there in the rod elliott article to be read. Read it then ask questions rather than just dismissing a carefully written article from someone who does this stuff for a living.
Out of your depth in an active vs passive discussion and unable to do some basic research on google.

Because so far you are the only one to dismiss Elliott as wrong. Try reading it again and asking considered questions. You'll be amazed the knowledge on here. but I will admit the ignorance can also be astounding at times if you fall into the wrong thread.
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OK I am out of my depth, please explain to me the relevance of BSC in the context of passive vs active implementation.

You seem to be more informed about such things.
 
#164
picowallspeaker said:
Hi, there was a little error: active means that the amplifier is within the speaker cabinet (no good) and you just plug your line level signal.
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This is wrong.
Active means line level crossover and one amp channel per driver.
It does not matter where amp and electronics are housed.

If you look at the Genelec range, who make nothing but active monitors, you'll find that for smaller speakers the amps are indeed in the speaker cab but their larger active main monitors house the amps in 19" racks outside of the speaker cab.
The same is true for the larger active ATCs, Quested or PMC monitors.
 
#166
AndrewT said:
Your misused/misquoted graph does not appear to stop at 40Hz.
It shows highest power (closest to 0dB) at the left axis.
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Are you just picking on me?
Music is mostly from 40Hz (debatable) .
The graph has a factor of 100 for the frequency axis, please understand that.
At lower frequencies squished together to the left, the highest level is marked as 0dB so that one could get a representative of the music power distribution.
That's how graphs are.
It is not misquoted or misused, that's your take on it.
that graph is very relevant.
 
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#167
Charles Darwin said:
This is wrong.
Active means line level crossover and one amp channel per driver.
It does not matter where amp and electronics are housed.

If you look at the Genelec range, who make nothing but active monitors, you'll find that for smaller speakers the amps are indeed in the speaker cab but their larger active main monitors house the amps in 19" racks outside of the speaker cab.
The same is true for the larger active ATCs, Quested or PMC monitors.
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Charles you are correct.
However, there has been a flood of new so called 'near field studio monitors' made for home recording, that are actually passive speakers with an amplifier builtin the enclosure - they are wrongfully referred to as Active! when they should be called Powered.
You and I know they are not, but they are selling them as such, and I believe this is the source of confusion.
I could be wrong.
 
#172
KenTajalli said:
OK I am out of my depth, please explain to me the relevance of BSC in the context of passive vs active implementation.
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Baffle step corrects for low frequency roll off where the wavelength>> baffle width. You want to boost LF by 2-4dB. With a passive system you cannot boost, you can only cut. So to get (say) 3dB BSC you have to attenuate everything above the baffle step frequency. BUT you still have to amplify it as if there is no correction. So you are throwing away power. In an active setup you deal with BSC with the driver that needs it and handle the boost in the crossover before the amplifiers. So you get stacked gains.

Now there are other ways to skin the BSC cat. For example a 2.5Way. Zaph|Audio Whilst not quite efficient enough to quite join the club is a solid 90dB/W and, due to some good design choices (and possibly some luck) has very little loss in the crossover. 100W would go a very long way with that speaker.
 
#174
billshurv said:
Baffle step corrects for low frequency roll off where the wavelength>> baffle width. You want to boost LF by 2-4dB. With a passive system you cannot boost, you can only cut. So to get (say) 3dB BSC you have to attenuate everything above the baffle step frequency. BUT you still have to amplify it as if there is no correction. So you are throwing away power. In an active setup you deal with BSC with the driver that needs it and handle the boost in the crossover before the amplifiers. So you get stacked gains.

Now there are other ways to skin the BSC cat. For example a 2.5Way. Zaph|Audio Whilst not quite efficient enough to quite join the club is a solid 90dB/W and, due to some good design choices (and possibly some luck) has very little loss in the crossover. 100W would go a very long way with that speaker.
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Not a bad explanation, thank you.
So both passive and active systems, seem to leave the lower frequencies at their original level, but because of BSC they have to reduce the higher frequencies in order to compensate, right?
Since (through mathematics! reply #159) it has been shown,
that you need more power to generate lower frequencies,
BSC dictates more power is needed for lower frequencies,
and human ear deficiencies dictate more power for lower frequencies,
would you accept that these are foundations to correctly state that:
You need more power at lower frequencies?
And that is what I have been saying, a 400W passive system, would have almost all of its 400W available for bass (and not as much for higher frequencies),
but an active system with just 100W for bass amplification, has only 100W.
It can not possibly go louder on music than a 400W (all else being equal).
 
#175
Hiten said:
I am not buying anything. It is a genuine question, so I discarded the active and wattage criteria to avoid confusion and to be on topic of the thread.
Regards.
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if you are genuinely asking, search for GOTO drivers. Some claim 106 dB/w/m, and cost about $15k...

I have seen system on internet, when compression driver designed for low frequencies with horn size of the pickup truck was used, no idea about efficiency, but most likely even higher then cone drivers
 
#177
KenTajalli said:
And that is what I have been saying, a 400W passive system, would have almost all of its 400W available for bass (and not as much for higher frequencies),
but an active system with just 100W for bass amplification, has only 100W.
It can not possibly go louder on music than a 400W (all else being equal).
Click to expand...

If you listen to single tones your argument holds (as pointed out by Rod in his article, which you clearly haven't properly read or you would have quoted that section). Generally most of us listen to music. With music the 1+1=4 holds as music is (shock horror), many tones across many octaves.
 
#179
There's definitely something to be said for peak voltage suppression by removing the "riding" HF from the LF spectrum, though the 400W equating to 100+100 is an overstatement of the reality. As Ken says, music spectrum is more like pink noise, and the biggest peaks are typically in the bass.
 
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