League For High Efficiency Loudspeakers

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#143
KenTajalli said:
I give up!
excuses after excuses.
ATC can not design any loudspeaker with proper driver sensitivity matching.
Neither can Meridian.
Click to expand...

Uhm...

You don't HAVE to match sensitivities in an active system, it's one of the big advantages. You can have high efficiency where it doesn't influence box size, and less efficient bass drivers while keeping a reasonable enclosure volume.

Of course, I prefer unreasonably large enclosures, but hey, that's me 🙂
 
#144
badman said:
Uhm...

You don't HAVE to match sensitivities in an active system, it's one of the big advantages.
Click to expand...
but you do in passive systems, right?
ATC makes active and passive versions of most of their range, in hifi and pro studio monitors.
Linn used to do the same.
I am sure there are others too.
I take it that their treble drivers too, are more sensitive than their midrange.
And laws of physics has nothing to do with anything, it takes the same power to move a heavy bass driver diaphragm in a visible way compared to a few grams of a dome tweeter diaphragm!?!
And a little triangle bell is not as loud as a large cello in an orchestra.
I could go on, but enough.
 
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#145
KenTajalli said:
but you do in passive systems, right?
ATC makes active and passive versions of most of their range, in hifi and pro studio monitors.
Linn used to do the same.
I am sure there are others too.
I take it that their treble drivers too, are more sensitive than their midrange.
And laws of physics has nothing to do with anything, it takes the same power to move a heavy bass driver diaphragm in a visible way compared to a few grams of a dome tweeter diaphragm!?!
And a little triangle bell is not as loud as a large cello in an orchestra.
I could go on, but enough.
Click to expand...

You don't seem to be putting things together. The mids/tweeters are likely padded in their active systems, pads which could be eliminated in an active system.

Not sure what you're talking about with the comparisons to instruments... they really don't apply to what I'm saying?
 
#146
badman;452698 Not sure what you're talking about with the comparisons to instruments... they really don't apply to what I'm saying?[/QUOTE said:
Imagine you are sat in a concert hall towards the back.
The cellos are at the front row, while the percussionist is at the back row, furthest from you.
The percussionist picks up his little bell triangle and taps it gently with the hammer, you hear it well at a certain loudness, now the cellist is playing a few bars, how much energy should he exert to get the same loudness at your position, more than the percussionist or less?
Of course a lot more, even though a cello is acoustically loaded.
Reason is our ears are more sensitive in 'a few kHz ' compared to few hundred Hz.
The lower the frequency, the less sensitve we are.
Add to that the laws of physics that dictates that more energy is needed to move enough air mass to create lower frequencies.
Hence my argument that more watts are needed in bass frequencies compared to mid and high.
Some people disagree, stating you need the same.
That's the basis of our disagreement.
Click to expand...
 
#149
KenTajalli said:
Hence my argument that more watts are needed in bass frequencies compared to mid and high.
Some people disagree, stating you need the same.
That's the basis of our disagreement.
Click to expand...

Not an argument, more an unfounded assertion that a bit of maths might sort out. FWIW when I have finished the current round of mods on my speakers above 400Hz will be about 10dB less sensitive than below.

Given only two pages ago you had to have baffle step correction explained to you that might be a hint you are at a disadvantage against some of those here who know what they are talking about. Look at it as an opportunity to learn rather than to butt heads! I always do.
 
#150
billshurv said:
Not an argument, more an unfounded assertion that a bit of maths might sort out. FWIW when I have finished the current round of mods on my speakers above 400Hz will be about 10dB less sensitive than below.

Given only two pages ago you had to have baffle step correction explained to you that might be a hint you are at a disadvantage against some of those here who know what they are talking about. Look at it as an opportunity to learn rather than to butt heads! I always do.
Click to expand...
Show me the math. I like to learn always.
Not knowing an abbreviation is a sign of what?

So far I have seen no explanation fro my peers! As to why I am wrong, just claims.
 
#151
Gents, unless you run your speakers and amps to the limit, the argument is really irrelevant. I use few hundred milliwatts at normal listenig level. So it does not matter if I have twice as much watts in bass section or not.

Btw I just got me older B&C 12" coaxials...12CXT or like that...with 98 dBwm in lf and 102 dBwm in tweeter. So, what should I make with these?
I do have some 12" and 15" woofers as well...I smell a project comming.
 
#152
Hopefully this will help (we'll stick with amplifier wattage and say they're all matched impedance wise)--no intent at disparaging!

Let's work out this simple problem:

88 dB into 1 W woofer crosses over to a
94 dB into 1 W midrange which crosses over into a
100 dB into 1 W tweeter.

In a passive system you would need to pad the tweeter by 12 dB and the midrange by 6 in order to flatten the sensitivity curve?

Alternatively, to play at 100 dB, you need:
4 watts into your woofer
2 watts into your midrange
1 watt into your tweeter

Setting the respective gains appropriately on each of these 3 drivers will do the trick. (Remember your V^2/R terms and you can back-track it to input sensitivity!)
 
#153
KenTajalli said:
Show me the math. I like to learn always.
Click to expand...

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.
Not knowing an abbreviation is a sign of what?
Click to expand...
Out of your depth in an active vs passive discussion and unable to do some basic research on google.
So far I have seen no explanation fro my peers! As to why I am wrong, just claims.
Click to expand...
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.
 
#154
adason said:
Gents, unless you run your speakers and amps to the limit, the argument is really irrelevant. I use few hundred milliwatts at normal listenig level. So it does not matter if I have twice as much watts in bass section or not.
Click to expand...

Well, there is the 'hybrid' case of a highish sensitivity full range in open baffle requiring a woofer to unload it from the grunt work - the full range being powered by a fleawatt amp and the woofer with something more manly.
 
#155
I hope this newbie question is not offtopic. But can anyone give a 2 way (Tweeter+woofer) linear response speaker driver choices for lets say active crossover amplification by again lets say 'AmpCamp' amplifier which would not distort and clip at 85dB SPL*. (* an approximate figure just to discuss driver choices)
To put it simply in other words which drivers would be appropriate for a 5 watt amplifier which would give linear response and as much lower extension as possible.
Thanks and regards.
 
#157
Sorry for that. So if we set out to make active system with two amplifiers of 5 watt each for two channels (i.e. total four amplifiers) what driver would be suitable for that. Tweeter I guess would be ok with 5 Watt amp. But which woofer driver/s would be a good candidate ?
Regards
 
#158
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.
Active two-way means that the signal must be splitted in two bands by the means of an electronic crossover ( be it either active or passive ) and then sent to the amplifiers.
So you need that thingy (the electronic crossover )

😡

If you want to enter into Adason's league go ahead
and make your own thread 😛
BTW yesterday I made another rhyme : Fresh from the trash :spin:

The reason why 5 W are not enough for hifi is that music peaks demand power ten times more, so 50 W...
If you owned a 50 Watt amplifier, some folks might say that it's not sufficient and 150-200 W would be the optimum, and so on...

So often you'll find that for 5 W ( called flea-power amps, go figure )
the speakers used would need to be very efficient ( trasformation from electrical power to acoustical ) and a parameter for high efficiency is Sd ( the surface area of the cone) which will lend you to 15 " inch woofers having 98 dB efficiency and tweeters...well, oh, tweeters 🙄

I would stay in a more comfortable zone of 5-6 " woofers which obviously would exhibit much lower efficiency

Disclaimer: I play in all leagues, to each his own ...
 
#159
KenTajalli said:
The lower the frequency, the less sensitive we are.
Add to that the laws of physics that dictates that more energy is needed to move enough air mass to create lower frequencies.
Hence my argument that more watts are needed in bass frequencies compared to mid and high.
Some people disagree, stating you need the same.
That's the basis of our disagreement.
Click to expand...

Bill, Ken is right (if ‘laws of physics’ is the point of disagreement 🙂)
Lamda is at the denominator
Acoustic Sources - DiracDelta Science & Engineering Encyclopedia

George
 

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