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Multi-Way Conventional loudspeakers with crossovers

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Old 8th November 2012, 03:59 PM   #701
tinitus is offline tinitus  Europe
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ah, ok, yes, I forgot, passive xo components in series have a rising impedance in their stopband
but the paralel curcuits ?

whatever, I question if thats really any advantage at all, or just another annoying disadvantage
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Old 8th November 2012, 10:55 PM   #702
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Originally Posted by chris661 View Post
I'm dubious of that webpage.
10dB = x10 power.
So the distortion at 1900Hz is <0.1% (first graph), not the 2.2% they claim.
It is entirely possible, of course, that I've missed something.
Chris
I plan to try my own test. Connecting a driver through 100 Ohms is close enough to current drive and then compare with direction connection at reduced level to get the voltage across the driver the same

This should be easy enough to reproduce
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Old 8th November 2012, 11:08 PM   #703
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Originally Posted by CLS View Post

Try active on compression drivers and horn without extra cautious, hell breaks loose.
I'd be grateful if you could explain to me why this is the case.

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Originally Posted by CLS View Post
For example, HF noises and distortions of an amp can be attenuated by the passive LP section. So those only appear on the tweeters. But in an active system, they can appear on both tweeters and mids.
Yes and to my way of thinking if that is happening then the electronics needs fixing so that it is not a problem.
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Old 9th November 2012, 12:08 AM   #704
CLS is offline CLS  Taiwan
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Originally Posted by tinitus View Post
that could have been nice in some cases(many)
but can't say I have had that luck, quite the opposite
....
Hi, that quote is for a talking about the passive components between amp and drivers...

Well, I should say there're different sets of problems. Passive components help in covering up some flaws because there's some loss anyway. OTOH, they produce other problems along the way. I guess the latter is what you mentioned.



To 5th element,

Compression driver and horn combinations have more or less 110dB/w sensitivity. The best a cone driver can get is around 100. (For real bass, you need multiple drivers to get this.)

So, in a passive system consists of CD+horn and cone drivers, the best you can get is around 100db/w for the entire system (set by the lower ones). In most cases it's lower. In other words, CD+horn has to be attenuated by 10dB or more.

In a real world system, efficiency around 90 is decent already. If CD+horn joint this, the attenuation has to be increased approaching 20dB.

10~20dB difference among drivers in a speaker system is a big deal. Period.

The problems in noise floor, low level linearity of active devices, the cascade effects of them (gain structure), or even bit depth (for those dsp-based oxver)... all become obvious or intrusive in an amp-CD direct-drive combination.

----

As to whether the equipment needs fixing or not, it's actually a big question to ask, in the level of philosophy, in my way of thinking.

That reminds me of something. Once I spent some hours on my car in the basement, then came back home with the heavy tool box in my hand, exhausted.

My lovely son opened the door for me, asking "So, you got your car fixed?"

I said, "You know, a car can never be completely fixed. There's always something to be fixed. It's endless."

Same in audio.
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Old 9th November 2012, 12:25 AM   #705
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Originally Posted by CLS View Post
Passive components help in covering up some flaws because there's some loss anyway. OTOH, they produce other problems along the way.
In information transmission systems there are only signals and noise. Loss is heat and noise. So you've got components creating heat, noise, and more flaws.

Regards,

Andrew
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Old 9th November 2012, 12:58 AM   #706
Pano is offline Pano  United States
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Sure, but does it really matter?
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Old 9th November 2012, 12:58 AM   #707
CLS is offline CLS  Taiwan
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In the 'heat' portion, there'd also be some flaws from the upstream included.

Well, let's not keep on hair-splitting. The major point is in 'optimal operating range of each stage'. It's different in passive or active in many cases.
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Old 9th November 2012, 01:19 AM   #708
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Originally Posted by CLS View Post

To 5th element,

Compression driver and horn combinations have more or less 110dB/w sensitivity. The best a cone driver can get is around 100. (For real bass, you need multiple drivers to get this.)

So, in a passive system consists of CD+horn and cone drivers, the best you can get is around 100db/w for the entire system (set by the lower ones). In most cases it's lower. In other words, CD+horn has to be attenuated by 10dB or more.

In a real world system, efficiency around 90 is decent already. If CD+horn joint this, the attenuation has to be increased approaching 20dB.

10~20dB difference among drivers in a speaker system is a big deal. Period.

The problems in noise floor, low level linearity of active devices, the cascade effects of them (gain structure), or even bit depth (for those dsp-based oxver)... all become obvious or intrusive in an amp-CD direct-drive combination.
Yes, I get that, but you still haven't answered why it is an intrinsically bad idea to connect a compression driver directly to the output of an amplifier. If the whole argument is based on sensitivity mismatches and systems where the electronics are inappropriately configured or specified, then to me that isn't really a problem as per say.

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As to whether the equipment needs fixing or not, it's actually a big question to ask, in the level of philosophy, in my way of thinking.
If you've got a system that is showing unacceptable noise levels or is revealing an unacceptable level of crossover distortion in your amplification. Then, if it is possible to alter the systems design so as to overcome these problems, then yes, fixing is the appropriate term to use.
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Old 9th November 2012, 01:35 AM   #709
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Sure, but does it really matter?
Only if seeking high fidelity.
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Old 9th November 2012, 01:50 AM   #710
Pano is offline Pano  United States
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Or only if seeking an idea of high fidelity?

In reality, when you sit down in front of a pair of speakers with well engineered, well implemented crossovers and listen to some tunes - can you really tell me which is "better"? Which sounds more like music? Passive or active?
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