Bear your post shows that you are looking for the Zobel to improve your sound. Just "trying" it means you expect it.
That puts you into the category of expecting a Zobel to give something for nothing, when the science says the opposite.
The Zobel can only give a measurable effect when it forms part of a filter. It needs to have another impedance against which it reacts to create that filter.
In an active drive situation the output impedance of the amplifier and the parasitic impedance of the cable are tiny in comparison to a Zobel at Audio Frequencies and thus cannot give big effects.
You are projecting your own thoughts.
I have no such expectation.
Historically, the Zobel has been espoused as being "of benefit". This is "in the literature". You ought to know this.
I am merely conveying my experience in terms of listening.
You can say over and over what can and can't be - but unless you actually take the time try this yourself, over time, and in a variety of situations you are only speaking in academic terms.
Of course if the listener has limited HF range to his/her hearing then truly all amplifiers, cables, tweeters, zobels, etc. start to converge very strongly.
_-_-
Hi there Bear. Just to clarify, .....your statement above is in relation to your active systems with the driver connected directly to the amp, yes?
Cheers, Kimbo
If I've seen it in the literature, it is more to describe it as a tool that may be useful, and that is true: there are times when a Zobel will help you shape response a little better than if not used.
What I object to is the novices that then assume that a Zobel is a great thing and need to be used every time. This is the same as those that think they need to add baffle step correction as a distinct network section in every system.
It is silly.
A Zobel is a tool that may or may not be needed. It doesn't improve sound other than as it helps to shape response. There may be other ways to achieve the same response and they should ultimately sound the same.
I have been fortunate to work with a lot of brilliant engineers and none of them get hung up on topology. You specify the target you want your driver section to measure like. You measure the driver. You divide one by the other and that defines the filter. At that point you consider what topology most efficiently fits the target shape.
Zobels seldom figure into that approach.
David
No.
Most systems, even today are not multi-amped with active xovers.
Most speakers made DIY or commercial are not active speakers.
So, most of my experience is not with active systems.
My view is that now in 2014 it may be possible to make active xovers that are sufficiently, ummm... "transparent".
I know that DSP based xover/correction is "hot" right now, but even recently these things just did not sound quite right to me, perhaps that is or has changed. I'm open to it, and would be very happy to find that they are - that would solve a range of issues that can not be fixed as a group otherwise (as you doubtless know).
Perhaps it is worth addressing this group of issues via DSP even if one gives up something else. It's the nature of what we are doing, there are compromises with everything.
_-_-
OK...that clears that up then. My original post (and title of the topic) refers specifically to Active systems. So when you say....
Then of course that is correct....in relation to passive systems. In other words, in a system with a passive crossover, adding more elements such as a Zobel changes the response. I'd be amazed if it didn't.
Cheers, Kimbo
Then of course that is correct....in relation to passive systems. In other words, in a system with a passive crossover, adding more elements such as a Zobel changes the response. I'd be amazed if it didn't.
Cheers, Kimbo
You should have made it clear you were discussing a different loading situation.
We were discussing active drive.
Your comments on crossover type drive are pointless, since they are off topic.
No, but Peter very kindly did in post #51 and his approach to the test was more rigourous than I would have done. Academically I couldn't see that there'd be an issue and Peter's test then demonstrated the same, for which I am very grateful. Thanks Peter!
Measurements are one aspect.
Listening is another.
I'd not count on measurements to reveal if something is or is not actually audible. They may give a good indication.
Also, I'd not rely upon what I heard with a mid range performance system to be dispositive of the matter.
Again, it may actually have no audible effect, but I rather doubt that in practice this is the case.
Listening is another.
I'd not count on measurements to reveal if something is or is not actually audible. They may give a good indication.
Also, I'd not rely upon what I heard with a mid range performance system to be dispositive of the matter.
Again, it may actually have no audible effect, but I rather doubt that in practice this is the case.
^^ That wasn't my point. Any 'DC' and I would argue it's not DC as the level varies and is transient in nature, is low unless the clipping is severe and if you're not a fool and abusing your system it shouldn't happen often. It certainly should not be the cause of death of a healthy tweet.
At least once a week I read someone on a forum somewhere pointing to the flattened top of a waveform and saying it's DC when it's not.
At least once a week I read someone on a forum somewhere pointing to the flattened top of a waveform and saying it's DC when it's not.
Wasn't what I said....
May have missed a punctuation mark, but offset and clipping are two conditions that a cap protects a tweeter from.
Clipping peaks are not DC, but to a voice coil for small periods of time, actually have a very similar effects. Some can take it, most tweeters cannot.
This does not apply just to active systems.
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No, it can't.
Severe clipping turns a sine into a square wave and a square wave contains all odd-order harmonics at full level which stresses tweeters sometimes beyond their capabilities.
So basically clipping creates high levels of high frequency harmonics which were not present in the original waveform and which may fry tweeters in the long term. A cap will not protect a tweeter from that.
except in the case of an amplifier, clipping IS DC. The amp is not capable of producing beyond its bandwidth to begin with. But clipping represents the output devices saturated in the "on" condition, and essentially allowing the power supply rail(s) to flow directly to the output terminals; DC.
The fact that clipping is likely to be of short duration (a flat topped waveform corresponding to the input frequency) and swinging from the plus to the minus rail does not change what it is.
The Fourier description of a square wave - the harmonics - simply does not take place in reality, in this situation.
So, it is not "DC" in the sense that a battery has been connected to the tweeter continuously, but it is actually DC in as much as there are no harmonics creating the signal, or being sent to the tweeter. The leading and trailing edge, however does look like a high frequency...
The fact that clipping is likely to be of short duration (a flat topped waveform corresponding to the input frequency) and swinging from the plus to the minus rail does not change what it is.
The Fourier description of a square wave - the harmonics - simply does not take place in reality, in this situation.
So, it is not "DC" in the sense that a battery has been connected to the tweeter continuously, but it is actually DC in as much as there are no harmonics creating the signal, or being sent to the tweeter. The leading and trailing edge, however does look like a high frequency...
Yes, but I wasn't talking about sine waves. I specifically referred to asymmetrical waveforms. When they are clipped, there can be a DC component on the output, in addition to the AC.
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