HI guys I have searched everywhere but can't find any straight forward explanation about how the information found in an impedance curve should be interpreted. I know that it peaks at Fs and generally rises as we go up in the frequency range but what does it mean??
What is the use of the impedance curve?
In what way can it affect the sound of your speaker ?
How does a good amplifier react to this impedance curve and what sonic anomalies can happen ??
Why is the impedance curve important ??
What is the relationship between the impedance curve and the sound or the way the speaker reacts ?? Does impedance affect the transient speed ??
Thanks for your time guys
What is the use of the impedance curve?
In what way can it affect the sound of your speaker ?
How does a good amplifier react to this impedance curve and what sonic anomalies can happen ??
Why is the impedance curve important ??
What is the relationship between the impedance curve and the sound or the way the speaker reacts ?? Does impedance affect the transient speed ??
Thanks for your time guys
The picture does not affect the sound.
The picture lets the designer see what the driver does in response to a swept sinewave.
A knowledgeable designer can infer a lot from the picture, but he/she will usually want more. A phase plot and frequency response plot along with the impedance plot are probably the minimum he will be looking at to determine if he/she wants to use that driver or keep looking for another candidate.
I suspect, the designer will want to get his/her hands on a sample before committing to a design. Then it's down to development of the filters to gets the best out of that driver.
I know I have told you nothing, but I think the point I'm making is that one needs quite a bit of skill to really use those plots.
The picture lets the designer see what the driver does in response to a swept sinewave.
A knowledgeable designer can infer a lot from the picture, but he/she will usually want more. A phase plot and frequency response plot along with the impedance plot are probably the minimum he will be looking at to determine if he/she wants to use that driver or keep looking for another candidate.
I suspect, the designer will want to get his/her hands on a sample before committing to a design. Then it's down to development of the filters to gets the best out of that driver.
I know I have told you nothing, but I think the point I'm making is that one needs quite a bit of skill to really use those plots.
Well, you have to know what those curves are in order to use your skills to do whatever you want.
could anyone can answer my questions please ?
It's always referred to the amplifier, as it represents its load .
As you know -and Andrew knows it better - the impedance
varies with frequency....and in AC phase is very important because
when giving power to the load the amplifier works with voltage i.e.
it tries to maintain it ( trough the supply rails ) and when driven hard
the current demand may cause phase rotation that may cause overload
to the power devices ----- Let's go to school
As you know -and Andrew knows it better - the impedance
varies with frequency....and in AC phase is very important because
when giving power to the load the amplifier works with voltage i.e.
it tries to maintain it ( trough the supply rails ) and when driven hard
the current demand may cause phase rotation that may cause overload
to the power devices ----- Let's go to school
The impedance curves are very important because:
- You read with their resonant frequency speaker,
- Selects the filter cutoff frequency,
- Adjusted increase in impedance due to inductance coil speaker for increasing frequency,
The more wavy characteristic impedance of the more difficult to match the appropriate amplifier. It is commonly said that the columns are difficult to drive.
Have a nice day
- You read with their resonant frequency speaker,
- Selects the filter cutoff frequency,
- Adjusted increase in impedance due to inductance coil speaker for increasing frequency,
The more wavy characteristic impedance of the more difficult to match the appropriate amplifier. It is commonly said that the columns are difficult to drive.
Have a nice day
It is in the sub forum 'fullrange' , so it is quite meaningless ( the Imp-plot)
It is when there are more drivers connected thru a crossover network
that it has to be carefully studied . For example , a solid state amplifier
which has a lowish damping factor compared to a vacuum tube equipped one,
would guarantee a more stable response in all the audio spectrum.
In a tube amplifier, where DF is dictated by transformer's output impedance,
the current and voltage would 'follow' the impedance curve , causing peaks
and dips in the frequency response -not linear.
I'm with aarvin 2. I understand the frequency range graph, but if I don't have an impedance graph, how will that affect the design of a two way speaker?
What should I do with this impedance chart if I'm building a two-way with this woofer? Visaton 9025 W170S 6.5" Woofer with Treated Paper Cone 8 Ohm 292-568
Thanks,
Mike
What should I do with this impedance chart if I'm building a two-way with this woofer? Visaton 9025 W170S 6.5" Woofer with Treated Paper Cone 8 Ohm 292-568
Thanks,
Mike
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what phase plot?
He only mentioned the impedance plot.
I don't think one can teach speaker design based on using an impedance plot.
I think the opener needs far more information thatn an impedance plot and far more knowledge than he is owning up to to design a speaker.
He can copy other speaker design/build articles/Threads.
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I think the OP and I are in the same boat: we want to design speakers, but we're working toward understanding the science behind speaker building. Building others' designs is fine, but designing one or more is what we're patiently and inquisitively after. Thanks.
Mike
indeed, also the acoustic load will make some parameters change .
Everything is depending on other factors . The most important ones are under
the Q ( quality ). Moving mass , the motor ( Electrical Q ).
For speaker design, specially in DIY when you know which is driving which,
you can keep the design easy for your amplifier .
On the other hand, you can very skilled and aim for power & control, so you can manage to power a complex load such a 3-4 way loudspeaker with your 200 W amplifier which is stable under any load .
Exactly , the other specs like Qts, Fs, waterfall plot etc , are easy to understand and it's very easy to understand how they affect the sound.
But for a full range single speaker design , what information does the Impedance graph tell me about the sound behavior of the speaker?
OK, here's a post from the Parts Express Tech Talk forum. The author, Paul Carmody, has designed some outstanding speakers: Overnight Sensations for one.
https://sites.google.com/site/undefinition/diy-faqs-driverimpedances
I think I'm seeing the impedance curve is used for designing a crossover. You would use the impedance at the crossover point to calculate your crossover. I don't think there's any point to it for a full-range single driver speaker other than it's affect on the amp.
Mike
https://sites.google.com/site/undefinition/diy-faqs-driverimpedances
I think I'm seeing the impedance curve is used for designing a crossover. You would use the impedance at the crossover point to calculate your crossover. I don't think there's any point to it for a full-range single driver speaker other than it's affect on the amp.
Mike
Sigh,,,,
You need to understand the impedance curve because even a full range will need some network to manage BSC, some eq, maybe a notch for breakup. You need to know that 8 ohm speaker is really closer to 6 where you need to do BSC, and it may be 15 Ohms where you need to add a notch. If you had a FR, and had no network on it, driven by a decent voltage amplifier, besides it not working very well, THEN it would not really matter.
The impedance curve can tell you a few other things if it is high enough resolution and not tampered with. ( many published charts fail this test) Any little glitch in it will be a point where basket reflections or breakup modes are present. One last tidbit. In a ported box, the two peaks will be the same amplitude if you got the Q correct.
It can tell you if you have a inappropriate driver with too low an impedance at any point that a crappy amp can't drive without turning into an oscillator or fuse. Handy to know that the lower the impedance of the load, the higher the distortion from the amp. Yea, those 4 ohm speakers should be used as pairs in series.
Does it tell you how it sounds? Not at all! It is information you need to know to build a speaker system with a speaker driver.
You need to understand the impedance curve because even a full range will need some network to manage BSC, some eq, maybe a notch for breakup. You need to know that 8 ohm speaker is really closer to 6 where you need to do BSC, and it may be 15 Ohms where you need to add a notch. If you had a FR, and had no network on it, driven by a decent voltage amplifier, besides it not working very well, THEN it would not really matter.
The impedance curve can tell you a few other things if it is high enough resolution and not tampered with. ( many published charts fail this test) Any little glitch in it will be a point where basket reflections or breakup modes are present. One last tidbit. In a ported box, the two peaks will be the same amplitude if you got the Q correct.
It can tell you if you have a inappropriate driver with too low an impedance at any point that a crappy amp can't drive without turning into an oscillator or fuse. Handy to know that the lower the impedance of the load, the higher the distortion from the amp. Yea, those 4 ohm speakers should be used as pairs in series.
Does it tell you how it sounds? Not at all! It is information you need to know to build a speaker system with a speaker driver.
Thanks for that info! I think that more closely answers the OP's (and mine too) questions.
Mike
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