Hi,
Tried idea on VituixCAD to use series notch filter on tweeter for pretty high frequency ~11.5-12.5kHz, Q of ~0.8 to ~1.4. All the frequencies and Q between kinda work and give good results on perceived sound quality, graphs are better too. With that notch filter I can get away only with capacitors in the path between tweeter and amp, no resistors are needed, no additional L-pad. Sensitivity looks more or less the same with "side" filter vs inline resistor. Graphs differ, but nothing out of the ordinary.
Tweeter is dome fabric, 25mm, crossover freq is ~2.4kHz, tweeter Fs is 1500Hz, 8Ohm. The setup that interests me is 3rd order + notch explained above,
In the animated gif there are 3 examples:
"R1" 3rd order and resistor in front - 1 side bypass route
"R2" 4th order and resistor in front - 2 side bypass routes
"R5" 3rd order and series notch after - 2 side bypass routes
The questions are:
1. What is the extra purpose of resistor in line with tweeter except for reducing the sensitivity: General improved sound quality - can it be measured or/and heard? Filtering of some unwanted hissing? Some protection vs amp clipping or some artefacts coming from source such as accidentally disconnected wire, power loss and so on?
2. If it is recommended to do this - can I get away with some "dummy" of 0.1-0.5 Ohm or more is needed?
All 3 variants attached, but the first two are just similar xover, with 3rd or 4th order crossover.
Tried idea on VituixCAD to use series notch filter on tweeter for pretty high frequency ~11.5-12.5kHz, Q of ~0.8 to ~1.4. All the frequencies and Q between kinda work and give good results on perceived sound quality, graphs are better too. With that notch filter I can get away only with capacitors in the path between tweeter and amp, no resistors are needed, no additional L-pad. Sensitivity looks more or less the same with "side" filter vs inline resistor. Graphs differ, but nothing out of the ordinary.
Tweeter is dome fabric, 25mm, crossover freq is ~2.4kHz, tweeter Fs is 1500Hz, 8Ohm. The setup that interests me is 3rd order + notch explained above,
In the animated gif there are 3 examples:
"R1" 3rd order and resistor in front - 1 side bypass route
"R2" 4th order and resistor in front - 2 side bypass routes
"R5" 3rd order and series notch after - 2 side bypass routes
The questions are:
1. What is the extra purpose of resistor in line with tweeter except for reducing the sensitivity: General improved sound quality - can it be measured or/and heard? Filtering of some unwanted hissing? Some protection vs amp clipping or some artefacts coming from source such as accidentally disconnected wire, power loss and so on?
2. If it is recommended to do this - can I get away with some "dummy" of 0.1-0.5 Ohm or more is needed?
All 3 variants attached, but the first two are just similar xover, with 3rd or 4th order crossover.
Attachments
In the "R5" filter I do not need it. And it sounds best.
And in any case I have at least 2 in line with tweeter.
All the parts in the XO is in the signal path.. everything in your schematic is between the tweeter and amp.
Your amp is feeding the drivers alternating current.
The notch filters are connected in paralell between 'negative' and 'positive', before the tweeter.
AC is sinusodial.
The notch filter alters the tweeters behavior, which would be impossible if the components were not in the signal path.
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Some find this a problem with a purely active filter, and it doesn't matter if they change it since they can compensate with EQ. In your case your value of resistance is determined by the need to match levels so if you have a problem with hiss you'll have to approach it in the context of the system.
Essentially no, but the resistor does make a difference as seen in the simulation, and that difference can be measured or heard.
No. Strictly passive system. At it simulates best without resistor in series with tweeter.
This is tricky question, it is a little bit of a language barrier to formulate it.
I am asking more if the resistor in series has something more to do that just reduce sensitivity. I am not into audiopholery and not into esoteric stuff - it is more of a question if there is another extra difference than reduced SPL?
That is true. I like your answer. But parallel stuff I see more like a "shunt".
My idea is that stuff in series with tweeter have more impact. And the question is if that impact (of a resistor) gives smth more than reduced SPL of the signal. It is more of practical experience.
The resistor changes the response. Mostly it reduces the response but the effect can be different at different frequencies. If you know the response you are trying to create, you can do whatever you need to make it happen.
No they aren’t. Some of them are shunts to ground.
No they aren’t, they are a combination of series and parallel elements, and AC doesn’t have positive and negative terminals.
The word is ‘sinusoidal’, and although sine waves are AC, not all AC is sinusoids. Music, for example.
@ejp , @AllenB It is hard to express myself... I try to reformulate my question:
Does the series R1 resistor, which is of 5.6Ohm, have any other effect or purpose to the tweeter except reducing its SPL? Any extra protection? Some filtering or other signal alteration, which is of some value or detrimental to the system sound?
Does the series R1 resistor, which is of 5.6Ohm, have any other effect or purpose to the tweeter except reducing its SPL? Any extra protection? Some filtering or other signal alteration, which is of some value or detrimental to the system sound?
I had the same experience a few weeks ago.
Adding a resistor in series with the tweeter dramatically lowered the sound quality.
The solution for me was to add a resistor in parallel instead. This didn't affect the sound other than lowering the SPL.
Perhaps a higher-quality resistor would have helped, but I didn't try it.
Adding a resistor in series with the tweeter dramatically lowered the sound quality.
The solution for me was to add a resistor in parallel instead. This didn't affect the sound other than lowering the SPL.
Perhaps a higher-quality resistor would have helped, but I didn't try it.
Please elaborate -- I don't see why (just) a parallel resistor would attenuate the tweeter. Appreciated.
Yes it can have. If it's a small enough Wattage resistor, it will burn out before the tweeter gives up at high SPL, saving the driver by breaking the circuit between the amp and the tweeter.
Moreover it slightly reduces DC coming from the amp, although a series capacitor is much more effective in that.
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