Hello,
I'm looking for expertise on tweaking some high pass filter in order to enhance the tweeter's output.
1.Would there be beneficial and not detrimental to the phase, crossover point and else, to play with 2ohm resistor? Is it considered to be before the filter? Could a parallel capacitor be beneficial there?
2. In order to preserve the crossover point - does lowering the 2ohm resistor require higher value of 3.5/1.5 capacitor?
3. Could I play with 3.8ohm as well (value change, parallel capacitor)? How does exactly the lamp and the resistor work in tandem.? How detrimental to the sound is this?
4. The 10ohm resistor, parallel to the tweeter, (value change, parallel capacitor)? Any effect on the tweeter's level (or just to smoothen the response, as I read somewhere)or To protect the amplifier (and woofer) in the event of the tweeter being blown (i.e. open-circuit)??
5, Could one bypass the 3.5/1.5 capacitor-the 2ohm resistor-th 10ohm capacitor at once/with one common bypass capacitor all together?
The tweeter is 8ohm
Too many questions, I realize, sorry.
Much appreciated!
BTW, I'm in a process of replacing all capacitors ... The photo shows intermittent state... JB JFX , bypassed with CDE 104K and 940C
I'm looking for expertise on tweaking some high pass filter in order to enhance the tweeter's output.
1.Would there be beneficial and not detrimental to the phase, crossover point and else, to play with 2ohm resistor? Is it considered to be before the filter? Could a parallel capacitor be beneficial there?
2. In order to preserve the crossover point - does lowering the 2ohm resistor require higher value of 3.5/1.5 capacitor?
3. Could I play with 3.8ohm as well (value change, parallel capacitor)? How does exactly the lamp and the resistor work in tandem.? How detrimental to the sound is this?
4. The 10ohm resistor, parallel to the tweeter, (value change, parallel capacitor)? Any effect on the tweeter's level (or just to smoothen the response, as I read somewhere)or To protect the amplifier (and woofer) in the event of the tweeter being blown (i.e. open-circuit)??
5, Could one bypass the 3.5/1.5 capacitor-the 2ohm resistor-th 10ohm capacitor at once/with one common bypass capacitor all together?
The tweeter is 8ohm
Too many questions, I realize, sorry.
Much appreciated!
BTW, I'm in a process of replacing all capacitors ... The photo shows intermittent state... JB JFX , bypassed with CDE 104K and 940C
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Ok for first resistor removal and 'that thing associated. Those go before the woofer, go figure.
Ok for removal of 0.1 caps.
The L-pad with that 10 μF NPE ( why not a film cap in there?!) in between can be altered in the proportions so the tweeter receives the right output.
I would leave it out then add...
Ok for removal of 0.1 caps.
The L-pad with that 10 μF NPE ( why not a film cap in there?!) in between can be altered in the proportions so the tweeter receives the right output.
I would leave it out then add...
Start with:
2ohm 10W - replace with a jumper
10ohm 10W - remove
10uF NPE - replace with 10uF film capacitor
If there are too many high frequencies, then other resistor values can be installed.
2ohm 10W - replace with a jumper
10ohm 10W - remove
10uF NPE - replace with 10uF film capacitor
If there are too many high frequencies, then other resistor values can be installed.
The resistance of the bulb increases as it runs hot. The resistor sets an upper limit to the tweeter level reduction.
According to the schematics, both tweeter and mid bass are limited with that lamp.
The bulb/resistor is not uncommon. A lot of commercial speakers used this protection scheme.
It could be removed. But it's up to the OP.
Dave.
It could be removed. But it's up to the OP.
Dave.
Removal of the resistor 10ohm /strap it , or completely disconnecting the parallel leg?
What result would be achieved?
(BTW, film caps are in, but the 100uF for the woofer)
Should I consider replacing the JB JFX with "brighter" caps?
Just take it off the PCB, nothing more. It's as if you deleted it from the schematic.
I am not familiar with those capacitors. Keep them.
I am not familiar with those capacitors. Keep them.
If you ask me, instead of 3.8ohm 20W, a jumper would be used. I have a slight impression that that lamp only spoils the sound. You don't have to remove it, bridge it with a piece of wire for test. You are left without that protection, but it will surely sound better.
This is fun, because of 'I read somewhere' must lead to a book! So the effect of a 10 Ω resistor attached in // to a tweeter ...
Certainly it will burn some power! Might have some impact at the impedance peak so the 10 uF cap 'sees' a flatter impedance.
Indeed, L-Pad is mislabeled because of the C in between. My fault.
And we have that 2 Ω resistor. A resistor impedes current to flow
so, reduce its value, bypass it, jumper, eliminate it ( useful for future projects)
Also the 10 Ω 10W resistor in series with the cap ( 100 uF) seems strange, isn't it?
Whazzat, a well damped 1st order ?
Whazzat, a well damped 1st order ?
So, if I keep the 10ohm resistor, the resulting R=4.4440hm... theoretically.
W/o the 10ohm resistor the R eventually Z is upto the driver only (no data of it whatsoever)
The expected outcome is hard to predict, as if any damage on the driver could result, please?
There are some excerpts here, 4ohm vs 10ohm drivers:
Does higher ohms mean better sound?
The advantage of higher ohms is that it offers a more detailed sound. Higher ohms can provide a greater range of sound, from high-end treble to low-end bass. This makes it easier to distinguish individual sounds and create a more immersive listening experience.
Which speaker is better 4 ohm or 8 ohm?
Differences Between 4 Ohm Speaker and 8 Ohm Speaker
Efficiency: The 4 ohm speaker is more efficient at converting electrical power into sound, resulting in a higher output for the same input power.
Is higher or lower ohms better speakers?
Generally, there are 2, 4, and 8-ohm speakers. If the resistance is high, the sound will be better, crispier, and cleaner. However, the 4-ohm is the prevalent one. The more resistance or impedance, the less power you need, while the lower the ohm, the more power you need.
If your amplifier is designed to drive a 4 ohm speakers, then 4 ohm speakers will play louder at the same power than 8 ohm speakers. If your amplifier is designed to drive a 8 ohm speakers, then 8 ohm speakers will play louder at the same power than 4 ohm speakers.
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Not having electrically related background, and limited speaker expertise, I find the two statements in bold kind of opposing in nature.
Louder vs more detailed?
W/o the 10ohm resistor the R eventually Z is upto the driver only (no data of it whatsoever)
The expected outcome is hard to predict, as if any damage on the driver could result, please?
There are some excerpts here, 4ohm vs 10ohm drivers:
Does higher ohms mean better sound?
The advantage of higher ohms is that it offers a more detailed sound. Higher ohms can provide a greater range of sound, from high-end treble to low-end bass. This makes it easier to distinguish individual sounds and create a more immersive listening experience.
Which speaker is better 4 ohm or 8 ohm?
Differences Between 4 Ohm Speaker and 8 Ohm Speaker
Efficiency: The 4 ohm speaker is more efficient at converting electrical power into sound, resulting in a higher output for the same input power.
Is higher or lower ohms better speakers?
Generally, there are 2, 4, and 8-ohm speakers. If the resistance is high, the sound will be better, crispier, and cleaner. However, the 4-ohm is the prevalent one. The more resistance or impedance, the less power you need, while the lower the ohm, the more power you need.
If your amplifier is designed to drive a 4 ohm speakers, then 4 ohm speakers will play louder at the same power than 8 ohm speakers. If your amplifier is designed to drive a 8 ohm speakers, then 8 ohm speakers will play louder at the same power than 4 ohm speakers.
------
Not having electrically related background, and limited speaker expertise, I find the two statements in bold kind of opposing in nature.
Louder vs more detailed?
This is not true. For the same amplifier output power, the efficiency is the same for 4ohm and 8ohm speakers. For the same output voltage from the amplifier, there is twice the power at 4ohm, hence the +3dB louder sound at 4ohm when measured at 2.83VRMS. With that voltage, an 8ohm speaker gets 1W and a 4ohm speaker gets 2W. If both received 1W, their loudness would be identical if they are of identical construction.
Also incorrect.
Without the 10ohm in parallel, the impedance is exactly the same as the tweeter impedance. I guess it's not hard to measure the speaker's DC resistance.
Everything you wrote about loudspeakers, impedances, amplifiers is mostly incorrect. Too much philosophy for a simple thing. Try what I told you and let us know the result. Remove the 10ohm in parallel with the tweeter, bridge the 2.2ohm in line with the tweeter and bridge that lamp ąnd 3.8ohm resistor.
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Hi All,
I assembled external crossover, made all the corrections suggested (strapped the bulb-resistor, strapped the 2ohm resistor),
Setup side by side two speakers (corrected and uncorrected one) feed from same channel (right one on the amplifier, speakers A+B), signal to the speakers through speakers splitter, source is CD player, Brothers in Arms Shm-cd.
Results:
1.Prominent change in treble (level of sound), more so in mids (higher), they feel like forward positioned as well. The uncorrected speaker sounds like muffled one. No definitive say on any change in the level of detail though. Not sure if the sound picture is for real.
2.Attached (alligator clips) the 10ohm parallel resistor - on and off-the sound resembles the one of uncorrected speaker very closely with the resistor on.
This came as surprise to me as the role of the parallel resistor was way too noticeable, the strappet other resistors have less than expected influence.
Plan:
1.Finding optimal value of the parallel resistor.?
2.Value change of the capacitors in order to match the changed impedance?
I played with online XO calculators, the closer results I've got (3rd order HP, any type ) is 5uF and 15uF (around 2100Hz). If the 2ohm resistor is off, the capacitance should be bigger with 20% (roughly) for each capacitor.
All calculators provide same order for low and high filters, what is not the case here. Would you suggest a calculator with individual order choice by segment, please?
All comments are highly appreciated.
Thx
I assembled external crossover, made all the corrections suggested (strapped the bulb-resistor, strapped the 2ohm resistor),
Setup side by side two speakers (corrected and uncorrected one) feed from same channel (right one on the amplifier, speakers A+B), signal to the speakers through speakers splitter, source is CD player, Brothers in Arms Shm-cd.
Results:
1.Prominent change in treble (level of sound), more so in mids (higher), they feel like forward positioned as well. The uncorrected speaker sounds like muffled one. No definitive say on any change in the level of detail though. Not sure if the sound picture is for real.
2.Attached (alligator clips) the 10ohm parallel resistor - on and off-the sound resembles the one of uncorrected speaker very closely with the resistor on.
This came as surprise to me as the role of the parallel resistor was way too noticeable, the strappet other resistors have less than expected influence.
Plan:
1.Finding optimal value of the parallel resistor.?
2.Value change of the capacitors in order to match the changed impedance?
I played with online XO calculators, the closer results I've got (3rd order HP, any type ) is 5uF and 15uF (around 2100Hz). If the 2ohm resistor is off, the capacitance should be bigger with 20% (roughly) for each capacitor.
All calculators provide same order for low and high filters, what is not the case here. Would you suggest a calculator with individual order choice by segment, please?
All comments are highly appreciated.
Thx
Yes. you have to correct a little backwards. That tube was probably taking away some of the high frequencies, leave it bridged.
Since you are already adjusting the sound subjectively without measuring, try 22ohm, 27ohm, 33ohm parallel resistor. That resistor affects the cutoff frequency and Q factor of the tweeter filter. To start, buy cheap ceramic resistors 10W and try. No need to buy some expensive fancy resistors. If it doesn't go well, it can be adjusted with series and parallel resistor values. Let's say 1ohm in series and 15ohm in parallel to the tweeter. You can also buy those values.
In the end, by combining these resistors, you will arrive at the optimal values. It has to be like that, it can't be any other way. I have all resistor values from 0.22ohm-100ohm for those tests. They are cheap. 🙂
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It might be easiest to first try it as it is (without parallel 10ohm resistor) and remove the 1.5uF that is in parallel with the 3.5uF so that only 3.5uF remains. This will reduce the mid frequencies and leave the highs.
Hi again,
All tests were done with complete box -woofer and tweeter engaged. With tweeter only, the response is pretty much non-characteristic one.
Perhaps the woofer goes up well beyond 2200Hz.
1.Adding parallel resistors (upto 30ohm did no benefit, kind of weird feel listening to)
2.Playing with the Caps values, at 2.2uF was the optimal, least changed, but as good as the uncorrected speaker.
3. Running fixed frequency signals (all Rs strapped, 10ohm parallel R, returned audible stronger representation (above 1250Hz) then the response of the uncorrected box.
4. Up To 12.5KHz is audible (by me), next frequency of 16KHz is out of reach.
Then I compared stock box (from a second pair) and they seemed same to me... weird ...
I have long wires , 18AWG for the external XO, dunno what inductance, capacitance adds to the XO; then new capacitor 2.2 that is not burned in.
Besides the fact that drivers deviate in specs.
I was looking for ways for means of measuring drivers, overall response, ets. -like DATS3, OmniMic, besides the costs, too many non-conclusive reviews.
Currently the speakers are burning in the new Audyn Qtex4 I got yesterday.
Not sure how to proceed from here, perhaps the drivers are at their limits, imposing cap on the response and else. For $500 cad per pair, 20 some years ago that's maybe the limit of them.
All tests were done with complete box -woofer and tweeter engaged. With tweeter only, the response is pretty much non-characteristic one.
Perhaps the woofer goes up well beyond 2200Hz.
1.Adding parallel resistors (upto 30ohm did no benefit, kind of weird feel listening to)
2.Playing with the Caps values, at 2.2uF was the optimal, least changed, but as good as the uncorrected speaker.
3. Running fixed frequency signals (all Rs strapped, 10ohm parallel R, returned audible stronger representation (above 1250Hz) then the response of the uncorrected box.
4. Up To 12.5KHz is audible (by me), next frequency of 16KHz is out of reach.
Then I compared stock box (from a second pair) and they seemed same to me... weird ...
I have long wires , 18AWG for the external XO, dunno what inductance, capacitance adds to the XO; then new capacitor 2.2 that is not burned in.
Besides the fact that drivers deviate in specs.
I was looking for ways for means of measuring drivers, overall response, ets. -like DATS3, OmniMic, besides the costs, too many non-conclusive reviews.
Currently the speakers are burning in the new Audyn Qtex4 I got yesterday.
Not sure how to proceed from here, perhaps the drivers are at their limits, imposing cap on the response and else. For $500 cad per pair, 20 some years ago that's maybe the limit of them.
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