Hi! You mean is a bipolar electrolytic more acceptable than a film capacitor?
The value of the capacitor in the bass section will be large. A bipolar electrolytic will be cheaper and smaller than the equivalent film capacitor.
It's OK to use an electrolytic in parallel with a bass speaker, whereas using a film capacitor in series with a tweeter is normally preferable.
The value of the capacitor in the bass section will be large. A bipolar electrolytic will be cheaper and smaller than the equivalent film capacitor.
It's OK to use an electrolytic in parallel with a bass speaker, whereas using a film capacitor in series with a tweeter is normally preferable.
No,I meant the bass section where the capacitor is responsible for the HF cutoff. Sorry for my English.
The parallel capacitors have much less influence on the sound than the ones in line with a driver. If you want to max everything out and you use very good drivers, I'd take a MKP or MKT. Would I use an electrolyte in other situations? Depends on the part value, if it's a biger capacitor, I likely would use a bipolar electrolyte of good quality (smooth foil).
I think there is a language problem, so allow me explain that all crossover capacitors must be bipolar - more usually called non-polar or NP for short.
You can choose to use either electrolytic bipolar capacitors or plastic film bipolar capacitors as has been explained above by ICG, where MKP and MKT are film types.
Decide by listening
There are audible differences between non-polar Electrolytic , and MKT , and MKP capacitors.
Some listeners seem to not hear much difference for the capacitor connected in Parallel in the Bass section , but other listeners do hear specific differences and usually find a preference for one type of capacitor more so than the other types.
To decide , I recommend you try two or all three types and listen - after you have completed your project and have Treble -{and also Mid-range if you are using a 3-way design }.
As you are in Moscow you will be able to find the very good quality Russian made K78 series of Polypropylene -{ MKP }- capacitors at reasonable prices.
I do not know if there are any Smooth Foil non-polar electrolytic caps made in Russia ,
however the best ones I know of are made for Mundorf in Germany ,
and I refer only to their "E-Cap PLAIN" specified type , and not their "RAW" specified type which is lower audio quality.
Also , you could try a Russian MBGO capacitor , which is apparently a Waxed Paper dielectric capacitor.
Waxed Paper caps are designed for low frequencies AC operation , thus may work well in the Bass section because most of the higher frequencies that are required to be removed by the filter will be sufficiently removed by the series Inductor and the Woofer -{ bass speaker }- itself will not have higher treble frequencies.
An idea which is worth trying because it does produce audible change which some listeners like , is to connect a small resistance in Series with the capacitor in that bass circuit when a Polypropylene -{ MKP }- cap is used.
Use a Resistance of approximately 12% of the Nominal Impedance of the Woofer -{ bass speaker }- ,
example: try 1 ohm with an 8 ohm woofer.
{ 8 ohm Nominal Impedance speaker may have a DC resistance of approximately 6 ohms.}
There will not be much current through it , and because it is such low resistance there will be only small voltage across it , thus not much Power dissipation , thus a 5 watt resistor will be sufficient in a Home audio loudspeaker
-{ but you would need a 10 watt resistor or higher power rated for a Public Address loudspeaker }.
What is the actual Capacitance you need in the bass circuit for your loudspeaker ?
There are audible differences between non-polar Electrolytic , and MKT , and MKP capacitors.
Some listeners seem to not hear much difference for the capacitor connected in Parallel in the Bass section , but other listeners do hear specific differences and usually find a preference for one type of capacitor more so than the other types.
To decide , I recommend you try two or all three types and listen - after you have completed your project and have Treble -{and also Mid-range if you are using a 3-way design }.
As you are in Moscow you will be able to find the very good quality Russian made K78 series of Polypropylene -{ MKP }- capacitors at reasonable prices.
I do not know if there are any Smooth Foil non-polar electrolytic caps made in Russia ,
however the best ones I know of are made for Mundorf in Germany ,
and I refer only to their "E-Cap PLAIN" specified type , and not their "RAW" specified type which is lower audio quality.
Also , you could try a Russian MBGO capacitor , which is apparently a Waxed Paper dielectric capacitor.
Waxed Paper caps are designed for low frequencies AC operation , thus may work well in the Bass section because most of the higher frequencies that are required to be removed by the filter will be sufficiently removed by the series Inductor and the Woofer -{ bass speaker }- itself will not have higher treble frequencies.
An idea which is worth trying because it does produce audible change which some listeners like , is to connect a small resistance in Series with the capacitor in that bass circuit when a Polypropylene -{ MKP }- cap is used.
Use a Resistance of approximately 12% of the Nominal Impedance of the Woofer -{ bass speaker }- ,
example: try 1 ohm with an 8 ohm woofer.
{ 8 ohm Nominal Impedance speaker may have a DC resistance of approximately 6 ohms.}
There will not be much current through it , and because it is such low resistance there will be only small voltage across it , thus not much Power dissipation , thus a 5 watt resistor will be sufficient in a Home audio loudspeaker
-{ but you would need a 10 watt resistor or higher power rated for a Public Address loudspeaker }.
What is the actual Capacitance you need in the bass circuit for your loudspeaker ?
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This is conventional wisdom.
Ideally, a film capacitor should be used. But in that application, it is not as critical as a series capacitor for a tweeter.
Even less critical is the capacitor in the impedance correction circuit. I built a version of Elliott Sound Products impedance correction tester for woofers. I have so many old crossovers it was a freebie to build and I'm learning a lot playing around with it. Very humble parts can make huge improvements in crossovers. Best bang for the buck upgrade is the series capacitor for the tweeter and midrange.
Questions about this trick.
1) Why we should use this 12% value? Is this thumb rule?
2) Maybe value of this resistor should be dependent on value of parallel capacitor? Lets say I have 22uF capacitor and 4 Ohms driver. What resistor value should I take?
3) Will be there some difference in sound if I will take 10W resistor instead of 5W resistor ? Will be there some difference in sound if I will take two series resistors instead of one?
And general questions about this parallel capacitor itself.
1) If I will increase its value then to which side will LPF filter slope move? To right (higher frequencies) or left (lower frequencies)?
2) What happens to sound when parallel capacitor performance degrades with time (lets say electrolytic capacitor after 15 years or so).
Currently I have old speakers that play voices very thin, like "small voices". Its hard to hear actual words in song. I suspect that this can be caused by degraded parallel capacitor of mid-bass 4 ohms driver. Is it valid suspicion?
What type of capacitor did you finally install? Please share.
Thanks
At 22µF the difference between a electrolytic smooth foil and a basic MKP is small really. The MKP is about 120-150% the size and about 150% the cost of a good electrolytic. No-brainers to me. The loss factors of these electrolytes are relatively small, so exchanging these with film types doesn't require compensation.
That being said a lot of the cap mystifications have risen from results of replacing old lossy and degenerated electrolytic caps with film types. Such changes are audible for sure.
That being said a lot of the cap mystifications have risen from results of replacing old lossy and degenerated electrolytic caps with film types. Such changes are audible for sure.
Not sure you are correct here.
Here are sizes of MKP vs electrolytic from same brand:
JCC-22/400 - Cap. 22µF 400VDC 5% MKP Jantzen Cross-cap dia- 34/ 44mm axial (4,200 EUR)
JBPCG-22 - Cap. 22,00µF 70VDC smooth 5% ELE. BP 105°C dia- 26/38mm axial (2,700 EUR)
Maybe I am missing something? Please check it out.
If old electrolytic capacitor had significant losses (ESR, ESL) and if these losses were taken into consideration during original design process then replacement of such capacitor without impacting sound in negative manner is going to be hard. This is my newbie opinion, not a holy truth fact.
Perhaps, but rarely are you able to find someone who is able to explain it.
Anyway, consider this. The Voltage that amasses across the parallel capacitor is applied directly to the driver.. not the case for a series cap.
At Mouser, I didn't find any 22µF POLYPROPYLENE caps for less than ~$6 each (Panasonic EZP-Q25226LTA) and they were HUGE (58x30x45mm). The SMALLEST ones I found were TDK B32774D4226K, $9 each and 32x22x37mm. The 22µF Nichicon BiPolar UVP1J220MPD was 46¢ and 8x12mm. So the Nichicon BP was 13 times less $$$ and 270 times less volume.
Can't understand what you saying.
You took 100 uF bipolar electrolytic in parallel 10 uF MKP?
Or what?
What brands of capacitors?
Did you do some recapping work or fresh build from scratch?
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