Don't worry that much. It's not significant.
1st order series are very forgiving re. driver impedances, etc.
As Planet10 said earlier the term Zeta is the important bit, it will determine the slope of both halves of the filter.
Zeta = 1 is exactly like 1st order parallel Butterworth and by varying Zeta by varying the values of your passive components, a coil and a cap, you get either an overdamped or underdamped response at the desired xo freq.
Get a copy of XSim or VituixCAD and play with it, you'll quickly see what's happening.
1st order series are very forgiving re. driver impedances, etc.
As Planet10 said earlier the term Zeta is the important bit, it will determine the slope of both halves of the filter.
Zeta = 1 is exactly like 1st order parallel Butterworth and by varying Zeta by varying the values of your passive components, a coil and a cap, you get either an overdamped or underdamped response at the desired xo freq.
Get a copy of XSim or VituixCAD and play with it, you'll quickly see what's happening.
I am pretty sure it does. I wish i could find th simulator that showed the changes as curves in response as you vary the specific C & L combination.
From Jeff Bagby’s XO Calculator
dave
That's great, but you'll miss big time on all the benefits a simple 1st order series xo offers particularly in the range of 200 - 500 Hz.
On the other hand this is one way to discover that parallel filters are not a panacea and definitely not any easier to get right.
Wish you luck and a lot of patience.
On the other hand this is one way to discover that parallel filters are not a panacea and definitely not any easier to get right.
Wish you luck and a lot of patience.
I once saw visiting a professional for loudspeaker crossovers.
A big developer crossover board where you could make the dimensioning of the crossover simply by switching the parameters for coils and condensers together.
He sat then at listening position just switching the needed parameters.
Had a reference loudspeaker to compare with.
So you can do it without measurements.
A big developer crossover board where you could make the dimensioning of the crossover simply by switching the parameters for coils and condensers together.
He sat then at listening position just switching the needed parameters.
Had a reference loudspeaker to compare with.
So you can do it without measurements.
I want to marry a 20cm 8 ohm fullrange driver Beyma 8agn with a no name 4 ohm bass with a series filter as a one and a half way system. The Beyma not being filtered but only the bass.
I have 220uF at hand giving something around 150Hz crossing for the bass. (bass gets shorted with the capacitor)
I guess in this configuration the impedance add up in the bass like 4+8 ohms?
I have 220uF at hand giving something around 150Hz crossing for the bass. (bass gets shorted with the capacitor)
I guess in this configuration the impedance add up in the bass like 4+8 ohms?
I've always wanted to build such an XO control panel; but with a tray of parts plus electrician's twist caps / \ and alligator clip wire could test and tweek in real time. For example, move clip along a resistor chain to decide attenuation; clip/unclip parallel capacitors, series inductors etc.
Re: your 1.5way connected in series, the bass driver had better be more sensitive than the fullrange, as it gets less than 4/12 of the total voltage.
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If you mean a series xover, then this will not work as you think. You have to have the coil in the main leg or you are essentially shorting your amplifier above the Fc of the 220uF cap.
Again, series xovers do not add the impedances of the drivers like you presume. More often than not when using the conventional circuit layout for these, the adjacent driver is shorted in the bandwidth for the intended driver so they stay the relative impedance of the drivers to either side of the xover point.
If this is not what you are referring to, then it is likely not a series xover. Look up Acoustic Reality Series Crossover for clarification. Peter "Friend" recommends removing the cap across the woofer, but in my experience this shelves down the woofer response by placing the (now hot!) resistor directly across it.
If you think none of the above is what was queried, and you have your 2 drivers directly in series with the cap across the woofer, as it could be inferred that way, it likely will not work as expected unless you also place a large value Icore coil across the widerange.
@wolf_teeth
I decided to use classic parallel design with 1mh inductor on bass.
Here the project:
https://www.diyaudio.com/community/threads/show-your-outdoor-fun-loudspeakers.411007/
I skipped using the valuable Beyma 8agn for outside use (where I live it never rains, like in California) and efficiency is better matched like this.
Is this not a series network?
I decided to use classic parallel design with 1mh inductor on bass.
Here the project:
https://www.diyaudio.com/community/threads/show-your-outdoor-fun-loudspeakers.411007/
I skipped using the valuable Beyma 8agn for outside use (where I live it never rains, like in California) and efficiency is better matched like this.
Is this not a series network?
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Usually yiu see that with 2 drivers the same. The cap shunts the HFs around the bottom driver so it only reponds at LF. Impendance above the roll-off will be the driver running FR, the sum of the 2 below. It crooses over 1 of the drivers and they are connected in series, it is the simpliest of LP as a single cap in series with a tweeter is the simplest HP.
How it would work with 2 different drivers would be “interesting”
A much better drawing and a more thorough explanation.
http://www.planet10-hifi.com/downloads/Dual-Driver-Wiring.pdf
dave
How it would work with 2 different drivers would be “interesting”
A much better drawing and a more thorough explanation.
http://www.planet10-hifi.com/downloads/Dual-Driver-Wiring.pdf
dave
I saw that this thread had been revived so I wanted to report the outcome of my project.
The drivers that I had selected were the Tang Band W5-1611 full range and the Parts Express Eminence 15" poly cone woofer (#290-4009, no longer available). Again, these were speakers that I had on hand and matched well in terms of sensitivity at the crossover point I selected, 350Hz. The TB W5-1611 has a reputation of not having the very exaggerated rise in the high frequencies that many other full-range speakers produce. Being a poly cone driver, its rise toward the highs is more gentle and restrained. The PE Eminence 15" driver also has a poly cone so it does not have the huge spike in the upper mid range frequencies that so many other woofers produce. It also has a foam surround for good edge damping and an interesting rise in low-frequency response that begins at approximately 150Hz and produces a 4dB shelf that subsequently rolls off from 40Hz at 6dB per octave. Resonance is factory listed at 24Hz and that is what I measured. I used a resonance compensation network on the W5-1611 and a Zobel on the Eminence 15, crossed over parallel first-order 6dB per octave at 350Hz. I chose this point to allow as close as possible to a two-octave distance between the W5-1611 resonance and the flat response of the Eminence 15 at the limit of its high frequency extension.
I chose an open baffle configuration for this design. I have long wanted to try an open baffle speaker build, never having owned or heard one. A WAW/FAST design seemed ideal for open baffle, and since I had cabinet materials on hand I chose baffles that are 24" (61cm) wide and 40" (101.6cm) high. The center of the W5-1611 is mounted at 33" (83.8cm). Because I back-mounted mounted the Eminence 15" on the front of the panel and front-mounted the W5-1611 on the rear of the panel (with a chamfer on the front edge of the mounting hole to reduce diffraction) I was able to make the spacing of the center of the drivers right at 11" (28cm) which keeps them very close to the maximum ideal spacing of about 10" (25.4cm). This way of mounting the drivers combined with a backward tilt of the baffle of 8 degrees allows the full range drivers to be on-axis with my ears (the W5-1611 beams its high-frequency response quite narrowly, which is an advantage to me in my situation) and keeps me in the first-order lobe of the crossover at my preferred listening distance of one meter or less, and, I hope, gives me an approximation of time alignment of the drivers. I mounted side wings on the baffles to allow the back tilt and this configuration is very stable on the floor.
If you look at the provided photo you will see that I placed the speakers in a picture-window niche that is 82" wide by 88" high by 40" deep. I wanted to insure that I conformed to the rule of having a minimum of one meter distance between the rear of an open baffle speaker and a wall, and this niche provides that. Shown in the photo are the shade blinds closed in front of the window. The inner edges of the speakers are open into the space of the niche but the outer edges are touching the room walls that meet the side walls of the niche at right angles. I drive the speakers with my vintage Sherwood S7110B receiver, rated at 20 watts per channel into 8 ohms, factory rated to drive 4 ohm speakers. This was my first receiver, bought new by me back in the Stone Age, recently reconditioned by myself with new capacitors and other improvements. It not only has a lot of nostalgic sentimental value for me, it also produces a great sound to my ears.
And so, to the punch line: These speakers sound effing great! I have never before heard speakers sound like this. The three dimensional effects of the direct sound coupled with the reflected rear radiation make vocals sound like the singer is directly in front, standing in the room (or the niche, in my case). Elements that are centered in the stereo balance are presented solidly, right in front, yet other sounds that are panned right or left are clearly heard in their respective positions in the stereo field. I have finally come to understand what speaker reviewers mean by "soundstage". And the impact of the various musical sounds has changed in a good way. Drums are now more present, more truthful in their percussive nature. Bass sounds are present without any smearing of the tone. Bass guitar and double bass have a quality that sounds real. I believe the speakers have an honest 90dB sensitivity, including in the bass range, with their placement in my room. I never have to turn the receiver volume control past 10 o'clock, even when listening to the Who (Keith Moon's drums on "Tommy" sound amazing, his tom tom fills like thunder). Any setting higher than that would be deafeningly loud at my seating position.
I do not say that the speakers are perfect. I can hear some occasional resonances in the bass range that I believe are the room modes of the niche coming into play. I can also hear some upper midrange resonances, again occasionally, that I believe are in the 1kHz to 2kHz range. These resonances do not diminish my enjoyment of the speakers and are not pronounced on all recordings. For me, the advantages of the open baffle design along with their place in my room and my listening distance outweigh the imperfections that I hear. The fact that they respond well to the equalization controls of the Sherwood receiver to make the tonal balance more pleasing is reassuring to me, and the fact that I don't have to adjust the tone controls always to the same values for all recordings tells me that they must be giving a fairly truthful representation of various recordings which do not all have the same sound signature.
I have felt no need to tweak the crossover. These speakers do not have the shrieking upper midrange response that feels like an ice pick in the ears, and they are not in any way deficient in bass. They are very smooth and as I said before respond well to EQ. The three dimensional effects of the open baffle design are remarkable. I would enjoy experimenting with placing them in other positions in my home, but the floor space requirements do not make that practical. In the niche they stand, and in the niche they shall remain.
The bottom line is that I have drunk deep of the wine of both open baffles and first order crossovers, and I feel great! Count me as one of the converted.
Edit: Apologies on the picture. I had to repeatedly crop the image to make it accepted by the thread. I hope it still shows the arrangment of the speakers as I intended it to do.
The drivers that I had selected were the Tang Band W5-1611 full range and the Parts Express Eminence 15" poly cone woofer (#290-4009, no longer available). Again, these were speakers that I had on hand and matched well in terms of sensitivity at the crossover point I selected, 350Hz. The TB W5-1611 has a reputation of not having the very exaggerated rise in the high frequencies that many other full-range speakers produce. Being a poly cone driver, its rise toward the highs is more gentle and restrained. The PE Eminence 15" driver also has a poly cone so it does not have the huge spike in the upper mid range frequencies that so many other woofers produce. It also has a foam surround for good edge damping and an interesting rise in low-frequency response that begins at approximately 150Hz and produces a 4dB shelf that subsequently rolls off from 40Hz at 6dB per octave. Resonance is factory listed at 24Hz and that is what I measured. I used a resonance compensation network on the W5-1611 and a Zobel on the Eminence 15, crossed over parallel first-order 6dB per octave at 350Hz. I chose this point to allow as close as possible to a two-octave distance between the W5-1611 resonance and the flat response of the Eminence 15 at the limit of its high frequency extension.
I chose an open baffle configuration for this design. I have long wanted to try an open baffle speaker build, never having owned or heard one. A WAW/FAST design seemed ideal for open baffle, and since I had cabinet materials on hand I chose baffles that are 24" (61cm) wide and 40" (101.6cm) high. The center of the W5-1611 is mounted at 33" (83.8cm). Because I back-mounted mounted the Eminence 15" on the front of the panel and front-mounted the W5-1611 on the rear of the panel (with a chamfer on the front edge of the mounting hole to reduce diffraction) I was able to make the spacing of the center of the drivers right at 11" (28cm) which keeps them very close to the maximum ideal spacing of about 10" (25.4cm). This way of mounting the drivers combined with a backward tilt of the baffle of 8 degrees allows the full range drivers to be on-axis with my ears (the W5-1611 beams its high-frequency response quite narrowly, which is an advantage to me in my situation) and keeps me in the first-order lobe of the crossover at my preferred listening distance of one meter or less, and, I hope, gives me an approximation of time alignment of the drivers. I mounted side wings on the baffles to allow the back tilt and this configuration is very stable on the floor.
If you look at the provided photo you will see that I placed the speakers in a picture-window niche that is 82" wide by 88" high by 40" deep. I wanted to insure that I conformed to the rule of having a minimum of one meter distance between the rear of an open baffle speaker and a wall, and this niche provides that. Shown in the photo are the shade blinds closed in front of the window. The inner edges of the speakers are open into the space of the niche but the outer edges are touching the room walls that meet the side walls of the niche at right angles. I drive the speakers with my vintage Sherwood S7110B receiver, rated at 20 watts per channel into 8 ohms, factory rated to drive 4 ohm speakers. This was my first receiver, bought new by me back in the Stone Age, recently reconditioned by myself with new capacitors and other improvements. It not only has a lot of nostalgic sentimental value for me, it also produces a great sound to my ears.
And so, to the punch line: These speakers sound effing great! I have never before heard speakers sound like this. The three dimensional effects of the direct sound coupled with the reflected rear radiation make vocals sound like the singer is directly in front, standing in the room (or the niche, in my case). Elements that are centered in the stereo balance are presented solidly, right in front, yet other sounds that are panned right or left are clearly heard in their respective positions in the stereo field. I have finally come to understand what speaker reviewers mean by "soundstage". And the impact of the various musical sounds has changed in a good way. Drums are now more present, more truthful in their percussive nature. Bass sounds are present without any smearing of the tone. Bass guitar and double bass have a quality that sounds real. I believe the speakers have an honest 90dB sensitivity, including in the bass range, with their placement in my room. I never have to turn the receiver volume control past 10 o'clock, even when listening to the Who (Keith Moon's drums on "Tommy" sound amazing, his tom tom fills like thunder). Any setting higher than that would be deafeningly loud at my seating position.
I do not say that the speakers are perfect. I can hear some occasional resonances in the bass range that I believe are the room modes of the niche coming into play. I can also hear some upper midrange resonances, again occasionally, that I believe are in the 1kHz to 2kHz range. These resonances do not diminish my enjoyment of the speakers and are not pronounced on all recordings. For me, the advantages of the open baffle design along with their place in my room and my listening distance outweigh the imperfections that I hear. The fact that they respond well to the equalization controls of the Sherwood receiver to make the tonal balance more pleasing is reassuring to me, and the fact that I don't have to adjust the tone controls always to the same values for all recordings tells me that they must be giving a fairly truthful representation of various recordings which do not all have the same sound signature.
I have felt no need to tweak the crossover. These speakers do not have the shrieking upper midrange response that feels like an ice pick in the ears, and they are not in any way deficient in bass. They are very smooth and as I said before respond well to EQ. The three dimensional effects of the open baffle design are remarkable. I would enjoy experimenting with placing them in other positions in my home, but the floor space requirements do not make that practical. In the niche they stand, and in the niche they shall remain.
The bottom line is that I have drunk deep of the wine of both open baffles and first order crossovers, and I feel great! Count me as one of the converted.
Edit: Apologies on the picture. I had to repeatedly crop the image to make it accepted by the thread. I hope it still shows the arrangment of the speakers as I intended it to do.
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