Sheesh! Terrible typo !so have to do some more twerking with that.
Sheesh! Terrible typo !so have to do some more twerking with that.
This just looks downright weird/wrong. You can't just cascade two identical filter stages that way.Seems you are right and I have been misguided - this should be more correct, but will have to do more research now, because my source was wrong:
Bass to Mid-Woofer Crossover (200Hz):
- Impedance at 200Hz: 4.5 Ohm
- First Stage:
- Series Capacitor: 176 uF (100V)
- Shunt Inductor: 8.8 mH (250W)
- Second Stage:
- Series Capacitor: 176 uF (100V)
- Shunt Inductor: 8.8 mH (250W)
Mid-Woofer to Mid-Tweeter Crossover (1200Hz):
- Impedance at 1200Hz: 6 Ohm
- First Stage:
- Series Inductor: 0.22 mH (250W)
- Shunt Capacitor: 22 uF (100V)
- Second Stage:
- Series Inductor: 0.22 mH (250W)
- Shunt Capacitor: 22 uF (100V)
Mid-Tweeter to Tweeter Crossover (8000Hz):
- Impedance at 8000Hz: 3 Ohm
- First Stage:
- Series Capacitor: 6.6 uF (100V)
- Shunt Inductor: 0.079 mH (250W)
- Second Stage:
- Series Capacitor: 6.6 uF (100V)
- Shunt Inductor: 0.079 mH (250W)
All your suggestions I will take into account, maybe I can use it as you say to tweak and test, a DSP won’t be in my final design though. I have built a subwoofer before, not that it is really the same. I am now thinking about some cheaper drivers for this first build…Since you are willing to dump serious money into this project, have you considered an active xover, maybe one of the nice DSP units available now. It has been a while since I have looked into them, but I was quite intrigued by the tweakability of some of these units. Even if that is not your final destination it would provide you with a way to test your system without building and tweaking many variants of a discrete xover. You should also plan on building and rebuilding those cabinets multiple times; the first is never satisfactory.
One of the best sounding speakers I have ever heard was a particle board box with an Altec 604 duplex speaker stuffed into it. The guy who built it said it was his 23rd iteration on the cabinet. It was put together with nails and caulk -- no glue so he could knock it apart and rebuild it quickly. The crossover was a single capacitor. That was back in the '60s -- when 50 Watts was a lot of power, hum and hiss was how you knew the final was on and T-S wasn't even a dream yet, but had it been around I doubt it would have led to this box. Good speakers are still more art form than mathematics.
But setting that aside, have you ever built a speaker before? Most people start out building 2-way bookshelf speakers and taking on the learning curve gradually, not trying to build a Rolls Royce on their first gambit. Putting a couple toes in the water first can save you time and frustration in the long run, especially if you don't know how to swim.
I realize I am throwing water on an oil fire...
And here I go being verbose again. Forgive me, I've been away a while.
That is a surprizing assertion. In 60 years I have never seen it happening. Paralleling/serializing capacitors is pretty predictable.ou can get weird responses when stacking capacitors.
Capacitors of differing values each have their own reactance to various frequencies - when you end up with a net value it will have a known effect but there are individual filtering effects that colour the sound when using caps of different values in parallel - also caps in series will increase the ESR of that section of a filter network. Phase relationships of different value caps in parallel may not match as their charge times will differ so they will tend to crossfeed.That is a surprizing assertion. In 60 years I have never seen it happening. Paralleling/serializing capacitors is pretty predictable.
These effects happen typically at frequencies above 50kHz for electrolytics and much higher for film or ceramic caps. We're talking about audio frequencies here.Capacitors of differing values each have their own reactance to various frequencies - when you end up with a net value it will have a known effect but there are individual filtering effects that colour the sound when using caps of different values in parallel
Of course, but typically, connecting two 100uF caps in series will result in the same ESR as that of a 50uF of similar technology. ESR is roughly inversely proportional to capacitance. Again for similar technology.- also caps in series will increase the ESR of that section of a filter network.
Don't worry, Kichhoff is taking care.Phase relationships of different value caps in parallel may not match as their charge times will differ so they will tend to crossfeed.
Not to feed the veer but the best sounding general purpose universal 2-way crossover (designed for an amplifier plug-in accessory) that I experienced, used a staggered pole filter alignment that uses a simple one-pole response in the sensitive crossover region for minimal phase issues between drivers. Additional poles away from the crossover point add more protection without phase problems.I will only add (FWIW) that after (too many) years of mucking about with DIY speakers, the only things that were remotely successful sound-wise, were single full-range drivers in simple enclosures, and two-way designs that were bi-amped with 4th-order Linkwitz-Riley crossovers.
Successful passive crossover design (especially three-way or more) can be a very fraught enterprise.
I'm not the speaker guy here but there are a few specifications probably considered more important to speaker manufacturers/users.I do not understand why I cannot find a single driver from a single manufacturer that has IMD numbers in their spec sheets, this seems to me the single most important value one would need to determine the quality of the driver, no?
IMD being dependant on the combination of several frequencies, the actual result depends very much on how the loudspeaker is used, particularly the range of frequencies.I do not understand why I cannot find a single driver from a single manufacturer that has IMD numbers in their spec sheets, this seems to me the single most important value one would need to determine the quality of the driver, no?
[As mentioned I tried easyEDA, but must be doing something wrong] -- If you can -- CLEARLY -- draw your schematic out on paper and take a -- GOOD -- photo of it, then send me a PM with your schematic photo and I will create one for you using one of my 3 schematic CAD-programs!!! Sound like a plan???I was just hoping someone could assure me the calculations were correct… As mentioned I tried easyEDA, but must be doing something wrong, because the nets are not connecting properly, so I gave up.
Wow - thanks I am doing some more research at this stage and recalculating everything, I am even considering using cheaper drivers for the build, but nothing is final yet. I just realized I need to put more time into this, so I am sure to get a good result. Once I am further in the process, I may well draw upon your resources, thank you so much for being so generous!![As mentioned I tried easyEDA, but must be doing something wrong] -- If you can -- CLEARLY -- draw your schematic out on paper and take a -- GOOD -- photo of it, then send me a PM with your schematic photo and I will create one for you using one of my 3 schematic CAD-programs!!! Sound like a plan???
Be certain to use all of the proper symbols and notate all of the component values, voltages, wattages, etc.
/
I understand these are of course essential, but what does a frequency response mean if the speaker cannot maintain its individual frequency linearity when more frequencies are played simultaneously - which in praxis would be all the time.I'm not the speaker guy here but there are a few specifications probably considered more important to speaker manufacturers/users.
1- frequency response
2- sensitivity
3- power handling
JR
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