I've got an odd winter project in the works that is pushing the limits of practicality. A set of speakers that are compact, cheap, sound good, and extend very low for classical and especially pipe organ music. I've considered a DSP amp, but am concerned with the quality of the Dayton 4x100W amp and DSP in general, and I already have the recommended crossover components for the Dayton CX120 driver. What I'm working on now is a low pass filter for the 6.5" subwoofer that is in the same enclosures (I want L&R bass). The cabinets will be small, <0.5cuft external with a 1" square widely flared port tuned most likely to 32Hz. About the only thing in my favor is the fact that I don't need loud, just around 60dB.
About the filters, I read somewhere that adding a resistor can change how the crossover reacts, I assume that is only true if the resistor is on the driver side of the circuit, not the amp side? Because I may want to add a lot of resistance to the full range to balance it with the bass.
Also, WinISD gave me this impedance graph. Will that higher frequency peak mess things up? How do I get rid of it?
Perhaps more importantly, how do I deal with the lower peak? The low peak matters because I might use a low pass filter around 18Hz to help boost the bass as it approaches 32Hz, and due to the small driver & enclosure I may need that filter set way lower than 32Hz for output to peak there, at least according to my ears. I've done something similar to a 6.5" ported sub with a 23.9Hz 3rd order filter that greatly flattened its response from 28Hz and up, crossing over well with an unfiltered 6.5" 60ohm sub at around 80Hz.
Can WinISD export it's graphs to Vituix?
BTW I'm pretty new to a lot of this stuff. I've learned a ton in the past month to give some of my budget winter projects a fair shot at success short of buying a microphone to record sweeps for fine tuning, rather than slapping stuff together with basic online calculators and hoping for the best with more than total disregard for phase alignment.
Thanks
About the filters, I read somewhere that adding a resistor can change how the crossover reacts, I assume that is only true if the resistor is on the driver side of the circuit, not the amp side? Because I may want to add a lot of resistance to the full range to balance it with the bass.
Also, WinISD gave me this impedance graph. Will that higher frequency peak mess things up? How do I get rid of it?
Perhaps more importantly, how do I deal with the lower peak? The low peak matters because I might use a low pass filter around 18Hz to help boost the bass as it approaches 32Hz, and due to the small driver & enclosure I may need that filter set way lower than 32Hz for output to peak there, at least according to my ears. I've done something similar to a 6.5" ported sub with a 23.9Hz 3rd order filter that greatly flattened its response from 28Hz and up, crossing over well with an unfiltered 6.5" 60ohm sub at around 80Hz.
Can WinISD export it's graphs to Vituix?
BTW I'm pretty new to a lot of this stuff. I've learned a ton in the past month to give some of my budget winter projects a fair shot at success short of buying a microphone to record sweeps for fine tuning, rather than slapping stuff together with basic online calculators and hoping for the best with more than total disregard for phase alignment.
Thanks
Simulating is going to help answer these questions. Vituix can help trace existing plots.
Instead of adding a resistor in series with the full range driver to match it with the sub
(which would waste a lot of power), attenuate the signal at the input of the full range amplifier.
You can use a 10k stereo pot, or else a pair of properly chosen series resistors.
(which would waste a lot of power), attenuate the signal at the input of the full range amplifier.
You can use a 10k stereo pot, or else a pair of properly chosen series resistors.
The existing plot for the 6.5" driver is not for my enclosure and doesn't have the lower peak that WinISD predicts.
Is there a way to draw a custom impedance graph in Vituix to experiment with?
I plan to have these cabinets run by a 2ch amp, a left & right channel, so no turning down the full range before the amp output. I don't see how much power will be wasted at such a low full range output. It will probably be running around 20-400mW while the sub is running 20-40W.
Is there a way to draw a custom impedance graph in Vituix to experiment with?
I plan to have these cabinets run by a 2ch amp, a left & right channel, so no turning down the full range before the amp output. I don't see how much power will be wasted at such a low full range output. It will probably be running around 20-400mW while the sub is running 20-40W.
Here's an impedance file for the image in your first post. Vituix will do it, look under 'tools'.
This plot does not include voice coil inductance. The proper measurement would be expected to rise at higher frequencies.
This plot does not include voice coil inductance. The proper measurement would be expected to rise at higher frequencies.
That helped a lot. I figured out how to trace an image. Any tips for adjusting phase when 2 drivers are out by 90 degrees? I might just have to live with it or try a different order of crossover?
Also, which are better: IQ or IXQ coils from US coils? What's the difference? The website doesn't give a detailed comparison.
Also, which are better: IQ or IXQ coils from US coils? What's the difference? The website doesn't give a detailed comparison.
Can I presume 90 degrees isn't what you need and you want to bring them closer? Adjust the frequency, Q and slope of one or the other until you find a fit.
One uses finer laminations. This would reduce eddy losses. As the price is different, compare the resistance.
Interestingly the IQ are lower resistance than the more expensive and presumably better IXQ, except the IXQ comes in slightly smaller gauge wire series and at much higher inductance, like a mini Super Q.
I have 3 similar designs about figured out such that with the same components I can try a 2nd and 3rd order on the sub and some variations on the full range.
I'll just try the 4x100W DSP amp on my next 2 way double sided extended range outdoor speaker project since it doesn't use a tweeter, so maybe the amp's hiss won't be quite so bad.
Thanks for all the help so far.
I have 3 similar designs about figured out such that with the same components I can try a 2nd and 3rd order on the sub and some variations on the full range.
I'll just try the 4x100W DSP amp on my next 2 way double sided extended range outdoor speaker project since it doesn't use a tweeter, so maybe the amp's hiss won't be quite so bad.
Thanks for all the help so far.