I'd like to share my a speaker I recently completed with everyone. This would mark my first passive speaker, while I have made many active speakers, I felt my life demanded a bit of simplicity. I was hesitant to try passive filtering as I didn't want to buy a bunch of components I might not use, but I ended up using exactly what I purchased for the first filter iteration. I was a little surprised at how my vituix cad simulated xover just didn't sound very good. There was a large difference above 5khz which I attribute to my measurement mic (cal file was used but still off). My crossovers topology didn't change at all, but I had to swap around some of the components.
Overall I am fairly pleased with the end result. Subjectively speaker is very inoffensive to listen to, nothing bad sticks out and the tonality is neutral with a stable and engaging soundstage. My general criteria for a succesful passive speaker is that aside from room EQ, it just just needs a high and/or low shelf filter for preference. This speaker certainly meets that criteria. The overall cost of drivers and crossover components was around $200 USD. I'm pretty sure my round over bit used on this cabinet was the most expensive part used.
As far as cons, this speaker I beleive has quite a low sensitivity. I have not taken SPL calibrated measurements but based on the gain increases I need to get this speaker to a volume I want, it seems apparent that it's probably fairly low. I have plenty of amp power so this isn't a problem for me. The port tuning is also a bit higher than I would've like, but unfortunately the port I already had cut a hole for was limited to 4". Vcad's enclosure tool tells me a 5-6" port would extend the low end. It's also a bit hard to make a comment on bass extension as I have the box stuffed full of dampening materal which is likely reducing the ports effectivenss quite significantly. I plan on alleviating this issue in the future.
The cabinet is 9 liters ported for the Dayton DSA135 woofer. The tweeter is an SB Acoustics 26STCN. I intended to veneer these speakers but the money just wasn't there and I thought paint would help keep overall costs down. I suppose I got about as good of results as one can get with a spray can, I can easily achieve professional results with veneer but paint seems a lot harder to get right. Color is Rustoleum Maui Blue which I quite enjoy looking at, vibrant but not distracting. I'd like to thank my gf for pushing me away from the orange I was originally going to go with.
On axis response taken in room (lots of room reflection issues below 600hz). Green is taken with a class A/B crown xli800, brown is wiring the tweeter in reverse polarity. I also tested the speaker with an Aiyima a07, and amplifier that for me has unfortunately responded pretty poorly in regards to load dependency with certain speakers. I wanted this speaker to behave well with load dependent amplifiers and it appears to behave fine.
edit - forgot to add dispersion. Not sure how accurate this is. I could only capture out to 90 degrees. I live next to a highway and it is very noisy outside.
Crossover schematic is as follows. Driver is the woofer, driver 2 is the tweeter. All values should remain static aside from the final 7.5uf capacitor in parallel with the tweeter. This component is responsible for tilting the upper end of the tweeter down and can be adjusted to taste, lower values will raise the tweeters upper range response. I simply chose a value that sounded fine to me subjectively, I may adjust the value myself in the future.
Speaker electrical impedance. One could argue it's on the low side, but I haven't run into issues with any of the amplifiers I've used the speaker with.
Overall I'm glad I took the passive plunge, I feel more equipped and confident to handle future passive speakers and have a better understanding of the shortcomings of my analysis process. I have these entered for this years speaker competition run by Parts Express.
Overall I am fairly pleased with the end result. Subjectively speaker is very inoffensive to listen to, nothing bad sticks out and the tonality is neutral with a stable and engaging soundstage. My general criteria for a succesful passive speaker is that aside from room EQ, it just just needs a high and/or low shelf filter for preference. This speaker certainly meets that criteria. The overall cost of drivers and crossover components was around $200 USD. I'm pretty sure my round over bit used on this cabinet was the most expensive part used.
As far as cons, this speaker I beleive has quite a low sensitivity. I have not taken SPL calibrated measurements but based on the gain increases I need to get this speaker to a volume I want, it seems apparent that it's probably fairly low. I have plenty of amp power so this isn't a problem for me. The port tuning is also a bit higher than I would've like, but unfortunately the port I already had cut a hole for was limited to 4". Vcad's enclosure tool tells me a 5-6" port would extend the low end. It's also a bit hard to make a comment on bass extension as I have the box stuffed full of dampening materal which is likely reducing the ports effectivenss quite significantly. I plan on alleviating this issue in the future.
The cabinet is 9 liters ported for the Dayton DSA135 woofer. The tweeter is an SB Acoustics 26STCN. I intended to veneer these speakers but the money just wasn't there and I thought paint would help keep overall costs down. I suppose I got about as good of results as one can get with a spray can, I can easily achieve professional results with veneer but paint seems a lot harder to get right. Color is Rustoleum Maui Blue which I quite enjoy looking at, vibrant but not distracting. I'd like to thank my gf for pushing me away from the orange I was originally going to go with.
On axis response taken in room (lots of room reflection issues below 600hz). Green is taken with a class A/B crown xli800, brown is wiring the tweeter in reverse polarity. I also tested the speaker with an Aiyima a07, and amplifier that for me has unfortunately responded pretty poorly in regards to load dependency with certain speakers. I wanted this speaker to behave well with load dependent amplifiers and it appears to behave fine.
edit - forgot to add dispersion. Not sure how accurate this is. I could only capture out to 90 degrees. I live next to a highway and it is very noisy outside.
Crossover schematic is as follows. Driver is the woofer, driver 2 is the tweeter. All values should remain static aside from the final 7.5uf capacitor in parallel with the tweeter. This component is responsible for tilting the upper end of the tweeter down and can be adjusted to taste, lower values will raise the tweeters upper range response. I simply chose a value that sounded fine to me subjectively, I may adjust the value myself in the future.
Speaker electrical impedance. One could argue it's on the low side, but I haven't run into issues with any of the amplifiers I've used the speaker with.
Overall I'm glad I took the passive plunge, I feel more equipped and confident to handle future passive speakers and have a better understanding of the shortcomings of my analysis process. I have these entered for this years speaker competition run by Parts Express.
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