warning: lengthy post with piles of images ahead..
summary: I tune in some of the crossover values by listening tests after not being happy with my first efforts, then assemble them properly onto the PCBs into external enclosures, to make future experimentation easier.
corrected and cleaned up crossover using component values I can buy (using Jantzen components for pricing it up):
And the modelled PCD response:
.. well I ordered a a pair of econowave PCBs from Zilch in December.
But the last few months I've had the remodelled crossovers laid out on cardboard while I've been tuning them. What a mess!
The original crossover I specced out in the above circuit sounded just a bit too bright too me, and trying different with attenuation via various resistor LPAD combos it didn't quite sound right. What sounded OK on one style of music sounded terrible with another.
I ended up trying various values out of curiosity, simming them up in speaker workshop for a sanity check, then adding them to the crossover and having a listen.
Adjusting the values of the RC high frequency compensation network yielded much better results, even though "on paper" it has more of a slight tail off in the high end than the "flat" values I started with.
I ended up trying a bunch of assorted capacitor/resistor values over a few weeks:
..
also tweaking the values in the notch filter (taken from the Econowave SR crossover) to make it bit flatter around the crossover point.
I ended up adding a 1uF cap in parallell to the 8.2uF cap for a total of 9.2uF.
The RC network I settled on was 14ohm/1.77 uF, made from 4 x 56 ohm 3watt resistors in parallel, and a 1uF cap with a 0.68uF cap.
final crossover:
and modelled response:
Also during this time after reading of other peoples d220ti tweaks I damped the Pyle waveguide with bituminous flashing tape:
and did filled the back of the compression driver with bluetak and cleaning cloth:
This has definately made the waveguide deader sounding when tapped, hard to say if it has helped soundwise as i don't have measurements, but I think so.
Now to clean up the messy crossovers and put them properly on the circuitboards:
As later on down the track I want to experiment with active crossovers I decided to build the crossovers into an external box that will sit out of sight behind the speakers, and found a ABS jiffy box of the right dimensions at my local electronics shop.
as per Zilch's suggestion I screwed 2 terminal tagboards onto the corner mounting holes and used them to mount the Zobel network and the notch filter, and "LPAD" resistor (not a true LPAD as I'm only using one in parallel, but it modelled up well in Speaker Workshop).
I had to mount the high pass inductor upright as I had gotten a larger size than would sit down snug, also the notch filter inductor I bolted to the side of the enclosure using a bracket I fashioned from polymorph plastic.
Also the Jantzen inductors I used didnt have screw holes, so they are cable tied down I've damped them from rattling about with some ugly, but functional blobs of hot glue:
leading to some now nicely packaged up external crossover units:
that can sit neatly in behind the speaker boxes.
The result is some speakers that really sound BIG yet detailed and pleasant, on all kinds of music that I've tried (some jazz, rock and a lot of ambient and electronic dub). I've been happily listening to "On Land" by Brian Eno and really getting lost in the sound.
should've taken pics of this process) Then I Dremeled the Old horns so they would fit around the new waveguides but still retain the look of the original speakers.Okay,that's it,my longest post ever. lol , thanks so much to all who have contributed to this along the way.
