my0x Messages: 23 Registered: October 2012 Location: Philadelphia, PA
Chancellor
Yes - I've been veneering my cabinets this week- two panels per night with a homemade press setup involving plywood plates, 2x reinforcements, a gallon of wood glue, and clamps and straps. I also received packages from Sonicraft (where Alpha Core ribbon inductors were on sale) and Parts Express for the B^C drivers and large caps. I hope to get the veneer finished this weekend, but I think final assembly will go into next week or week after depending on other things. Getting excited! I'll try to put more pics up on the forum sometime.
my0x Messages: 23 Registered: October 2012 Location: Philadelphia, PA
Chancellor
So I finished my 4pi's last week. I have about 3hrs of burn in time so far, and I am enjoying them despite how 'young' they are! Will post an update after more time with them and after I get placement sorted. These are smooth...voices just float!
About the zobel 8ohm 100w resistor - I had ordered the inexpensive 'dummy load' resistors from parts express, however I have seen folks using other heatsinked resistors here on the site. How important is the quality here before I fully button things down? My crossovers are otherwise built with decent components: Mills resistors, alpha-core 16ga ribbon inductors, Sonicap 6.8 and Solens for the large caps, and drivers are the JBL 2226 and B&C 250.
More pics later and listening impressions as they mature.
Thanks Wayne!
PS. If you have another set of silver pi decals, I think a set would look great on these cabinets.
Wayne Parham Messages: 18783 Registered: January 2001
Illuminati (33rd Degree)
The dummy load resistor is a good part, non-inductive and plenty of thermal capacity. You've got good Mills resistors elsewhere, so stick with the dummy load you're using. It's a good part.
Send me your mailing address by private message or email and I'll mail you a couple silver logo decals.
my0x Messages: 23 Registered: October 2012 Location: Philadelphia, PA
Chancellor
PS...really enjoying the 4pi speakers. Still breaking in , and not in their final locations due to house repairs, but these are good! I can't wait to get my Oracle Alexandria functional again.
my0x Messages: 23 Registered: October 2012 Location: Philadelphia, PA
Chancellor
OK - finally ran an spl sweep. This was taken with REW 5.0, using the internal mic on my mac. Magenta is the left channel, teal is the right channel. Like Lucasmateo's test, there is less spl below the crossover point. There are other anomalies too, but perhaps some of this is from the low quality test equipment and procedure. What is good is that both channels measure similarly! Matthew
Wayne Parham Messages: 18783 Registered: January 2001
Illuminati (33rd Degree)
That's very odd. It's like your tweeter attenuation isn't there. Then again, in one recent case, we saw woofers that were defective give this kind of response. Once the woofers were reconed, their output rose to normal levels.
I'm betting the dip at 6kHz is your microphone. I suppose it could be the compression driver, but that's unlikely since both do it. So I'm thinking it's probably the mic.