AudioRoundTable.com - RDF feed
type: channel
description: Audio advice and discussions with audiophiles and professionals. Free discussion forums, open to all and frequented by industry experts. Ask questions and get advice on stereos, speakers, hi-end amplifiers, pre-amps, home theater, tube hi-fi, turntables, vinyl, tweaks, music, films, video, DVDs and more.
items: 4pi
items: Re: 4pi

4pi
type: item
description: For the upgraded drivers, the DE250/2226H..... They appear to be wired out of phase compared to the stock drivers ? Next what watt rating on the 20 ohm and 30 ohm resisters. Thx
creator: Kgveteran
date: 2010-10-15T00:50:26-00:00

Re: 4pi
type: item
description: All resistors in the tweeter circuit are 10 watt non-inductive types. The Zobel in the woofer circuit is a 100 watt non-inductive part. The JBL 2226 is "wired backwards". Some JBL drivers are wired that way, with forward cone motion caused by positive voltage on the black terminal. Normally it's the other way around, with forward motion caused by positive voltage on the red terminal. The chart below shows what JBL drivers are wired this way: Notice for JBL Transducer Users Compression drivers are a little more complicated. For one thing, forward diaphragm motion means different things to different people. Would you consider "forward" to mean away from the magnet? That would be moving away from the listener. Or would you consider "forward" to mean moving towards the listener? That's moving in towards the magnet. Some companies have listed them one way, others, the other. And either way you look at it, there is a path within the driver, and that adds a slight delay, different phase for each frequency. Then there's the reactive nature of the horn itself, phase moving around at low frequencies in the critical crossover region. So it's best to measure each model driver to know how it acts when evaluating or comparing them. Bottom line: Wire the drivers as shown in the schematic, because they have been tested as shown and are known to work properly that way.
creator: Wayne Parham
date: 2010-10-15T01:15:40-00:00

Re: 4pi
type: item
description: Yes Sir !!! Thanx for the interesting perspective on perceived phase wiring. I never gave a thought to motion..... Again, I can't wait to get these assembled
creator: Kgveteran
date: 2010-10-15T13:12:18-00:00