Modded Zaph ZRT?

[johngalt47]

I bought the 18W/4531G00 instead of the 18W/8531G00 that Zaph used. The published T/S params are pretty close; the 4 ohm version being about 3 db louder. I'm inclined to try his xover but reduce the series resistor on the tweeter as a start.

Any comments?

[ernperkins]

Re: Modded Zaph ZRT?

I'm afraid you'll have to completely re-do the xover due to 8 ohm to 4 ohm change. I'd return the 4 ohm and exchange for the 8 ohm. Much less risky. Sorry....

[Chris Roemer]

Re: Modded Zaph ZRT?

I agree, but (if you can't swap the woofers) one way to adapt from 8 to 4 ohms (besides the aforementioned 3dB tweeter adjustment) would be to halve the coil and resistor values, and double the cap values. That's (basically) how many MTMs get developed, at least initially. Can you sim it?

[johngalt47]

Re: Modded Zaph ZRT?

Sure....and I was planning on measuring them, PCD, etc if adapting the existing xover was not going to work. I was just looking for an easy way out.

[jonasz]

Re: Modded Zaph ZRT?

Or you can build the Optimo instead. Looks like a reduced bafflestep design and would work good against a wall.

http://www.humblehomemadehifi.com/do...ptimo_copy.pdf