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unknownuser
04-27-2008, 06:14 PM
I was going to attempt to use this MTM design but became stuck when I noticed a difference in the parts for the X-over to be different. The schematic has a 20 ohm resister while the parts list at the bottom of the DIY page says I should order 7 ohm resistors. Which is correct?


(Originally posted by: Jr. Goon)

turn2
04-27-2008, 06:37 PM
Provided Link: http://www.rjbaudio.com/RS180MTM/rs180-rs28-mtm.ht (http://www.rjbaudio.com/RS180MTM/rs180-rs28-mtm.html)


I would say it must be a 7 ohm, but I've never done that project. Check the link for some interesting comparisons by Roman Bednarek, as well as the Dr. K crossover diagram.

bobraus
04-28-2008, 08:25 AM
The Dr. K schematic had a misprint. The 7 ohm resistor should be the correct value. The 20 ohm will not give you the intended sound.

I have built the Dr. K, Natalie P and Roman's MTM. (both later designs listed on the above mentioned link) The Dr. K fell a distant third in my comparison of the three designs when compared with Roman's MTM now in residence in use for my modest home theater set up.

The Dr. K was not unlistenable by any means- just less refined, nuanced and musically involving for me personally. Others have said similar things so I am not a lone voice and though the Dr. K design may be the least costly in crossover parts by a few dollars I would urge you to consider one of the other designs.

Roman's mtm is a remarkable design in light of the fact that it was not tweaked with actual listening- (it was only modeled on the computer). As such it is a very credible design and serves my DVD movie sound duties and TV cable watching well.

If you are looking for music listening primarily the Natalie P would be my choice for acoustic jazz, classical or vocal recordings. Both the Natalie P and Roman mtm offer sonic payback beyond the modest investment required to assemble both designs.

> I was going to attempt to use this MTM
> design but became stuck when I noticed a
> difference in the parts for the X-over to be
> different. The schematic has a 20 ohm
> resister while the parts list at the bottom
> of the DIY page says I should order 7 ohm
> resistors. Which is correct?