My RS180 MTM Design

[DjDisturbed]

Re: My RS180 MTM Design

They look great in the pictures and on paper.

[fntn]

Re: My RS180 MTM Design

Just a wee bit simpler crossover than the NatP or Marsh's elliptical / 4th order. It's a beautiful thing when a simpler approach is good enough and works.

[upsman]

Re: My RS180 MTM Design

The port tuning is at 40Hz. I do not know where it is being crossed over at to the sub, that is being done by the studio tech.

Jeff What are the dimensions of the port used.......Thanks

[cwad8505]

Re: My RS180 MTM Design

Well..dang.. Now I MUST build these! soon as I finish my Nano NTN's and Zaph BAMTM..this stuff is like crack for the ears..Highly addictive! Thanks again Jeff for a beatiful design both externally and electronically..
Thanks,
Chris

[Pete Schumacher]

Re: My RS180 MTM Design

I may do that one day. Right now I have the "Seas flavored" version (27TDFC/G) with some Pete Shumacker designed crossovers in them.

Post the XO I sent you. I'd like to see how close the woofer XOs are to each other. They're both real simple.

[fastbike1]

Re: My RS180 MTM Design

It's a 1 cubic foot box tuned to 40 Hz. Any box program will give you the set of dimensions that will achieve 40 Hz.

Jeff What are the dimensions of the port used.......Thanks

[Jeff B.]

Re: My RS180 MTM Design

I intended to post this chart too, but forgot. Here are the transfer functions for the crossover for those that are interested in this.



There was more interest in this design than I anticipated. Thanks, guys.

Jeff

[Jeff B.]

Re: My RS180 MTM Design

It's a 1 cubic foot box tuned to 40 Hz. Any box program will give you the set of dimensions that will achieve 40 Hz.

That would be my suggestion. I would have to call the studio to have someone tell me exactly what diameter and length they are, as I do not remember exactly.

[fastbike1]

Re: My RS180 MTM Design

You are being way too modest. There are several designers here whose designs offer much to learn. You are definitely one of them. ;)

I intended to post this chart too, but forgot. Here are the transfer functions for the crossover for those that are interested in this.



There was more interest in this design than I anticipated. Thanks, guys.

Jeff

[robertclark]

Re: My RS180 MTM Design

Post the XO I sent you. I'd like to see how close the woofer XOs are to each other. They're both real simple.

Here you go....................

[foxfire3]

Re: My RS180 MTM Design

Here you go....................



[ATTACH]15112[/ATTACH]

I wonder if Pete's has a lower crossover point with the larger 33uF cap.?

[Pete Schumacher]

Re: My RS180 MTM Design

I wonder if Pete's has a lower crossover point with the larger 33uF cap.?

Probably just a touch, more like 1500 if I can remember correctly. It's been a long time since I modeled that up.

What I find refreshing is that my XO attempt is so close to Jeff's. I just went with the cheap option by subbing a small cap and resistor for the small inductor to make the tank.

:p

[robertclark]

Re: My RS180 MTM Design

I'll bring these down to DoubleTap's in May so you can hear them.

[endless]

Re: My RS180 MTM Design

Jeff
I am working on a new HT setup, I have built a HIVI SP-10 sub to start it off and love it. I was considering the USHER project on PE for my L/R/C speakers but you have really posted a gem of a project here. Of course you can predict my next question, what changes would be needed to lay one of these down for a center channel?
Out of the question due to the MTM vertical/horizontal issue?
Many thanks for a beautiful project.
Steve in Maui

[Jeff B.]

Re: My RS180 MTM Design

Jeff
I am working on a new HT setup, I have built a HIVI SP-10 sub to start it off and love it. I was considering the USHER project on PE for my L/R/C speakers but you have really posted a gem of a project here. Of course you can predict my next question, what changes would be needed to lay one of these down for a center channel?
Out of the question due to the MTM vertical/horizontal issue?
Many thanks for a beautiful project.
Steve in Maui

Due to the fairly low crossover point, if it were directly in front of the listening area it wouldn't be too bad placed horizontally. I am not certain without really digging into it what the angle of the listening window would be though.

However, can your home theather amp handle a group of speakers that all drop below 4 ohms?