My RS180 MTM Design

[AlexRivera]

Very Nice!! Great job on the Xover, too!
Marvin

Thanks Marvin, I really like how crossovers look in those perforated boards.

[filmslayer]

those look great

[AlexRivera]

Just Measured one of the speakers with my very limited knowledge in Omnimic and in my garage, used a short sweep and placed the Omnimic about 1 meter away at the tweeter level as suggested, no special placing or preps, nothing and this is the graph that came out, how does it look?

[marvin]

Very Nice!! Great job on the Xover, too!
Marvin

[AlexRivera]

I finished assembling these last night and all I can say is that I LOVE THEM, I used the standard 2" port from PE w/o cutting it, which is 6" long so its tuned for 34Hz, to me they have an awesome bass response and I'll probably leave them like that, I have only tested them in my garage which is ~7500 cu.ft. and they still sounded great!

I'm still waiting for PE or someone else to put together a "Speaker measurement for Dummies with OmniMic" post or video so I know how to properly measure them.

Crossover




Cabinets



Added Dampening Material



Installed Crossover, Port and Binding Posts




Added some gasket to the baffle area...


Finally Mounted the Drivers

[PWR RYD]

Question for the experts, do you guys usually run ZMA and T/S Tests with LIMP to get the parameters for your specific drivers to be used or you just trust the Vendor's?

Thanks,
Alex

I always measure my drivers.

[AlexRivera]

Question for the experts, do you guys usually run ZMA and T/S Tests with LIMP to get the parameters for your specific drivers to be used or you just trust the Vendor's?

Thanks,
Alex

[AlexRivera]

I'm finally getting started with these beauties today, ended up choosing close to the best crossover components I found on PE and instead of building that Trans Laminate cabinet (cause of the delay) I ended up ordering a pair of those Dayton Audio MTMC-1.0CH 1.0 cu. ft. MTM Curved Speaker Cabinet In Cherry, we'll see how everything comes together using the same Woofers and Tweeters as Mr. Bagby.




I'll keep you posted and of course I'll bug you with questions as I make some progress.

Alex

[Wushuliu]

FWIW, I think I've been listening to these for almost a year now.  I honestly put these together for a reference system - "What does 'good' sound like?" I'm still not convinced that I have them placed in the room optimally or that I totally nailed the cross over.  I'm certainly not convinced I have a great set of ears.  I like them.  At times they've seemed a little bass-shy, but that could be that I'm using an amp with no EQ functions, or non-ideal placement or if I'm just not used to what "flat" sounds like.  I have no regrets about building them and have total gratitude to Jeff for posting his initial thread.  I'm still using the "messed up" baffles from a year ago.  I have a new set of blanks, but the messed up baffles don't seem to be messing with performance.  I just filled the bad holes and shifted my screw hole arrangement.

The bass shy could be related to how 'clean' the low frequencies are for the RS 180. For more boom you'd probably want the MLTL version. Would be neat if one could turn it into a 3-way though like some of other Jeff's monitor designs.

[kraigo]

FWIW, I think I've been listening to these for almost a year now.  I honestly put these together for a reference system - "What does 'good' sound like?" I'm still not convinced that I have them placed in the room optimally or that I totally nailed the cross over.  I'm certainly not convinced I have a great set of ears.  I like them.  At times they've seemed a little bass-shy, but that could be that I'm using an amp with no EQ functions, or non-ideal placement or if I'm just not used to what "flat" sounds like.  I have no regrets about building them and have total gratitude to Jeff for posting his initial thread.  I'm still using the "messed up" baffles from a year ago.  I have a new set of blanks, but the messed up baffles don't seem to be messing with performance.  I just filled the bad holes and shifted my screw hole arrangement.

[kraigo]

FWIW, I used 2x 2" diameter by 7.25" deep PVC tubes centered as closely as I could to the centers of the woofers for ports.  I run at low enough levels that thermal issues are really an afterthought, but as long as I needed to use two ports anyway with the curved cabs, I might as well use them to help with cooling.

[AlexRivera]

That picture shows the passive filtering for the amplified version of the speaker. That's not the crossover for the passive version of the speaker.

Yes, I thought you may have used similar components on the non powered one , wasn't that the case?

[Jeff B.]

Hi All,

I got my hands in a pair of R28AS-4 so I'll try to implement the original design in a Trans Laminate cabinet, what would you recommend as far as crossover components go?

I'm not asking about $150 dollars Caps but more about what's the recommended quality to get the closest to the original design?

I wish I was experienced enough to be able to tell from the picture what components Mr. Bagby used .

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Thanks,
Alex

That picture shows the passive filtering for the amplified version of the speaker. That's not the crossover for the passive version of the speaker.

[AlexRivera]

"pretty salty" means expensive. A 50uF in a poly might be $15, where a NPE would be $1.10. Any decent poly for everything but the 50uF in teh woofer circuit (there use a NPE) and you will be fine. I typically use Dayton poly caps, or Audyn.

Hahahah, struggling with slang here, OK, I got it now.

Thanks Paul!

[bullittstang]

"pretty salty" means expensive. A 50uF in a poly might be $15, where a NPE would be $1.10. Any decent poly for everything but the 50uF in teh woofer circuit (there use a NPE) and you will be fine. I typically use Dayton poly caps, or Audyn.