Natalie vs. Jeff B.'s RS180 MTM design?

[Applesauce]

Can anyone compare these two, both excellent-looking designs? One seems the epitome of simplicity (Jeff B.'s), while the other, the Natalie P, seems the complete opposite, with a (series?) crossover that's nearly undecipherable to me. I know there's more than one way to make an omelette, but these are polar opposites! Jeff B., for instance, doesn't make any mention of the supposed "dark side" of the RS180.

I'm drawn to both, but for different reasons. I'd like to build an RS180 MTM, and both seem like solid, well-thought-out designs. Can anyone comment on one or both, especially regarding the differences in crossover complexity?

Also, does anyone have any suggestions for implementing the non-shielded RS180 in any of the many existing MTM designs?

[turn2]

Can anyone compare these two, both excellent-looking designs? One seems the epitome of simplicity (Jeff B.'s), while the other, the Natalie P, seems the complete opposite, with a (series?) crossover that's nearly undecipherable to me. I know there's more than one way to make an omelette, but these are polar opposites! Jeff B., for instance, doesn't make any mention of the supposed "dark side" of the RS180.

I'm drawn to both, but for different reasons. I'd like to build an RS180 MTM, and both seem like solid, well-thought-out designs. Can anyone comment on one or both, especially regarding the differences in crossover complexity?

Also, does anyone have any suggestions for implementing the non-shielded RS180 in any of the many existing MTM designs?

I doubt you'd be disappointed with either design. Do note this: The 2 designs use a different tweeter. I believe the concensus is that the new RS180's are virtually drop-ins for the old shielded version. Not so with the RS28A(S).

[djg]

And the tweeter for Jeff's design is out NLA, according to the thread.

www.rjbaudio.com/projects.html has a comparison of several crossovers for this speaker. A bit dated, but you may find it interesting.

[Wolf]

I believe there are more than just those 2 out there...

Natalie P
Dr. K
Jeff B (For shielded RS28)
RJB MTM and 2.5 MTM
John Marsh's RS28 Modula MTM
Dave Brown's MTM

See this linky:
http://www.rjbaudio.com/RS180MTM/rs180-rs28-mtm.html

Later,
Wolf

[djg]

Huh.

[Wushuliu]

I's be interested in hearing about any comparison as well. Hopefully someone will give a shot and try both XOs since there are so many RS180 MTMs out there. I built the Modula MTMs as well as a simpler XO by Jay Kim and they sounded more alike than not.

[Deward Hastings]

C'mon, kids, here we are, more than a decade into the twenty first century, and you're arguing which is better, a '36 Dodge or a '37 Chevy.

The RS180 and the RS28 are, at least, still very good drivers . . . very difficult to beat for the price. But those crossovers? Archaic, almost barbaric, every one of them. Straight out of the dark ages. Put a MiniDSP, or any other good active crossover, on those drivers (LR4, notch the breakup, delay the tweeter, baffle step if you wish) and you will easily have a better loudspeaker than any of those mentioned in the posts above. And that's before you start tweeking . . .

History is fine, history is fun, but history class is not the place to design loudspeakers . . .

[Wushuliu]

Isn't it bedtime, Grumpy?!

[parodielin]

Could I have a MiniDSP tutorial with RS180 + RS28F? Any takers? Wusu..... (Sorry to call your name but you wrote such excellent tutorials...)

I's be interested in hearing about any comparison as well. Hopefully someone will give a shot and try both XOs since there are so many RS180 MTMs out there. I built the Modula MTMs as well as a simpler XO by Jay Kim and they sounded more alike than not.

C'mon, kids, here we are, more than a decade into the twenty first century, and you're arguing which is better, a '36 Dodge or a '37 Chevy.

The RS180 and the RS28 are, at least, still very good drivers . . . very difficult to beat for the price. But those crossovers? Archaic, almost barbaric, every one of them. Straight out of the dark ages. Put a MiniDSP, or any other good active crossover, on those drivers (LR4, notch the breakup, delay the tweeter, baffle step if you wish) and you will easily have a better loudspeaker than any of those mentioned in the posts above. And that's before you start tweeking . . .

History is fine, history is fun, but history class is not the place to design loudspeakers . . .

[turn2]

C'mon, kids, here we are, more than a decade into the twenty first century, and you're arguing which is better, a '36 Dodge or a '37 Chevy.

The RS180 and the RS28 are, at least, still very good drivers . . . very difficult to beat for the price. But those crossovers? Archaic, almost barbaric, every one of them. Straight out of the dark ages. Put a MiniDSP, or any other good active crossover, on those drivers (LR4, notch the breakup, delay the tweeter, baffle step if you wish) and you will easily have a better loudspeaker than any of those mentioned in the posts above. And that's before you start tweeking . . .

History is fine, history is fun, but history class is not the place to design loudspeakers . . .

Build, document in detail and publish that and you may get a following. I for one would be too much of an idiot (and maybe too lazy) to go in cold.

[Applesauce]

Build, document in detail and publish that and you may get a following. I for one would be too much of an idiot (and maybe too lazy) to go in cold.

Ha! I'm with you. A far cry from smart enough, that's for sure. I got my masters... But not in anything related to anything that might be useful here.

Thanks for all the info, everyone else. I'd seen all those links - more I was hoping for a clearer explication of why there might exist such very different crossovers to do much the same job.

[Applesauce]

I believe the concensus is that the new RS180's are virtually drop-ins for the old shielded version. Not so with the RS28A(S).

Right. I'd caught that. It looks like Solen still has some of the RS28A-S in stock, so I might go that route (although I have no need for shielded drivers). Conversely, I might go with one of the designs using a Seas tweeter... Open to suggestions here, too! I guess all I've really settled on is that I want to build a stand-mounted MTM with the RS180, and I'm still open to a tweeter (and thus, filter).

[fastbike1]

The active crossovers still use the "archaic" topology . . . LR4, notch, etc.
Seems like it requires similar work to learning PCD, plus requiring bi/tri/etc amping.

Build, document in detail and publish that and you may get a following. I for one would be too much of an idiot (and maybe too lazy) to go in cold.

[Deward Hastings]

Seems like it requires similar work to learning PCD,

Much easier, since almost all the complexity goes away when you "normalize" driver impedance and acoustic centers . . . and you can model it all on the right hand side of PCD if you wish.

[fjhuerta]

C'mon, kids, here we are, more than a decade into the twenty first century, and you're arguing which is better, a '36 Dodge or a '37 Chevy.

The RS180 and the RS28 are, at least, still very good drivers . . . very difficult to beat for the price. But those crossovers? Archaic, almost barbaric, every one of them. Straight out of the dark ages. Put a MiniDSP, or any other good active crossover, on those drivers (LR4, notch the breakup, delay the tweeter, baffle step if you wish) and you will easily have a better loudspeaker than any of those mentioned in the posts above. And that's before you start tweeking . . .

History is fine, history is fun, but history class is not the place to design loudspeakers . . .

Everytime I look at how much I spend in passive elements, and the cost of a pair of MiniDSPs, I wonder... why bother anymore? I may just get two Class-D 4 channel amps, two MiniDSPs, and forget about passive elements and their losses.

[Wolf]

Why don't you just let others build passive xovers like they want to and quit trying to shove 'activeness' down their throats? It gets old, Deward.

Active is impractical, you require 6 channels of amplification for a 3-way, sure you can optimize levels easily, but that is still likely 3 stereo power amps.

This also means that you cannot easily translate the system to another position somewhere else in the world without having to tweak it back into place, and cart all of that stuff there as well.

If you like active circuits, that's fine, but not everyone should be told they should be doing it that way. As you also should recall, not everyone agrees with the way you xover the RS180 anyway.

I'll stick with my passives.
Later,
Wolf

[Deward Hastings]

Why don't you just let others build passive xovers like they want to and quit trying to shove 'activeness' down their throats? It gets old,

Why don't you just let others build active xovers and experience their superiority, and quit trying to shove 'passiveness' down their throats, Wolf? It gets old . . .

[Wolf]

Why don't you just let others build active xovers and experience their superiority, and quit trying to shove 'passiveness' down their throats, Wolf? It gets old . . .

That's a matter of preference, Deward, and I'm not. I don't say, "Why don't you have those made with passive xovers instead of active xovers because passives are superior!", like you do in opposing terms. If they ask about passives, I help. Period. That's the difference.

And also- you're in the minority when it comes to xovers anyway. More passives are built than actives.

I have heard active systems, mainly 'BESL System 5', and I was not impressed so far to say that it was better than every passive system I've encountered- becauese it wasn't.

Later,
Wolf

[martyh]

That's a matter of preference, Deward, and I'm not. I don't say, "Why don't you have those made with passive xovers instead of active xovers because passives are superior!", like you do in opposing terms. If they ask about passives, I help. Period. That's the difference.

And also- you're in the minority when it comes to xovers anyway. More passives are built than actives.

I have heard active systems, mainly 'BESL System 5', and I was not impressed so far to say that it was better than every passive system I've encountered- becauese it wasn't.

Later,
Wolf

Dang Junior!

[fntn]

While I've been derided for suggesting that digital crossovers like MiniDSP would eventually surpass passive builds in total numbers, possibly in 5 years - I don't consider passives to be "child's play". This statement:

"C'mon, kids, here we are, more than a decade into the twenty first century, and you're arguing which is better, a '36 Dodge or a '37 Chevy.

The RS180 and the RS28 are, at least, still very good drivers . . . very difficult to beat for the price. But those crossovers? Archaic, almost barbaric, every one of them. Straight out of the dark ages." -Deward Hastings


- is a bit over the top and condescending for someone who knows better. As Wolf said, not everybody wants three to six amplifiers and lots of extra cabling to deal with. And the performance differences are not exactly "night and day" enough to warrant the "C'mon kids" non sense. JeffB's simple MTM RS180 crossover is most likely very, very hard to beat from a cost standpoint. And given his track record, it probably is pretty difficult to beat from a sonic standpoint. The condescension isn't very appropriate.