Pluto-like speakers using different drivers...Rs125...

[nerd of nerds]

Hello!

I've been looking at the pluto contemplating creating a clone of it. I was thinking of using the Dayton RS125 as the woofer and the Aura 2" as the tweeter (same tweeter as the pluto). This seems like a nice combo as the RS125 has nice output to 2.5k (i'd use it out to 1khzish, like the pluto).

I'd like to try this project becuase i really like building amplifiers and this would give me a chance to make a spiffy active XO and some gainclones...as well as experiment with active crossovers...

Would those 2 drivers work okay for this project/experiment? A cheap omnidirectional speaker would be sweeeet...

[nerd of nerds]

awww cm'on. NO one has any kind of opinion on this?!

[Jonasz]

I think it will work great, just be sure to take care of the breakup. Why not try and make a couple of subs with the RS10" (or RS8") too? :P

http://www.linkwitzlab.com/Pluto/subwoofer.htm

[Landroval]

I'd go for a RS180. A single RS125 can't do much.

[joecarrow]

Nerd,

There is more to the pluto than meets the eye; I think you would do well to start out trying to come as close as possible to the original design. The RS125 may be a good driver, but you will still need to deal with cone breakup.

The reason why a 7" driver might not work as well as the original 5" driver is because it's not going to be omnidirectional to as high of a frequency. An alternative to get higher SPL down low would be to have a second pluto tube suspended above the floorstanding one, so the two woofers are firing toward each other. I don't know if you would run into cavity resonances or not, but it seems like it should work.

Good luck, and keep us updated!

[nerd of nerds]

Nerd,

There is more to the pluto than meets the eye; I think you would do well to start out trying to come as close as possible to the original design. The RS125 may be a good driver, but you will still need to deal with cone breakup.

The reason why a 7" driver might not work as well as the original 5" driver is because it's not going to be omnidirectional to as high of a frequency. An alternative to get higher SPL down low would be to have a second pluto tube suspended above the floorstanding one, so the two woofers are firing toward each other. I don't know if you would run into cavity resonances or not, but it seems like it should work.

Good luck, and keep us updated!

I wouldn't use the 7" anyway as it would be expensive to buy PVC big enough to house it. Not to mention haivng 2 huge tubes on either side of my telly would look like ass...

The breakup on the RS125 starts to get bad after the 2.5-2.8khz dip, well after the 1khz XO frequency i'd be using. I could definetly go lower than that but at what cost to tweeter performance...idk...The crossover will be 4th order active fwiw.

And as far as a matching sub, i already have a pretty decend TB 8" that works fine for my needs. As much as i'd LOVE to have a dipole 18" sub, that just isn't gonna happen ;-) I'm 17 (well, in 20ish days) and still live at home with my parents <_< But do not by any means think that because of my age I can't do this project...I've been reading schematics since i was seven, soldering since 8-9, and studying speaker design since i was 14.

Thanks for the help!

EDIT: I just realized that the RS125 shielding could hinder air flow in a tube...

I know I saw on some forum a guide on removing the shielding from the RS series of drivers but can't find it...I think for this driver to work that thing has gotta go...

[Dennis H]

The RS125 only has 2.8mm of Xmax so that will really limit the bass output. The RS150 has more cone area as well as 4mm Xmax but it still won't move as much air as the Peerless SL used.

Dayton has an unshielded 4-ohm version of the RS150 meant for car audio. It might work.

[nerd of nerds]

The RS125 only has 2.8mm of Xmax so that will really limit the bass output. The RS150 has more cone area as well as 4mm Xmax but it still won't move as much air as the Peerless SL used.

Dayton has an unshielded 4-ohm version of the RS150 meant for car audio. It might work.

I won't really need a lot of bass output from it as it will be crossed over to the subwoofer around 100hz-150hz, but I am looking into the RS150 as it appears to be the same size as the peerless driver. I'm just wondering how exactly he got that driver to fit...iirc linkwitz uses 4" pvc and the peerless is about 5-15/16" in diameter...

[Dennis H]

P is a 4" Clay to 4" Plastic rubber coupler with a steel clamp to tighten it onto K.

[nerd of nerds]

Yeah, I've seen that...I'm guessing the pvc is 4" ID with 1/4"ish walls?

[Davey]

And there's even more to it than that.

The mounting position of the coupler on the pipe is also important. Drivers with largish magnets, or shielding as you mentioned, are not an option because they will project into and fill much of the pipe opening. Some sort of a spacer between driver frame and the coupler connection would be required in that case. Also, the packing density/amount/arrangement of the poly-fill is a concern.

The Peerless driver specified by SL is superior to any of the RS drivers for this application...IMHO. Since you're already going to use the Aura tweeter I'm not sure why you'd want to re-invent the wheel.

Cheers,

Davey.

[nerd of nerds]

And there's even more to it than that.

The mounting position of the coupler on the pipe is also important. Drivers with largish magnets, or shielding as you mentioned, are not an option because they will project into and fill much of the pipe opening. Some sort of a spacer between driver frame and the coupler connection would be required in that case. Also, the packing density/amount/arrangement of the poly-fill is a concern.

The Peerless driver specified by SL is superior to any of the RS drivers for this application...IMHO. Since you're already going to use the Aura tweeter I'm not sure why you'd want to re-invent the wheel.

Cheers,

Davey.

Because reinventing the wheel is fun :rofl: The magnet on the RS150-4ohm version doesn't look TOO obstrusive...

[joecarrow]

In order to re-invent the wheel, you need to know what's so cool about the wheel to begin with, and then do everything you can to avoid taking a step backwards.

Here are some of the benefits of the woofer already selected:
-Long xmax for its size. This controls the bass output.
-Essentially omnidirectional up to the 1 khz crossover. A larger diameter woofer will start to get directional at a lower frequency. Could you go to six inches? Probably. Eight inches"? Probably not, not without a lower crossover.
-Cone material has minimal breakup that needs to be dealt with in the crossover. If you go to a metal cone, breakup must be addressed in the crossover.
-Small magnet allows use in a tube.

The only other drivers I know that fit most of these criteria are the Ascendant Audio midbass, or the Adire Extremis. They both have some extreme Xmax, neodymium motors, paper/poly cones, and are only 6.5 inches in diameter. It might be a stretch and it might require a slightly lower crossover- but depending on the off axis response at the upper range you might have a chance.

Disclaimer- I still have not seen any measured data on that Ascendant driver.

[cjd]

Aurasound has some drivers that fit the bill in a small size as well.

C

[nerd of nerds]

Aurasound has some drivers that fit the bill in a small size as well.

C

I haven't seen any decent measurements on any of those aurasound drivers though (other than the 3"), but they do look quite impressive on paper. I am working on getting a really nice measurement system set up so measuring stuff in the next few weeks will be possible...

And yes, i understand what is so great about the wheel. I never wanted to go bigger than the peerless driver anyway. I am looking into different driver solutions, I never had my heart set on the dayton anyway...

[cjd]

The RS150 or RS180 in a similar setup would really be pretty sweet IMHO. They should do superbly in a TL. It's more the specifics of that driver setup.

I actually heard one (Bill Horn's I think?) with one of the Dayton "Euro" woofers (don't recall what tweeter) with the woofer up-firing - in the room we were in, the sound was very interesting, to be sure.

My fun is in inventing my own rolling devices, even when heavily influenced by the work of others. So, take the concept, understand the requirements, and then play within the rules (and have fun!)

C

[Landroval]

One important thing of course is the size of the enclosure tube. With RS125, Aura NS4, etc small 4"-4,5" drivers you shouldn't go much over 3-4 litres. The CSS WR/FR125 likes a little more space and gives quite decent bass output, check it out, it could suit your plans quite well. The only problem with it is the huge magnet assembly, but a slightly larger top part for the tube should fix that.

[Jonasz]

Maybe the Seas Excel 5" with the neo-motorsystem would work? It has decent xmax (4mm) and a very small motor.

The downside is obviously the price, but it may be worth it?

[Hdale85]

Its very pretty with that copper phase plug

[joecarrow]

That driver would, in my opinion, be a step backwards. You lose radiating area to the phase plug, and it has even less excursion. Keep in mind that the Pluto is a small sealed design with a 5" woofer, and it is severely limited below 100 hz.

Maybe I'm being stubborn with this, but I think Pluto's biggest weakness is its bass capabilities. If you're going to change it, that's what you don't want to make worse. If you have stereo subwoofers crossed high that's a different matter- but it changes the character of the system.

[AJINFLA]

Maybe I'm being stubborn with this, but I think Pluto's biggest weakness is its bass capabilities

I think that's why SL added this low cost sub http://www.linkwitzlab.com/Pluto/subwoofer.htm
If I was building a Pluto, I would use the Peerless. If I were building something that looked like the Pluto, I wouldn't.

cheers,

AJ

[joecarrow]

Oh yeah, I dont know what level of performance these woofers have- but I came across these 5.25" woofers made by tang-band: http://www.partsexpress.com/pe/showd...number=264-831

Half the price, and a good deal more excursion. Anyone know if these things are worth $30?