Totem Arro Klones... any ideas?

[fjhuerta]

A friend of mine asked me to build her a set of "slim, tall, small" speakers, and I showed her the Arros. She loved them.

http://www.totemacoustic.com/products/columns/arro/

Crossover frequency: 2.4 kHz, 2nd order Linkwitz-Riley (optimized)
Woofer: 4.5" / 114 mm sandwich cone double magnet”
Tweeter: 1 impregnated textile dome 0.75" / 19 mm (low resonance freq.)

The woofer is pretty small... I like that.

Anyway, I was thinking about the drivers for this project. I suppose the tweeter could easily be one of the Dayton Neos (although I wouldn't cross it over at 2.4 KHz 2nd order!) or the Vifa DQ25.

Which woofer would you pick? I was thinking about one of the Peerless for sale currently at PE. Do you have any suggestions?

[JonMarsh]

Plan on some serious damping to kill the column resonance, or doing a TQWT aligment. :W

Hard to recommend a woofer off the top of my head in that size category- most of the 5's are so low in efficiency, and aren't much less expensive than a decent 6. Looks like a Peerless nomex or poly would be your best bet, though I'd consider the smaller Seas ER15RLY.

[Brian Bunge]

Why not build Roman's Microbe SE's into a slim tower?

http://www.rjbaudio.com/Microbe%20SE/microbe%20SE.html

[Jed]

Seas 22TafG and maybe one of the 5" http://www.parts-express.com/pe/show...number=295-600

[fjhuerta]

[QUOTE=JonMarsh]Plan on some serious damping to kill the column resonance, or doing a TQWT aligment. :W

[QUOTE]

Ughh.. forgot about column resonance.

I can't deny it, though - the Arros are very pretty.

Maybe it could be a small bookshelf with the rest of the column just for show.

The microbe may be out of the question - she likes relaxing music, so I'd rather go for a simpler crossover with a paper - plastic cone....

[Dennis H]

About the column resonance, you could put the port up high on the back and put enough stuffing in the bottom to kill the resonance.

[Jed]

About the column resonance, you could put the port up high on the back and put enough stuffing in the bottom to kill the resonance.

I've seen some people use a HR port tuned to resonance inside the box in its own sub enclosure. Maybe that would work?

Dennis do you know the calculations to determine the resonance frequency of a column?

In my Lineup Maxx L16 Mk 2 I had to use quite a bit of stuffing to kill the impedance wobbles created by the narrow and long enclosure. It would be nice to just tune that out with a simple internal chamber and port tuned at that frequency. I mean I could see it in the impedance measurement centered around 175hz, but it would be nice to know ahead of time exactly what frequency to tune the resonance out with a separate port enclosure in addition to the port that sees the outside of the box.

Jed

[Dennis H]

I mean I could see it in the impedance measurement centered around 175hz, but it would be nice to know ahead of time exactly what frequency to tune the resonance out.

That sounds like 1/2 wavelength. Is the box about 39" tall? I don't know if you should try to tune out a single frequency. You're going to have multiple peaks and nulls as the box dimension lines up with various multiples of a wavelength. Seems to me it's just like a bass trap in a room where a broadband absorber works better than one tuned to a single frequency.

[Jed]

That sounds like 1/2 wavelength. Is the box about 39" tall? I don't know if you should try to tune out a single frequency. You're going to have multiple peaks and nulls as the box dimension lines up with various multiples of a wavelength. Seems to me it's just like a bass trap in a room where a broadband absorber works better than one tuned to a single frequency.

Yeah you are probably right because it was more like a ripple at multiple frequencies. The dampening material killed the ripple so I'll leave it at that I guess. The truth is always in the measurement even if it is a lot more work!

[Landroval]

Check this out: http://gagnefr.googlepages.com/theclarro
François Gagné's Clarro's. Should give you good hints for cloning the Arro.

Or maybe this TQWT with RS100-4 could be a good starting point:

http://www.lautsprecherbau.de/index.html/JTI2bmF2aWQlM0Q2MDY3JTI2c2lkJTNEbjQ4NjNhYTBjNWNmNDglMjZiJTNE.html

[fjhuerta]

Peerless drivers... good hint!

I'm not really sure a 3/4" tweeter can handle a 2nd order filter at 2.4 KHz, though. I may go up to the 1" Dayton Neo.

[HareBrained]

Check out Dan's (dlnuebec) Duo-T over on PE's Tech-Talk. It uses a Paul K. design MLTL for the TB W5-704 and the Vifa D26NC tweeter (which is still in stock at Madisound). It's a semi-omni design that won DIY Dayton a couple of years ago. If you're/she's willing to spend more, the Duo-S uses a SS 15W Revelator. The 15W gets about 1/3 octave lower but the 704 ain't no slouch (at 1/10th the cost).

Now, you could just build either of those since it's exactly what you're looking for, or if you're in a designing mood, use the woofer/enclosure with the woofer reoriented to the front and select whatever tweeter you want. Measurements for both woofers are readily available.

Paul K was kind enough to gen-up a MLTL for the SB17 that posted on PE (but unbuilt). If you're willing to go that big, it looks to be a very nice enclosure for a smallish amount of money. F3~35Hz, very smooth predicted response, and in ~32L. I captured it for future reference.

The SEAS L16 is a smallish driver that's willing to play low in a small enclosure. Jed's Maxx's and Linkwitz's Plutos prove that. If you really want small, the L12 would be a very good choice. According to Zaph's measurements, it's got a built-in 3db of BSC. I imagine, it too would work well in a MLTL. You just need to license MLK's program, or ask someone who has them.

[Duke of Dorkdom]

One thing to remember about, I believe all, Totem column speakers is that some of the height is a built in stand, so to speak. You're suppose to fill the bottom section with sand, cat litter, whatnot to "fine tune" the bass. Reason I bring this up is the column resonance isn't as nasty as a first look would have you believe.

[JonP]

Dennis do you know the calculations to determine the resonance frequency of a column?

In my Lineup Maxx L16 Mk 2 I had to use quite a bit of stuffing to kill the impedance wobbles created by the narrow and long enclosure. It would be nice to just tune that out with a simple internal chamber and port tuned at that frequency. I mean I could see it in the impedance measurement centered around 175hz, but it would be nice to know ahead of time exactly what frequency to tune the resonance out with a separate port enclosure in addition to the port that sees the outside of the box.
Jed

Hey Jed... there are a few calculators out there, and if you haven't seen it yet, Bill Collo's site should be a stop for several handy ones more or less rotating around subwoofer design. The box calc program is very handy at giving you the many possible resonances in a particular box shape. All free.
Subwoofer Builder

A few driver recommends... the Peerless 832875 is sold out (might get more?) at PE, maybe not at Madisound... would be a good 5.25", and you really could go narrow box with the truncated frame. Linkwitz originally used it in the Pluto, till it went out of production.
If you want somewhat bigger, the HiVi 6.8 that John M used in the NeoCC design is very similar to that Dynavox, and looks like what's in one of the larger Totems...

And finally, for those who haven't heard... Martin King has brought back updated versions of his MathCad TL/MLTL/ box/dipole frame/etc calculating sheets, after a long hiatus... ;x(

[Jed]

Hey Jed... there are a few calculators out there, and if you haven't seen it yet, Bill Collo's site should be a stop for several handy ones more or less rotating around subwoofer design. The box calc program is very handy at giving you the many possible resonances in a particular box shape. All free.
Subwoofer Builder

A few driver recommends... the Peerless 832875 is sold out (might get more?) at PE, maybe not at Madisound... would be a good 5.25", and you really could go narrow box with the truncated frame. Linkwitz originally used it in the Pluto, till it went out of production.
If you want somewhat bigger, the HiVi 6.8 that John M used in the NeoCC design is very similar to that Dynavox, and looks like what's in one of the larger Totems...

And finally, for those who haven't heard... Martin King has brought back updated versions of his MathCad TL/MLTL/ box/dipole frame/etc calculating sheets, after a long hiatus... ;x(

Thanks for the great info!

Jed