[bdp24]

Thanks for the advice.

I already have purchased a kit of a pair of duel 8" for a sealed servos from Rythmik.  see http://www.audiocircle.com/index.php?topic=112798.msg1316435#msg1316435. And about a year ago I was well on my way to finishing a pair of stands http://www.audiocircle.com/index.php?topic=126451.msg1334003#msg1334003 that would incorporate the servos when I got sidetracked.  I am just now getting back to that project.    What I would be interested in for OB servos would be either triple 8" (16 ohm) or dual 8" (8 ohm) versions.  So I am interested in a drawing so I can build it myself.  Ruben does incredible work, but these look pretty simple and within my capabilities. 

Of course, I don't really need these, as I have a pair of LS-6s and a LS-C, but the wedgie thread has me fascinated. As for the servo, I'm completely sold.  For about a year now I have been using a single 2x8" MDF box with the Rythmik HX580 that completely blows me away.  It replaced a 13" SVS PB ultra (which could shake my 25' x 15' x 6.5' to 14' cathedral ceiling room to the point of being scared), and I haven't missed it.  The servo is phenomenal.

Danny doesn't have plans for an H-frame for the 8" woofers, but you could take the dimensions from the plans for the SW-12-16FR (seen by "clicking" on the plan's title, found right by the pics of that woofer in the driver's listing on the GR website) and extrapolate them to get the same for 8" woofers.

[Captainhemo]

I'd think someone  who's made / built the triple  8's will chime in with some  exact measurements.... 
Looking quickly at the Rythmik site I see the 8" drivers  have an 8.78 OD  and need 5"  of  clearence.  If you made each "box" front and beck  approx 10 x 10 x 5.5-6 you'd be fine.
I'd  still double up the side panels, tops, and bottoms.  A single layer baffle and the 4 braces will be fine
So using a .75 thick baffle  / braces,  you'd be lookjing at 31.5 tall by  11.75 - 12.75 deep   then  your top/ bttom plates
Of course if youi're doing doubles,  shorten  the height up  to 20.75".  Also, I didn't  tagger the braces like some do, you could save a bit more height by doing that
You could probably open that 10"  x 10"  a little bit if you wanted a little  more clearence....

jay

[Outofthewoods]

Hey Guys,

I will draw some plans and post them here tomorrow. I've got it all laid out full scale. I just need to pull the measurements and draw it up.

Ruben

[jseipp]

That is extremely generous of you, Rubin, as I'm sure all here will agree.  This is a great community!

[jseipp]

Not to leave out so many others I've learned from here .

[ACHiPo]

Here is where you can learn more about the servo technology.

http://www.rythmikaudio.com/technology.html

Danny,
Thanks.  Rhythmik's servo sub technology is already on my short list as a source for a multi-sub swarm-like approach.  I'm struggling with wire logistics (I want wireless, but am not sure it will work right), and I haven't found just the right mix of small, medium, and large subs to scatter around my room.  The OB concept is interesting, but I'm not sure of room placement, etc.

AC

[Danny Richie]

Danny,
Thanks.  Rhythmik's servo sub technology is already on my short list as a source for a multi-sub swarm-like approach.  I'm struggling with wire logistics (I want wireless, but am not sure it will work right), and I haven't found just the right mix of small, medium, and large subs to scatter around my room.  The OB concept is interesting, but I'm not sure of room placement, etc.

AC

When we add rear subs at the shows we use a pair of the 12" servo subs in a sealed box turned down to a low frequency setting and connect them with some 25 foot long shielded RCA cables.

They smooth out the room and add a little reinforcement to the bottom end. 

[ACHiPo]

When we add rear subs at the shows we use a pair of the 12" servo subs in a sealed box turned down to a low frequency setting and connect them with some 25 foot long shielded RCA cables.

They smooth out the room and add a little reinforcement to the bottom end. 

That's kinda what I had in mind.  It's just running 4 xlrs or rcas and making 4 more holes in the floor is not too appealing, but I'm thinking I may have to figure it out.

So do I take it that the key is the servo and not so much the OB for sub reinforcement?

[Danny Richie]

That's kinda what I had in mind.  It's just running 4 xlrs or rcas and making 4 more holes in the floor is not too appealing, but I'm thinking I may have to figure it out.

So do I take it that the key is the servo and not so much the OB for sub reinforcement?

We use the OB subs in the full range speakers up front and just even out the room loading in the back corners of the room with the sealed box servo subs running out of phase from the main speakers.

[mlundy57]

Danny,
Thanks.  Rhythmik's servo sub technology is already on my short list as a source for a multi-sub swarm-like approach.  I'm struggling with wire logistics (I want wireless, but am not sure it will work right), and I haven't found just the right mix of small, medium, and large subs to scatter around my room.  The OB concept is interesting, but I'm not sure of room placement, etc.

AC

The last time I looked at running wireless for my sub I found out that the wireless transmission only works down to 30 Hz. Unless the technology has changed since then, you would lose a lot of what the servo subs have to offer by going wireless.

Mike

[Tyson]

That's kinda what I had in mind.  It's just running 4 xlrs or rcas and making 4 more holes in the floor is not too appealing, but I'm thinking I may have to figure it out.

So do I take it that the key is the servo and not so much the OB for sub reinforcement?

Try OB first without the swarm approach first, you might find you just don't need it.  Just going to OB from a box is such a huge step up over traditional boxed bass, you might not even need to mess with the extra subs....

[ebag4]

Try OB first without the swarm approach first, you might find you just don't need it.  Just going to OB from a box is such a huge step up over traditional boxed bass, you might not even need to mess with the extra subs....

+1

[Tyson]

+1

And I say that as someone that has spent significant time in a friends dedicated audio room with a swarm of boxed Rhythmik servo subs.  As good as it is (and it's awesome), it's still not at the level of the Super 7's and Super V's that I've heard using the OB 12 inch woofers. 

Also, remember that OB and swarms actually work against each other.  OB works because it excites LESS room modes, a swarm approach works because it excites MORE room modes.  It kind of doesn't make sense to do them together.

[ACHiPo]

And I say that as someone that has spent significant time in a friends dedicated audio room with a swarm of boxed Rhythmik servo subs.  As good as it is (and it's awesome), it's still not at the level of the Super 7's and Super V's that I've heard using the OB 12 inch woofers. 

Also, remember that OB and swarms actually work against each other.  OB works because it excites LESS room modes, a swarm approach works because it excites MORE room modes.  It kind of doesn't make sense to do them together.

Tyson,
Thanks.  Is there some good information on OB servo sub placement?  If it excites fewer modes (not sure how that works if it's putting out energy the room will amp/null) do you place it in a null, and if so, which frequency (I have several nulls to choose from  )

AC

[Odal3]

I like H-frame and dual 12 inches best - goes lower and louder than the triple 8 inch, and is still the perfect size to act as a "stand" for a midrange and tweeter.

Super - thanks for sharing!

[Tyson]

Tyson,
Thanks.  Is there some good information on OB servo sub placement?  If it excites fewer modes (not sure how that works if it's putting out energy the room will amp/null) do you place it in a null, and if so, which frequency (I have several nulls to choose from  )

AC

I'd place them close to the main speakers for a starter. 

[S Clark]

I just bought a servo amp and pm-ed to Danny about placement for a two 12" open baffle sub.  In my room, he said in between the main speakers.
I've got to get some of that OB servo bass.  It will ruin you for anything else.  Tyson is right.  I don't understand why this hasn't become the standard.

[bdp24]

I just bought a servo amp and pm-ed to Danny about placement for a two 12" open baffle sub.  In my room, he said in between the main speakers.
I've got to get some of that OB servo bass.  It will ruin you for anything else.  Tyson is right.  I don't understand why this hasn't become the standard.

Around here, it has!

[ACHiPo]

I'd place them close to the main speakers for a starter.

Thanks.  Not really looking for another project, but we'll see how things develop.

[Outofthewoods]

Hey Guys,

Sorry for the wait. I had to lay it out again from scratch as my original layout was done using 1 1/4 inch MDF everywhere. This scribble will give you the essential dimensions and you can account for additional material thicknesses as you desire. 1 1/4 - 1 1/2 inch material thickness is recommended for the top, bottom, and sides.

Not shown in the pic, but the drivers are centered left to right. 5 1/2 inches from the outside face of the side panels is centered. The baffle is also 3/4 inch thick as drawn. Braces are 6 inches deep.

Best,

Ruben 



Here is how they look when built using 1 1/4 inch material for all parts.