[SteveCornell]

I posted a similar question in another post but thought I'd give this it's own topic...
I hope you don't consider this blasphemy  but.........

 What would sealing up the open baffle section of say an OB7 plus or the OB5 do to the overall performance of the speaker, I need to build a set of speakers for my HT but I need to keep them closer to the walls than what is optimum for the OB designs.

 Would the crossover components used in the OB design need to be altered to use the MTM in a sealed design and would the (2) sealed on top, MTM-center, and (2) sealed bottom design still work out with this scenario, if this would work I would also build an OB5, seal the MTM section and move 1 woofer to each side for a center speaker playing horizontally.
 
 I understand that the "airyness" of the OB design would be lost, but I really like the look of the 7 driver tower and if the entire crossover network would not need redesigned I'd like to experiment with a different cabinet design, electrically nothing would change in the speaker but I was unsure if the same crossovers could be used.
 
 Thanks in advance for your advice (or tomato throwing, if I offend anyone by defeating the purpose of the OB design) 
Steve

[TRADERXFAN]

You would have to redo the network...

Why not just get the N3?

[SteveCornell]

I am considering the N3, I guess what I'm trying to envision is a sealed N3 with 4 sealed M130s (as in the OB7) instead of the transmission line.

[TRADERXFAN]

Well, now that I think of it, there was a speaker Danny was involved with, somewhat like you describe... the RA8...
http://www.audiocircle.com/index.php?topic=20593.msg195406#msg195406

Very sensitive. But ribbon, not neo pdr tweeter. Not that there is anything wrong with the ribbon. Just a bit different.  I think it had some ports though. 

-Tony

[SteveCornell]

Tony,

Thanks for the link.... YES, that's the look I'm wanting and I want the quickness and dynamics that I would think a configuration such as this could achieve.

[TRADERXFAN]

So may I ask why are you against going open baffle?

I think if you want dynamics, you should talk to Danny about that p-audio driver.

I bet Danny could help you put that in a sealed box and have more dynamics than you would believe... 

I was thinking about using those 12" drivers he uses in the v-1, in ported boxes (would need to be huge) for a dedicated home theater.

-Tony

[SteveCornell]

I don't want the speakers any more than 12"-18" from the rear wall and I only have about 18" on the sides (see pic) so the OBs won't have enough room to breath.
The entire wall will be 703 fiberglass panels covered in GOM fabric, plus there will be bass traps in the corners (size will depend on what I need after I get some in-room speaker measurements)
the room is 13' wide and 34' long, 8' ceiling.

[TRADERXFAN]

Ah the mini's... I remember those.

I understand your situation on the OB. Also about looking for a narrow speaker, you don't want it right up on the wall.   

Is the screen hanging or mounted on the wall?  Perhaps you could get an acoustically transparent screen and could put identical speakers LCR behind the screen where you wouldn't be so limited to narrower speakers, and get some space away from the front wall?  You seem to have the available length...

Just a thought.

-Tony

[SteveCornell]

The screen is mounted and no room to move anything back any further, I have 2 rows of 3 recliners (2nd row on a riser) and a bar behind that and then the stairway at the back of the room.

[iskandam]

Well, now that I think of it, there was a speaker Danny was involved with, somewhat like you describe... the RA8...
http://www.audiocircle.com/index.php?topic=20593.msg195406#msg195406

Very sensitive. But ribbon, not neo pdr tweeter. Not that there is anything wrong with the ribbon. Just a bit different.  I think it had some ports though. 

-Tony

How does the Neo planar magnetic tweeter compare with ribbon tweeters in terms of resolution, speed, dynamics, and overall sound quality?  Is there an advantage of using one over the other?

[HT cOz]

Building your own speakers does lend to customization, but you have to understand that with the Neo-3 TL you already have a fantastic solution to your room.  Think about it this way it is the right tool for the right job... Can you use a sledge hammer to hang a picture?  Sure, but why would you when you have a hammer? 

Take that extra energy and dollars and put them to better use.  Diffraction wall treatments, Power Conditioner, servo sub, rear speakers, pre-pro, amps, etc. 

[Danny Richie]

In answer to an earlier question, yes the crossover would have to be redesigned going from open baffle to sealed.

Secondly, before I went with 4 M-130's below an N3S (sealed version) I think I'd be more inclined to use a side firing servo sub. It has a lot more flexibility making it easy to balance the output as per your room. It would play much lower too.

You know, a pair of the SW-12-08 servo subs in a front firing box (or even a single for that matter) would make a nice stand for a center channel too. 

[SteveCornell]

Danny & HT cOZ
Thanks for the reply, after sleeping on it last night I will probably just go with the N3s and leave them as designed, and I'm thinking about adding a pair of the servo subs to go with them, I can still use my big ole coffee table 18" Malstrom with 1200 watts  for getting crazy with HT.
I really like the look of all those 5"s in an array but alas I'm sure the N3s with the port to the front would probably be a better fit for my room

[dvenardos]

What is the recommended distance from the rear wall for rear porting?
Or alternatively, at what distance should you consider switching from rear porting to front porting?

[Danny Richie]

When the distance to the rear wall starts getting less than a foot then it is time to start considering letting that TL open to the front.

[TRADERXFAN]

How does the Neo planar magnetic tweeter compare with ribbon tweeters in terms of resolution, speed, dynamics, and overall sound quality?  Is there an advantage of using one over the other?

Here is a link to what Danny had to say about them:
http://www.audiocircle.com/index.php?topic=21620.msg192169#msg192169

 I have a pair of the OB2x (ribbon) and the ob7(neo3 planar). I can't really describe the difference. Both are VERY nice.

-Tony

[iskandam]

Here is a link to what Danny had to say about them:
http://www.audiocircle.com/index.php?topic=21620.msg192169#msg192169

I have a pair of the OB2x (ribbon) and the ob7(neo3 planar). I can't really describe the difference. Both are VERY nice.

-Tony

That's exactly what I needed to know.  Not to derail or hijack this thread, but I wonder if the added airiness of ribbon tweeters is caused by their ability to reproduce frequencies above 20 khz.  There was a study done by Tsutomu Oohashi on hypersonic effect that suggests that even though most people can't hear above 20 khz our brains can still perceive those hypersonic frequencies and identify the sound as being more airy and spacious.

[Danny Richie]

There was a study done by Tsutomu Oohashi on hypersonic effect that suggests that even though most people can't hear above 20 khz our brains can still perceive those hypersonic frequencies and identify the sound as being more airy and spacious.

There may be some merit to that.