[pbrstreetgang]

Trader whats the room size your obs are in and did you get the woofer upgrades?

[TRADERXFAN]

PB tough to say. My living room is open to kitchen, den, and dining room, plus long hall... I would just have to call it very large.  However, I sit fairly close to them, about 7-8' away. I have the non-x woofers.  I had planned to use them in a smaller room.... 

[Tweaker]

I'm thinking an open baffle stand mount mini-monitor would be rather cool. Seems like an overlooked design.

I think the difficulty there is that you can't get much bass at all out of an open baffle 2 way a single, open baffle, 5 1/4" driver... so you need the box to boost the bass frequency which requires a 3 way and therefore going to be bigger than a mini-monitor...

I guess that's explains why it's an overlooked design. Using two of the M-130X drivers, though, one sealed and the other open should allow for a small enough speaker to work as a monitor. Mate it with a good sub and I think it should make for a pretty good sounding sub/sat system.

[Wind Chaser]

Using two of the M-130X drivers, though, one sealed and the other open should allow for a small enough speaker to work as a monitor. Mate it with a good sub and I think it should make for a pretty good sounding sub/sat system.

You just described the RAW OB2X, except that it is ported rather than sealed and doesn't require a sub. 

[Tweaker]

Using two of the M-130X drivers, though, one sealed and the other open should allow for a small enough speaker to work as a monitor. Mate it with a good sub and I think it should make for a pretty good sounding sub/sat system.

You just described the RAW OB2X, except that it is ported rather than sealed and doesn't require a sub. 

I just looked at a photo of the OB2X and no, it's not what I described. The OB2X is a floor stander. That's not what I'm interested in. What I'm interested in is a OB monitor something like the Nomad Audio Sentinel   
except using a more conventional tweeter mid/woofer configuration.   
 There are some of us who, for a variety of reasons, prefer monitor speakers to floor standers. 

[HT cOz]

I just looked at a photo of the OB2X and no, it's not what I described. The OB2X is a floor stander. That's not what I'm interested in. What I'm interested in is a OB monitor something like the Nomad Audio Sentinel   

I just looked up the original OB-7 thread.  It appears to cross-over to the boxed woofers around 350hz.  Given that the MTM OB section is more efficient, I don't think a TM OB monitor would work.  There has to be something near the TM OB to play those frequencies.

http://www.audiocircle.com/index.php?topic=41724.0

Cheers,
Robert

[pbrstreetgang]

IIRC that mtm OB xover with the 130/16 is 180HZ

[HT cOz]

IIRC that mtm OB xover with the 130/16 is 180HZ

Ah Im still learning, perhaps is plays as high as 350hz???

[Wind Chaser]

I just looked at a photo of the OB2X and no, it's not what I described.

Robert,

Didn't you say something about "using two of the M-130X drivers"??

For the record, those are woofers - not full range drivers

The idea behind the mini monitor is to to have a speaker that takes up as little space as possible.  But in reality, most so called mini monitors have pretty significant foot prints, meaning they take up just as much space as the floor stander, if not more. 

The foot print of the Sentinel 10" X 17".  That's more than twice the size of OB2X.

[Tweaker]

I just looked at a photo of the OB2X and no, it's not what I described.

Robert,

Didn't you say something about "using two of the M-130X drivers"??

For the record, those are woofers - not full range drivers

The idea behind the mini monitor is to to have a speaker that takes up as little space as possible.  But in reality, most so called mini monitors have pretty significant foot prints, meaning they take up just as much space as the floor stander, if not more. 

The foot print of the Sentinel 10" X 17".  That's more than twice the size of OB2X.

 
 
 The idea of a stand mount monitor, for me, is that combined with a good subwoofer, they can be positioned for best imaging and midrange performance, another words well out into the room and the sub can be placed for best bass performance, like say -in a corner! All done without being visually obtrusive. The floorstander you keep bringing up can't be placed both for deepest bass and best imaging/midrange performance. Any placement is going to be a compromise unless an EQ is used.
Because I have enjoyed my sub/sat system so much but have been intrigued by OB designs I thought it might be interesting to hear the results of the two combined.   
Geez.





 

[Danny Richie]

Okay, everyone take a breath.

Any of those configurations are pretty easy options to implement.

The upper M-130X can be in free air. The lower M-130X can be in a small .3 cubic foot sealed box to give you a -3db down point in the mid to high 70's (maybe 80Hz). Or it can be in a small floor standing, ported box, giving you a -3db of 55Hz with the same small footprint as if it were on a stand.

Or the M-165X woofer can be used in a larger (think deeper) ported enclosure of about 1.0  cubic feet, and side loaded near the floor, to give you a -3db of 40Hz.

I could even do a pair of M-165X woofers in a sealed box of the same size, also side loaded, and run in series with each other. This wouldn't give you as much low end extension but it would be tight, clean, and handle more power. It would also sound great crossed to a Direct Servo sub. 

HT cOz, the drivers in the OB-7 cross at the 180 to 200Hz range and at 1,800Hz.

[Tweaker]

Any of those configurations are pretty easy options to implement.

The upper M-130X can be in free air. The lower M-130X can be in a small .3 cubic foot sealed box to give you a -3db down point in the mid to high 70's (maybe 80Hz). 

Great! That's what I was hoping to hear. My existing monitors are high passed using an ACI inline 80Hz filter so I wouldn't have to change a thing. How would the x-over differ using two M-130X per speaker, especially with one being OB?

[Wind Chaser]

Tweaker / Robert?

Sorry if I’m coming off to you as being contentious or trying to convince you to buy a the same speakers I have - they are not available anyhow…  I assumed your interest in the concept of an open baffle mini-monitor was from the perspective of space constraints.

I’ve own a number of stand mounts and mini monitors over the years, and between airborne cats, rambunctious kids or whoever says, “Oops, I’m sorry…” I have found these types of speakers tip and fall too easy.  IMO there isn’t any benefit to a stand mount other than potential visual appeal as you said.

Your intrigue in OB is worth exploring.  Those that experience it usually don’t go back to enclosed designs. 

Again, I’m sorry if I rubbed you the wrong way.

Peace,

John

[Tweaker]

It's alright. Just a misunderstanding.
After having lived with no-baffle speakers for some time (Maggies, Acoustats), I've come to appreciate the impact a box has on the sound but really like the flexability of a sub/sat system along with, again, being able to place the sub where it performs best and the monitors where they perform best. And my wife likes the unobtrusiveness. Actually, my maple VR1's on their black stands look quite elegant without dominating the room.
As long as OB speakers don't suffer from the same sort of imaging weirdness as planar dipoles I'm sold on the idea without even having heard one yet. 

 -Jon (not Robert).

[dawaro]

The upper M-130X can be in free air. The lower M-130X can be in a small .3 cubic foot sealed box to give you a -3db down point in the mid to high 70's (maybe 80Hz). Or it can be in a small floor standing, ported box, giving you a -3db of 55Hz with the same small footprint as if it were on a stand.

What would you recommend for the volume and port size for the small floor standing version?

[Danny Richie]

If you wanted to do something like that I do have some ports (2" ports) that are sized to tune the M-130 optimally in a .4 cubic foot box. They are only 1.29 each.

[Danny Richie]

This kit is now available for purchase on line from our web site:

http://www.gr-research.com/index.asp?PageAction=VIEWPROD&ProdID=147