[Danny Richie]

Danny:

I feel for you over the Neo 3 supply situation. With so many of your designs dependent on it, it has to hurt. What is the status about renewed delivery?

You are not kidding. It has really impacted my sales.

I have been looking for an open baffle kit to build. Went all the way through the Wedgie thread only to find that it, too, was impacted by the Neo supply problem. I thought they, with the still undisclosed bass section, would be the answer for me.

Man, I love those speakers. They are really great open baffle speakers for small to medium sized rooms too.

Now, I see these NX-Otica, and think they could work. The NX-Treme is just too tall for me (read WAF). I wonder why you went to 16 inch driver design over the LGK?

They are just 6.5" woofers. The larger woofers offer a little more body and bass impact. They also play much lower so the crossover point to the servo subs is around 80Hz instead of 200Hz. And with the really low crossover point to the custom Neo tweeter in that deeper 1.5" wave guide, they really don't give up much to the smaller and lighter weight 3" LGK's.

The issue I have with buying the NX-Otica is the need for subwoofers. I have two JL Audio f113s, but as you know, those are sealed boxes. I really want open baffle bass. To get open baffle bass with the NX-Otica, it seems I will need another stack of speakers, which is undesirable (WAF again, without even asking). Is it possible to take two of the bass woofers and replace them with servo woofers in a U, W or H configuration? It seems those would fit within the cabinet. The speakers would then be 4-ways.

You could use your JL Audio subs with the NX-Otica's. It won't be full open baffle and it will give up a lot to the servo subs, but you could use them.

Even with the Wedgie kit the additional servo subs are needed for the base. So the cost of the bottom end is pretty close.

The NX-Otica is a four piece system though. You could go with just the upper MTM section on an H frame of a pair of the servo subs. It might look a little odd, but it would work.

[jzexport]

Thanks for the very quick response, Danny.

My mistake on the drivers. I saw 16 and jumped to the conclusion that was diameter without thinking it through. Duh. I wondered how you could get the tweeter height correct. The obvious answer was it's not possible, but didn't challenge myself.

Cost matters, of course, but the cost of adding the bass is less an issue than fitting it into a single tower. Please explain further what you mean by a 4 piece system. If I went with the upper MTMs would I just cutoff the baffles in the flat pack to shorten them? Aren't we not then at the same place as putting a bass unit under the Wedgie? Is it possible to DIY what you were contemplating as the bass unit for the Wedgie to go under the NX-Otica?

Josh

[Jonathon Janusz]

Although I unfortunately can't be in the market for these, for sake of the crowd, I thought to ask how you were addressing wire management with the cabinets?  I also didn't see anywhere at first glance for a mounting point for binding posts/tube connectors.

Congratulations again on getting as much as can be had out of the last ride for the BG tweeters!

[jzexport]

Danny:

With the crossover to the sub at 60 Hz or so, would a single sub tower work getting the low-pass from both mains? If it does, I assume it does not have to be located near the mains. Correct?

Josh

[Captainhemo]

Although I unfortunately can't be in the market for these, for sake of the crowd, I thought to ask how you were addressing wire management with the cabinets?  I also didn't see anywhere at first glance for a mounting point for binding posts/tube connectors.

Congratulations again on getting as much as can be had out of the last ride for the BG tweeters!

We have included  holes in the braces to pass the wiring thourgh which will be orientated to the  insde (full wing) of the cabinets.   C/O boards  that fit snuggly betweenthe no rez and screw to the top of the bases will have a  monting point for the tube connectors (they'll of course mirror each other  for left/right cabinet).






I used some cool little "rubber feet:" on the bottom of my amp boxes for my subs, trying  find a  place to get a bunch of them  so we can  throw 8 of them in  with the kits for the bottom of the  c/o boards
jay

[R_burke]

Extremely well thought out - good job.  Can't wait to see final product   

[mlundy57]

Aren't we not then at the same place as putting a bass unit under the Wedgie? Is it possible to DIY what you were contemplating as the bass unit for the Wedgie to go under the NX-Otica?

Josh

Josh,

Yes it will work. The original design is for use with three 8" drivers per side:






I modified it for two 12" drivers to fit the Wedgies. Wider and deeper but height is the same (plinth not on in this pic):




It will be easy to modify this 12" version to fit the wider NX-Otica or X-Otica. The front piece would need to be 1" wider than the front of the NX-Otica then the dimensions of the top, bottom and internal brace would need to be adjusted to fit. The 12" base units are 17-1/4" deep so the 14" deep NX-Otica will fit on top of the wider wedge without having to make any adjustments to the side panels.

By making the front piece 1" wider there will be 1/2" between the sides of the NX-Otica and the sides of the wedge base units.

Mike

[jzexport]

Mike:

Thanks for the detailed guide to the bass units. They look like a good aesthetic match.

I am still going around on this, though.

By taking away the 4 M165 woofers, the bass units will have to cover their range up to at least 160 Hz. Not sure about that.

This still requires 2 bass units, which is putting the total cost above my budget. Eliminating 4 M165s/side, doesn't even cover half the cost of 1 SW-12-08FR/side. It does answer the space question, but at a lot of added cost and the possible compromise in quality of eliminating the M165s?

I am still thinking going with the NX-Oticas as designed and adding a single double SW-12-08FR subwoofer, if it can be located away from the NX-Oticas, as subwoofers usually are placed away from the mains or surrounds? If so, I also don't know if the SW-12-08FR subwoofer can be placed near a wall or if it has to be 3 feet out in the room?

Josh

[Danny Richie]

I am still thinking going with the NX-Oticas as designed and adding a single double SW-12-08FR subwoofer, if it can be located away from the NX-Oticas, as subwoofers usually are placed away from the mains or surrounds? If so, I also don't know if the SW-12-08FR subwoofer can be placed near a wall or if it has to be 3 feet out in the room?

How about a pair or a triple 12" on its side and positioned between the two speakers in the middle of the room?

[Captainhemo]

Mike:

Thanks for the detailed guide to the bass units. They look like a good aesthetic match.

I am still going around on this, though.

By taking away the 4 M165 woofers, the bass units will have to cover their range up to at least 160 Hz. Not sure about that.

This still requires 2 bass units, which is putting the total cost above my budget. Eliminating 4 M165s/side, doesn't even cover half the cost of 1 SW-12-08FR/side. It does answer the space question, but at a lot of added cost and the possible compromise in quality of eliminating the M165s?

I am still thinking going with the NX-Oticas as designed and adding a single double SW-12-08FR subwoofer, if it can be located away from the NX-Oticas, as subwoofers usually are placed away from the mains or surrounds? If so, I also don't know if the SW-12-08FR subwoofer can be placed near a wall or if it has to be 3 feet out in the room?

Josh

Josh
If you are thinking on dual 12"  OB  subs to pair with the MTM section of the X-Ottica's, they will have no problem playing up to frequencey needed to cross to the NQ's of an MTM.

If you were going with the NX-Otica as designed,,  you  kind of want  the OB base facing  towards your listening position... there are nulls at the sides so it can not be beside you.  I don't see why you couldn't have it behind  the  LP and down the road, you could always add a 2nd tower
I used a single  dual 12" H-frame with my OB7's for a period of time and it did work  pretty well. However, when I added the 2nd tower, it  really became  obvious  a tower on either side of the room was the way to go.  The subs are crossed around 70 hz to my OB7's, although that is considered Omni directional. adding the 2nd tower definitly added low end  end movement and  I'd say  improved imaging (soundstage)

Hope that helps a bit
jay

[Captainhemo]

How about a pair or a triple 12" on its side and positioned between the two speakers in the middle of the room?

and, you could always add a 2nd tower down the road...
I think  if you were going to use a single tower, one on its side in the center of the room would be better than 1 orientated vertically on the side of the room

jay

[jzexport]

Jay and Danny:

Your responses are homing me in.

I think working with the NX-Oticas as designed is the way to go. As for the bass unit ...

I can have the double-12 facing me, it would just be off to the side of the right speaker, up to 7 feet to the right and possibly in the corner.

Danny's idea of having a triple on its side between the speakers is intriguing. This is in a home theater arrangement. The NX-Oticas will be the L and R. So, I will have to put a C on top of the H-cabinet. Don't see why that wouldn't work. Except the decision is not mine alone .

Nobody answered yet about the placement of the H-cabinet. Can it be in the corner? If it is on its side between the NX-Oticas, how far should it be from the front wall? Same as the NX-Otica's 3 feet or can it be closer?

Danny, can you say anything yet on the cost of the flat pack?

To muddy the waters, if I do not do this, I am going to build Troels Gravesen's OBL-15. http://www.troelsgravesen.dk/OBL-15.htm. It is a 34Wx36H 3-way open wide baffle. 15 in bass speaker, 8 inch mid and 34mm tweeter in a waveguide. It is all passive, so it's plug and play with what I have. It will cost about $2,000 plus wood. Anybody care to comment?

Josh

[Danny Richie]

Jay and Danny:

Your responses are homing me in.

I think working with the NX-Oticas as designed is the way to go. As for the bass unit ...

I can have the double-12 facing me, it would just be off to the side of the right speaker, up to 7 feet to the right and possibly in the corner.

With a crossover point at near 80Hz you'll want to the woofers to be fairly close to the speakers. Going with a single unit off to one side will put it pretty far away from one of the speakers.

Placing it in the center keeps it equal distance from both speakers and will blend easily.

Danny's idea of having a triple on its side between the speakers is intriguing. This is in a home theater arrangement. The NX-Oticas will be the L and R. So, I will have to put a C on top of the H-cabinet. Don't see why that wouldn't work. Except the decision is not mine alone .

It can be just a pair on their side.

And you can stand mount your center channel right behind it. It can even be a couple of feet behind it. I even have some X-Voce's left in stock that would blend with these pretty well. Or for a smaller speaker the Carnegie Acoustics CSC-1 would work well too. They use the same tweeter.

Nobody answered yet about the placement of the H-cabinet. Can it be in the corner? If it is on its side between the NX-Oticas, how far should it be from the front wall? Same as the NX-Otica's 3 feet or can it be closer?

I'd avoid the corner and go for the middle of the room.

Danny, can you say anything yet on the cost of the flat pack?

Don and Jay are working on the flat packs and will have some prices for me shortly.

To muddy the waters, if I do not do this, I am going to build Troels Gravesen's OBL-15. http://www.troelsgravesen.dk/OBL-15.htm. It is a 34Wx36H 3-way open wide baffle. 15 in bass speaker, 8 inch mid and 34mm tweeter in a waveguide. It is all passive, so it's plug and play with what I have. It will cost about $2,000 plus wood. Anybody care to comment?

I have designed a lot of open baffle speakers, and this design illustrates perfectly everything that I try to avoid. It might as well be an in-wall speaker. With a baffle that large the sound stage and imaging depth will really suffer. Everything will appear to come from the baffle forward. This why I fold the baffle back into a winged design. It provides the needed front to back separation of a big baffle but without the surface reflections.

I am also not a big fan of the crossover parts used in those things. Those Jantzen inductors are all made from recycled Copper over in China. Then electrolytic caps, necessary connection points, long binding posts...

And the center of the tweeter is only 30" high. That's pretty low. That will keep the sound stage height really low too.

I like the drivers though. I bet I could do a lot with them in a different application.

[jzexport]

Danny:

I knew you weren't a fan of the Jantzen crossover components. I was more interested in the baffle design, which you addressed. I am making a leap of faith into the open baffle concept, not having heard a single one. I have a very nice system that many might question my wanting to change. But, I want that sense of being at the performance that I do not now have without loss of clarity, detail and resolution. I think open baffle could be that answer. I have read pros/cons on the wide open baffles ala OBL-15, and there are both sides, as in most things. People who have built the OBL-15 speak highly of them and do not report bad things about imaging and soundstaging. Don't get me wrong, I do not doubt your experience. I just don't understand enough myself to get it. I am sure it comes down to diffraction, front/back propagation delay, and relative direct versus reflected sounds. I wish I knew more to engage. I feel pretty ignorant.

I will have to look at the room layout and show my wife some ideas. I don't think I have room to put the C behind the bass unit. The C will have to be on its side on top of the bass unit. The bass unit can be a double or triple. It can even be an 8-incher.

Does the bass unit have to be 3 feet from the wall?

Josh

[Danny Richie]

As for there being two sides regarding wide baffles verses what I am doing with smaller baffles it really comes down to experience verses ignorance. And I don't mean for that to sound as bad as it does. The guys using the wide baffles do so to gain low frequency extension and simply don't know any other way to go about it. The big baffle presents a huge problem though.

Even Sigfred Linkwitz has gotten away from the wider baffle design of the Orion and gone to an almost zero baffle design with his new LX model. And it was a good move on his part. I always had a hard time listening to the Orion because of the issues with the wider baffle. It just made the speakers sound flat compared to what I was used to. The problem with the zero sized baffle is that it requires a ton of EQ to correct for the effects of it. He is covering that with a electronic or digital correction system though.

When you get down to it is simple physics. And I have a ton of measurements showing the effects of different baffles, wings, wing depths, etc. If you have the tools to see what the effect really is then it becomes real easy.

On your question about the bass unit having to be three feet out into the room. Yes, it has to be at least three feet out and more is better.

[jzexport]

Danny:

Thanks for the further explanation. I sense that I may have irked you. I certainly didn't mean to and I meant no challenge. As I said, I am the ignorant one here.

Also as I said, I am going to look at my layout and see if this can work.

Josh

[bdp24]

Danny:

Thanks for the further explanation. I sense that I may have irked you. I certainly didn't mean to and I meant no challenge. As I said, I am the ignorant one here.

Also as I said, I am going to look at my layout and see if this can work.

Josh

Josh, Danny is not alone in finding a wide baffle to have negative effects upon a loudspeakers performance. One of the major discoveries made in loudspeaker research in the past three or four decades has been of the deleterious effect of a wide baffle upon the sound quality of loudspeakers, especially in regards to imaging, but also frequency response. Manufactures of loudspeakers with "advanced" design go to a lot of trouble to make their speakers with a baffle as small as possible---Kef, Vandersteen, Wilson, and the other high-end companies making box speakers. The DIY OB hobbiests are way behind the curve in this area.

[mlundy57]

Josh,

As it was explained to me, the reason for the 3ft from the wall has to do with reflection timing. If the reflections off the front wall reach your ears too close in time to the direct wave from the speaker the sound is muddied and smeared. The closer to the front wall, the more the smearing. 3ft separates the direct and reflected waves enough that they are perceived as two distinct sounds. Not only does this eliminate the smearing, it provides a sense of spaciousness to the sound.

I have experimented with my open baffle speakers being 3ft from the front wall, closer and farther away. With at least 3ft, the sound seems to come from the entire front wall for width and height (soundstage is wider and higher then the actual speaker placement. And this with the speakers only 5ft apart (try that with box speakers). For depth, the front wall disappears in that the soundstage seems much deeper than the distance between the speakers and where the wall should be. In a larger room (20ft x 25ft) I found the 5ft from the front wall and 7ft apart sounded best.

However, moving them closer than 3ft had a number of deleterious effects. In addition to smearing and less clarity, I found that moving the speakers closer to the front wall collapsed the soundstage.  The closer to the wall, the more the soundstage shrunk.

If you can use the single sub on it's side between the speakers, and have the sub at least 3ft from the wall then go for it. This will give you the best performance with a single OB sub. If you put the center channel speaker on top of the sub, put some kind of damping material between the two.

If there is no way you can get the 3ft distance from the front wall for the sub, the second best choice would be to use one of the 12" sealed servo subs. You could place this wherever it worked best (sub crawl). I used this method for six months after building the Wedgies while saving up for the OB bass units. However, do be aware that this is a compromise. You will get your bass but it won't quite mesh properly. After having listened to both types of bass, I am of the firm opinion that OB bass is the only way to properly integrate bass with OB speakers.

Mike

[Danny Richie]

Danny:

Thanks for the further explanation. I sense that I may have irked you. I certainly didn't mean to and I meant no challenge. As I said, I am the ignorant one here.

Also as I said, I am going to look at my layout and see if this can work.

Josh

No, not irked at all. I just felt like further explanation was needed. You're fine.

[jzexport]

Danny,

Is the 3 feet from the front, center or back of the H - frame cabinet?

BP 24,

I would like to see links to the research you mention on the influence of baffle size. I am not sure that citing trends on baffle size in closed box commercial designs translates into optimum baffle size for open baffle designs.

Josh