[Danny Richie]

Like say a Neo 3 and M165X?

Mike

If I were going to use other drivers to cover the lower ranges then I might opt for a higher sensitivity version of that woofer. But those would work well together in an omni design.

Another trick that can be used as the woofer gets bigger in diameter is to start tilting it forward a little.

[Danny Richie]

What about if you used the Neo 8 for the tweeter? It goes down to 500hz, right?

The Neo 8 is too tall to use as a stand alone tweeter. It has very limited vertical off axis response.

And a single unit really can't be crossed over that low. The mid-range is not a good place for a crossover anyway.

[Jonathon Janusz]

Like say a Neo 3 and M165X?

If I were going to use other drivers to cover the lower ranges then I might opt for a higher sensitivity version of that woofer. But those would work well together in an omni design.

Another trick that can be used as the woofer gets bigger in diameter is to start tilting it forward a little.

Wouldn't trying this with a pair of M165X also require a possibly prohibitively large box size to work, unless they were tuned to play not very low?  Still a "+subwoofer" kind of speaker, but with additional weight in the lower midrange from the extra cone area the additional woofer provides?

A neo-2 "omni" could be interesting, but this is all probably just a hypothetical discussion, as getting past the "weirdness" of the omni designs would probably still keep the interest (read: sales volume) low, even though on paper it looks like it would be a pretty simple DIY build.  Kind of like the big brother of the AV-O.

A neo3 tweeter with a pair of M130 woofers gives us the O-3.  Any thoughts on the difference in the speaker to be had in putting the helper woofer behind the main woofer, as designed, versus putting it below the tweeter on the front baffle, as we are discussing here?

[Danny Richie]

Wouldn't trying this with a pair of M165X also require a possibly prohibitively large box size to work, unless they were tuned to play not very low?  Still a "+subwoofer" kind of speaker, but with additional weight in the lower midrange from the extra cone area the additional woofer provides?

The XBL^ motor tends to be a little heavier in output in the lower ranges. This works well to compensate for baffle step loss. But in the omni design there really is not typical baffle step loss. So that woofer might be a little bass heavy in that application.

A neo-2 "omni" could be interesting, but this is all probably just a hypothetical discussion, as getting past the "weirdness" of the omni designs would probably still keep the interest (read: sales volume) low, even though on paper it looks like it would be a pretty simple DIY build.  Kind of like the big brother of the AV-O.

Getting past the un-traditional look really hurts it sales wise. The X-Omni is a bit the big brother to the A/V-O. It sounds great and is very low cost. Still looks too odd for most though.

Any thoughts on the difference in the speaker to be had in putting the helper woofer behind the main woofer, as designed, versus putting it below the tweeter on the front baffle, as we are discussing here?

There are trade offs. Doing it all over again I would try the lower woofer in the O-3 below the tweeter. It shifts the time delay between the two woofers to more of an in phase relationship and would give the speaker a more traditional look.

[Jonathon Janusz]

The XBL^ motor tends to be a little heavier in output in the lower ranges. This works well to compensate for baffle step loss. But in the omni design there really is not typical baffle step loss. So that woofer might be a little bass heavy in that application.

So, maybe a pair of the 16-ohm standard M165 would fill the bill better, assuming the box wouldn't get out of control big?   These seemed to do well for the X-MTM?  Alternatively, considering your description of the M165X as maybe a little bass heavy, could the design be done as a sealed box - using the higher but gradual roll off from this configuration to take advantage of the "extra" bass - clean bass with plenty of weight that extends lower than it probably should on paper?

There are trade offs. Doing it all over again I would try the lower woofer in the O-3 below the tweeter. It shifts the time delay between the two woofers to more of an in phase relationship and would give the speaker a more traditional look.

Interesting. . .

Related question regarding the 45-degree tweeter baffle - would the radiation pattern of the neo3 be more suited to overcoming some of the disadvantages of putting the tweeter on a front facing baffle rather than the angled one?  Do you think the dome tweeter is a better solution for these designs as a generality considering the characteristics of its dispersion pattern?

[Danny Richie]

The upper woofer needs to be a single woofer not a pair in parallel. So you'd need to stick with the 8 ohm woofer.

The Neo has a better horizontal dispersion (by a little), but a more limited vertical.

Being able to lay a dome tweeter over a little is an advantage, especially if it has a rising response in the top end. Then the response doesn't change if you move off axis.

A tweeter with a wave guide would be good too as it would help align the drivers physically.    Which reminds me, another good thing about the smaller woofer is that it isn't as much offset.

[Jonathon Janusz]

Sorry if I wasn't really clear; we're still talking about a MTM arrangement.  I was just thinking the M165 vs. the M165X.  I was just presuming the use of the 16-ohm version assuming they would be run in parallel.  My bad on that one.

Interesting note on the use of the dome tweeter (and how the rising response would interact).  This is part of how the Lucid/Virtue speaker does its magic, yes?  Would the neo's dispersion pattern work against it a little in use in an omni speaker versus that of a dome tweeter, or is it really more a decision on where one wishes their trade off to be made - monitor like imaging versus bigger sweet spot/better walking around the room listening?

The smaller woofer has some advantages to be sure, but moving back to the larger woofer for a minute - considering the design of the x-omni box puts the single woofer in an ideally sized cabinet in a clever way which makes the overall cabinet dimensions very small, would adding the second woofer either mess with the speaker in having to increase the baffle size/overall dimensions of the box to accommodate the additional volume needed for the second woofer (bigger tweeter baffle, bigger baffle on the upper woofer), or would it maybe just lose its "lifestyle" sizing, say, by adding the additional volume to the back of the speaker on an angle - would almost look like some of the DIY small single-driver horn cabinet designs out there. 

Danny, I think part of the appeal of the idea here would be as you suggested earlier to package an O-3 type speaker in a more "sellable" package, and I also think that although the average audiophile may find the design of an omni off putting, the big sound out of a "lifestyle" sized speaker is an attractive selling point.  Maybe another point in the favor of the smaller woofer is to keep the overall package size of the speaker down to a point where if one were building a bigger speaker, there would be more productive/easier ways to maximize the results from the use of the additional space?

[Danny Richie]

Sorry if I wasn't really clear; we're still talking about a MTM arrangement.  I was just thinking the M165 vs. the M165X.  I was just presuming the use of the 16-ohm version assuming they would be run in parallel.  My bad on that one.

The 16 ohm woofers are a better choice for a MTM design but not for an omni.

Interesting note on the use of the dome tweeter (and how the rising response would interact).  This is part of how the Lucid/Virtue speaker does its magic, yes?  Would the neo's dispersion pattern work against it a little in use in an omni speaker versus that of a dome tweeter, or is it really more a decision on where one wishes their trade off to be made - monitor like imaging versus bigger sweet spot/better walking around the room listening?

The Neo is a higher resolution tweeter, but the dome design does have a consistent off axis.

The smaller woofer has some advantages to be sure, but moving back to the larger woofer for a minute - considering the design of the x-omni box puts the single woofer in an ideally sized cabinet in a clever way which makes the overall cabinet dimensions very small, would adding the second woofer either mess with the speaker in having to increase the baffle size/overall dimensions of the box to accommodate the additional volume needed for the second woofer (bigger tweeter baffle, bigger baffle on the upper woofer), or would it maybe just lose its "lifestyle" sizing, say, by adding the additional volume to the back of the speaker on an angle - would almost look like some of the DIY small single-driver horn cabinet designs out there. 

Yes, you could add an additional front firing woofer just to pick up the lows just I I did on the Virtue Audio speakers. And yes, the cabinet size would increase.

Danny, I think part of the appeal of the idea here would be as you suggested earlier to package an O-3 type speaker in a more "sellable" package, and I also think that although the average audiophile may find the design of an omni off putting, the big sound out of a "lifestyle" sized speaker is an attractive selling point.  Maybe another point in the favor of the smaller woofer is to keep the overall package size of the speaker down to a point where if one were building a bigger speaker, there would be more productive/easier ways to maximize the results from the use of the additional space?

I could design some speakers like that. Tough to sell though.