Fun With Speaker Design

Jaytor · « **Reply #40 on:** 13 Aug 2020, 01:55 am »

For a linear array of drivers to act like a line source, you have to be seated in the near field. For a normal listening room situation, Danny's Line Force design is probably the shortest you can get away with. For a desktop monitor where you are sitting a couple feet away, you might be able to get away with a shorter array, but there probably isn't much benefit.

For a normal listening room speaker, you're better off sticking to one tweeter. You can get away with multiple midrange drivers as long as they are close together (e.g. Super 7, NX-Otica) since the wavelengths are considerably longer.

Hobbsmeerkat · « **Reply #41 on:** 14 Aug 2020, 12:38 am »

Thanks for the info!
I don't have the money or resources to test this sort of thing, so I'll just set a few ideas aside that won't work.

Ill be working with the user Creative Cut Desings to develop some cabinet plans for some of these designs, to see if we can have some fun testing these designs.

Killian has also offered to build some test kits as well, so I'm excited to see what we can achieve with these designs.
I dunno if they're entirely "realistic," but I honestly love the fun of exploration & learning from what these idea can lead to.

I sill want to work on designing a waveguide that can be oriented based on the position of the speaker too, be it mold-injection or 3D printed.. so be on the lookout on my Neo3 deep-cup thread as I work on planning some designs to test in the future.

Hobbsmeerkat · « **Reply #42 on:** 20 Aug 2020, 03:24 am »

Okay, Update time!

On my Neo3 thread, I used my NX-Studio kit to get rough measurements, to produce a more accurate waveguide that will be easier for those that want a simpler installation that can also be re-oriented for vertical/horizontal use.

And with that, I moved forward on designing a cutout that should work in the Studio MTM design:
6" diameter circle with a 0.24" recess, leading to a 5" diameter hole on the inside.
I'm actually quite proud of this design...

The outer rings around the woofer holes signify where the outer edge of the woofers mounting base sits. Enough to cover the bottom/top screws, but not the edge of the waveguide when in the vertical position. I also had to expand the overall size of the cabinets a little bit to better match the needed volume, and give a little extra space to the waveguide.

Argoncat · « **Reply #43 on:** 20 Aug 2020, 11:03 am »

Looks fantastic! I thought sketchup has (or had) a plug-in to export a design into a cut list, is that gone in the current version? I’d be interested in helping you test the design and refine dimensions, I have a workshop / machinery to support some experimentation.

I’m curious to see how the asymmetrical rear neo 3 “vent” sounds, will a pair of speakers balance out rearward projection or will the design need to project rearward in both left and right? This of course adds some fabrication challenges but the unexpected is always the best part about experiments.

Hobbsmeerkat · « **Reply #44 on:** 20 Aug 2020, 01:03 pm »

It might, but im just using the free version. I also haven't looked into that yet either. But it may still be possible? Tho it is the free online only version, so it might not be possible.. (yay for subscription services!)

The tricky part will definitely still be the rear slope. I still need to find a way to simplify the process it a little more, tho.

The idea behind the left/right vent is for a wider sound stage. It will probably loose some depth compared to the standard Studios, but it can still function as a center channel, which was it's design idea.

Hobbsmeerkat · « **Reply #45 on:** 26 Aug 2020, 04:57 pm »

Okay, finally got around to making my own "cut sheet" for all the parts pieces required for the build of a center channel/bookshelf.

This is a simplified version, using a more "squared" slope and all using .75" MDF

Full dimensions are 8.5" x15" x 26.5"
Tweeter cut-out is intended for use with my 3D printed design in my Neo 3. A 6" outer radius with an inset of .25" and an inner radius of 5". Woofer holes are the standard 5.75"

The angle on the shelf is 26.5°, the sides of the slopes are designed to sit on top of the back panel. (I forgot to add it here, but a 4.5"x2" piece is needed at the front of the slope.) The small piece on the bottom right sits .75" below the outer edge, and allows a custom speaker grill to be added.

Hobbsmeerkat · « **Reply #46 on:** 26 Aug 2020, 05:19 pm »

I missed a couple details, so here's an update of the cut sheet:

Here's the link to the full quality version:
http://puu.sh/Gm6mW/6f99210230.png

hawkeyejw · « **Reply #47 on:** 26 Aug 2020, 05:45 pm »

Very cool Hobbs! I may have missed it, does Danny already have a crossover designed for this configuration? It would be cool to see someone put together an all NX home theater system.

Hobbsmeerkat · « **Reply #48 on:** 26 Aug 2020, 06:00 pm »

Quote from: hawkeyejw on 26 Aug 2020, 05:45 pm

Very cool Hobbs! I may have missed it, does Danny already have a crossover designed for this configuration? It would be cool to see someone put together an all NX home theater system.

Not at the moment. It will need to be assembled & sent to him for testing, tho I imagine it wont be too different from the standard NX-MTM or Studio crossovers?

Hobbsmeerkat · « **Reply #49 on:** 26 Aug 2020, 11:40 pm »

Made some more small adjustments, the slope is now 5" wide, but otherwise the same overall design.

This is how the cut list should appear once assembled:
Old design on the left, new on the right.

VinceT · « **Reply #50 on:** 4 Oct 2020, 03:32 pm »

Has there been a MTMWWaf version of the Oticcas?

Reason being that could be stacked on top of a servo sub and keep the footprint of one speaker, and still get benefits of the woofers.

VinceT · « **Reply #51 on:** 21 Oct 2020, 04:29 am »

I am not sure if any of these configurations are possible. I often thought of a NX-Otica Mini that can be stacked on a double servo sub that has the footprint of a single speaker keeping the hole thing under 6 feet tall. The NX-Otica MTMs look great, but from what i read folks miss that mid bass from the woofers in comparison to the full NX-Oticas. Too bad the configuration in my home won't allow 4 speaker placements to accommodate the NX-Oticas with servo subs. Maybe with something along these lines, someone could have their cake and eat it too. I would say one downside would be the tweeter is a little high up, but maybe this could be addressed with a slight forward lean of the upper baffle downward toward the listening position.

Hobbsmeerkat · « **Reply #52 on:** 21 Oct 2020, 02:44 pm »

Quote from: VinceT on 21 Oct 2020, 04:29 am

I am not sure if any of these configurations are possible. I often thought of a NX-Otica Mini that can be stacked on a double servo sub that has the footprint of a single speaker keeping the hole thing under 6 feet tall. The NX-Otica MTMs look great, but from what i read folks miss that mid bass from the woofers in comparison to the full NX-Oticas. Too bad the configuration in my home won't allow 4 speaker placements to accommodate the NX-Oticas with servo subs. Maybe with something along these lines, someone could have their cake and eat it too. I would say one downside would be the tweeter is a little high up, but maybe this could be addressed with a slight forward lean of the upper baffle downward toward the listening position.

Yeah, i totally understand your thoughts, and is how i came to my design choices with some of the monster towers most of which are essentially an inverted otica or Xtreme "mini" with 4 missing woofers to keep the height managable.

My concerns with the left design is that a single NQ woofer might not be enough to make enough differences in the midband vs an Otica MTM, & will lead to a thinner midrange. The taller tweeter issue is definitely an issue i had to work with, luckily the NX waveguide does a lot to help with the overall sound dispersion, so it's not too much of a worry to be a little lower than the tweeter.

I dont really have too many thoughts on the right design cuz I don't think I've ever seen the LGKs used in an OB setting, or how they would be utilized..

VinceT · « **Reply #53 on:** 22 Oct 2020, 03:55 am »

Regarding the single NQ driver output, that is a very interesting question. Danny uses this configuration in the NX-Studio Monitor but in a sealed cabinet and does incorporate them with servo subs.

The concept using the LGK drivers is essentially the top end of a Wedgie monitor. Looking at it now, I would look at narrowing the baffle to the same width as a Wedgie design above the waveguide. This concept intrigues me the most just because those LGK's from what I hear are just so fast and detailed, and you have two drivers that don't take up much more room versus the one NQ driver; so in theory you may get a little more output (I could totally be wrong). As far as balance between the drivers and output for the midrange with these concepts, I simply do not have the expertise to guess. Another potential concern is having the woofers so close to the tweeter. I am not sure if that would cause any issues.

I will say I have heard some 3 way designs where the midrange was above the tweeter, with the woofer below on the bottom. Granted these were sealed box towers, but I always thought putting that mid range on the top like that really created a nice spacious sound with a box speaker, especially with vocals and horns. These are just concepts that have been stuck in my brain and trying to incorporate the woofers in the design to gain more low mids, to me that is such an important part of the music. I will be the first to admit from a speaker design standpoint I am not qualified to even discuss if these concepts are even doable. I would love it if something like this was possible, with my space limitations and layout I could have something a little closer to the NX-Otica. Of course assuming with these concepts, adding the woofers there would be anything at all the gain compared to the MTM NX-Otica or Wedgie with servo sub. I think there could be, if you don't lose too much of the mid output.

Cheytak.408 · « **Reply #54 on:** 22 Oct 2020, 06:25 am »

With many closed box speaker designs (the kind I am extremely familiar after 40+ years of building them) putting the mid at ear level with the tweeter below and slightly outboard of the centerline will get very close to the zero delay plane that produces very good time alignment in the critical upper mid region. Makes for an extremely coherent loudspeaker.

VinceT · « **Reply #55 on:** 27 Oct 2020, 03:41 am »

The LGKs are very intriguing, but are going to be tough to integrate with woofers being the Wedgies go down to about 200Hz, the dual 165NQ's go down to 100Hz with the NX-MTM monitor and will be much easier to cross to a woofer, which has already been done very successfully. You could do something like this on top of a dual servo sub and keep the whole thing at about 6 foot tall, while only taking up 2 speaker positions in your room. I would think halving the woofers to 4 from 8 versus the full NX-OTICA would still give you a little kick in the pants in the mid bass compared to the NX-MTM monitor. The Mini Xtremes on the left put the tweeter one speaker position lower on the baffle versus the Mini Oticas which may be beneficial in some rooms. I am not sure which would sound better, I would be curious to hear from some in the know.

VinceT · « **Reply #56 on:** 30 Jan 2021, 02:49 am »

This popped into my head the other night. I was listening to some old ADS monitors I set up as a system in my kid's room, which happened to be a sealed box and always loved the mid bass these put out. Which got me thinking about the NX Studios and how nice they should sound. Just curious if there have ever been any experimentation with a hybrid type monitor combining the MTM-Oticas with the NX Studios in a 3 way design? This would be a MTMM (or MTM design depending on how they measure) with the low end driver being in a sealed box with the two mid range drivers in a open baffle above the tweeter. I am sure the same cabinet could be used for the NX-Studios, just a new front baffle design would be needed.

The X-Static has been a very succesful design, and this has some of the characteristics of that speaker. With the crossover design, I assume you could find somewhere to cross around 100-125 hz that would work for the low end X-over where the TMM tops end of the monitor would naturally roll off assuming the measurements stayed the same compared to the MTM-Oticas. Of course this is all an assumption and in practice this may not work. If it does, perhaps it could be that solution to get more mid bass out of the monitor size cabinets without having to jump up to full Oticas for people with space limitations? Assuming there isn't something else in the works already at the GR Research Lab in TX.

Edgar77 · « **Reply #57 on:** 30 Jan 2021, 09:32 am »

Where are all the pictures?

I am relative new to this forum and I look at some old and not so old threads and on many of them the description implies that there are pictures but I don't see any pictures.
Do I do something wrong or is that a problem with this forum or how can I see these "old" pictures.
Thanks

Edgar

BPT · « **Reply #58 on:** 30 Jan 2021, 12:34 pm »

Here's a full ranger. What about an NX Otica in WWMTMWW form sitting on top of a 14" cube with open back containing opposing servo 12s on each side of the box crossed over around 50Hz. Servo amp will have to be in it's own box.
Chris Hoff

VinceT · « **Reply #59 on:** 30 Jan 2021, 02:15 pm »

There is an issue with the board. I can't see or post any either.

There is a need for many that can't use 4 speaker position in their listening space due to space limitations. The only solution is to go vertical. The only concern would be tweeter height if you decide on stacking oticas or xtremes on subs.

In my situation I am more near field so a monitor stacked on a servo sub would be ideal.

Chris - do you know if that configuration been attempted yet with servo subs? That seems very interesting.