Hey guys, I'm planning on building some speakers for my home cinema and music listening setup, my proposed design is below. Im currently using Genelec 8030c's and love the sound but want more SPL. I have been searching a lot on this fourm and online and the 18Sound 6ND430 pops up a lot as an excellent mid-bass driver with highish sensitivity. I was orginally considering an MT version using the 4ohm version of the driver, but the 4ohm seems to perform worse than the 8 or the 16ohm versions and also appears to be OOS everywhere. I chose the Seas DXT for similar reasons to the woofer in that it seems to be a proven design and has been used countless times to great effect.
The design I propose is a slim, tall and fairly wide design. Reading online I can see lots of different comments about the DXT and baffle size, in that the DXT either likes a very narrow baffle or a wide baffle. My baffle is around 320mm wide by 572mm tall, with planned roundovers on all edges. My only concern is the performance of the DXT on this baffle, is it wide enough for this driver or would it be better to make the baffle as small as possible? I plan to cross-over around 2khz, how much of an issue will this present with the woofer C-C spacing?
Is this a good design for my requirements which are: Wide horizontal dispersion similar to the Genelecs, capable of reference level SPL (105DB) with great dynamics, flat on-axis and linear off axis response with a gently sloping power response, low distortion (both drivers show low distortion so should be no problem).
The cabinet will be sealed, as I see no reason to port given that a subwoofer will take over in the range of 80-120hz. The Hypex FA122 should give 125wrms into the parallel wired 8ohm drivers, modelling in WINISD shows around 110db in the sealed cab at the minimum 80hz cross-over frequency, which is in excess of the 105db requirement, so reference levels should be no problem.
What other drivers should I be considering for this project?
The design I propose is a slim, tall and fairly wide design. Reading online I can see lots of different comments about the DXT and baffle size, in that the DXT either likes a very narrow baffle or a wide baffle. My baffle is around 320mm wide by 572mm tall, with planned roundovers on all edges. My only concern is the performance of the DXT on this baffle, is it wide enough for this driver or would it be better to make the baffle as small as possible? I plan to cross-over around 2khz, how much of an issue will this present with the woofer C-C spacing?
Is this a good design for my requirements which are: Wide horizontal dispersion similar to the Genelecs, capable of reference level SPL (105DB) with great dynamics, flat on-axis and linear off axis response with a gently sloping power response, low distortion (both drivers show low distortion so should be no problem).
The cabinet will be sealed, as I see no reason to port given that a subwoofer will take over in the range of 80-120hz. The Hypex FA122 should give 125wrms into the parallel wired 8ohm drivers, modelling in WINISD shows around 110db in the sealed cab at the minimum 80hz cross-over frequency, which is in excess of the 105db requirement, so reference levels should be no problem.
What other drivers should I be considering for this project?
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Alternatively looking at these as a lower cost version of the 18 Sound drivers https://www.sbaudience.com/index.php/products/woofers/rosso-6mw150d/
Just a quick note that I use the 6ND430 in my smallest PA speakers, and I'm consistently pleased with how much sound can come out of those tiny boxes. The 6ND430 holds up well under pressure, and I'd recommend it wherever a high-quality 6.5" midbass driver is required.
Chris
Chris
I think the 2,5 way option might be preferable. Not everyone gets a MTM design right and the vertical polar symmetry isn’t an advantage most of the times. I think the 2,5 setup is possible with the Hypex, plus a well-chosen coil for the passive 0,5 branch.
The DXT does fine on a lot of baffles, this comparison points out the use of well-chosen bevels (there’s more about that on that site). If you‘re determined on the MTM design, consider one of Augerpro’s elliptical waveguides with appropriate tweeters, they enable closer M-M spacing while horizontal directivity is better controlled and probably better matched to a 6,5” than the DXT.
The DXT does fine on a lot of baffles, this comparison points out the use of well-chosen bevels (there’s more about that on that site). If you‘re determined on the MTM design, consider one of Augerpro’s elliptical waveguides with appropriate tweeters, they enable closer M-M spacing while horizontal directivity is better controlled and probably better matched to a 6,5” than the DXT.
I'm working very slowly on a similar thing but with a 12" driver below the MTM. The 6ND430 was on the bench but as a classic choice for a WMT design.
In chose two 5" in spite of one 6nd430. But each time with the same idea of a recessed tweeter for good timing matching tin the XO area, though this Seas Tweeter was not selected. Tweeter not chosen yet, but migth end between a cat 378 morel (which could br a good power handling solution with your choice of midwoofer) and a wave guided SB26CDC, to stay in my budget.
I 'd try to keep the cut-off at 2k hz avoiding the tweeter spacing to be < 0.75 the wave length, but nearer to the full WL.
In chose two 5" in spite of one 6nd430. But each time with the same idea of a recessed tweeter for good timing matching tin the XO area, though this Seas Tweeter was not selected. Tweeter not chosen yet, but migth end between a cat 378 morel (which could br a good power handling solution with your choice of midwoofer) and a wave guided SB26CDC, to stay in my budget.
I 'd try to keep the cut-off at 2k hz avoiding the tweeter spacing to be < 0.75 the wave length, but nearer to the full WL.
The Somasonus waveguides were my first plan of action, but I can’t seem to find an online service that’s less than around £100 per waveguide. I’ve been thinking about combining the waveguide stl file with a baffle drawing and getting the whole front baffle CNC with the waveguide built in.
Maybe a TM could work better than this, with 6.5” somasonus waveguide, SB26ADC aluminium tweeter like the Genelecs I enjoy. The B&C 6NDL38 seems like a good alternative, cheaper than the 18 Sound, available in 4ohms, slightly more XMAX and similar freq response.
£100? You mean CNC for sure. Over here services count about €35 to €50 for reasonable 3D prints.
Could you send a link of the services you use? All the ones I’ve seen for the UK are very expensive.
Go for it. Nice project 🙂
The SB26ADC in a waveguide is a brilliant driver, and a super bang for the buck .... listening to the right now 🙂
No doubt that both 6ND430 and 6NDL38 are super drivers, and that they will be able to stand some more beating than "hifi" drivers. But the question is whether you actually need this?
A cheaper alternative is SB Acoustics SB17NBAC35-8. Don't think it gets that much better. Look at the Revel Performa 3, using these drivers with more than a good result
http://www.sensibleaudio.dk/2022/05/27/what-drivers-do-they-use-revel/
Also Wilson uses a similar driver (but with different diaphragm .. same as the Satori)
When comparing to Genelec, which for sure makes some awesome monitors, I think their drivers look more "hifi" than Pro ..... but miss more insights to really know ...
Another thing: Of course depending on where you place Xover and how steep (do go for full DSP active), consider whether the tweeter will actually be able to follow 2 pro 6.5" drivers
The SB26ADC in a waveguide is a brilliant driver, and a super bang for the buck .... listening to the right now 🙂
No doubt that both 6ND430 and 6NDL38 are super drivers, and that they will be able to stand some more beating than "hifi" drivers. But the question is whether you actually need this?
A cheaper alternative is SB Acoustics SB17NBAC35-8. Don't think it gets that much better. Look at the Revel Performa 3, using these drivers with more than a good result
http://www.sensibleaudio.dk/2022/05/27/what-drivers-do-they-use-revel/
Also Wilson uses a similar driver (but with different diaphragm .. same as the Satori)
When comparing to Genelec, which for sure makes some awesome monitors, I think their drivers look more "hifi" than Pro ..... but miss more insights to really know ...
Another thing: Of course depending on where you place Xover and how steep (do go for full DSP active), consider whether the tweeter will actually be able to follow 2 pro 6.5" drivers
A member who benchmarked a lot of 6" and 8" PA prefered the sound of PHL drivers,B&C came after. There is also Eminence who has good and more affordable good 6" and 8" as the Beta 8" , but with a 8" you need the WG for the tweeter. In a classic MT, Somasonus (augerpro member) has also 8" round WG, certainly easier for the routing than the eleptical WG (though there is a jiig for the router you can 3D print too).
@scholl member did a great job with this 18thsounds in a classic WMT with a wavecore tweeter similar to the Morel cat378 and he didn't miss his previous compression driver in this treble area.
According your budget a 15" Fane then a Beta8A then a WG tweeter since you have a DSP plate amp should be a great system. Of course you can also choose a littlier hifi bass driver for a cabinet of a reduced size and low bass till, like the good basic Peereles 10" to 12" or the more expensive Seas 10". See Paul Carmody 3 ways for illustration. A great 8" too seems to be the B&C 8PE21 or the Audax 8" PR170, but you need a higher cut off in the lows with both ( 500 hz or more).
But of course the 6nd430 is great, though expensive.
Edit : the SB Audience should be good too in the budget camp as you have a DSP to tame its nasty high end break ups.
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Thanks to markbakk I now have some services for 3d printing that are relatively cheap. I'm now thinking of maybe a TM instead of MTM. To make up for the loss in SPL going from MTM with 6.5" to TM, I am considering using an 8". The B&C 8NDL51 seems to be a very good contender for this, coupled with the Somasonus 8" waveguide and SB26ADC. These will be used as LCR in a HT setup, as well as for music listening. This would then open up the option to create a smaller 5/6" based surround speaker using the SB26ADC and smaller somasonus waveguide!
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I'm looking for fairly high output all the way down to the crossover region 80-120 in a sealed cab. The 5" Genelecs do well at around a 120hz crossover but when listening at high volumes its clear the woofers are starting to become unhappy. I figured going with pro drivers for the woofer would lead to greater dynamics and also higher output and power handling down low. Modelling an 8" B&C woofer, it should be coasting along at the levels I listen to.
Made an order from SGD3D for the 8" waveguide in PETG to test. Not expecting anything special from the finish but this is just for the purposes of building and testing the speaker, once I'm happy with the design and performance, I plan on getting the waveguide CNC'd as part of the whole front baffle.
Now just to decide on the woofer. The C-C spacing in my design looks to be around 185mm so probably looking at a crossover around 1800-2000hz. The B&C 8NDL51 seems like a good option but the cone breakup seems to be 1600hz, could probably take care of this with DSP or lower the crossover a little. I'm also looking at the 18 Sound 8NMB420 which seems to have a little flatter response.
Now just to decide on the woofer. The C-C spacing in my design looks to be around 185mm so probably looking at a crossover around 1800-2000hz. The B&C 8NDL51 seems like a good option but the cone breakup seems to be 1600hz, could probably take care of this with DSP or lower the crossover a little. I'm also looking at the 18 Sound 8NMB420 which seems to have a little flatter response.
with a room at 21°C you are near to 1900 hz as a wave length spacing (181 mm). Up to 1.2 WL you should be fine in theory having some margin; phase tracking... You certainly can also if a 2 ways on stands, play with the heigth according the ears at seated down listening position ? As say hifijim I would sim it first (Vituixcad ?). Wood became expensive.
What seems wrong is a spacing between 0.5 to 0.75 the WL. This should be avoided if I understood it rigth. But it is hard to acheive so close distance with a wave guide anyway.
What seems wrong is a spacing between 0.5 to 0.75 the WL. This should be avoided if I understood it rigth. But it is hard to acheive so close distance with a wave guide anyway.
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