Oh. there it IS, in the white paper! That bump around 400 in DI and dip in power response in same region:
That's also where the crossover frequency is for the bass to midrange and given the geometry/driver layouts that's going to generate mild off axis perturbations too from the shift in interference.
^^^
🥷
shīfù , do you feel the improvements in using a coaxial are worth taking a scalpel to one's favourite driver?
@fishball79
Do you know when the Satori MTCP-8 coaxial may be released? It's been in R&D awhile; are they still going ahead with it? Is a dedicated midrange also coming?
🥷
shīfù , do you feel the improvements in using a coaxial are worth taking a scalpel to one's favourite driver?
@fishball79
Do you know when the Satori MTCP-8 coaxial may be released? It's been in R&D awhile; are they still going ahead with it? Is a dedicated midrange also coming?
Absolutely!
I've even contemplated trying to convert the SB15/17 series into a coax too. Remove the dust cap and surround. Replace surround with a flat piece of rubber/foam, or corrugated fabric, to remove the diffraction issues created by large half roll surrounds. I was thinking mostly about the ceramic/metal cones.
Gentlemen,
Not to veer the discussion away from the possibility of a co-axial unit, how well would a ribbon tweeter + ~4" mid work in this application?
Not to veer the discussion away from the possibility of a co-axial unit, how well would a ribbon tweeter + ~4" mid work in this application?
I have one in the works but it will be 200mm wide. I was thinking of the SB12MNRX2 and Fountek CD3 as the low cost option or upcoming 4” Purifi pure mid + tweeter as the top performance option. And planning on using quad 8” woofers. Basically a slim version of my 12” 3 way pictured in post #3.
Its difficult to know if a medium but symmetrical dispersion coaxial 3 way is preferable to a wide horizontal (+/-60 degrees) but narrow vertical dispersion (+/-15 degrees) 3 way.
But this LS60 made me realise that most people would probably be happy with the 0.28L of Vd.
have you got a 4” in mind?
Its difficult to know if a medium but symmetrical dispersion coaxial 3 way is preferable to a wide horizontal (+/-60 degrees) but narrow vertical dispersion (+/-15 degrees) 3 way.
But this LS60 made me realise that most people would probably be happy with the 0.28L of Vd.
have you got a 4” in mind?
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zman, others, wondering various driver configurations: Woofers on the sides have at least two benefits, they are not on the front making diffraction less of an issue. They both diffract (tweeter / mid output, which have to be on the front) as well as possibly demand wider baffle, which would also impact diffraction performance. Not for the woofers but for the mids. The other is the vibration cancellation. Both these work with any speaker concept. Although one would have the vibration cancellation with opposing woofers on any speaker concept there seems to be many things going on with this particular KEF, all possible problems seemingly well balanced out. It makes lot of sense to put woofers of 3 way speaker somewhere else than on the front, if at all possible.
Woofers aside, then there is the mids and highs. If the coaxial is replaced by ribbon its fine but pay attention to diffraction performance at least as the ribbon is much narrower than the baffle huge roundovers would be needed, or waveguide, to have as little diffraction as the KEF tweeter, which is effectively in a waveguide and in a minimal baffle. Might be very different construct. Wouldn't be a point source anymore either.
To my eye, it is the whole package that makes this particular speaker nice, looks to be problem free for the SPL and bandwidth capability it has. Split out the coaxial, or widen the baffle beyond the drivers on it, add drivers on the front, change height of the side woofers etc. all start to introduce "issues" back in, the diffraction at least. One can make low diffraction system with any drivers, it just needs different construct than the KEF at hand.
This said, I'm not sure how much diffraction is fine enough though, so, what ever 🙂 The KEF probably has some issues that I'm not able to figure out from pictures, never heard it or any other KEF and I'm a hobbyist, so 😀 Message I'm trying to deliver is that many if not most speakers have at least some issues, as it is always a set of compromises what the customer demands, designer values and what he perhaps missed or didn't care about, or just didn't matter. Well measuring point source, I wouldn't want to change that in any way, other than more SPL capability and perhaps narrower dispersion, but this is again another construct. This is the nugget, looks to be very good set of compromises right here, not much trade-offs on the audio side and even size is quite small. Compromises have been pushed into cost (proprietary drivers, r&d), very good thing for audio quality in my philosophy at least.
Woofers aside, then there is the mids and highs. If the coaxial is replaced by ribbon its fine but pay attention to diffraction performance at least as the ribbon is much narrower than the baffle huge roundovers would be needed, or waveguide, to have as little diffraction as the KEF tweeter, which is effectively in a waveguide and in a minimal baffle. Might be very different construct. Wouldn't be a point source anymore either.
To my eye, it is the whole package that makes this particular speaker nice, looks to be problem free for the SPL and bandwidth capability it has. Split out the coaxial, or widen the baffle beyond the drivers on it, add drivers on the front, change height of the side woofers etc. all start to introduce "issues" back in, the diffraction at least. One can make low diffraction system with any drivers, it just needs different construct than the KEF at hand.
This said, I'm not sure how much diffraction is fine enough though, so, what ever 🙂 The KEF probably has some issues that I'm not able to figure out from pictures, never heard it or any other KEF and I'm a hobbyist, so 😀 Message I'm trying to deliver is that many if not most speakers have at least some issues, as it is always a set of compromises what the customer demands, designer values and what he perhaps missed or didn't care about, or just didn't matter. Well measuring point source, I wouldn't want to change that in any way, other than more SPL capability and perhaps narrower dispersion, but this is again another construct. This is the nugget, looks to be very good set of compromises right here, not much trade-offs on the audio side and even size is quite small. Compromises have been pushed into cost (proprietary drivers, r&d), very good thing for audio quality in my philosophy at least.
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TBH, many of these concepts are not new.
some moons ago a fellow by the handle of @ShinOBIWAN used to build some amazing cabinets for his speakers. Eg:
https://www.diyaudio.com/community/threads/apollo-construction-diary.201892/
All the ideas of minimal baffle area around drivers and facets and side mounting woofers have been done for a long time.
KEF have not reinvented the wheel here.
Its been around for a long time.
what they have done is cram it all into a smaller box. Because they had an industrial designer dictated the form factor.
And so that is what we are musing about here: can we design something comparable or better; given the limitations
I don’t expect some kind of acoustic breakthrough moment. I just expect a “wow, sounds bigger than I expected”
PS. I recently listened to the KEF Blade 2, Dutch & Dutch 8C and Revel F328Be for a few hours at a high end audio salon. I can tell you which one I would rather buy, and it wasn’t the KEF- I didn’t even bother to keep it in the photosnap.
so I’m not convinced yet about coaxial dot their single apparent source marketing.
Thr Revel F328Be, on the other hand, was such a solid contender for a “great box speaker, at a NOT crazy (audio jewellery) price”.
some moons ago a fellow by the handle of @ShinOBIWAN used to build some amazing cabinets for his speakers. Eg:
https://www.diyaudio.com/community/threads/apollo-construction-diary.201892/
All the ideas of minimal baffle area around drivers and facets and side mounting woofers have been done for a long time.
KEF have not reinvented the wheel here.
Its been around for a long time.
what they have done is cram it all into a smaller box. Because they had an industrial designer dictated the form factor.
And so that is what we are musing about here: can we design something comparable or better; given the limitations
I don’t expect some kind of acoustic breakthrough moment. I just expect a “wow, sounds bigger than I expected”
PS. I recently listened to the KEF Blade 2, Dutch & Dutch 8C and Revel F328Be for a few hours at a high end audio salon. I can tell you which one I would rather buy, and it wasn’t the KEF- I didn’t even bother to keep it in the photosnap.
so I’m not convinced yet about coaxial dot their single apparent source marketing.
Thr Revel F328Be, on the other hand, was such a solid contender for a “great box speaker, at a NOT crazy (audio jewellery) price”.
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The thing I want to copy is the cool finishes! Anyone know how to do those flat/satin finishes? Something a newb can pull off?
^* Concepts are age old, but for some reason they are not utilized that often together. This is the key, usually there is some aspect designer wants to use and it has some trade-offs, which again steer rest of the design. Every speaker is just set of various compromises and in the end it comes down to what sounds better, and budget, and aesthetics. To me the KEF just looks very cool way to have somewhat traditional shaped speaker with very low diffraction. One would need some spheres or 4 way open baffle stuff going on to achieve similarly low levels of diffraction while maintaining good SPL capability and wide bandwidth. Perhaps it doesn't matter much in the end for the sound, but this is just something I've been into lately, acoustics of the construct, and thus seeing the speaker in this perspective.
The Revel hasn't any of the feats, vibration cancellation or low diffraction baffle and it is not point source. I bet if it had low diffraction baffle and force cancellation setup it could potentially sound even better 😉 I guess both blade and F328 have enough SPL capability with enough big woofers and size. Never heard either.
The Revel hasn't any of the feats, vibration cancellation or low diffraction baffle and it is not point source. I bet if it had low diffraction baffle and force cancellation setup it could potentially sound even better 😉 I guess both blade and F328 have enough SPL capability with enough big woofers and size. Never heard either.
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As a small child, I feel that hull shaped plinth needs it's tipping point examined 🙂
The r3 driver is around 133mm with trim ring. About 128mm chassis. The french site lists it at 84euro for the R3 and R5, but 135euro for the R7 and R11. I fel sure it's the same part, and checking this, I see the same part number. I just got one for a R700 from kef, £135 plus the tenner post and then 20% tax.
I note the french site selling the LSX driver for about 100, which is going to be smaller and offer a lower x-over. The R100 was also available.
If anyone is about to fire off on some uni-q drivers, I do have some sat pointlessly on my shelf.
The r3 driver is around 133mm with trim ring. About 128mm chassis. The french site lists it at 84euro for the R3 and R5, but 135euro for the R7 and R11. I fel sure it's the same part, and checking this, I see the same part number. I just got one for a R700 from kef, £135 plus the tenner post and then 20% tax.
I note the french site selling the LSX driver for about 100, which is going to be smaller and offer a lower x-over. The R100 was also available.
If anyone is about to fire off on some uni-q drivers, I do have some sat pointlessly on my shelf.
In post #87 they are bronze being sold at different prices for different cabs, but seem to be the same driver. The LSX can be black at 98euros and mine are silver.
I hope that answers your question somewhere 🙂
There may be an ex-professional cabinetmaker lurking amongst us. Years ago I got advice from Pete Mazz,( I forgot his handle and whether he still active ) in veneering and finishing; thanks to him I never left a speaker prototype cabinet in raw unfinished form.
I shall this dig this up When I’m not dictating to my phone.
For painting I use few coats of sealer, a few coats of pigmented lacquer, then finished off with some clear coats of two pack lacquer, sanded lightly between coats.
The key to achieving good paint finishes is surface preparation (sealer) and the sanding between coats. I cannot stress this enough. Even a first timer can achieve an excellent gloss finish as long as care and time is taken. Successive coats of increasingly higher grit sanding; including use of wet sandpaper products can help.
For round-over or facets from MDF, after cutting or routing or machining your surface, Care must be taken to seal the end grain which is highly fibrous and porous. If the product suggest 2 coats, do it, or do 3!
Just Like painting Products, do two or three light coats, finely lightly sanded in between. If your sandpaper gets clogged, time to change sandpaper, Don’t let it clog up because it continue to use it will ruin your surface.
There are many new products now available, it’s not the same as the old oil based versus water-based product. Paints have become highly technologically advanced to minimise application/drying time etc. Have a chat to your local paint store specialist- some were developed/marketed for MDF but now there are many all-in one timber primers
Visit some woodworking forums or an educational YouTube channel; Usually a great source of inspiration and ideas.
My first speaker use 7-8 coats of sanding and finishing. It was hard to believe, but any perfectionist with 2 left arms can do it.
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I'm not looking to do gloss, but that satin/matte finish of these speakers. I really like that look. I could do vinyl wrap but then you have seams.