Hi all,
I'm running an interest check first of all.
The Fane 15" full-range driver looks pretty good in a lot of ways, but the T/S parameters make it difficult to work with unless you're willing to put up with a very large cabinet - Qts = 0.7 and Vas is 203L.
I'm thinking of organising a group buy for some upgraded units, and wanted to check interest levels.
I can see a few options here:
A - Same moving parts, just add more magnet
B - More magnet, cast aluminium frame
C - More magnet, cast frame, bigger voice coil aiming for more cone excursion and power handling.
D - Don't bother, the original is fine
I'm not looking for solid commitment or money at this point, but a rough idea of how many you might want to order would be good.
The T/S parameters I'm aiming for are simply to increase BL and drop Qes. That'd mean they'll be much happier in smaller cabinets, and also gain some efficiency.
Here's a quick sim of what we get if we go from the current BL=10.9 to BL=18.9:
This is in a 35L cabinet tuned to 73Hz. I know which I'd prefer.
With the increased BL, you could also go for a larger cabinet in the 100L range, which would give a response that slopes down towards the bass (probably matching room gain curves quite well) with LF extension into the 30Hz range before it rolls off.
So, I can see the improved version being useful for a few different markets:
- High-efficiency home HiFi - add a small valve amp and you're done.
- Professional Audio - stage monitors, main PA, etc.
- High-power home theatre surrounds.
A quick summary of the upgraded product:
- 15" Full-range unit
- Powerful motor means it'll be happy in compact enclosures
- Exceptionally high efficiency - 102dB @ 2.83v in 2pi.
- No need for a crossover
- Possible option for cast aluminium basket
- Uses existing recone materials
- Possible to get very deep bass, but larger enclosures would be needed.
I think that's everything. I've (hopefully) set up a poll so you can tell me what you think of all this.
Cheers all,
Chris
I'm running an interest check first of all.
The Fane 15" full-range driver looks pretty good in a lot of ways, but the T/S parameters make it difficult to work with unless you're willing to put up with a very large cabinet - Qts = 0.7 and Vas is 203L.
I'm thinking of organising a group buy for some upgraded units, and wanted to check interest levels.
I can see a few options here:
A - Same moving parts, just add more magnet
B - More magnet, cast aluminium frame
C - More magnet, cast frame, bigger voice coil aiming for more cone excursion and power handling.
D - Don't bother, the original is fine
I'm not looking for solid commitment or money at this point, but a rough idea of how many you might want to order would be good.
The T/S parameters I'm aiming for are simply to increase BL and drop Qes. That'd mean they'll be much happier in smaller cabinets, and also gain some efficiency.
Here's a quick sim of what we get if we go from the current BL=10.9 to BL=18.9:
This is in a 35L cabinet tuned to 73Hz. I know which I'd prefer.
With the increased BL, you could also go for a larger cabinet in the 100L range, which would give a response that slopes down towards the bass (probably matching room gain curves quite well) with LF extension into the 30Hz range before it rolls off.
So, I can see the improved version being useful for a few different markets:
- High-efficiency home HiFi - add a small valve amp and you're done.
- Professional Audio - stage monitors, main PA, etc.
- High-power home theatre surrounds.
A quick summary of the upgraded product:
- 15" Full-range unit
- Powerful motor means it'll be happy in compact enclosures
- Exceptionally high efficiency - 102dB @ 2.83v in 2pi.
- No need for a crossover
- Possible option for cast aluminium basket
- Uses existing recone materials
- Possible to get very deep bass, but larger enclosures would be needed.
I think that's everything. I've (hopefully) set up a poll so you can tell me what you think of all this.
Cheers all,
Chris
a good steel basket with no sharp edges is fine with me. ((Eminence Kappa12a, K43 type) I've dropped steel basket speakers with little damage to the basket and cast P-audio basket, breaking the basket at the rim - More motor please in the variant to get qts into the vented box (and Karlson) region. Fane don't seem to be directly available in the US.
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More magnet for sure. I’d also like a cast basket but I fear that would be very expensive unless there was large order. A new basket would also have different aerodynamics which may change the response.
The issue I see with going all out on upgrades is that we would really be creating a new driver entirely and who knows what that would sound like.
The issue I see with going all out on upgrades is that we would really be creating a new driver entirely and who knows what that would sound like.
Scott: I think that is what we're counting on.
Chris: here's a neo ring that might work? Will have to check the measurements.
40mm O.D x 25mm I.D x 5mm thick Neodymium Magnet - 9.7kg Pull | first4magnets.com
Chris: here's a neo ring that might work? Will have to check the measurements.
40mm O.D x 25mm I.D x 5mm thick Neodymium Magnet - 9.7kg Pull | first4magnets.com
Really? I stand corrected, I thought the only major point being made in the original post was behaviour below the mass corner [i.e. increasing EM damping to allow more practical enclosure sizes]; I didn't see any reference to how this might affect behaviour across the rest of the range.
It looks like there is a lot of interest in changing the magnet only. Perhaps a change to a Neo magnet would yield the desired results. This could be roughly the same size or smaller and perhaps even lower in weight. Wouldn’t that result in fewer changes due to aerodynamics and stress on the steel basket than going with a larger, heavier conventional magnet
It looks like there is a lot of interest in changing the magnet only. Perhaps a change to a Neo magnet would yield the desired results. This could be roughly the same size or smaller and perhaps even lower in weight. Wouldn’t that result in fewer changes due to aerodynamics and stress on the steel basket than going with a larger, heavier conventional magnet
Hi Scott,
I think the lack of motor power is the big problem with the 15" unit.
Playing with Hornresp (admittedly, just sliding BL up and down) suggests the range above the mass corner will simply gain efficiency as you'd expect from a more powerful magnet. I think Hornresp would be good for a first-order approximation of the range above the mass corner.
Are there other effects that ought to be considered?
So far, there haven't been a whole lot of votes here, so I suspect the market is going to be pretty limited for a batch of drivers - probably not enough to get this off the ground.
Given that, I'm probably going to investigate simply adding magnets and iron to the existing motor. I have a pair of the stock drivers on their way, and will make a seperate thread of modifications.
Chris
Just raising the mass corner a significant amount will audibly change its tone, harmonic structure based on dim memory of 'dialing in' a 1939 Sears Silvertone/RCA console's wide range 12" field coil [no whizzer, etc.] and more recent comparisons between old/abused Altec wide range woofers before/after the AlNiCo magnets were drained/re-zapped, which will theoretically impact the dual whizzer's responses in [guessing] somewhat unpredictable ways, though if a 'bullwhip' analogy is appropriate, then its already 'strong' whizzer output will be even worse ['sharper'/sibilant].
Anybody got a wide range field coil driver w/whizzer to do comparison tests with?
GM
Chris -GM's beaten me to it, but exactly what he said. Don't forget Hornrsp uses driver data that is primarily focused upon the rising response / acceleration BW below the driver's mass corner. Valuable in itself but largely runs out of relevance as far as the direct driver output is concerned >Fhm, with the nominal assumption being that the mass-controlled BW is flat (unless affected by the cabinet loading) until VC inductance rolls it off. With wideband drive units that operate in more-or-less controlled resonance for much of their BW, it isn't quite as simple, especially when sub-cones & other emitting surfaces coupled to the VC (or decoupled for that matter) come into play. You may find you need to change the coil, possibly the spider & some adhesives also. May. Perhaps. Maybe. Fane will be able to advise, but if you haven't already, I'd be inclined to drop them a line & get their engineering department to advise. IIRC the late John Wycoff with his 12in Hammer units had to get Eminence to make numerous changes relative to the base driver, in addition to the mild increase the motor power; that took quite a few prototypes. Not trying to put a downer on this idea (I like it, & I'm with you that the weak motor & the large box size that results are significant limiting factors), but it's probably better to at least consider these from the off, if only to tick the 'ruled out / non-issue' box.
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Not to reply to the same post as everyone else, but yeah.
I am no expert in driver design, but having an interest in FR drivers I've ofcourse looked at the AN drivers over the years, they seem to be have many similar materials and build between the different magnet versions (Ferrite, Neo, Alnico).
The only driver left with Neo And Ferrite options are the Classic 8 and the Super 8, and of those, only the Classic 8 has different magnet strength:
http://www.commonsenseaudio.com/an8classicspecs.jpg
http://www.commonsenseaudio.com/an8classicneospecs.jpg
http://www.commonsenseaudio.com/an8cfspecs.jpg
http://www.commonsenseaudio.com/an8neospecs.jpg
If memory serves me correct (Not always!), I seem to remember the same trend of the bigger sized drivers, some reduction of peaks and variation in the lower frequencies, up top the variations are more profound with varying results, not always for the better, but all in all a quite different graph than the lower BL units. Ofcourse changing the magnet strength will influence the sound.
My desire is having a "Pro" version of the FC152, just like there is a Pro verison and a Sovereign version of the 15-500, with little difference between the two, other than slight increase of general build quality, magnet strength and a cast chassis. So just a slight "beef up" in build quality, less focus on price, a little bit different performance is to be expected IMO.
A little bit naive to expect the same driver when you change vital components.
Was editing but missed the time limit:
Pro 15-600N vs Pro 15-600 seem relatively similar, but it's Neo 21.9 BL 1.1 flux density vs Ferrite 17.5 BL 1.0 flux density. The stronger Neo version has a little bit less dip on 1khz, and on axis HF extension seems to go slightly higher, other than that not much difference other that the obvious FS and Q changes.
I expect the wizzer will behave differently also, some for the better, some for the worse, off axis response might change less than on axis response though. And I prefer use the FC152 with more "toe in" and less EQ than what makes the graphs pretty.
Pro 15-600N vs Pro 15-600 seem relatively similar, but it's Neo 21.9 BL 1.1 flux density vs Ferrite 17.5 BL 1.0 flux density. The stronger Neo version has a little bit less dip on 1khz, and on axis HF extension seems to go slightly higher, other than that not much difference other that the obvious FS and Q changes.
I expect the wizzer will behave differently also, some for the better, some for the worse, off axis response might change less than on axis response though. And I prefer use the FC152 with more "toe in" and less EQ than what makes the graphs pretty.
For those concerned about the mid-high range, have a quick look at the PDF for this driver: Speaker Detail | Eminence Speaker
It features Eminence's FDM (Flux Density Modulation) technology. I suspect all it does is move the ferrous polepiece in and out of the magnetic structure, but I could be wrong. The T/S parameters show quite a swing, with Qts going from 1.29 to 6.02. However, the mid-high range looks like it's attenuated pretty linearly.
I'm not going to claim simply adding more magnet will have the same effect - Eminence might've worked really hard on a way of reducing flux density in a way that maintains the frequency response.
It does seem possible, though, that the mid-high range will simply gain a few dB in sensitivity with minimal changes to the response.
Reading around further, I believe these guys: FluxTone Products - FluxTone Guitar Speakers
Are using field-coils in their guitar speakers, and I suspect they're simply changing the field coil current flow with their clever box. No measurements, but people like what they hear.
Kaffiman, it's difficult to figure out what changes are being made by the changing magnetic field strength - you might just be looking at reflections from the larger ferrite magnet.
Chris
It features Eminence's FDM (Flux Density Modulation) technology. I suspect all it does is move the ferrous polepiece in and out of the magnetic structure, but I could be wrong. The T/S parameters show quite a swing, with Qts going from 1.29 to 6.02. However, the mid-high range looks like it's attenuated pretty linearly.
I'm not going to claim simply adding more magnet will have the same effect - Eminence might've worked really hard on a way of reducing flux density in a way that maintains the frequency response.
It does seem possible, though, that the mid-high range will simply gain a few dB in sensitivity with minimal changes to the response.
Reading around further, I believe these guys: FluxTone Products - FluxTone Guitar Speakers
Are using field-coils in their guitar speakers, and I suspect they're simply changing the field coil current flow with their clever box. No measurements, but people like what they hear.
Kaffiman, it's difficult to figure out what changes are being made by the changing magnetic field strength - you might just be looking at reflections from the larger ferrite magnet.
Chris
Chris, I do not think on axis response at 1khz and up is that influenced significantly from the physical form of the magnet, the spider and rear of the basket is in the way of direct reflections from the magnet either way. The basket itself has bigger effect in this area because of the structure is closer to the cone.
This is why I compared the Fane Pro 15-600N vs the Pro 15-600, they are seem equally built in all areas but magnet type and strength.
I think it should be possible to just drill some holes on the basket, drill and tap some suitable alu braces to each side and cut off the excess steel around it to compare, also make two halves of a carbon steel disc with fittings to attach together with screws, and one disc to add on the back to expand the magnet structure and couple it magnetically as best as possible.
Edit:
Oh, and I do suspect that increasing the voice coil diameter will have significant detrimental effect towards the reproduction of higher frequencies.
Edit2:
Oh, maybe you meant that the design of the cooling system for the Neo magnet has an effect on the sound? Yes, that may be, Neo magnets do not cope with heat as well, and need more optimalized cooling solutions. Many Neo magnets are specced for 80c while there are a lot of Ferrite magnets that are specced for 120c.
This is why I compared the Fane Pro 15-600N vs the Pro 15-600, they are seem equally built in all areas but magnet type and strength.
I think it should be possible to just drill some holes on the basket, drill and tap some suitable alu braces to each side and cut off the excess steel around it to compare, also make two halves of a carbon steel disc with fittings to attach together with screws, and one disc to add on the back to expand the magnet structure and couple it magnetically as best as possible.
Edit:
Oh, and I do suspect that increasing the voice coil diameter will have significant detrimental effect towards the reproduction of higher frequencies.
Edit2:
Oh, maybe you meant that the design of the cooling system for the Neo magnet has an effect on the sound? Yes, that may be, Neo magnets do not cope with heat as well, and need more optimalized cooling solutions. Many Neo magnets are specced for 80c while there are a lot of Ferrite magnets that are specced for 120c.
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I think upgrading the basket should be the first thing to look at, by upgrading the basket it would also lead to the magnet becoming more effective due to losses using a steel frame. They may well have a suitable basket from the pro range as an off the shelf upgrade, so not expensive if they have. Upgrading the basket would then allow for closer tolerences in the magnetic gap which would further increase the effect of the existing magnet, but to take advantage of that would mean new pole piece and top plates, so good opportunity to turn to a larger magnet if and I say if it would really help.
Reducing the tolerances in the gap would also increase thermal coupling of the coil to the magnet structure to result in lower power compression enhanced to a small degree by the aluminium basket being a more effective heatsink.
Existing motor appears to already have some sort of shorting ring judging by the low 'le', also quoted xmax suggest it may be using a t shape pole piece?
Reducing the tolerances in the gap would also increase thermal coupling of the coil to the magnet structure to result in lower power compression enhanced to a small degree by the aluminium basket being a more effective heatsink.
Existing motor appears to already have some sort of shorting ring judging by the low 'le', also quoted xmax suggest it may be using a t shape pole piece?