I use a Vifa 3" fabric dome and I'm really happy with it, but I discovered in the course of building my 3-ways and doing a lot of reading, that this is really dependant on; i) where (frequency) and how (crossover type, slope, etc) you put the low and high points for the bandpass crossover,
ii) the specs and capabilities of the other drivers.
I guess the ideal situation is for the drivers to share as much each of the frequency spectrum as possible, BUT a very important consideration for the crossover between the woofers and the mids is to avoid as much as possible crossing in really ear sensitive human vocal regions. (somewhere in the 500 to 1000Hz area). Unfortunately due to the typical capabilities and specs of most midrange drivers, this is exactly where manufacturers recommend that you cross them over!
I think that to get any advantage in using a mid at all, you need one that will be able to perform well over frequencies where you will probably be most likely to notice problems, so you do need to choose really carefully and integrate it with other drivers as smoothly as you can.
One way to do this is to use a good small cone because they are typically resonant much lower than domes and therefore you can often cross them around 300-400, but they can be less nice in the upper mid region, so if you choose to do this ideally you'd not want to cross to the tweeter too high.
The way I got around it with my domes was to use a nice steep (4th order linkwitz riley) crossover between the woofers and mids at about 500. I did use an active crossover though because higher order passive crossovers this low can be really problematic. A side note her: bi-amping this way was easily the single most noticable and satisfying improvement I have ever made!
I tried them at 4000 to the tweeter but they seemed to "ring" way too much so I backed it down to 3200 and now they are sweet. Used a passive 4th order linkwitz riley - complicated but worth it.
I guess if I was going to do it again I'd go for a high quality small diameter (maybe 4") cone crossed at about 300Hz to the woofers, but I got my domes for an excellent price given their capabilities.
As far as the comment made by François about dispersion goes, this again depends on the passband, but I'd guess domes may offer better dispersion over the higher frequencies.
I don't know what domes are listed in parts express but mine are Vifa D75MX-31-08's, 3" coated fabric dome.
ii) the specs and capabilities of the other drivers.
I guess the ideal situation is for the drivers to share as much each of the frequency spectrum as possible, BUT a very important consideration for the crossover between the woofers and the mids is to avoid as much as possible crossing in really ear sensitive human vocal regions. (somewhere in the 500 to 1000Hz area). Unfortunately due to the typical capabilities and specs of most midrange drivers, this is exactly where manufacturers recommend that you cross them over!
I think that to get any advantage in using a mid at all, you need one that will be able to perform well over frequencies where you will probably be most likely to notice problems, so you do need to choose really carefully and integrate it with other drivers as smoothly as you can.
One way to do this is to use a good small cone because they are typically resonant much lower than domes and therefore you can often cross them around 300-400, but they can be less nice in the upper mid region, so if you choose to do this ideally you'd not want to cross to the tweeter too high.
The way I got around it with my domes was to use a nice steep (4th order linkwitz riley) crossover between the woofers and mids at about 500. I did use an active crossover though because higher order passive crossovers this low can be really problematic. A side note her: bi-amping this way was easily the single most noticable and satisfying improvement I have ever made!
I tried them at 4000 to the tweeter but they seemed to "ring" way too much so I backed it down to 3200 and now they are sweet. Used a passive 4th order linkwitz riley - complicated but worth it.
I guess if I was going to do it again I'd go for a high quality small diameter (maybe 4") cone crossed at about 300Hz to the woofers, but I got my domes for an excellent price given their capabilities.
As far as the comment made by François about dispersion goes, this again depends on the passband, but I'd guess domes may offer better dispersion over the higher frequencies.
I don't know what domes are listed in parts express but mine are Vifa D75MX-31-08's, 3" coated fabric dome.
My impression is that shape of a driver has little to do with dispersion (except where the shape helps decouple part of the cone or dome, so that the smaller part acts like a smaller driver for higher frequencies --common in woofers). Cones and domes are usual shapes because their geometry makes them stiffer than a flat surface of equal mass.
Oops -- sent reply off before finishing it: dispersion is determined by size of driver relative to wavelength of frequency produced. If the driver is small compared to the wavelength, it will be relatively omnidirectional, but as wavelength gets shorter, dispersion gets more and more restricted. The difference in dispersion patterns in the transition from a large woofer to a smaller midrange is part of the difficulty invovled in speaker design, since what is heard, even in the sweet spot, is not just sound directly radiated, but involves how the whole room is energised.
Cone V Dome
I have used both over the years.
I find that the cavity that is associated with the shape of the cone has an effect on the sound. I guess it might be a kind of horn effect? So I have noticed variations in the sound of midranges based on the depth of the cone, and the size of the center dome, or lack there of in the case of the phase plug design.
Domes have no cavity, so they don't have the cavity sound. However there is a second devil in the details. Midranges also suffer from the rear wave being reflected off of the magnet and coming back through the cone/dome. Most dome midranges suffer from this reflection worse than their cones. If you disassemble the dome, you usually find the flat metalic face of the magnet structure directly behind the entire dome. Better designed dome tweeters now have a hole bored into the magnet to let the back wave escape ( B&W nautilus, JBL studio ). I don't know if there is a dome midrange of this design out there. I would guess that a soft dome would be more succeptable to passing this reflection, but I don't know if hard dome midranges are (metal) a lot better.
I think my favorite cone is made by Vanderstein. It has a miniscule magnet structure ( made possible by rare earth magnets) - to avoid reflections. I don't know if you can buy the driver separately.
There are also cone midranges that have the cone filled in (Phase Technology) So these would avoid the cavity sound and the thick cone would probably not pass the reflected sound off the magnet.
There ya go, way too much information.
I have used both over the years.
I find that the cavity that is associated with the shape of the cone has an effect on the sound. I guess it might be a kind of horn effect? So I have noticed variations in the sound of midranges based on the depth of the cone, and the size of the center dome, or lack there of in the case of the phase plug design.
Domes have no cavity, so they don't have the cavity sound. However there is a second devil in the details. Midranges also suffer from the rear wave being reflected off of the magnet and coming back through the cone/dome. Most dome midranges suffer from this reflection worse than their cones. If you disassemble the dome, you usually find the flat metalic face of the magnet structure directly behind the entire dome. Better designed dome tweeters now have a hole bored into the magnet to let the back wave escape ( B&W nautilus, JBL studio ). I don't know if there is a dome midrange of this design out there. I would guess that a soft dome would be more succeptable to passing this reflection, but I don't know if hard dome midranges are (metal) a lot better.
I think my favorite cone is made by Vanderstein. It has a miniscule magnet structure ( made possible by rare earth magnets) - to avoid reflections. I don't know if you can buy the driver separately.
There are also cone midranges that have the cone filled in (Phase Technology) So these would avoid the cavity sound and the thick cone would probably not pass the reflected sound off the magnet.
There ya go, way too much information.
I agree with comments about sounding different, and about the problem of backwave reflection in both cones and domes, but the specific issue I was addressing was dispersion, not overall sound quality.
Quite a few domes have some sort of foam or damping material over the pole piece of the magnet in the hope that this will help minimise backwave. Venting the pole piece helps also, but the vents don't seem wide enought to actually completely stop reflections. Some also have the pole piece bevelled -- this ought to help.
Quite a few domes have some sort of foam or damping material over the pole piece of the magnet in the hope that this will help minimise backwave. Venting the pole piece helps also, but the vents don't seem wide enought to actually completely stop reflections. Some also have the pole piece bevelled -- this ought to help.
Here's a rough drawing of one I hope to build someday. It's sort of a wideband inverted cone with perimeter horn loading/waveguiding. My goal would be to critically damp it by tuning the rear transmission line and cavity.
An externally hosted image should be here but it was not working when we last tested it.
Mos
I was just about to ask the same question myself, lucky i searched! The Visaton catalogue is a good read for this comparison. They have domes and cones for about euro90.
The domes look fantastic, eg G50FFL, exceptionally linear frequency repsonse with gentle rolloff's at each end, nice waterfall spectrum.
The cones on the other hand, eg AL130M, (a highly rated driver in some quaters) has a frequency plot that is flat virtually nowhere, with some fair sized peaks in the highs, and a waterfall that gets messy in the highs as well.
The only thing is, as previously mentioned, the dome is only useble down to 800Hz. Also, Visaton seem the be more keen on the cone mids in their kits, especially the higher range models. There must be a lot more to this question than the specs alone can reveal!
Mark
I was just about to ask the same question myself, lucky i searched! The Visaton catalogue is a good read for this comparison. They have domes and cones for about euro90.
The domes look fantastic, eg G50FFL, exceptionally linear frequency repsonse with gentle rolloff's at each end, nice waterfall spectrum.
The cones on the other hand, eg AL130M, (a highly rated driver in some quaters) has a frequency plot that is flat virtually nowhere, with some fair sized peaks in the highs, and a waterfall that gets messy in the highs as well.
The only thing is, as previously mentioned, the dome is only useble down to 800Hz. Also, Visaton seem the be more keen on the cone mids in their kits, especially the higher range models. There must be a lot more to this question than the specs alone can reveal!
Mark
Yup.
BTW, the only speakers I ever owned using a dome midrange was a set of Technics SB501s which were the front channels in a Technics Quad system. Those were the days!
I still have the spec sheet for the speakers and it lists the crossover points at 600 and 4000. The dome itself was only about 3 inches (7.5cm) and was housed in a finned enclosure with a solid cap. I thought this would have intereferred with the wave but that's how they did it. I'm sure the dome was paper.
BTW, the only speakers I ever owned using a dome midrange was a set of Technics SB501s which were the front channels in a Technics Quad system. Those were the days!
I still have the spec sheet for the speakers and it lists the crossover points at 600 and 4000. The dome itself was only about 3 inches (7.5cm) and was housed in a finned enclosure with a solid cap. I thought this would have intereferred with the wave but that's how they did it. I'm sure the dome was paper.
hey. im interested in using dome mids aswell, i have had these before
http://www1.jaycar.com.au/productVi...&pageNumber=&priceMin=&priceMax=&SUBCATID=434
and they sound nice and smooth, they have like a semi-wet foamy thingy behind the actual dome to absorb the backwave.
i plan to get them again as i sold my last [pair to a mates dad since his cone mids died
http://www1.jaycar.com.au/productVi...&pageNumber=&priceMin=&priceMax=&SUBCATID=434
and they sound nice and smooth, they have like a semi-wet foamy thingy behind the actual dome to absorb the backwave.
i plan to get them again as i sold my last [pair to a mates dad since his cone mids died
Ive used both cones & domes . The dome was a Dynaudio D52AF (rear chambered) and the cone an Audiotechnology 15H52.
Each has their strengths & weaknesses.
The dome I've found produces better low-level detail & ambience, You really get a feel for the acoustics of the recording venue. However there are some limitations - narrow frequency range & limited (softened) dynamics.
The cone I used has virtually unlimited dynamics & produced clearer vocals (due mainly to the more optimum crossover points).
IMHO, both can sound great, but overall I think a small, light, dedicated midrange cone is the best choice and that's why dome mids are relatively rare.
Each has their strengths & weaknesses.
The dome I've found produces better low-level detail & ambience, You really get a feel for the acoustics of the recording venue. However there are some limitations - narrow frequency range & limited (softened) dynamics.
The cone I used has virtually unlimited dynamics & produced clearer vocals (due mainly to the more optimum crossover points).
IMHO, both can sound great, but overall I think a small, light, dedicated midrange cone is the best choice and that's why dome mids are relatively rare.
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