This was an interesting read, despite mostly skipping posts by OP, I did value knowledgeable folks staying around and providing great advice. Hoping to benefit from their experience!
I'm chewing on the idea of using a wideband driver as midrange in an active dipole multiway, approx within 300 to 1800Hz. Can't listen to these drivers, hence the question: In your experience does a dedicated good midrange have better mids than a very good widebander?
Some noted WB: DX3, Lii Crystal 10, Visaton B200, Fostex ESigma line, Seas FA22rcz.
The emphasis on WD midrange performance makes me wonder if their mids are better than a dedicated mid, like my current B&C 8PE21, or Troel's JA-8008-HMQ, AE TD8M. Certainly open to learn about top performers! Higher sensitivity preferred.
I'm chewing on the idea of using a wideband driver as midrange in an active dipole multiway, approx within 300 to 1800Hz. Can't listen to these drivers, hence the question: In your experience does a dedicated good midrange have better mids than a very good widebander?
Some noted WB: DX3, Lii Crystal 10, Visaton B200, Fostex ESigma line, Seas FA22rcz.
The emphasis on WD midrange performance makes me wonder if their mids are better than a dedicated mid, like my current B&C 8PE21, or Troel's JA-8008-HMQ, AE TD8M. Certainly open to learn about top performers! Higher sensitivity preferred.
In my case, the deciding factor will mostly be a well behaved (for the band pass you intend to use) driver that suits your design, whether it is a full range driver or a dedicated mid. It also rules out some of those full range that have a wild ride that some people call "character".
For example, I've read great things about the SBAudience mid NERO-6MRN150D, but I have yet to listen to one.
I will need to come up with something I can try it in.
For example, I've read great things about the SBAudience mid NERO-6MRN150D, but I have yet to listen to one.
I will need to come up with something I can try it in.
I think the drivers you mention are not that good (except maybe the fostex ones, but not for this purpose).
Better look at drivers that are flat in the midrange, low distortion and have a good dispertion like smaller Mark Audio, Jordan, Scanspeak 10F series, Fountek FR88EX, Faital 3FE and 4FE series, ... The thing is bigger fullrange drivers have a worse dispertion and often resonances in the passband where you don't want it in your setup. The one exception may be the Alpair 10P, where the resonances are there, but very surpressed by how the cone is made, so hardly an issue. The CHN110 metal cone comes close to that and is also bigger and more sensitive. But in general a smaller cone makes a better midtweeter than a big cone.
Better look at drivers that are flat in the midrange, low distortion and have a good dispertion like smaller Mark Audio, Jordan, Scanspeak 10F series, Fountek FR88EX, Faital 3FE and 4FE series, ... The thing is bigger fullrange drivers have a worse dispertion and often resonances in the passband where you don't want it in your setup. The one exception may be the Alpair 10P, where the resonances are there, but very surpressed by how the cone is made, so hardly an issue. The CHN110 metal cone comes close to that and is also bigger and more sensitive. But in general a smaller cone makes a better midtweeter than a big cone.
Not that some of these don’t have decent midrange, but there are others that do mids better. The FE108e∑ would fit into that, but from the others a larger than needed mid is inquired about.
B200 & FA22 need phase plugs. I am very leary of the Lii drivers.
dave
Best IME to limit flat BW to the driver's point source, i.e. ~ the VC's diameter = ~34400/pi/1800 = ~60.8 mm/2.4". Of course this would likely require a [much] larger frame size than desired, so scale it as required with the trade-off of lower power handling, wider polar response without a WG.
Not IME, but my choices way back when were very limited so YMMV, but IME in more recent decades is that folks 'raised' on complex XOs/filters tend to ignore the 'quality' of the mid's total BW required for the desired slope order, so WB/FR drivers may still be preferred overall.
True, but I recommended just limiting it to the driver's point source BW to principally limit the driver's TL, breakup modes and acceleration BW below its upper mass corner [Fhm = ~2*Fs/Qts'] to any filter's slope order BW.
For sure we know from long experience that even this relatively limited BW can be anything but 'flat', though is normally a 'good enough' way to describe the [Fhm] - [VCf] BW.
[Qts']: [Qts] + any added series resistance [Rs]: http://www.mh-audio.nl/Calculators/newqts.html
[Rs] = 0.5 ohm minimum for wiring, so may be higher if a super small gauge is used as a series resistor plus any added resistance from an XO/whatever.
For sure we know from long experience that even this relatively limited BW can be anything but 'flat', though is normally a 'good enough' way to describe the [Fhm] - [VCf] BW.
[Qts']: [Qts] + any added series resistance [Rs]: http://www.mh-audio.nl/Calculators/newqts.html
[Rs] = 0.5 ohm minimum for wiring, so may be higher if a super small gauge is used as a series resistor plus any added resistance from an XO/whatever.
Thank you for all the inputs!
No need for the driver to be larger that what it needs to be. My bias towards larger drivers is more out of ignorance and search for higher efficiency than experience.
Are the Fostex 108EZ or Alpair 10P good candidates for open baffle? Limiting bandwidth to about 300 to 1800Hz.
Any other Markaudio driver that is great midrange performer? I see many models. From prior post in this thread I noted that while the 108EZ is noted as having great mids, the larger siblings aren't.
I'm also skewed towards SETs but not set in stone. The 10P description notes it was intended for low-power amps.
The ScanSpeak 10F series seems to be low sensitivity. I have Faital 3FE in a small box and while good, don't think is much better than 8pe21 in mids - of course it goes much higher. Haven't heard 4FE.
No need for the driver to be larger that what it needs to be. My bias towards larger drivers is more out of ignorance and search for higher efficiency than experience.
Are the Fostex 108EZ or Alpair 10P good candidates for open baffle? Limiting bandwidth to about 300 to 1800Hz.
Any other Markaudio driver that is great midrange performer? I see many models. From prior post in this thread I noted that while the 108EZ is noted as having great mids, the larger siblings aren't.
I'm also skewed towards SETs but not set in stone. The 10P description notes it was intended for low-power amps.
The ScanSpeak 10F series seems to be low sensitivity. I have Faital 3FE in a small box and while good, don't think is much better than 8pe21 in mids - of course it goes much higher. Haven't heard 4FE.
Yes. Given what i recall from MJK’s OB primer, the lower XO might well need to be higher since where it is put is tied to the baffle width. The tweeter XO might be low enuff to not cause issues, i have heard implementations where losing the tweeter brought better top end.
Both of these have a vintage top, controlled and sloped down, the Mark Audio more neutral, the Fostex really seductive.
As far as mids go, the metal cone MAs probably do midrange best, and MAOP 7/10.2 might well be the best they make. I have 7 ;^) and 10.2 is getting rave reviews. The A5.3 i understand has also been MAOPed, which being monoSuspension, is likely even better (sensitivity and max loudness limited) but i would not use it open baffle. But any of the current generation Alapirs, metal or paper (except A7p) do midrange really well and other factors like sensitivity and loudness could play a role.
I would advixe listening to any of these w/o the tweeter and only add it after you have the woofer/mid transition sorted.
The most common issues with the metal cones is peopel who have issues with HF ringing. Not something i had any issues with, with the treated drivers i listen to.
I have one more OB in me, i have the basic design, 8 10” OB woofers, and had originally chosen to use A10PeN.
dave
That is what the best phase-plug-less FRs work to achieve. The 19mm dome on the FF85wk or Alpair 5.2/3 do a pretty good job.
dave
I don't know about the Fostex 108EZ, but the 10P in an OB start to roll off at about 200hz (but slowly) to an F3 of about 100Hz so with the crossover at 300Hz should be no issue. The driver is liked speced +/- 89dB sensitive, so a low power amp can work in the right space. I've run similar sensitive CHN110 fullrange for a while with a 7.5W class A amp and did not lack volume but my listening space is rather small. If you use this driver with a limited bandpass with a similar powerfull amp it should be enough in most spaces. If you use a passive crossover a part of the sensivity is eaten by it so you will need a bit more power.
The driver can handle in reality about 30w (altough it's rated higher) without distortion, above that it start to distort (but does not break).
I spent some time looking into Alpairs and Fostex 108EZ (sigma). It was mentioned above FE108EZ the larger siblings aren't that good in the mids so didn't pursue further. The 108EZ, like the Alpair 7MS are 50cm Sd and 86dB sensitive (7MS), which I need to get my head around since I'm coming from 8PE21 with 220cm2 and 98dB sensitivity and I have two of them per side. I'm in the process of building a new test baffle and will try using just one 8PE21 instead of two, try a 5" Faital 5MN8 I have (99dB, 94cm2...close to 10P's 88cm2), and Faital 3FE22 (33cm2). Maybe I learn I don't need as much radiating surface for midrange.
The MOAPs look great but expensive and would rather get my feet wet with Alpairs.
Is the midrange of the Alpair 12P on par with that of the 10P and 10.3? Thinking midrange up to 2.5 or 3kHz. Forum member warrjon posted here a measurement of 12P in dipole without baffle which looks like it would work (naked) from about 600Hz, and maybe a small baffle enables a 400Hz xo point.
Alpair 12P/10P/10.3/7MS have nice low Le and highish minimum impedance that look like good match for SETs. However the 90dB or so sensitivity has me wondering if the system wouldn't be dynamically limited (I listen at 80-85dB SPL avg). The 12P (91dB) gains about 1.5dB sensitivity over the 10P (89.6), which gains about 1.5dB sensitivity over the 10.3 (88), and 2dB over the 7MS (86). The 7MS is rated 15W, and at 15W it would make about 98dB SPL at the listening position but at rated power distortion might be high? Feeding 4W would imply 92dB SPL at the listening position...am I thinking this wrong?
The MOAPs look great but expensive and would rather get my feet wet with Alpairs.
Is the midrange of the Alpair 12P on par with that of the 10P and 10.3? Thinking midrange up to 2.5 or 3kHz. Forum member warrjon posted here a measurement of 12P in dipole without baffle which looks like it would work (naked) from about 600Hz, and maybe a small baffle enables a 400Hz xo point.
Alpair 12P/10P/10.3/7MS have nice low Le and highish minimum impedance that look like good match for SETs. However the 90dB or so sensitivity has me wondering if the system wouldn't be dynamically limited (I listen at 80-85dB SPL avg). The 12P (91dB) gains about 1.5dB sensitivity over the 10P (89.6), which gains about 1.5dB sensitivity over the 10.3 (88), and 2dB over the 7MS (86). The 7MS is rated 15W, and at 15W it would make about 98dB SPL at the listening position but at rated power distortion might be high? Feeding 4W would imply 92dB SPL at the listening position...am I thinking this wrong?
In all fairness making note about the Fostex drivers of different sizes, and talking about 'midrange capability' in that same capacity probably won't answer your question about whether the Alpair is a good replacement for the B&C. After all, in the first case you're talking about different breakup behaviour coming in at different frequencies. I assume you're not using the B&C in that region and the Alpair won't be a problem either?
Good, should be compared to Fostex FF85wk and Alpair 5.2/3 (CHN-50 is a cheap version).
Not in my opinion. People, i believe, are drawn to it because it is bigger — a fallout of a generic male straight, mine is bigger than yours.
Maybe, but they play well with SETs much better than many imagine.
dave
Sorry Allen, but I didn't understand. Which region are you referring to? Right now I'm using the 8PE21 from 300 to 1800Hz in OB with 12" wide baffle.
Ok, that's a reasonable band for the 8PE21, where it's mostly pistonic.. you don't get much into the breakup (or the beaming). The Alpair is smaller so you can expect the same.
This means the larger part of your differences will be noticeable in the form of the response, which is something you can take control of yourself.
This means the larger part of your differences will be noticeable in the form of the response, which is something you can take control of yourself.