Start resonating way to low to cross over at 2Khz, i would not cross this higher than 1500Hz and only with a higher order crossover. And FS and EBP is to high to use this in a sealed to 45Hz, it may work in a TL, but not in a sealed one.
OP, I should mention, I overlooked your want of a sealed cab. The Misco driver I mentioned would need a vented alignment to get down into the 40's
After thinking through it, I think you are giving some contradictory specs that makes it nearly impossible to fulfil... You are thinking of sealed and high efficiency... and good bass. You need to switch to BR or TL or MLTL or some other form of vented cabinet. Reason is simple, for high efficiency, you need a really strong motor, strong motor means high EMF hence very impedance at Fs. This means at Fs very little current will flow. If you look at free air, the peak can be 100ohm or so. Hence poor bass response. Normal woofers would go to 20-30 ohm. Switching to a vented cabinet, the tuning suppresses the movement of cone, hence no emf, and of course no impedance peak to worry about.
This thread is very interesting. I too use FR drivers in multi-way designs when I need to. In general, modest-sized FR drivers can be good mids in 3-ways (Jordan Eikona), and larger ones can be midbass in 2-ways (some of these 8" or larger drivers). I just do not like any FR driver used alone in a single-driver speaker. I too am looking for a high sensitivity driver to build speakers for a friend's SET amp. I'm not interested in huge enclosures or horns -- I'm hoping to get away with a bass reflex, and I think my friend can live without earth-shaking bass.
I was thinking of the 8" Fostex FF225WK as one candidate, and the 12" Classic Audio Nirvana as another. Mating a 12" driver to a tweeter seems like a bad idea under normal circumstances, but these vintage and valve amp lovers do it all the time in 2-way designs with their large 12" and 15" drivers, and they live with the beaming of the large drivers.
The 12" Audio Nirvana seems to be very attractive on sensitivity, allowing me to get maybe 92dB even after 5-6dB of BSC. I was thinking of mating either FR driver (Fostex or Audio Nirvana) with an SB29RDNC to get its 94dB sensitivity. None of these FR drivers will give me the most neutral or low distortion final designs, but I guess with you have an 8W amp to start with, you pick your poison and hope that my friend's exposure to large vintage driver designs will make him like what I can build more easily.
I was thinking of the 8" Fostex FF225WK as one candidate, and the 12" Classic Audio Nirvana as another. Mating a 12" driver to a tweeter seems like a bad idea under normal circumstances, but these vintage and valve amp lovers do it all the time in 2-way designs with their large 12" and 15" drivers, and they live with the beaming of the large drivers.
The 12" Audio Nirvana seems to be very attractive on sensitivity, allowing me to get maybe 92dB even after 5-6dB of BSC. I was thinking of mating either FR driver (Fostex or Audio Nirvana) with an SB29RDNC to get its 94dB sensitivity. None of these FR drivers will give me the most neutral or low distortion final designs, but I guess with you have an 8W amp to start with, you pick your poison and hope that my friend's exposure to large vintage driver designs will make him like what I can build more easily.
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You can have 2 of the 3 under Hoffman's iron law.. box size can be huge, I don't mind 🙂
That driver does look good, I think it's the one Audio Nirvana driver with high QTS - someone kindly posted it earlier. There's also a couple of Monacor drivers which may work.
Another way, which I'm resisting, is to double up ie run two 8ohm in parallel. There's this reissue Vifa, used in many classic designs which cd work well in a 2.5 way sealed https://willys-hifi.com/products/vifa-m21wg-09-08-bass-midrange
The problem with AN is that their published specs are often far of the real specs, and the lack of xmax. It's hard to get a solid bass out of them. If you like big fullrange drivers as midwoofer, the Fane 12-250TC or 15-300TC is a much better option, just like the Beyma 12G40 and some other "fullrange" p.a. speakers. They got at least some mm xmax and you can trust their published specs. I use the Fane 12-250TC as fullrange driver on low power and it gives a solid bass to 30Hz in a 174L ported, sealed it stays more arround 50Hz. Real measured sensivity is 98dB/2.83V/1m
I had heard of the unreliability of the AN driver specs. Your suggestion of alternate drivers is really very useful. I'll check them out, thanks a lot.
Who retails Fane drivers in the US or UK?
https://www.parts-express.com/FaitalPRO-15PR400-15-Neodymium-Professional-Woofer-4-Ohm-294-1270
This seems to be a good driver to mate to a high-sensitivity tweeter, doesn't it? 99 dB, 35 Hz Fs.... But more than twice as expensive as a Fane.
This seems to be a good driver to mate to a high-sensitivity tweeter, doesn't it? 99 dB, 35 Hz Fs.... But more than twice as expensive as a Fane.
The Faital 15PR400 is perfect for that and used a lot in that kind of configs. It's expensive, but worth it.
I would try the Wild Burro Betsy.
https://wildburroaudio.com/speakers/
BETSY:
Re 5.9 ohms
Fs 49.630Hz
Sd 22.966
BL 4.166
Qms 4.567
Qes .945
Qts .783
Spl 92.4db
Vas 86.387L
Mms 8.916g
Only a little over 100USD for a pair! They really do sound good, for the price a bargain.
In my OB the Betsy plays just as loud, if not slightly louder than my Fostex FE167, Fostex claims 95dB sensitivity.
https://wildburroaudio.com/speakers/
BETSY:
Re 5.9 ohms
Fs 49.630Hz
Sd 22.966
BL 4.166
Qms 4.567
Qes .945
Qts .783
Spl 92.4db
Vas 86.387L
Mms 8.916g
Only a little over 100USD for a pair! They really do sound good, for the price a bargain.
In my OB the Betsy plays just as loud, if not slightly louder than my Fostex FE167, Fostex claims 95dB sensitivity.
Hi Bill,
Actually what I meant to say is you cannot squeeze any good bass out of a full range because of the high impedance at resonance even if the cabinet is infinitely huge. Only way is to suppress the high impedance at Fs by using a vented cabinet.
What you would need is a woofer that goes high frequencies.... in which case look at SB acoustics...those can be used sealed but they are 95db... maybe 92...
Oon
I had really good success with SEAS FA22RCZ... The bass was phenomenal in a transmission line...
I will post a thread on it when I have some time...
Oon
Thanks for detailed response. I'll look at the driver you mentioned. I did consider an aperiodic vent to reduce Q and flatten impedance
Its great asking for sealed, I agree for nice accuracy.
And being ok with big boxes even better.
Its usually the opposite, people wanting bass in the smallest thing they can find...LOL
Of course knowing your looking at anything below 200 hz can have a 6 dB drop.
So seems more like your looking at multiple drivers for efficiency,
probably crossover at 200hz / 250hz
Its quite a design challenge. Im curious in seeing sims of actual drivers that do 45hz sealed
and can cross over at 2000. Seems kinda impossible really.
45hz sealed is possible, but any motor that can do that would have high inductance
making 2000hz not possible.
And if it was possible. I would only assume it would hit Xmax instantly.
Rather have multiple speakers that cover below 200. then have fullrange
that wont smear so much since its relieved of such low frequency.
And being ok with big boxes even better.
Its usually the opposite, people wanting bass in the smallest thing they can find...LOL
Of course knowing your looking at anything below 200 hz can have a 6 dB drop.
So seems more like your looking at multiple drivers for efficiency,
probably crossover at 200hz / 250hz
Its quite a design challenge. Im curious in seeing sims of actual drivers that do 45hz sealed
and can cross over at 2000. Seems kinda impossible really.
45hz sealed is possible, but any motor that can do that would have high inductance
making 2000hz not possible.
And if it was possible. I would only assume it would hit Xmax instantly.
Rather have multiple speakers that cover below 200. then have fullrange
that wont smear so much since its relieved of such low frequency.
However I am not sure you will get what you want with the SB either. The norex seems to have the most promise, good till about 10kHz. Sensitivity a little above 90db. Not sure if they will give you the sound you are looking for.
I was in similar shoes looking for a high efficiency mid woofer to get that high efficiency sound. What I was looking at are light cones and powerful motors. Most full range have limited x-max, the pro audio drivers have sensitivity. But they have a high Fs as well. In the end I settled for 2 drivers which I already have SEAS FA22RCZ and Dayton Audio pS220-8.They won't do well sealed though unfortunately drops really fast below 60Hz if using them sealed. The SEAS work interestingly well in TL, with its impedance peak suppressed, it produces some really fast bass. Courtesy of a cone that is half the weight of a normal 8" cone and a Fs of 30Hz. Haven't tried the PS220 yet but it has a third the weight of a normal cone...You might have better luck in the pro 10" category, maybe the Faitalpro 10FE200.
Oon
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Reading every thread on Vifa M21 reissue - don't quite understand is driver spec of 90db/1W and speakers using this driver have similar sensitivity rating of 89 or 90 .. read the 'secret sauce' is a high Q box, ie around 0.9 to 1.3.. (which might partially explain this) but wd still need some BSC surely.
The driver price isn't too expensive so a 2.5way cd be interesting. Box size wd be large, around 90-110. But not sure a high Q box wd work with addition of 0.5 driver (in this case)