https://www.parts-express.com/pedocs/specs/295-514--dayton-audio-um15-22-spec-sheet.pdf
Consider two of these behemoths wired is parallel-series running 400hz on down paired to either a wideband mid tweeter or conventional midwoofer and tweeter…….good lord. QTS and response graph suggests flat OB response below 30hz and clearly those wishing to boost the lower end?…..these drivers can take whatever you throw at em for sure.
Consider two of these behemoths wired is parallel-series running 400hz on down paired to either a wideband mid tweeter or conventional midwoofer and tweeter…….good lord. QTS and response graph suggests flat OB response below 30hz and clearly those wishing to boost the lower end?…..these drivers can take whatever you throw at em for sure.
Martin King popularised the higher Qt woofer for designs where minimal EQ is wanted or where it isn't available, and there's nothing wrong with that if you can achieve the goals.. For an ultimate design one has to question whether response smoothness or shape is a necessary priority.
According to different online sources, the Ultimax woofers are far from the best above 100 Hz.
What about the Faital Pro 18FH500 16 Ohm for example? Looks promising for OB, IMO.
https://www.dibirama.altervista.org...8fh500-16-sub-woofer-18-16-ohm-1200-wmax.html
What about the Faital Pro 18FH500 16 Ohm for example? Looks promising for OB, IMO.
https://www.dibirama.altervista.org...8fh500-16-sub-woofer-18-16-ohm-1200-wmax.html
There are lots of woofers that seem like they would be great and I’m sure many would be, but they need to be quiet in free air and many are not. I def would not run an ultimate 15 to 400hz, 200 maybe.
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Agreed Allen…..what differentiated MK’s high QT woofers from these Daytons is motor strengths and efficiency.…..the motors on these Daytons are FAR better than the weak magnets of the Alpha 15’s and Goldwoods he popularized. Yes, those drivers were more efficient but amp power is cheap these days and I’m not a SET amp kinda guy…..BUT….one could use a SET amp MT section and power a pair of the Ultimax with class D, ICE or AB separately.
To be clear I’m not Pooh poohing the idea, I ran a 15” car audio sub in open baffle and it worked great to about 150hz and was nice and quiet at full xmax
What's the big problem with raising apparent Qe by using some amplifier current feedback with these drivers having a serious motor compared to the classic selections? Edit: I guess that's off topic since checking and seeing that Ultimax 15 is already .95
One point to mention is that the kind of cone strength and mass of the UM15 is simply not necessary in open baffle loading. At some point it just becomes power loss, I think especially with a really low mechanical Q.
One point to mention is that the kind of cone strength and mass of the UM15 is simply not necessary in open baffle loading. At some point it just becomes power loss, I think especially with a really low mechanical Q.
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I once had a pair of UM12's in 4 cubic ft each and the only thing they did really well was heat up a Crest CA12.
OBs are gonna need a lot of EQ, which means you're pumping more and more power into that motor. Efficiency REALLY matters when you have to start adding EQ. Not that they would be able to take all that much. The high Q preference saves a lot of energy around Fs and thus current and thus distortion.
Nothing in the design of the UM range is expected to accommodate anything but sub frequency drive. The surface area of the surrounds is so high it's in serious competition with piston sd too, so they are not really hi fi either. The 12s actually sound like rubber. They're pretty much just theater shakers with some acoustic output on the side.
@Andrew Eckhardt It's funny, just looking at the spec sheet they look like the perfect partner for a 500Hz XO to a wide-range device. I was even looking at a pair as they line up well in my cabs but the issues you cite are fair, and I'll be happier keeping my cabs as is with better midbass drivers and accept that 15"s aren't necessarily all sub-capable.
All OBs need flattening/EQ and baffle support. Clearly the high QTS and response graph shows the UM15 would require less as typical woofers and is right there with OB specialized drivers. And then there’s power handling…..if you had to add EQ or even a Linkwitz transform, this driver can certainly take it where most 15’s would melt.
There seems to be some stereotyping of woofers going on here…….if someone wants to explain to me what is ‘wrong’ with the UM15 from 30hz to 400hz or so with a 2nd order Lp, I’m all ears.