-2.5 cubic feet (no stuffing or bracing considered) with the DS*A* 315 8 should almost do what you want. ..though more like 87-88 db average with baffle-step compensation. Really depends on if you want to take the "hit" to sensitivity, or are willing to compensate with the low-end of your midrange.
https://www.parts-express.com/pedocs/specs/295-534--dayton-audio-DSA315-8-specifications.pdf
..btw, the 6" version of this woofer measures really nicely (..lower non-linear distortion) - and hopefully this one does as well.
https://www.parts-express.com/pedocs/specs/295-534--dayton-audio-DSA315-8-specifications.pdf
..btw, the 6" version of this woofer measures really nicely (..lower non-linear distortion) - and hopefully this one does as well.
Why not try the CSS SDX10? I know both Jeff Bagby and and Javad Shadzi have used it in 3 way builds paired with some pretty high end drivers... they do play quite low in a small sealed box too.
Is EQ an option to get the sensitivity you need? If so - a CSS-SDX12 may help you here as it has xmax to burn. Whether or not it has a distortion profile to match the MR-13P I am not sure.
Bass distortion detection by all accounts seems to follow ELC from an experiment I just read. That is - we are more sensitive to distortion as frequency goes up. In the mid-bass the test subjects had trouble detecting 10% distortion. The assumption here is the experiment was valid.
I am also toying with the idea of a "full range" tower speaker for my next build.
PS: Using EQ doesn't mean going active. Depending on your source (e.g. streamer / digital) you can apply it here.
Bass distortion detection by all accounts seems to follow ELC from an experiment I just read. That is - we are more sensitive to distortion as frequency goes up. In the mid-bass the test subjects had trouble detecting 10% distortion. The assumption here is the experiment was valid.
I am also toying with the idea of a "full range" tower speaker for my next build.
PS: Using EQ doesn't mean going active. Depending on your source (e.g. streamer / digital) you can apply it here.
Adding stuffing to a sealed woofer box increases the effective volume by 15-25%. For the SB34NRX75-6, a 3.5cuft + firberglass stuffing(safe sealed box) moves the Qtc slightly below 0.7 with -F3 = 37Hz.
Zilch praised the bass from the SB34NRX75-6 in his SB12.3 design (MTM + W) kit.
I don't "hear" lower freq. non-linear distortion (as such). There isn't much in the way of "images" (reproduced sound sources) to be heard at those lower freq.s..
HOWEVER,
I do hear a difference in low-level "hall sound" effects. In fact I hear a greater effect at lower freq.s (signal dependent) with respect to "hall sound" than I tend to hear the effect of modest (a few percent THD) non-linear distortion at higher freq.s. (..though notably because the non-linear distortion at these lower freq.s is almost always much higher in level.)
Sorry guys, will catch up in a day or so. Just returned from hospital a few hours ago. Was hospitalised for 3 days for a titanium removal surgery. (I'd broken my right ankle badly last year.) The surgeon gave me 9 pieces of titanium after the surgery on Saturday. 😀
I did. I modelled a sealed box, and found the F3 and F10 too high. What am I looking for, or what am I missing?
Yes, the double-driver idea is a great one -- I may not be able to use it right now, but will keep it in mind for when it may work.
I understand what you're saying about the more dynamic sound, but I can't see how your model is a sealed box till 30Hz. I guess I need more help.
Will I really get 87-88 after baffle step compensation? It seems I'll barely get 87 in some portions of the curve without any compensation, going by the graph on the Tymphany website. (Aside: Is it only me, or are all of you too finding that the PDF spec sheet of this driver hosted on Parts Express has the actual SPL curve blank? It has all the grid lines and axes, but no actual SPL curve. There are several Peerless drivers on Parts Express whose spec sheets are like this.)
I didn't know about this driver. Will model it and add it to my spreadsheet.
My first preference will still be a 12", if I can. (It's just an itch I need to scratch, after having seen and heard the PMC MB2S, sans its 3" dome mid, of course. And while that one had TL bass, I want sealed.)
Yes, I've seen that kit, and in general, I've seen people doing dual-woofer 2.5" designs. I am trying to see if I can do a passive 3-way with a large woofer. There is always an idea for a different project, which will be a 3-way floorstander WWMT. I think I'll get a good design with that approach. But for this current project, I want to see if I can build a smaller 3-way with a single 12".
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I have two Dayton DS-390 15" drivers in my HT subwoofer. Mechanical quality is fine and I believe that the whole DS line has excellent value!
Based on general positive impressions about the Dayton DS series, and your comments, I decided to extend my exploration to other models in the series. I realised I hadn't looked at the DSA270 10". I modeled the driver and added an entry for it in my spreadsheet.
The sharp difference between the two 10" variants, paper cone and aluminium cone, are dramatic. One gives me 97 litres for my sealed enclosure, the other gives me 35 litres. But both are interesting options.
Will I prefer the DSA270 or the RS270P-8A? Both are paper cone, the RS is 50% more expensive, but has a cast, not stamped steel frame, has a phase plug, not a dust cap, and probably has more distortion reduction features than the DS. And the RS series looks prettier. 🙂 The downside is that the RS has perhaps 4-5dB less sensitivity than the DSA. (Easy to correlate with its 20% higher moving mass. I guess this means a more rigid cone?) Both have fairly severe cone breakup, and may need 4th order lowpass even if I cross over somewhere low like 300Hz. Both are very interesting options. And they both fit into almost identical enclosures -- one models Q=0.6 at 35 litres, the other at 41 litres.
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-based on the T/S parameters given and the spl graph (NOT from Tymphany, rather from Dayton Audio):
DSA315-8 12" Designer Series Aluminum Cone Woofer 8 Ohm Specification Sheet
..around 75 liters should do it (not including stuffing). It's about 92.5 db at 200 Hz.
Note: I look at this with "real-world" use. Remember that there is boundary gain (from the floor) and room gain. In a free-field or perfectly anechoic condition it wouldn't. Of course room modes will likely alter the response regardless for any given location within the room. Low freq.s are more about coming moderately "close" to a target value when looking at use.
Why are you landing up with 75 litres when I got 60 litres for Q=0.6? Different modelling software, or different T/S parameters?
I really don't care about a derived value like "q", instead I look for things like +1 db at 20 Hz, marginally better phase, and above 30 Hz ever so slightly better group delay.
I should also note that I don't care for "stuffing" in most designs - it adds resistance. Instead I prefer suspending "stuffing"/absorptive material inside the box away from cabinet panels. (..and this is more for higher freq. reflections with designs that are extending much past 100 Hz for their pass-band.)
I should also note that I don't care for "stuffing" in most designs - it adds resistance. Instead I prefer suspending "stuffing"/absorptive material inside the box away from cabinet panels. (..and this is more for higher freq. reflections with designs that are extending much past 100 Hz for their pass-band.)
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As ScottG said, final box Q is not the most important thing, you don't hear it isolated in a normal living room, you hear a combination of room/boundary response and box Q.
But if you want Qtc 0.6 for your peace of mind, that's another story.
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