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Alpine SWR-823D / 843D 8" Subwoofers
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Sound System Engineering
Alpine SWR-823D / 843D 8" Subwoofers
I've chimed in on a few threads talking about the new 8"s, but promised I'd make my own thread with details and a little Q&A for everyone ... so, here's a basic rundown of some details on the new 8" subs we are launching here in the next few weeks.
Segmented Motor Structure w/ 1pc Frame and Shorting Ring
There a 6 magnets, radially segmented and aligned around the shorting ring/frame/heatsink. The shorting ring is connected to the frame via three legs that allow the entire frame to act as a heatsink. We intro'd this design with our 2010 Type R 10" and 12" and we've carried this into the new 8"s as well …. it’s a pain in the butt to tool and assembly but the results are worth it. Check out the cut-view model, you can see on the left side, the shorting ring is directly connected to the exo-skeleton of the frame with one of three radial ribs the fit through the segments in the magnets.
350W RMS / 1000W Peak
Super Low Inductance:
0.55mH (843D) / 0.67mH Le (823D) and its very well tamed and symmetrical with respect to both displacement and current. Graphs attached.
H.A.M.R. Surround and FEA Optimized Spider
Just about perfect progressive compliance that is light and soft enough for super fast transients, but strong enough for full-power operation while unloaded in a vented enclosure or in free-air IB.
If any of you have been able to come to our CES Roadshow trainings, you’ll see the 823D run free-air at full clip on an M6 without a hiccup.
We’ve actually been running these as midbass/front subs (56-250Hz/20-250Hz) in the Camaro Demo car. The speed, accuracy and power of these guys in astounding! I’ve got an 8W3 here and an IDQ8 and they can’t hold a candle to it, especially when you get some real power into them (to my ears at least). This SQ isn’t only a function of the suspension, but during my final approvals, I found the difference in suspension materials to play quite a critical role … so I give the suspension credit here. Graphs attached.
CRC Pole Piece / High-Grade Y40 Magnets
14mm of Klippel verified Xmax (70%) stands out from the crowd not only in linear stroke, but also in symmetry. These are extremely well controlled woofers. Graphs attached.
These aren’t Jacob’s crazy eights … but they’ll get more than plenty loud and keep their composure while doing it. I absolutely love these in 0.50cubes @35Hz … tons of output for any sane person and a pair of them will smile all day on a PDX-M12.
Small Box Requirements:
In the CES Demo Camaro, we’ve got them in a plate steel enclosure roughly the size of the woofer’s magnet (0.1-0.2 cubes). For a QTC of 0.90, try a quarter cube. Essentially, they work in boxes smaller than the shipping container they come it. Ported, 0.3-0.5 cubes and keep them in the mid to upper 30s … and they’ll do it with SQ to boot in a vented enclosure.
They are 8s, so no 88dB numbers here, but they are 83.5dB efficient and have the excursion and power handling only to get louder from there.
That’s all I can think of for now. Feel free to ask any questions and I’ll be happy to answer them as time permits.
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if you do this. it'll help you. some sunny day ...
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