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sundownz

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Everything posted by sundownz

  1. sundownz

    SA-8 Pre-Order Thread for June 2011

    Shoot me an email.
  2. sundownz

    Question for Sundownz

    The parts are in stock; I still keep quite a few v.1 coils around -- but we will have to assemble them.
  3. sundownz

    "Monster" v.2 Prototype Due Soon

    is it soon yet? lol! Customs liked it so much they held it for about 11 days -- but it's almost here
  4. sundownz

    Sundown SD-2 "500-watt" Line Photos

    I have it in the first thread :drink40:
  5. sundownz

    brand new amp missing parts???

    You should have the new one soon.
  6. sundownz

    SA-8 Pre-Order Thread for June 2011

    The frame is different -- they are otherwise compatible.
  7. People ask me this alot... the short answer is that they make the speaker better. The long answer can be shown on some graphs. This graph shows inductance over excursion for a basic motor design. The center is at rest, left is rear stroke, and right is forward stroke. Why is the graph shaped this way ? Have you ever looked at inductors for a crossover ? You can get a high value in a small package with an iron core. So... what is a speaker motor ? A partially iron core inductor! As the coil moves back it gets more iron in the core! So the inductance rises. As it moves forward it gets more air in the core so it drops. Pretty cool, huh ? Now... the field can be absorbed by a conductive material in or around the coil -- so shorting rings come into play. One approach, which we use on the SA series and NS v.2 series, is a pole cap shorting ring -- note how it reduces forward inductance and at rest inductance. But not much in the way of rearward... Well the NS v.2 and Z v.2 both have a large magnet ID ring -- notice the huge effect on rearward inductance and at-rest inductance ? As a note... the SA will also have this ring shortly too. Now... having BOTH rings like the NS v.2 has now and the SA will have soon... huge effect across the board! Not only is the inductance more linear but it is much much lower. Why is this good ? 1) More power delivery to the coil as inductance causes "rise" 2) Less distortion -- inductive distortion is odd order and unpleasant; although a fairly small part of total distortion. 3) More high-end extension as inductance is a 6dB per octave low-pass crossover. 4) These rings also act as heat-sinks; although this effect is not a large reason to use them in and of itself. Can a speaker sound good without them ? Sure! Many great sounding speakers don't use them and they are pretty expensive too so don't always represent a good price to performance ratio. I do not plan to use magnet ID rings on lines less expensive than the SA series, for example, as the ring represents such a high % of the total cost of the speaker at that point (large chunk of aluminum, copper, or brass). But they do have benefits and I figured some of you might like to know what those are.
  8. sundownz

    Refurbished SA-8s : $85 + SH (Part II)

    Don't forget about these guys -- we are sold out of SA-8s but Mike still has them. He is on the road for work on and off but be patient for a good deal
  9. sundownz

    Shorting Rings - Why do we use them ?

    I miss this type of thing... we used to talk about things like this all the time online in 2001-2003 or so Ah, the memories! Trying to bring some of it back when I can.
  10. sundownz

    Shorting Rings - Why do we use them ?

    We used a pretty small motor for this discussion... 120mm OD magnet utilized. When I made enough room for the sleeve we dropped off 34% of the motor force factor (BL^2/RE) -- in order to get this back the magnet had to go all the way up to 150mm OD and in turn the back and top plate OD both had to expand as well. So much more steel and much more magnet. 634g magnet to a 1109g magnet -- we had to gain 75% magnet mass. Total motor went from 1890g to 3112g -- so a 65% gain overall in mass not counting mass added by the sleeve. So it is fairly significant in terms of cost to get a highly functional sleeve and to "gain back" the desired motor force lost by making room for it. And again, if this pans out for the target cost of the driver these thick sleeves do work great.
  11. sundownz

    Shorting Rings - Why do we use them ?

    * SA motor -- the top aluminum piece acts as a pole cap ring. * The brass piece is a magnet ID ring from a Z v.2 motor. This goes around the inside of the magnets below the top plate / above the back plate. It is sitting on the SA motor simply for reference purposes. * Acoustic Elegance drivers with pole sleeve shorting rings
  12. sundownz

    Shorting Rings - Why do we use them ?

    This thin sleeve has a nice effect at rest and on rear-ward -- seems to lose effect combined with the magnet ID ring, though, as that is equal to the magnet ID ring only. ----- So now lets do a thick sleeve : Full 1.0mm thick -- and the effect is MUCH better and also alleviates the issue of being cancelled out by the magnet ID ring. The only problem is you need to add more motor to compensate for this type of sleeve as it widens the gap a good bit -- for this example the pole had to go down from 35.7mm OD to 33.7mm OD to fit this sleeve. If the design budget allows for this then no problem -- the issue you end up with is spending more money on the motor by adding magnet to it. The benefit is that the sleeve is the most linear method simulated -- the Le curve is completely flat in this case. In most cases price to performance the magnet ID ring would be a better selection unless you are going for ultimate reference level.
  13. sundownz

    Question for Sundownz

    I suggest sticking to the v.1 coil in the v.1 motor.
  14. sundownz

    Sundown SA-12 Klippel Test

    The newest revision has two -- older ones have one on top of the pole. Cool beans. Was just curious as I was honestly a little surprised at the symmetry and linearity of the Le curve. Looks like pretty nice results overall. Indeed -- the dual shorting rings made for a very nice Le curve What can I say... I was more of an SQ guy before entering the business
  15. Finally got it done -- something I've wanted to do for quite some time now. Our published X-Max is dead on by both BL and CMS definitions -- we publish 19mm one-way travel. Inductive performance is above average as well. Our published T/S specs are also very well close to the Klippel data -- the one we sent in was just a tad less broken in than the unit published on our site so the Klippel FS was a few Hz higher but as you can tell if you know about the effects of break-in it will settle right in to exactly what we say Those that don't look at Klippel often may note the BL curve is slightly to one side -- this is not unusual in production tolerance. The shift represents the coil 2mm too far forward. This is within an acceptable production tolerance and as you can see does not interfere with the 19mm of published linear x-max. The CMS curve is also a tad tilted -- this is because a normal surround is always biased in stiffness one direction. Again, very normal behavior without going to an exotic type surround. Little bit of tech talk along with published Klippel data for you guys. Hope you enjoy.
  16. sundownz

    Any plans for a beefy 6.5?

    I have had quite a few inquiries on a strong 6.5" woofer... we'll have to see.
  17. sundownz

    Shorting Rings - Why do we use them ?

    The spacer on the SA is not a shorting ring -- the one on the Z v.2 initially was a shorting ring as it was a conductive material. Nuts on top of the frame are simply for ventilation and are not a shorting ring.
  18. sundownz

    Sundown SA-12 Klippel Test

    The newest revision has two -- older ones have one on top of the pole.
  19. sundownz

    SA-15 Boat Install

    Looks good Dave !
  20. sundownz

    SA-12 SHATTERED?wth?

    A re-cone kit is the cone, spider, coil, and triple joint ring glued together.
  21. sundownz

    SA-12 SHATTERED?wth?

    You can get a D4 re-cone -- all prices are listed here : If you are not comfortable doing a re-cone you can ship it to us to do it.
  22. sundownz

    SA-12 SHATTERED?wth?

    Too much excursion -- gain position does not tell us the power or even % of power coming from the amp. In the end too much was applied to the driver in a relatively large box size (way too big for a 1500-watt amp), mechanical limits were exceeded, and the ring was shattered. You will need a re-cone and I'd suggest a smaller enclosure if you plan to keep the amp / sub combo.
  23. sundownz

    SA-12 SHATTERED?wth?

    It has to be re-coned as that piece is below the spider - glued around the coil former. If that was broken something needs to be addressed in the system - how much power and what size box ?
  24. sundownz

    SA-12 SHATTERED?wth?

    Looks like the triple joint ring is in pieces there. Which can only result from an incredible amount of stress on the neck joint.
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