sundownz

Per driver.

Had a good time

I may have 12x used 2500s up for sale shortly... if you want to be put down for one if they arrive post in here. They will be 575 each shipped w/ 1-year warranty. I will update if I get them.

I am back !

I don't have any in stock to send Mike.

Only one item left.

For all questions on these e-mail mike at his address at the bottom of the first post.

If you are still having any issues I'd un-strap the amps and run each at 1 ohm as the first troubleshooting step -- occasionally amps just don't like to be strapped in some applications.

Cool story from CES today... I spoke with Jim from Alpine and he worked on both the new Type-R and Type-R shallow drivers; IIRC he designed the majority of both. Very cool guy -- interestingly he was aware of my test and aware of Sundown Audio and our products. Small world ! Talked with him for about an hour and it gives me more respect for Alpine knowing that they actually look at the smaller companies and what we are doing. I may also re-test the Type-R as Jim also thinks it should have fared better in the test; I also thought it would too based on all the solid engineering. So I'll re-do it at some point to make sure there were no errors.

Getting up super early tomorrow to catch my flight... will keep up as much as I can while I'm gone. Wish me luck on the flight

X-Max by motor is the same on all sizes -- around 25mm one-way

You may have an intermittent ground short -- very difficult to find. We had a speaker shorting to ground through it's own frame in Brandon's Bronco a few years ago -- and it was intermittent... huge pain to track down. Of course with any electronic device there is the possibility to fail without good reason as well - this is true with any electronic equipment from any manufacturer ever made.

Hope everyone had a good one ! I'm back @ work trying to wrap things up as much as I can before going to CES.

The DTR boards are fairly cheaply made units -- typically put out the power they claim but simply aren't a rugged, over-built design by any means. You pay more for an amp designed to handle more abuse and that isn't throw-away when blown.

That is a pretty big tear -- I haven't tried it on one that big... but we have fixed splits with gorilla tape on the back and goop on front.

They are similar enough that it shouldn't present an issue.

Someone has to take care of things while I'm away : ... and his wicked awesome tool set that I got him for Christmas has an accurate plastic caliper with it so he can measure the gaps, coils, etc

Nope. The 8s are the only SA unit that has more than 1% or so not pass QC testing -- 8s are pretty tricky to build.

Nice !

Originally posted over on SMD to answer a question - but I figured some folks over here may enjoy it as well : I need Bl/Bl Curve Explained - SMD Forum You will typically need a Klippel or DUMAX to measure the BL curve. You can assumme, though, that most overhung (long coils) at quite parabolic in nature... most under-hung have a flat spot in the center and then become parabolic. There are ways around this... Alpine flattens it out nicely in the new Type-R with some clever pole machine work: They machined in a bell shape inside the pole that flattens out the BL curve in the center -- here is an image from their patent: ---------- Some other examples below. First we have an overhung - the below is an approximation of the NS v.2 motor... very long gap / long coil design but still parabolic as it's overhung. As far as overhung goes the BL distortion is quite low as with the 71mm coil and 40mm top plate we achieve ~27mm linear one-way throw. * You see some of the coil sits outside the flux field and the flux is centered in the gap at highest level. ----- Next we have underhung - where you can immerse the coil in the peak flux field and it won't leave that area for some amount of stroke therefore giving you a small flat area before becoming parabolic. * One issue is the tall top plate and short coil tends to make the motors weak as there is poor flux utilization unless you use a giant magnet. ----- Now we have something really fancy called XBL^2 -- you have two gaps and the flux is steered around to immerse more coil than underhung and it also forces the flux out farther to extend the flat area of the BL curve. * Not the greatest example for SQ purposes as it's a big Neo SPL woofer... but you can see how the flux is broken up into two peak concentrations (dark blue areas) with some of the coil in each of those areas. The middle is no longer the strongest spot. As the bottom of the coil leaves the lower flux concentration it equally enters the top concentration so BL does not change for quite some time. These gaps can be stacked if necessary to achieve TONS of flat BL. ----- For the technical folks out there... I'm not attempting to fully explain any and all topologies -- just giving people a general idea of how they work. So lets keep the nit picking to yourselves. Feel free to add information if you like, though !

Merry Christmas everyone

Working late tonight on e-mails... several weeks behind on some messages. Sorry guys - finally have a moment to actually catch up a bit now, though.

We are operating on an e-mail, phone, orders, and everything delay right now... currently installing new phone system, new computers, network devices, etc... so slowing down anything computer related. Also have several big shipments coming in starting today and for the next week... then pre-order shipping will commence. This will take up ALOT of time. So please be patient during this time as we will be *extremely* busy.

Check for a speaker wire short to ground -- this will destroy the amp in exactly that way. First blown fuses, replace fuses, then blown power supply.

Femm to generate the flux concentration.