Sundown Audio SD-2 8" Prototypes

[sundownz Pro Seller]

Just got these in... designed them based on many requests for a really good sealed box 8" woofer. Power rating is pending testing but mechanically I designed them around 300 watts or so (half the spiders of the SA-8 v.2) -- we'll do our thermal cycle to determine the official rating. As is typical with our products the rating giving will be a "worst case" rating and many people will have no problem running a bit extra.

We built upon our newly tooled platform from the SA-8 v.2 so it shares many of the advantages of that platform from the get-go.

These feature an under-hung coil with predicted linear x-max of ~14.5mm one-way by 70% BL method using an 8-layer copper 2" coil with 1/2" of winding width.

The total depth for mounting is right at 4.75" measured,

I will be measuring actual T/S on them later on today after some break-in time. Pricing is also pending final costs from our parts suppliers.

On to the photos :

* E8 v.2 then SD-2 8" then SA-8 v.2

* For this design I used drilling in the basket as opposed to the vent ring to save depth.

* Solid pole like the other SD-2 woofers so there is no need to leave room to breathe behind them.

* Same spider as the SA-8 v.2 but only one layer (top layer)

Click to read more...

 

[05trailblazer 10+ year member]

some good ol mid bass for sure //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[sundownz Pro Seller]

I am happy with the mechanical behavior and observed thermal behavior so far playing them in free-air -- specs measured before break-in indicate I MAY have to make some small tweaks to it with the mass and compliance but it's about 90% there.

 

[05trailblazer 10+ year member]

btw you know what enlcosure u recommend for ported or they are better of sealed?

 

[sundownz Pro Seller]

btw you know what enlcosure u recommend for ported or they are better of sealed?

You can use the same ported boxes as our other 8s; 0.5 to 0.75 cubes

In a sealed box I am getting an F3 in the box modeler equivalent to an SD-2 10" model -- so I think I may leave it alone and produce it as it sits (pending listening tests in my car).

 

[SuperSaeYoung]

What do you do with the prototype after you finalize the design?

 

[sundownz Pro Seller]

I just installed the pair in my car (TWO SUBS) in 0.5 ft^3 sealed and took a nice listen... I am really quite impressed. Brandon, Thomas, and I all agreed that per box volume you will be pretty hard pressed to get this combination of output, bottom end, and sound quality. I need to get a little video... it was shaking my visors, rear view mirror, etc... obviously nothing insane but the output did surprise all of us.

Currently on my 200.4 bridged @ 1 ohm (turned way down) -- I wired it this way as I plan to test the new 1500D v.3 in my car soon as well as the new 125.4 on the fronts.

The only 8" out there that I know of that will out-perform these sealed is a JL Audio 8W7 (which is a GREAT woofer... my favorite JL product period)... but it does call for a MUCH bigger box to do it (0.875 ft^3). The JL has more x-max (19mm vs 14.5mm on ours) and models out with a lower F3 point but at the expense of about 3x the cost and over 2" more mounting depth.

If you put three SD-2 8s in the same 0.875 ft^2 as one 8W7 you would come out about the same price and end up with more output -- just depends on what you can fit as far as face area for woofers.

 

---------- Post added at 10:08 AM ---------- Previous post was at 10:08 AM ----------

 

What do you do with the prototype after you finalize the design?

I will often sell prototypes; but not always.

 

[JFossTheBoss 10+ year member]

Is this something you are going to be selling soon? How do they compare to the e8v2s? I was just about to order a pair, then I saw this. I'm looking to put them in a sealed enclosure with about 350w each. Whats the price and eta on these prototypes? I'm also looking to keep the price down as low as possible, so I may go with the e8s anyway. Just curious. Thanks

 

[sundownz Pro Seller]

Is this something you are going to be selling soon? How do they compare to the e8v2s? I was just about to order a pair, then I saw this. I'm looking to put them in a sealed enclosure with about 350w each. Whats the price and eta on these prototypes? I'm also looking to keep the price down as low as possible, so I may go with the e8s anyway. Just curious. Thanks

I don't have a specific ETA yet but I expect them in before the end of the year.

These are superior to the E8 -- especially sealed -- but they will cost around $135-$150 or so.

 

[JFossTheBoss 10+ year member]

I don't have a specific ETA yet but I expect them in before the end of the year.
These are superior to the E8 -- especially sealed -- but they will cost around $135-$150 or so.

Are the e8s no good sealed? I'm trying to get some new subs ASAP, so I think I'm going to go with the E series. What would be the ideal box size for both of these subs sealed? I don't have much space to work with. I don't want to change the topic of your thread, so figured you could post up a little comparison since I'm sure there will be other people wondering between the 2.

 

[sundownz Pro Seller]

The E8 does work sealed but the F3 is nearly 10 Hz higher -- both subs are going to like about 0.25 sealed each... the SD-2 is more forgiving of a bigger box but neither require a larger space.

 

[BIGJEFF64 10+ year member]

Those sa8 v2's just look so bad a$$

 

[Phoenix Risen 10+ year member]

the sa-8 v.2's are nasty, but its nice to have a good option for a solid small sealed box sub,

whats the displacement on the SD-2 compaired to the sa-8

 

[sundownz Pro Seller]

Okay here it is :



I am really pleased with these little guys //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[sundownz Pro Seller]

I am making one small change for production -- the pole extension is growing by about 1/2" -- I was able to shoot the coil completely out of the gap and scrape the winding on the top plate with about 3x rated power

With the extension pushed out that will become impossible at any power level -- as it would take over 30mm one-way to completely jump over the pole with the taller extension.

Had to push back this production run a bit to fit a few more things in; but I'd expect to see it in November to December.

Specs on the unit played for extended period in my car :

Re : 6.03 ohms (series)

Fs : 45.2 Hz

Qes : 0.63

Qms : 7.31

Qts : 0.58

Le : 6.26 mH

Sd : 30.68 in^2

Vas : 7.74 L

BL : 15.55 NA

Mms : 89 g

Cms : 138 uM/N

Sens 1w/1m : 82.29 dB

Box modelling programs will call for a bit over 0.5 each sealed -- I ran these in 0.25 each and they sound great. Being a very linear driver over stroke your Qtc at higher levels of travel would be about the same as a driver with a lower at-rest Qtc and non-linear CMS and BL curves.

In any event -- the specs are within a VERY small margin of my original test-bench break-in process on them... so the parts will show very little fatigue and change over time after initial break-in. Not a surprise as they were all designed around the much more powerful SA-8 v.2

They would have no issue with a ported box but I feel like their main advantage is performing better sealed than an SA-8 v.2

Also will be doing Klippel testing on this at some point as I've done with the SA-8 v.2 and SA-12 models.

PS: I notice I haven't mentioned one of the details yet... the former is an alloy material similar to brass with a spiral cut to help reduce eddy currents compared to a standard aluminum former.