Servo Sub woofer - Double Trouble + flat pack build

Theronbo · « **on:** 4 Oct 2022, 09:26 pm »

Have the bits painted & veneer glued on.

Gluing on some brass trim to edges of tops, bottom & sides…

Never enough clamps… sigh.

Vince in TX · « **Reply #1 on:** 5 Oct 2022, 06:23 pm »

Looking good! It didn't take more than four clamps on mine.

OtisSpunkmire · « **Reply #2 on:** 5 Oct 2022, 08:59 pm »

I am 80 percent done on my double trouble. I ran out of the Duratex... The sound is great.

Theronbo · « **Reply #3 on:** 5 Oct 2022, 09:30 pm »

The brass trim has been more problematic than I’d imagined…

It’s always the ‘simple’ stuff… but have never done before that turns out being a bear… if I had more clamps I could proceed faster.

The curved front… makes clamping the trim interesting.

dryan01uk · « **Reply #4 on:** 6 Oct 2022, 11:06 pm »

Quote from: OtisSpunkmire on 5 Oct 2022, 08:59 pm

I am 80 percent done on my double trouble. I ran out of the Duratex... The sound is great.

Looks great - I like the idea of hanging the amp box on the side (or on top) - how stable is that configuration?

I'm just waiting for my sub kit to ship, so hopefully, won't be too far behind you.

David

morganc · « **Reply #5 on:** 6 Oct 2022, 11:59 pm »

Not stable when those guys are playing. These guys move some serious air.

Theronbo · « **Reply #6 on:** 7 Oct 2022, 03:54 am »

This is my plan as well.

Mount plate amp box on the side with 1/2” standoffs.

The amp is HEAVY… thinking I’ll need at lest 6 mount points.

This keeps the length of wire minimal.

I’m assuming the amp pumps some heat too…

I put slits on top & bottom bits & drilled holes at top & bottom of back plate… another reason to offset mount it.

Theronbo · « **Reply #7 on:** 8 Oct 2022, 01:47 am »

Cabinet more or less completed.

Tyson · « **Reply #8 on:** 8 Oct 2022, 02:51 am »

Man, you are making fast progress. Looking good so far!

Theronbo · « **Reply #9 on:** 9 Oct 2022, 03:58 pm »

Okay, have it hooked up…

No pictures yet as I’ve had to reclamp the beast…

Note: If painting before assembly… mask off joint bits…. The flat packs are cut so precise that paint on joining surfaces makes assembly a BITCH!

But, I’m a dilettante cabinet maker… only do a couple builds a year … so…

Getting my Denon AV H4700X setup to use Sub in stereo mod was a pain… more about the configuration interface…

Lots of parameters…

The AVR sets crossover points … as does the Rythmik.

Started at 200hz… quickly moved down to 120…

Volume setting above 1/3 on the plate amp seems to induce distortion… with driver beating the crap out of itself…

Double, triple & quadruple checked wiring…

Drivers are parallel… servos serial…

If All this listening testing has proven one thing… the X-Statics have some really wonderful bass…
I do notice a new underneath power with the new sub… but it’s relatively subtle….

Theronbo · « **Reply #10 on:** 9 Oct 2022, 09:42 pm »

Just gluing the feet on… & playing with all the options…

Guess I mounted them backwards…

Not really concerned… since they are opposite firing… will position it sideways… so, people will be looking at the veneer rather than the drivers.

I did a little lighter stain on this than my C-Statics or x-Voce… seemed as I was staining them the veneer was taking more stain than the oak planks.

Not the best lighting. I’ll take more pics after another coat of oil …

Pretty pleased at how they turned out… pretty much as I envisioned when I started. How often does that happen.

Tyson · « **Reply #11 on:** 9 Oct 2022, 10:01 pm »

Careful with placing them sideways - there's usually a null to the sides of OB subs.

Theronbo · « **Reply #12 on:** 9 Oct 2022, 10:11 pm »

Hmm, interesting…

I assumed They would simply be energizing the whole room… is a large room. 20x30.
With 11.5’ ceiling.

Okay, so among all the many parameters to play with… speaker placement is another…

Tyson · « **Reply #13 on:** 10 Oct 2022, 12:44 am »

Quote from: Theronbo on 9 Oct 2022, 10:11 pm

Hmm, interesting…

I assumed They would simply be energizing the whole room… is a large room. 20x30.
With 11.5’ ceiling.

Okay, so among all the many parameters to play with… speaker placement is another…

Yes, and move them away from the walls. Treat them more like speakers than like subs.

Theronbo · « **Reply #14 on:** 10 Oct 2022, 01:03 am »

Wow, had the wiring for the drive coils all wrong…

I assumed they’d simply be parallel connections… well they sort of are… except since the are reversed… they want the signals reversed too… so the drivers are working together… not against each other…

That was ugly… they were not loud, & started distorting at 1/3 of the dial…

Didn’t figure out I’d messed up till I attempted the Audessy setup… which requires you set the subwoofer volume so it reads 75db…I couldn’t get it any where close without distortion… so, back to reading the instructions….

Hobbsmeerkat · « **Reply #15 on:** 10 Oct 2022, 02:46 am »

Driver coils are wired in parallel.
Servo coils are wired in series.

The necessary polarity flip applies to both driver and servo coils as well.

corndog71 · « **Reply #16 on:** 10 Oct 2022, 03:00 am »

Quote from: Theronbo on 10 Oct 2022, 01:03 am

Wow, had the wiring for the drive coils all wrong…

I assumed they’d simply be parallel connections… well they sort of are… except since the are reversed… they want the signals reversed too… so the drivers are working together… not against each other…

That was ugly… they were not loud, & started distorting at 1/3 of the dial…

Didn’t figure out I’d messed up till I attempted the Audessy setup… which requires you set the subwoofer volume so it reads 75db…I couldn’t get it any where close without distortion… so, back to reading the instructions….

You’re not the only one to make this mistake.

Theronbo · « **Reply #17 on:** 10 Oct 2022, 04:16 am »

It was mostly my fault…

But, if you’re gonna have someone wire up stuff…EXACTLY THE OPPOSITE… of how it’s normally done… i.e. red wire to black terminal… you might capitalize or All CAPs it… the way it’s written… it says to driver -

& I’m seeing a hyphen… not a negative symbol…

Though as I’ve become older I’ve noticed I assume more… my younger self was a programmer… was very literal person.

Seems this subwoofer makes my X-Statics sound better…

Might be imaging it. My guess: by filtering out the very low frequencies… the speaker does a better job rendering the other frequencies.

dryan01uk · « **Reply #18 on:** 11 Oct 2022, 06:47 am »

Gents,

As an aside, I’d like to buy some braided cable sheath for the cables running from the amp box to the subs – can you give me an indication of the sort of diameter, I should be tracking down or how else I should present them? (or is this included with the plate amp)?

There are very few details of this cable arrangement on the forum or in photos I've been able to find.

I was planning for some heat sleeve / wrap and an outer braided sheath but can’t work out what size I need apart from ‘pretty large’. I figure that you are both building OB subs at the moment so may be best placed to advise.

David

Theronbo · « **Reply #19 on:** 11 Oct 2022, 08:48 am »

As an aside…

I found mounting the amp on the side (with 3/4” offset, 3 1/2” lag bolts) was handy when wiring.

I put 2 holes through the back of the plate amp box. One to each sub compartment.

Then I could run the wiring between the subs through the plate amp box using the same holes, without requiring additional holes drilled.

Made for a cleaner look. Hides the back & forth wiring.