Ripole build - dual 18" Hawthorne Audio drivers

New Praetorian · « **Reply #40 on:** 6 Jun 2011, 10:33 am »

Hello Ed. I kind of lurk here on the circle from time to time. Especially if someone is building something for me

Tony, can you ever really have enough bass?

Seriously, I needed a new subwoofer to replace my SVS PC Ultra. With my current room setup, I have to put the sub in a corner behind the right speaker. Not only is this not ideal for bass in my room, it kind of detracts from two channel listening.

Thanks,
Jeff

Bob in St. Louis · « **Reply #41 on:** 3 Jul 2011, 09:47 pm »

There's been a lot of boring stuff going on lately, sanding mainly, so as a result there's not much worthy of photographing which is why I've been quiet.

I'm nearing the point where these several pieces will become "one" with each other.
It occured to me to make a quick time lapse of one of my test fit sessions so y'all (mainly Jeff) could see what I've been up to.

By the way, when it's in one piece, I can't lift it off my workbench. The final assembly will be on the ground.

>> Here's the video <<.

Bob

Bob in St. Louis · « **Reply #42 on:** 4 Jul 2011, 10:52 pm »

Glued those 12 "pillar things" today. Also a little more sanding, a little more painting, and a bit more staining.
This is the end result of a weekends work, and the way my workshop will look until next weekend.
(the cans and jugs are my clamps)

JohnR · « **Reply #43 on:** 4 Jul 2011, 11:14 pm »

That sure looks like everything is just balancing on that little portable saw...

Bob in St. Louis · « **Reply #44 on:** 6 Jul 2011, 02:08 am »

Yes, as a matter of fact, it is. I've put in a bit more air in the tires to accomodate.

Bob

Bob in St. Louis · « **Reply #45 on:** 20 Aug 2011, 08:16 pm »

The parts count is slowly diminishing. I'm down to four pieces of wood and a couple drivers.
From left to right is the bottom piece with the legs and wires attached, then the center sections, and to the far right are the drivers.
Today I've spent my time planning on where to run the wires internally, drilling holes, and routing the wires.
The last thing I want to see are crappy looking wires hanging out of the thing.

My plan by the end of the day is to have the unit in a "test fit" situation and playing music.

After that, all that remains is several coats of poly, some glue, a couple loose ends, and that's about it.

Bob

Bob in St. Louis · « **Reply #46 on:** 20 Aug 2011, 11:54 pm »

Wrapping speaker fabric around the magnet to keep debris out of the vent, then reinstalling the rubber surround:

In place:

JohnR · « **Reply #47 on:** 21 Aug 2011, 01:39 pm »

!!!

Very nice work Bob!

Are you going to try them in your system? Will they need EQ?

Bob in St. Louis · « **Reply #48 on:** 21 Aug 2011, 03:22 pm »

Thanks John. I've actually got it wired up and am using it now.
I'm feeding it through a Behringer DCX2496, and am adjusting XO points and slopes. No "real" EQing though.

Bob

versus rider · « **Reply #49 on:** 21 Aug 2011, 03:37 pm »

Hi Bob, would you mind running me through your set up, i.e. crossover points and driver types and what they are doing frequency wise. Is the ripole to cover just very low down and what does it sound like at the upper end of its use. I am planning a three way set up with a tractrix horn from 1500Hz up, an Audax PR170MO preferably from 150-200Hz up to 1500Hz and some kind of encloure with a 15" woofer, would a ripole work for me?

Blackmore · « **Reply #50 on:** 21 Aug 2011, 03:41 pm »

They can't be on right now. I don't feel my house shakin'

gooberdude · « **Reply #51 on:** 21 Aug 2011, 05:28 pm »

Srsly Bob,

How do these compare to your 16 other subwoofers??

Just going off the finished pics, the footprint of the beast isn't as imposing as I thought it would be.

How many neighbors are required to lift it?

richidoo · « **Reply #52 on:** 21 Aug 2011, 07:04 pm »

Lookin good Bob! Your enclosure fashion style is developing nicely! Soon you'll be on Stereophile cover!

neobop · « **Reply #53 on:** 21 Aug 2011, 09:33 pm »

Quote from: versus rider on 21 Aug 2011, 03:37 pm

Hi Bob, would you mind running me through your set up, i.e. crossover points and driver types and what they are doing frequency wise. Is the ripole to cover just very low down and what does it sound like at the upper end of its use. I am planning a three way set up with a tractrix horn from 1500Hz up, an Audax PR170MO preferably from 150-200Hz up to 1500Hz and some kind of encloure with a 15" woofer, would a ripole work for me?

You should consult with somebody about that 150Hz x-over for the Audax. It seems too close to it's resonant freq for comfort. Madisound sells the driver. You can call them for advise.

Sorry to go off topic. Those 18" cabinets are beautiful.

neo

versus rider · « **Reply #54 on:** 22 Aug 2011, 07:58 am »

wisfull thinking on my part 200Hz may be better. I may have been thinking about the AP170MO fs of 60Hz but lower sensitivity

Quote from: neobop on 21 Aug 2011, 09:33 pm

You should consult with somebody about that 150Hz x-over for the Audax. It seems too close to it's resonant freq for comfort. Madisound sells the driver. You can call them for advise.

Sorry to go off topic. Those 18" cabinets are beautiful.

neo

ebag4 · « **Reply #55 on:** 22 Aug 2011, 12:56 pm »

Very nice job Bob! It is not as large as I thought it would be. I'll bet the ratio of bass output to enclosure size is through the roof!!

Best,
Ed

Bob in St. Louis · « **Reply #56 on:** 1 Sep 2011, 12:43 am »

Versus Rider - Do you still need the specs, or did you determine otherwise?

Mark - You're right. They're not on. See "why" below.

Matt - My wife and I can lift it as a team, but she's not very dammed happy about it.

I'll be minimizing her assistance in lifting it. It isn't fun.

Rich and Neo, thank you both for the complements!

Ed - My photography skills didn't quite capture the mass of the device. It is 21"x21"x24" tall.
When all is said and done, I'll weigh it. Just for grins.

But here's the meat of why I'm posting today, and what I posted on the Hawthorne Audio forum......
Thanks to all for the kind words, and my apologies for the lack of communication. The project stalled a bit due to either, "A", the drivers are not suited for use in RiPole alignment, or "B", these handmade, prototype drivers have been electrically damaged in a previous life (I'm not the first user). Their sound quality was nothing short of amazing, but it had almost no output before it ran out of steam.

Regardless, Darrel Hawthorne has provided a pair of >> THESE << as replacement.

The physical dimensions of the rear basket area and magnet area are considerably different, so much modification will be necessary to the existing enclosure. My goal is to NOT have $150 worth of materials and dozens of hours go into the burn pile. I've got a four day weekend coming up and should be making progress then. Won't be much worthy of pictures, but trust me, I'll be in the workshop figuring things out.

The new 18" drivers arrived safe and sound today, and are very impressive with regard to heft and build quality. Their shipping weight alone was 65 pounds.

They've got an accordion suspension in the center front of the cone as opposed to the normal convex dustcap. Someone else may be able to tell you what the (solid as a rock) plate in the center of the cone is. I shot a couple pics, one with my hand and one with a marker for scale. These are serious drivers. Very serious.

More later....
Bob

gooberdude · « **Reply #57 on:** 1 Sep 2011, 02:18 am »

That cap would be a cool guard for my shower drain, or maybe a belt buckle.

opnly bafld · « **Reply #58 on:** 1 Sep 2011, 02:29 am »

Quote from: Bob in St. Louis on 1 Sep 2011, 12:43 am

They've got an accordion suspension in the center front of the cone as opposed to the normal convex dustcap. Someone else may be able to tell you what the (solid as a rock) plate in the center of the cone is.

Dust Cap Composition Porous cloth top spider/ heatsink

Bob in St. Louis · « **Reply #59 on:** 1 Sep 2011, 03:57 pm »

Quote from: gooberdude on 1 Sep 2011, 02:18 am

That cap would be a cool guard for my shower drain, or maybe a belt buckle.

One of the guys on teh Hawthorne forum said it would be great as a BBQ grate to "brand" the burgers.

Thanks for the words of wisdom Lin, much appreciated.