Jump to content



Photo

The BLACK HOLE Subwoofer


This topic has been archived. This means that you cannot reply to this topic.
92 replies to this topic

#1 of 93 ChrisA

ChrisA

    Advanced Member

  • PipPipPip
  • 479 posts
  • Join Date: Nov 25 1999

Posted October 25 2000 - 01:35 PM

I have been creating a cost no object/no restraints subwoofer that is superior to the Krell MRS and Wilson XS... It is what the Wilson XS should have been.

First and foremost, I would like to wholeheartedly thank Deon Bearden and Greg Monfort for their continual advice and support during their busy schedules. Deon spent July through September putting up with my endless questions and phone calls. Deon and Greg taught me an incredible amount and I very much appreciate it. If it wasn't for the both of them, I would not have been able to gone this far. Between their tutoring and lots of reading, the Black Hole subwoofer was born...

The $18,500+ Wilson XS subwoofer still uses the original first generation aura 1808 driver). Later, Seismic came out with an improved cone, the epoxy cone, called the 8196E. Just recently, they came out with the most advaced driver yet, the 8196HK..honeycomb kevlar with a new Butyl surround
The Black Hole Subwoofer uses the new HK driver. The Seismic 8196 HK driver is an amazing driver... 4 inch underhung design with radially arrayed neodymium magnets.
The Seismic 8196 HK driver (Honeycomb Kevlar) uses (2) cones, with the layer of honeycomb Kevlar in between. So although it appears the same.. the stiffness and the mass has greatly increased... The Fs is appreciably lower... Barry, Owner of Seismic Systems sent me parameters with an Fs around 15 Hz. Either way, it is a significant improvement in the driver, and will yield a flatter response curve (The Wilson XS still uses the paper cone, not even the Epoxy cone... The Wilson XS is also very underported).

The BLACK HOLE Sub (Single unit)

External Dimensions: 45" H x 28" W x 43.75" D
(Front baffle is 2.5" thick)
* 1.25 inch thick A/A Marine grade plywood throughout
* 2.5 inch baffle, double layer
* All 1.25 inch marine ply shelf bracing with horizontal
and vertical shelf bracing interlocking with 'I-beam' support of intersecting vertical and horizontal shelf braces.
* 9.75 inch internal diameter tube port made from 3/8 inch thick fiberboard, 10.5 inch outer diameter from www.cubiconcorp.com
* 0701 WBT binding posts!
* All cuts were precision, done with best cabinet
shop and expert millwork in Philadelphia.
* Weight, approximately 400 lbs. Will have final
result next month.


All commercial subs use extensive analog boosting and EQ extensively, while the BLACK HOLE design requires no equalization whatsoever do to the nature of this particular sub and its EBS alignment. (Albiet, the room can always use adjustment, hence the Meridian Room correction Posted Image ) Sealed subwoofers have increasing amounts of distortion as frequency decreases due to larger excursions... The excursion actually decreases, as most of you know, in a ported design a fair bit above and below the tuning frequency... The tuning frequncy in my design, the BLACK HOLE Sub is around 13-14 Hz. So while sealed subs are straining, the BLACK HOLE is at its BEST! I still have to do special electrical measurment to determine the final tuning frequency when all is said and done.

As someone once told me, "The subs that sound the best are those that can accurately reproduce the most bandwith!" (Assuming competent design of course). That is the KEY phrase. At level matched volume levels, the Black Hole sub will sound superior to other subwoofers. This is NOT about quantity, This is about Quality, and QUANTITY OF QUALITY. It is about reproducing the most bandwith into the deepest octaves, in the most linear fashion possible.

One of the best things about the BLACK HOLE is the low power requirements, you dont need gobs of power to get tremendous bass, this keeps voice coils cool and keeps the Qts of the driver operating at normal (cool) values with nominal voice coil resistance). When drivers heat up lots of bad things happen, including unwanted changes in the way they behave. I'll find the article that describes just how superior the Seismic 8196 driver is... It is almost unbelieveable.. Even at full rated power, this driver displays only 1-2% power compression, unparalleled power Conversion, 1100watts continuous 5000watts peak. This sub driver is designed for moderate to large enclosures.

I am very happy with the design and all out approach. I would like to build and sell more of these subs when I am done making them, however, they would be very expensive... aproximately $8,000.00 per subwoofer, $16,000.00 for a pair ala Wilson XS style, Either laminated together or sepaerate for more portability. In other words, I will build more for someone who has the money, desire, to own such an incredible subwoofer... I'm keeping these 4 for sure, using two stacked wilson XS style in the two from corners....

but I figure, why should I be the only one?
They outperform any commercial subwoofer, including the Wilson XS and Krell MRS, so I will sell them.

Again, I'd be happy to laminate two of these together and then laminate a surface on them to make this into a two driver subwoofer, to make a Wilson XS killer. Although the appeal is that this design uses a better driver, better materials, and a better ported design overall... so why even laminate two of them together when the can be stacked and more portable (rhetorical)...

I have a *max* port velocity of 15 M/s, full excursion... Wilson's is considerably higher, I estimate 25 M/s port velocity...

Commercial subwoofers put massive constraints on size due to shipping costs and limited market for large subwoofers. Every commercial sub manufacturer cuts corners in that regard, even Krell MRS and the 'huge' Wilson XS.

Admittedly, the Black Hole sub is significantly larger than the Wilson XS, but it is VERY reasonable when you can stack two BLACK HOLE subs (7.5 feet tall). The advantage to keeping them separate is not only portability, it is serior in terms of reducing standing waves... Wilson's 7 foot tall cbinet is entirely open internally. Why not divide a Wilson XS in half and elarging the port size, use more rigid materials for cabinet, a better crosbracing scheme, a better driver, etc... If you don't want the portability of separate enclosures and want maximum cabinet coupling, I will gladly laminate the Two Black Hole subs together to make a Wilson XS style sub... which is what I designed them for originally. By the way, the Wilson XS sub uses 1 inch MDF... Marine grade plywood has alomst 3 times the modulus of elasticity than even the best medite MDF...

BTW, The drivers used in the Krell MRS are decent, but nothing special IMO. They aren't even the top 15 inch driver from TC sounds...

> They use the Standard TC 15. 2.3" long
> coil, .5" gap height. 1.5" suround.
> Double stack 7.5" magnets. BL^2/Re of ~~ > 150.


The big point here is RIGIDITY, not DAMPING per see. There is a big difference between building a subwoofer and building a full range design which must cover the entire spectrum...

Subwoofers are easy to build once you know the basics...

Rigidity is the key to subwoofer enclosures, you cannot 'damp' the speaker sufficiently unless you build the subwwofer into the side of a mountain (slight exageration, but true). Therefore, you must shift the resonance of the box as high as possible above the operating bandwidth of the subwoofer. The material with the highest Modulus of elasticity is the most rigid and will 'move the least' and resonate only at higher frequencies...

Marine Ply and Baltic Birch are equally strong and offer a MOE of around 1,800,000 psi... that is approximately 3 times more rigid than even the best medite MDF. The reason commercial manufactures take short cuts here is because it is very hard to finish Plywood. I am making another laminate
on top of the plywood, proably 1/8" mdf with Black oak, or fiberglass coating then finished in flat black... I do not want piano black... the black hole sub must not only be magnificent in every aspect, it must absorb all light!

Dedicated subwoofers are least critical in shape of the box, especially if their operating range is going to be 0-80 Hz or less... The wavelenghts are so large that standing waves inside the box are not critical... true that you DO have to consider harmonics in BOTH direction... but only in a full range speaker is this more critical because bas drivers are crossed over much higher. Ideally, a SPHERE is the best shape, but if you keep the sub crossed at 60 Hz fourth order or thereabouts, you don't run into real life
standing wave problems. Now if I were doing a FULL RANGE SPEAKER, I would very much be tempted to put the bass driver in a spherical enclosure BECAUSE Bass drivers in 3 way speakers tend to get crossed over around 400 Hz, or thereabouts... The key is to separate what is best for a dedicated subwoofer and what is best for a bass driver in a full range design. In a full range design, it is oten best to actually use plywood or baltic birch internally, laminated to a second piece of MDF externally... this will give damping and rigidity. FOR DEDICATED SUBWOOFERS, RIGIDITY IS THE KEY. It is superior to use (2) layers of Baltic Birch or Marine Plywood, instead of a combo (MDF/Ply). I located hard to find A/A marine grade plywood 1.25 inches thick! Very hard to find... This is the best case scenerio. I also created the shelf braces (best possible scenerio) out of the 1.25 inch thick Marine Ply... Marine ply also has the advantage of being waterproof, and will last 'forever' at the very least it will resist humidity.....

Here are some pictures taken over the last few weeks ... I'll keep updating.

I started the construction process by laminating two layers of 1.25 inch thick marine grade plywood together for the baffle construction. A complete 'sheet' of Tightbond was applied between layers and approximately 600 pounds of force was created by stacking multiple layers of plywood (not shown) on top of the two layers.

Here are some of the tools, including (2) of the Large Bessey wood clamps...

http://users.erols.c...tting Ready.jpg


Here is a picture of the (4) Seismic 8196 HK drivers with the new butyl surround. You cannot see much of the surround because I left the protective shipping layer on the outer rim. http://users.erols.c...... baffles.jpg

Here are the ports from www.cubiconcorp.com done to my specification: The inside needs to be finished nicely, with a piano black finish. These are the raw ports. 3/8 thick fiberboard!

http://users.erols.c...tt/ThePorts.jpg


Here are the sides of these 1.25 inch thick Marine grade plywood:
http://users.erols.c...lywood-side.jpg

Here the 2 sheets are being held together and aligned. I then piloted with countersink, from the inside face of the baffle.... This was clamping just to align and drill pilot holes. Clamping for gluing was described above.
http://users.erols.c...fordrilling.jpg

My place is a Black Hole Sub Factory now: http://users.erols.c.../subfactory.jpg

I like to use a lot of glue, then simply wipe it up, especially as you clamp and screw... These Square drive screws are really top-notch..

I love these 2.5 inch baffles, at 100 lbs., I think they define rigidity.

http://users.erols.c...riousbaffle.jpg

A nice day today.. I used a drill guide to get the driver holes on the baffle perfect, McFeeley's Large T-Nuts are great, and really worked for me.

http://users.erols.c...randbaffle2.jpg http://users.erols.c...verinbaffle.jpg http://users.erols.c....hindbaffle.jpg


The new Rotary (random Orbit) was 100% what I needed.

Further, the Porter cable profile sander is VERY NICE! http://users.erols.c...ccessories2.jpg


The WBT Binding posts and Kimber wire for internal wiring: http://users.erols.c...accessories.jpg

Here I am ready to put the baffle on... a little glue
anyone? http://users.erols.c...thnutt/GLUE.jpg

The ports fit 100% snuggly and will be glued into their support structure, which is also a part of the vetical crossbrace (all bracing is shelf bracing AND interlocking (the best). That Millwork really did an incredible job with the precision cutting schedule I gave them.I had last week off and worked constantly. Everything went extremely well, although I have some serious wrist, hand, and finger pain. I went through 20 tubes of silicon (5 per sub), endless tightbond (25'ish containers), etc... After all 4 were siliconed, a day later they were fiberglassed according to spec...

http://users.erols.c....0nsulation.jpg

The Port tubes were then glued into place. 2 part epoxy was used for gluing the port tube internally. The port actually is placed through the 2.5 inch thick front baffle.
http://users.erols.c......r Panel..jpg

I took no more pictures were taken because I was too messy to even grab the camera. Autobody filler was used to seal all screw holes. This is recomended over wood filler by cabinet shops. "Bondo" is actually 2 part epoxy and is stronger, binds better and does not shrink. Only a 50-75 of a carton of 1500 screws remained, so there were a lot of countersinking holes to fill.

I then used the random orbit sander to smooth out the surface to be prepared for lamination of a Wilson Art Solid Black laminate. I chose the matte, texturized finish. Although the high gloss, smooth finish would have provided a piano black finish, I felt it was better to make the black Hole sub non reflecting, as I like total darkness in my A/V room.

I was entertaining slate, mrble, granite, Black Corian, etc.. but that was to expensive for my budget. Certainly anything can be used, inculding exotic woods...

The inside of the rear panel was painted flat black-- since the port tube has a 9.75 inch internal diameter, you would be able to see to the back panel. When you look inside the flat black port tube, you see NOTHING! The port disappears. I can't wait to see them once they have been laminated.

All I can tell you is that these cabinets are knuckle busters, perhaps even tank busters. The crossbracing scheme is very satisfying and provides incredible rigidity--I would not change a thing. This cabinet is totally optimized for this design.

The 4 black Hole subs are now at the cabinet shop as of yesterday--they are going to be finished within the next two weeks.

When I get them back, the next step will be to put some insulation on the rear wall, as well as mount the binding posts to the rear wall. The WBT 0701 binding posts, with the extension kit (shown in previous pictures) can go through 1.5 inch thick material with no countersinking. Then finally, I will mount the HK driver with appropriate gaskets... I'll take some more pictures when they come back from the cabinet shop.
SIGN THE PETITION: CONSUMER EXPECTATIONS OF HD-DVD Don't Settle for low-bitrate audio/video

Pictures: The Worm Hole Theater featuring the Black Hole Subs and Death Star Platform

Support a DISCRETE TACTILE TRANSDUCER CHANNEL. Add a NEW DIMENSION and SENSORY EXPERIENCE to YOUR THEATER

#2 of 93 Bing Fung

Bing Fung

    Advanced Member

  • PipPipPip
  • 30 posts
  • Join Date: Feb 19 2000

Posted October 25 2000 - 01:49 PM

Holy project Chris! Posted Image But when you have 3 802's i expect nothing less Posted Image

------------------
Bing Posted Image

My Home Entertainment Center
Bing

My Home Entertainment Center

#3 of 93 Seungsoo Hwang

Seungsoo Hwang

    Advanced Member

  • PipPipPip
  • 209 posts
  • Join Date: Aug 06 1999

Posted October 25 2000 - 02:09 PM

All I have to say is WOW.

#4 of 93 Ricky L

Ricky L

    Newbie

  • Pip
  • 1 posts
  • Join Date: Feb 15 2000

Posted October 25 2000 - 02:52 PM


*******INCREDIBLE*******

Its a great job!

Ricky

#5 of 93 Patrick Sun

Patrick Sun

    Advanced Member

  • 37,420 posts
  • Join Date: Jun 30 1999

Posted October 25 2000 - 03:11 PM

To quote Keanu: Whoa!

------------------
PatCave ; HT Pix ; HT Gear ; Sunosub ; Pat's DVDs ; Pat's LDs
"Jee-sus, it's like Iwo Jima out there" - Roger Sterling on "Mad Men"
Patcave | 2006 Films | 2007 Films | Flickr | Comic-Con 2012 | Dragon*Con 2012

#6 of 93 Tom Vodhanel

Tom Vodhanel

    Advanced Member

  • PipPipPip
  • 2,176 posts
  • Join Date: Sep 04 1998

Posted October 25 2000 - 03:24 PM



>>>All commercial subs use extensive analog boosting and EQ extensively, <<<


Well, I'd change that to *nearly* all...


>>>Subwoofers are easy to build once you know the basics... <<<


That is may be.

But there's a not so fine line between doing 500 software sims, and actually building a couple dozen subwoofers,and taking the time to document the performance of each variation anechoically.

There's no question in my mind these subwoofers will be amazing---as soon as I see DB's name involved in anything---I know it's going to be nutz. However, before I felt comfortable charging 8-16k for these...I'd sleep much better seeing some quasi-anechoic data on them...it may help *sales* if you could cite actual performance data too.

Just an idea of course...probably worth what you paid for it.

good luck regardless...and I'll look forward to hearing these beasts when you fire them up...I only live a few hundred miles away...

TV



#7 of 93 Bing Fung

Bing Fung

    Advanced Member

  • PipPipPip
  • 30 posts
  • Join Date: Feb 19 2000

Posted October 25 2000 - 03:41 PM

Chris, where can more data be found on those drivers? iwould even like just one Posted Image

------------------
Bing Posted Image

My Home Entertainment Center
Bing

My Home Entertainment Center

#8 of 93 ChrisA

ChrisA

    Advanced Member

  • PipPipPip
  • 479 posts
  • Join Date: Nov 25 1999

Posted October 25 2000 - 03:48 PM

Thanks Tom,

I plan on measuring them extensively when they are completed.... This was (still is!) a hell of a lot of work, so I'm not planning on turning into a high end subwoofer manufacturer, although I admit I'd like to! It sure beats doing 36 hour shifts getting tortured in a hospital.

Multiple Seismic 8196 HK drivers in an EBS alignment ... can't wait to fire them up! The funny thing was watching the Cabinet shop coming to pick them up yesterday... It was hilarious watching these four guys use an appliance mover getting them into their truck... I wanted to take pictures, but was sanding them outside up until the minute they picked them up... I neve worked so hard in my life...
kinda like this intern year but more physical on top of it...

"But there's a not so fine line between doing 500 software sims, and actually building a couple dozen subwoofers,and taking the time to document the performance of each variation anechoically"

That's why it is great to have such knowledgable consultants
who keep up on their AES journal readings as well as perform said experiments Posted Image Further, underhung motors and those with a high Bl seem to perform better (or closer to software predictions. The Seismic 8196 motor strength and the 4 inch underhung design speaks for itself.


Bing: www.seismicsubs.com
SIGN THE PETITION: CONSUMER EXPECTATIONS OF HD-DVD Don't Settle for low-bitrate audio/video

Pictures: The Worm Hole Theater featuring the Black Hole Subs and Death Star Platform

Support a DISCRETE TACTILE TRANSDUCER CHANNEL. Add a NEW DIMENSION and SENSORY EXPERIENCE to YOUR THEATER

#9 of 93 Chad Kuypers

Chad Kuypers

    Advanced Member

  • PipPipPip
  • 79 posts
  • Join Date: May 08 2000

Posted October 25 2000 - 06:46 PM

Chris,

HOLY MOLY!!! I have been looking forward to seeing your subwoofer(s) materialize ever since you talked about it here awhile ago. I am having trouble even imagining what 4 of your Black Hole subwoofers would sound like! YIKES!!! I look forward to your real-world experiences with them regarding measurements and sound quality. Those are some gigantic enclosures! How much do they weigh? Also, what is the volume and tuning of the enclosures?

Did you get your drivers through Seismic? I didn't see the 8196HK listed anywhere on their homepage, so I am curious. How much did you pay for the drivers? I was just wondering if the new subwoofer drivers that you have cost significantly more than the original Aura 1808, which went for around $750-1000. Sorry for all of the questions! Posted Image


Chad



#10 of 93 Anthony F.

Anthony F.

    Advanced Member

  • PipPipPip
  • 93 posts
  • Join Date: Jun 12 1999

Posted October 26 2000 - 12:52 AM

So you're going to use Bose Acoustimas speakers as mains with this, right? Posted Image I think you'd better call Cal-Tech to get someone to measure it. Great job!

#11 of 93 ChrisA

ChrisA

    Advanced Member

  • PipPipPip
  • 479 posts
  • Join Date: Nov 25 1999

Posted October 26 2000 - 05:36 AM

The Black Hole is really based on the Bose 901--I'm going to mount them in every direction and boost the 200Hz -20,000 region...

Chad, the new HK drivers are more expensive than the parer or epoxy version... approximately $50.00 more. I haven;t heard from Barry in a while, perhaps he is on vacation or away on buisness... External Volume is 45 x 28 x 43.75 =
55,125 in^3 / 1728 = 31.90 ft^3 ... Subtracting for port, driver, internal bracing, and wall thickness, leaves around 25 ft^3 for Vb ... I expect tuning frequency to fall very close to 14 Hz... I'll do the electrical measurment soon enough. Weight will be around 400 lbs when finished with
driver... 2 stacked would be around 800 lbs (Wilson XS style)...


SIGN THE PETITION: CONSUMER EXPECTATIONS OF HD-DVD Don't Settle for low-bitrate audio/video

Pictures: The Worm Hole Theater featuring the Black Hole Subs and Death Star Platform

Support a DISCRETE TACTILE TRANSDUCER CHANNEL. Add a NEW DIMENSION and SENSORY EXPERIENCE to YOUR THEATER

#12 of 93 Kevin Liedtke

Kevin Liedtke

    Member

  • PipPip
  • 27 posts
  • Join Date: Jul 10 2000

Posted October 26 2000 - 09:03 AM

That is awsome....

#13 of 93 james_w

james_w

    Newbie

  • Pip
  • 8 posts
  • Join Date: Mar 02 2000

Posted October 26 2000 - 11:01 AM

Very, very cool Chris! Posted Image
I can't wait to see it finished. Posted Image


------------------
Posted Image

#14 of 93 Mike Knapp

Mike Knapp

    Advanced Member

  • PipPipPip
  • 637 posts
  • Join Date: Aug 04 1997
  • Real Name:Mike

Posted October 26 2000 - 02:04 PM

Damn!

I hurt my back just looking at your pictures.

Mike

#15 of 93 Martin Schmencke

Martin Schmencke

    Advanced Member

  • PipPipPip
  • 36 posts
  • Join Date: Jun 03 1999

Posted October 26 2000 - 04:20 PM

That's because you were holding them up with one hand ....... Posted Image

#16 of 93 Daniel Marx

Daniel Marx

    Member

  • PipPip
  • 10 posts
  • Join Date: Jan 26 2000

Posted October 26 2000 - 04:56 PM

Holy Friggn' Moly. Have you absolutely lost you mind Chris? How do you even sleep at night, knowing that these things are on the absolute verge of completion? I get so anxious by the stage your at, I drop in the drivers and give a whirl! With or out without the pretty finish. Give me a towel so I can whipe the drool from my keyboard. Hope you don't mind, but I saved every one of your pictures. If they took that long to download, I didn't want to lose them once I got them. I have only one comment: I know with myself, when building multiple subs at the same time, I get absolutely beat working on just one, then to half to do it all over again to the other one, and in your case to do it over again, and then again....just wears me out thinking about all the work you must have gone through for only one sub. And then to quadruple it all! I realize you have complete confidence in your sims and design, yet if it were me (and this is just because I'm more lazy than anything else) I would've just built ONE of these Black Holes, done all my tests, measurements, and critical listening, and THEN determined if the design could be improved or should be improved and then build the second one. Give that a listen and maybe even build a third and fourth to slightly different specs depending upon how the first two turned out. I don't know, that was just a thought that crossed my mind as I thought about all that hard work, "What if it sounds awful!" "Now you've got FOUR of 'em!" Obviously you've done your research, picked a helluva driver and aren't cutting any corners so I DOUBT that will be the case. Good luck with the finishing touches. And keep taking lots of pictures. :-) And one other thing, PLEASE tell me these subs aren't going into your 12x16x8 foot living room!! I pity your neighbors. I truly do.

#17 of 93 TerryC

TerryC

    Advanced Member

  • PipPipPip
  • 219 posts
  • Join Date: Oct 19 1999

Posted October 26 2000 - 05:59 PM

Good to see you posted the pics on this forum...

Are these going into that small room mark mentioned! If so you need to do some peak SPL measurement by having Tom V come over, regular Rat Shack probably isn't going to cut it. I'm thinking you're going to give a lot of car audio SPL competitors a run for their money, I'm not 100% sure but I think anything around 145-157db is a good to awesome score.

Please have Tom over with all his test equipment, it will be wonderful to know what you are getting out of these monsters!

Terry


I'm guessing things didn't work out with the girl friend since you're building subs that no sane women is going to let into their home? Posted Image

#18 of 93 Gregg Hart

Gregg Hart

    Advanced Member

  • PipPipPip
  • 170 posts
  • Join Date: Apr 15 1999

Posted October 26 2000 - 06:18 PM

Insanely cool Chris. I can't wait to hear about them when they are done. Please do have TomV over to do some measurements. Maybe you could go on tour with these things. Kinda like Bose does. What kind of wattage/amps are you planning on using with these?

------------------
My Home Theater
My Home Theater

#19 of 93 ChrisA

ChrisA

    Advanced Member

  • PipPipPip
  • 479 posts
  • Join Date: Nov 25 1999

Posted October 27 2000 - 01:50 AM

Holy Friggn' Moly. Have you absolutely lost you mind Chris?
==========

Yes, I'm trying to become comfortably numb to get through intern year.

========
How do you even sleep at night, knowing that these things are on the absolute verge of completion? I get so anxious by the stage your at, I drop in the drivers and give a whirl! With or out without the pretty finish. Give me a towel so I can whipe the drool from my keyboard.
========

Let's just say that intern year and exhaustion from building these things has prevented me from even thinking about rushing anything. To be honest I'm still stressed out over my general situation to think about it. I'm supposed to move into the girlfriend's house in December.
Intern year, taking on this project, and trying to figure out what to do with our situation is very overwhelming. I'm having a hard time giving up my freedom. I decided to split the cost of renovating her basement to accomidate the theater. What happens if something doesn't work out? I'm having thoughts of someone pouring soda in my Bryston 7BST's and putting a hammer through the phase plugs on the B&W Nautilus 802's Posted Image Posted Image This year is very complicated.
=============

I'm guessing things didn't work out with the girl friend since you're building subs that no sane women is going to let into their home?
=================

Let's just say she enjoys watching movies (except for most action or sci-fi Posted Image I told her I wouldn't engage the Black Hole at full power, lest some rift open up between the towers.

================

Hope you don't mind, but I saved every one of your pictures. If they took that long to download, I didn't want to lose them once I got them. I have only one comment: I know with myself, when building multiple subs at the same time, I get absolutely beat working on just one, then to half to do it all over again to the other one, and in your case to do it over again, and then again....just wears me out thinking about all the work you must have gone through for only one sub. And then to quadruple it all! I realize you have complete confidence in your sims and design, yet if it were me (and this is just because I'm more lazy than anything else) I would've just built ONE of these Black Holes, done all my tests, measurements, and critical listening, and THEN determined if the design could be improved or should be improved and then build the second one. Give that a listen and maybe even build a third and fourth to slightly different specs depending upon how the first two turned out. I don't know, that was just a thought that crossed my mind as I thought about all that hard work, "What if it sounds awful!" "Now you've got FOUR of 'em!" Obviously you've done your research, picked a helluva driver and aren't cutting any corners so I DOUBT that will be the case.
===========

You are correct about the intensity of the work on these.. I have lots of cuts and a hopefully temporary carpal tunnel syndrome... There is something about intern year, due to its intensity that just turns you up a few notches. I can't wait until June 30th, 2001. 4 months down, 8 to go.

Basically The Black Hole is already a proven design. It is an enhanced Wilson XS... This Seismic motor is well known... The HK driver will only cause an 'improvement'. Decreasing Wilson's total cabinet size, while increasing Vb per driver, decreases power handling above Fb, but improves transient response, group delay, and extends bandwidth significantly by lowering Fb (in conjunction with port tuning). The Seismic motor is well known to this group, so there are no real suprizes. As You know, Deon used the Seismic driver in his BEAST, along with 3 passive Radiators... Anyway, Deon went over my design thoroughly, and it is very straightforward. All I did was choose the best materials, (within reason), build the most rigid box possible (I'm very happy with the crossbracing scheme I came up with-- it is very nice working with 1.25 inch thick Marine grade plywood as crossbracing in this case.) I must have drawn these subs 20 times over ... when the wood is this expensive, you can't afford to make any mistakes. I went over the cutting schedule and my drawings a dozen times. Of course, I drove all the people on the bass list crazy with all of the questions. I really appreciate Greg Monfort for putting up with me. There are so many details. I had to call a bolt company in Detroit to get the proper button head cap screws. People on the bass list were able to guide me in making the best choices for each part. It took me a month just to decide to use tightbond glue... I was almost prepred to use 2-part Epoxy, which can be nice in some instances, but would have been innapropriate with these precision cuts... glad I wasn't mixing 2-part epoxy for 4 of these!
====================

Good luck with the finishing touches. And keep taking lots of pictures. :-) And one other thing, PLEASE tell me these subs aren't going into your 12x16x8 foot living room!! I pity your neighbors. I truly do.

==================
I don't know who said I have a 12x16x8 room... I have a one bedroom apt right now (for at least 1-2 months more). The living room and dining room are one room, totally open to each other, that is specifically why I rented that place.
I keep it in the living room which is 13.5x17.5x8, but the room acoustically is much larger.. around 13.5x26x8... Then you have to consider the kitchen and hallway which are open to the dining room... acoustically it is fairly large.

I was supposed to have matched in radiology last year and should have known where I was going to be for the next 5 years... I should have been in my own house by now, but it didn't work out that way. Let's just say that I'm glad to have a system that will sound great now and will sound even better when I manage to improve the room. Wouldn't it be nice to have a 30Lx20Wx12H room, or perhaps a circular room ....
SIGN THE PETITION: CONSUMER EXPECTATIONS OF HD-DVD Don't Settle for low-bitrate audio/video

Pictures: The Worm Hole Theater featuring the Black Hole Subs and Death Star Platform

Support a DISCRETE TACTILE TRANSDUCER CHANNEL. Add a NEW DIMENSION and SENSORY EXPERIENCE to YOUR THEATER

#20 of 93 Alan Ross

Alan Ross

    Advanced Member

  • PipPipPip
  • 30 posts
  • Join Date: Aug 17 1999

Posted October 27 2000 - 05:44 AM

"Wouldn't it be nice to have a 30Lx20Wx12H room, or perhaps a circular room .... "

Yes Chris, then you can use your subs as tweeters and build some REAL subs. Anyone knows where to get the "Back to the Future" drivers?

------------------
Best regards,
Alan
Best regards,
Alan