Gravity Well Of A DarkStar

Wind Chaser · « **Reply #820 on:** 30 Jun 2006, 09:59 pm »

Quote from: Wind Chaser on 29 Jun 2006, 10:51 pm

By this time tomorrow afternoon I should be able to post some preliminary thoughts.

Imagine meeting a very nice girl you really like - but she's a virgin. Then you meet her identical twin. All things being equal the only difference is the virgin’s twin is a major slut!

That’s sort of where I am at with the B200’s. The new drivers need to be jabbed for at least 60 to 100 hours for a reasonably fair comparison as the modified drivers have the advantage of more than 400 hours on them. Until then any comparison is pointless, so in the meantime I’ll concentrate on doing what must be done with the virgins.

As for the Augie Visaton combo - two very enthusiastic ears way up crazy over the rainbow! JohninCR, you need to take your Augies out of the box and send them out on a date with the B200. You’ll hear Pink Floyd as if it were for the first time… again.

John

...

LarryC · « **Reply #821 on:** 6 Jul 2006, 08:05 am »

New visitor here!
…….it started out simple enough, just the desire to listen to music I had on my PC thru my stereo system with only a limited budget. (Ripped CD’s and downloaded singles) This lead to the discovery of Squeezebox3 in May ‘06. WiFi & sounds better than CD’s! WOW. Learned that Flack was more than ‘dissension’ and spent several weeks Flacking 700 CD’s – still not done. Rediscovered so much music – and all at my fingertips!!

Discovered T-Amp June ’06. Shamed my amp for $30. Charlize came into my life a couple of weeks later for $100. Now were talking! – beautiful music! WOW WOW

Then I stumbled into a Darkstar and got lost in it for several weeks. Gravity is so strong; one has no chance of breaking free! So much information, I felt like I was drinking from a fire hose. A chance encounter with an old friend reveals the captivating sound is for real. WOW WOW WOW So it begins – a call to Dave Dlugos at Planet10 and my B200’s and Phase Plugs show up by July further enhanced with a ductsealed basket and foam/felt damper added to the magnet. (thanks Dave) Many OB boards had been cut by this time and made for a glorious and musical 4th of July!
3/4" MDF - Heights- 48", 42", 36", 32"; without wings and with
wings; widths- main baffle: 10",12" 18"; wings: 4",6",8",10",12" – quick disconnect hinges.
Settled on 32” high, 10” main baffle, 10” & 12” wings, also adjustable horizontal baffle board above driver.
I then made the bold proposal that WAF be addressed by the wives. My wife is an
artist; and she and her local artist friends have picked up the challenge and
are looking at the potential of "speakers as pieces of art". It is the last piece awaiting completion. I know that participation in a project brings about ownership and ultimately acceptance of the final outcome. But, I’m in no hurry now, the sound is wonderful and I can enjoy and explore so much music so easily.

Thanks so much to those of you who paved the way and allowed a traveler to benefit from your endeavor. The captured light from the Darkstar so clearly illuminated the path and allowed a rapid approach. I would never have believed that a hi-fi system with such marvelous sound could be obtained for $750 complete!

Photos of the journey: http://www.websiteonline.net/b200/b200.htm

Vinnie R. · « **Reply #822 on:** 6 Jul 2006, 12:56 pm »

Hi LarryC,

Welcome to Audiocircle, and a special welcome to the Gravity Well!!!!!

I really enjoyed reading your post and hearing about your experiences, and seeing those pictures!

Have you had the chance to compare the stock B200 vs. the modded ones with phase plug?

I am not surprised that you decided that the 10" wide front baffle was your favorite. This is what I am using now (after trying wider versions) and it works the best. Having the wings start out as close to the B200 works best (JohninCR told me about this a while ago and I haven't looked back).

I am also interested in hearing about your adjustable horizontal board above the driver. Have you listened to it installed vs. not installed? Have you had the chance to play with the angle?

Congratulations on all your hard work!

Best regards,

Vinnie

Wind Chaser · « **Reply #823 on:** 6 Jul 2006, 05:54 pm »

Hey Larry,

I was wondering who you were and if you were going make yourself known. Welcome to the higher end of audio. You’ve got a butt kicking system on a dime so to speak. Well done! What are you using to power your Charlize?

My stock B200’s still have a long way to go before they catch up with the hours on the modified drivers. I was hoping to do a quick sneak preview *comparison but when I attempted I noticed that Dave had soldered leads to the terminals on the driver making it impossible to slide the crimped leads on.

I finally got around to cutting some 1” thick MDF. I chose to do something similar to Nigel Smith’s 12th baffle. It’s a trapezoid, 39.5” tall, 20” wide at the bottom and 16” wide flat across the top. The center of the top driver’s hole is located 29.5” from the floor and the center of the bottom driver’s hole is located 7” from the floor. Baffles will be tilted back 5 degrees without wings. There are details I need to work out, how to make them stand up, the way to mount a Charlize on each baffle and cosmetics. Still waiting for the inductors to arrive.

* Dave did comparison between the modified B200 and stock 15” Silver Iris coaxial. Scroll about half way down and you’ll see Dave’s comments…

http://www.hawthorneaudio.com/forum/viewtopic.php?t=237

John

LarryC · « **Reply #824 on:** 7 Jul 2006, 12:28 am »

Vinnie,

Quote

Have you had the chance to compare the stock B200 vs. the modded ones with phase plug?

I don’t have a second pair of B200’s (yet), so my comparison between stock B200 and modded with phase plugs is based on my ‘memory’ of hearing a friends about a month ago. My first impression is a wider sweet spot compared to the rather narrow one I had auditioned. Several listeners are able to sit within it and enjoy the full soundstage. Female Jazz vocals are also less bright to my ears, smoother. Room characteristics and placement may also have something to do with this – these OB’s are so tunable. Here are Dave’s observations before he sent them to me:
“…dramatically improved high frequency dispersion,
spreading out the on-axis hot spot to a more even & balanced response
over a widened window. As well it made the midrange more "relaxed"
decreasing a coloration in vocals -- this wasn't as dramatic as in
some drivers, and if you couldn't compare to an unmodded driver you
might well miss that there was ever a problem in the 1st place --
this speaks to how well balanced this driver is out of the box.”

Quote

I am also interested in hearing about your adjustable horizontal board above the driver. Have you listened to it installed vs. not installed? Have you had the chance to play with the angle?

I have listened to it installed and not installed. 90 degrees to standing straight up and everything in between. 65 degrees seems about right; somewhat more bass, but even more important to me, firmer bass – again room positioning has a real effect. I believe that this ‘horizontal wing’ extends the linear height of the baffle just like the side wings extend the total linear width. I think that this was the key to getting the OB’s down to the 32” height with no perceivable difference in sound. I’m using an 8” deep board effectively extending the height to 40”. I tried boards between 4” – 12” and the 8” sounded right.
Baffle video: http://www.websiteonline.net/b200/b200_hbaffle.avi

LarryC

LarryC · « **Reply #825 on:** 7 Jul 2006, 12:41 am »

John,

Quote from: Wind Chaser on 6 Jul 2006, 05:54 pm

What are you using to power your Charlize?

Elpac AC Adapter 12v 4.15amps / 6ft DC output cord plus 6ft AC input cord
This may have the reach you need. I had this from an earlier project, but matches Charlize perfectly.
photos:
http://www.websiteonline.net/b200/elpac_12v_bottom.jpg

http://www.websiteonline.net/b200/elpac_12v_top.jpg

LarryC

hungrych · « **Reply #826 on:** 7 Jul 2006, 07:45 pm »

Hi,

I apologize if this has already been brought up, but is there any effective way to set these up in a bookshelf/monitor size? Like for use at a desk. Thanks!

planet10 · « **Reply #827 on:** 7 Jul 2006, 09:03 pm »

Quote from: Wind Chaser on 6 Jul 2006, 05:54 pm

I noticed that Dave had soldered leads to the terminals on the driver making it impossible to slide the crimped leads on.

A little solder wick should clean the terminals right nice... but IMHO solder is better.

Larry, glad to here you are enjoying your B200s... i may well have to try the narrow baffle -- then they might fit in my room (not that i'm low on speakers)

dave

Wind Chaser · « **Reply #828 on:** 7 Jul 2006, 10:39 pm »

Dave,

I certainly did not mean that as a complaint. In fact it's probably a good thing... keeps me focused on putting hours on the new drivers. Speaker cables will eventually be soldered to the driver terminals and the amps PCB. There's no connection quite like a direct connection!

John

Vinnie R. · « **Reply #829 on:** 8 Jul 2006, 02:35 am »

Hi Larry,

Thanks for your response to my questions and thanks for posting all your pics (and that video...great idea!).

Please keep us posted on how your setup is working out for you!

Thanks,

Vinnie

hungrych · « **Reply #830 on:** 9 Jul 2006, 04:58 am »

Quote from: JohninCR on 8 Jul 2006, 02:52 am

Quote from: hungrych on 7 Jul 2006, 07:45 pm
Hi,
I apologize if this has already been brought up, but is there any effective way to set these up in a bookshelf/monitor size? Like for use at a desk. Thanks!

Sure. You just have to keep in mind that it's an 8" driver and not shielded (so they can't be too close to your monitor. You'll need a sub anyway, so keeping the front profile not much larger than the driver is easy.

Cool. Is there any particular baffle size you would recommend or just experiment?

JLM · « **Reply #831 on:** 9 Jul 2006, 11:04 am »

hungrych,

10 inches is a practical limit for baffle width with the B200, just don't set it up to look (act) like a box with no back (with the wings/top). The example above of adding different length side "wings" and an adjustable top plate is close to the ideal for floorstanders. JohnCR has images of a smaller version where the sides/top are fixed and no square corners. Keep the angle between the baffle and sides/top at least 135 degrees (half way between square and flat).

This is the old open baffle struggle of bass output vs. baffle size question. The bigger the baffle the lower the frequency that the rear wave cancels the front wave, but as the baffle gets bigger you lose the dipole effect for higher frequencies. Using the wings/top provides a most useful middle ground solution. Large baffles also provide a surface for sound from the opposite channel to reflect off (a bad thing). Just accept the fact that open baffles don't do deep bass.

If you're willing to give up dipole diffusion and depth of soundstage infinite baffles provide another option. You'll need a cavity (cabinet volume) of 4 - 10 times the driver Vas. Closets, unused bedrooms, or garages (in temperate climates) work well (avoid slaming hinged doors into those spaces as the contained air can blow out your driver cones). This concept is often used for subwoofers where the diffusion/soundstaging aren't issues.

markC · « **Reply #832 on:** 9 Jul 2006, 01:10 pm »

Hi LarryC;
Welcome to Audiocircle. Would you mind sharing the centre height of the driver please?

LarryC · « **Reply #833 on:** 9 Jul 2006, 08:09 pm »

Quote from: markC on 9 Jul 2006, 01:10 pm

Hi LarryC;
Welcome to Audiocircle. Would you mind sharing the centre height of the driver please?

MarkC,

Height from floor to center of driver is 23". Baffles are tilted back 4 degrees.

mcgsxr · « **Reply #834 on:** 9 Jul 2006, 10:06 pm »

LarryC, welcome to AC, and welcome to the club of the "doer"s! Nice to see someone else strike up the light, playing around with configurations, and sharing the results.

Love that innnovative top panel mount, allowing for infinite adjustment, that is just well done!

nodiak · « **Reply #835 on:** 10 Jul 2006, 01:07 am »

Just curious, with all the 1.5 systems that deal with filling in low end roll off using a largish inductor on a second B200, has anyone tried using a circuit like Bob Brines and Martin King (and others) use for baffle step correction but on a single B200? I used a 1.9mH coil and a 4 ohm resistor in parallel and inserted on the positive lead on FE167e's once and it evened out the response. Basically the midrange is pulled down and the lower and upper end left as is.
With the 1.5's some are doing here the low end is brought up to similar level as midrange, and top end is unchanged. Does anyone feel the top end needs a boost too?
Would be interesting to compare 1.5 type to single B200 with "bsc" circuit.

Don

(These are questions of curiosity, no subtle attack on any method. I'd be interested in any study in this direction. I no longer have B200's but keep up with the thread. Maybe I'll rejoin the travels again later.)

opnly bafld · « **Reply #836 on:** 10 Jul 2006, 02:25 am »

Hello Don,
I don't feel the top needs boosted and a few friends that have heard them were happy with the highs also.
Lin

JLM · « **Reply #837 on:** 10 Jul 2006, 04:58 pm »

Don,

The biggest issue I see with adding a compensation circuit is loss of efficiency. With MLTLs there is already good bass reinforcement that OBs lack, so the question becomes how much compensation do you want to try to provide? Compounding this is the fact that many who are drawn to the B200 drivers have small amps.

As an alternative, has anyone tried adding a Hawthorne Augie to the B200? Perhaps boosting the mid-bass from the B200 to match up to the Augie would be the ticket.

opnly bafld · « **Reply #838 on:** 10 Jul 2006, 05:17 pm »

I have used the 15" Augies with 1 B200, and with 2 B200s, with good results.

Right now I am not using them because I have been too lazy to cut and try "thicker" baffles.

Perhaps in the next week I will mark this off my to do list.
Lin

markC · « **Reply #839 on:** 10 Jul 2006, 09:23 pm »

I have just installed a pair of 15" infinite baffle sub drivers in the back wall of my listening room that separates the room from a crawl space. They integrate very well with my current speaks. I currently have a pair of B200's doing break-in duty in the garage on my little Panasonic mini system. This weekend, I'll be cuttin' up some mdf and I hope to be able to have good bass integration with the B200's. My only concern is that I'll have to cross the subs in @ a higher frequency. With the current speaks the subs are totally non detectable as to their location. I hope they stay that way with a higher low pass. I've got them crossed @ 40hz right now, but hope not to have to bring them in above 70 or so. I'm sure the higher the cross over freq. the more detectable they will become. To have the bottom end coming from behind would be totally unacceptable. Only one way to find out for sure!