Quote:


That's pretty much what I had in mind to try.  I'd build a box with the side that attaches to the baffle being maybe 2 1/2"X1 1/2"X the space between the footers.  The rest of the box would be just to hold lead shot in a clean looking way.  By the time I do this, my speakers will weight over 100 lbs each.  I'll either take them off the isolation platforms entirely or beef those up considerably.  I have heavy felt pads on the footers already so they will still slide on my wood floors fairly easily.

As I posted before, I missed the original remark about base function and mass.  Doh!  

Tonight I decided enough casual / handicapped listening.  Time to clear some speakers out and put the new Anniversary edition CSP325 preamp into the mix.



By placing the Big Betsy next to instead of 90 degrees behind as you saw in the previous picture, and adding the preamp, everything has transformed into a wonderfully full, wide sound.  The bass came up with the Big Betsys moved to the new location.  Normally of course they wouldn't even be in the room, but right now I have nowhere else to put them.  

The preamp really takes the 25th Anniversary Zen Triode to the next level, as it should since the combo is double the price of the amplifier alone.  If it didn't make you go "holy crap" then it really wouldn't be worth the money.

So this evening as I randomly browse through material, nearly everything is sounding better than ever!  It's like nothing can get dry now, and the detail and presence is simply exquisite.  

Right now I am listening to the Bach Cello Suite 1 (prelude) by the Stanley Clarke Band from their album titled "The Message" in 24bit and I have to tell you the Cello in this recording - the sound shouldn't be possible from even 24 bit digital but yet I'm hearing it sound like tape. I attribute this primarily to the addition of the CSP325 preamp. I am certain had I played this last night before the changes I wouldn't have thought anything about it. Tonight however, I hear it and it's like seeing a leaf up close for the first time. Just incredible. The texture and tone and the imaging is so dimensional that before I could hear the face and sides of each sound source, but now I can hear a wrap around effect that just breaths making everything more sharply focused in 3D space.  The effect is when you move your head instead of hearing the performer move left or right, you now just hear more behind him on one side or the other and he doesn't move, just like in real life.  As you move your head, your perspective changes, not the position of the performer.

I knew to make these changes before I ever even auditioned these speakers, but I like to work from handicaps to see what it might sound like in less ideal circumstances. The frequency balance was right on the edge of being great and more recording / ZROCK dependent than I would have liked, but the other baffles were cancelling a lot of the bass which is what caused this condition. Now that they have been moved there is significantly more bass and overall warmth and of course the imaging is now boundless.  

This is really good, and I mean REALLY good. I'm pretty sure the Big Betsy baffles setting next to the Crystal 10 baffles are sympathetically contributing a touch of 50Hz body, and I don't even care because I'm delirious with sonic pleasure and if that's what it actually took than so be it. Time will tell, hell, they might still be killing bass for all I know. You wanted to take this journey in real time with me, so there you go.

I haven't listened to the preamp for the past few weeks to clear my head of it so I can do an objective final evaluation before we start production next week. I am so glad to have it back! Wow, it just fixes everything. I didn't even know half the recordings I had were as good as they are! That's the scary part. There are many recordings that got to go set in the corner after having offended at least one of my sensibilities on some evening... Then I try them again, like now, and I have to waste a lot of time researching the label of the actual track release to see if it is the same recording because it sounds so different. We're right in there with my vinyl rig now, which is rare. That really is worth the price of a preamp if it's the right one.  At least it is to me.

Also, I have never heard the preamp on drivers this good, so I feel like I'm hearing it for the first time tonight and I'm damn impressed. It's just so amazing how it takes a somewhat chaotic sound quality and just tightens everything up, organizes it, and fixes it so that the amp can be played as though it had over twice the power with no danger of clipping whatsoever. It actually does what a ZROCK2 does to restore body and tone but in a completely different way.

In total, this system is pretty expensive, probably 6 or 7 grand for the speakers and ZROCK2. Another 6 or 7 grand for the amp and preamp.  But I can tell as someone who has heard a few systems including those at ten times this price point, this delivers the goods.  It's is exactly the famous Decware Zen Triode sound that anyone can buy for $998. and a pair of speakers, but the sound has been magnified in the same way the Hubble Telescope transformed astronomy. There are no earth based telescopes that can even get close.  


Low volume listening has improved by 60% or more since my last posts on that topic. I attribute that to both changes, but am surprised nonetheless by the rather dramatic improvement. Possibly everything I said earlier about having to be played loud was complete crap. We'll see. Tonight might just be a dream for all I know... a damn fine one I can tell ya.



Steve

Long post coming up:  F15 OB vs Beolab 8000 shootout

About 4 months ago I offered to repair a speaker that belonged to a friend of my wife.  What showed up was a pair of Bang & Olufsen 8000's, also referred to as Beolab 8000's, one not working and one fully functional.  They are a pencil shaped powered speaker that is going for about $1000 a pair on Ebay.  When I first saw them I figured they couldn't possibly sound good - small volume aluminum enclosure with a port - how could that work?

I dove in and fixed the problem - decomposing foam, due to age, turns acidic and eats away the 120 vac trace that powers the main transformer - easy fix (although fairly messy due to the foam goo).  Once working, I was quite impressed with their sound.  So impressed, that I bought a single, not working, speaker that was on auction on Ebay.  That one had a bad standby transformer, $17 for a suitable non-OEM replacement part (including shipping).  I then started looking for a 2nd speaker.  Two months ago, a broken amp/power supply showed up on Ebay at a price I couldn't turn down, so I bought it for spare parts.  It also had a bad standby transformer.  Finally, a second non-working speaker appeared on Ebay and I got it.  It came two days ago, and I got it fixed in about half an hour - same eroded foil on the circuit board due to decomposing foam.  Now the Beolab 8000's are set up next to the big F15 OB's for some serious listening.







The Beolab 8000 speakers take a line level input, so it was just a matter of turning down the volume (way down) on the Zkit60 amp I'm using to power the F15 OB's to get equal volume for A/B testing.  What I heard shocked and surprised me.  The Beolab speaker is a good speaker, very good.  It was sold from 1992 to 2010 (18 years) without significant change and still commands about $1000/pair on Ebay.

But...

I never would have bought them if I had the F15's in the big OB's to compare them to when I first heard them.  Note:  I did have the corner horns.

The detail of the F15's is sooo superior that its not even debatable.  And, of coarse, the sound stage is quite a bit bigger.  I found myself listening to songs on the F15 OB's, picking out something - like the strike of a cymbal, and then going to the Beolab's.  It was there - but you really wouldn't pick it out unless you were listening for it.  With the F15 OB's it was right there in your face.

I next configured the spectrum analyzer and white noise generator to see if that would tell me anything more.  If it does, I'm not really seeing it.  If anything, I would say the Beolabs should sound better than the F15 OB's.  But they don't, not even close.


Beolab frequency response:




F15 big OB frequency response:



Note:  subwoofer in place for both speakers.


Just another testament as to how good the F15's in the big OB's are sounding.

Dan

Thanks for the comparison dank.  Yeah I saw that chart and said “what???”

Dan,  it's really a great illustration of just how useless frequency balance measurements are ; ).  Or put another way, how nearly impossible it is to tell how something sounds from looking at one.

Steve

I have to wonder what the designer's Crystal 10's sounds like in the enclosure they designed and offer it in? They look pretty interesting.

Yes, I'm pretty sure it does.  Time will tell when I take them out of the room.   I'd really be impressed with the BBJ if the bass stays the same without the BB in there.

Steve

Will,

If that's true it can only get better. I am so used to gauging break-in by hearing the fibers in the cone loosen up and relax enough to minimize the "cone sound". I always thought that took longer than the suspension loosening up, but I suppose I'm guilty of not wanting to realize that every driver will be different. In the case of this one, since I couldn't hear the cone on minute one it has really thrown me off. I'm listening to some simply recorded Elvis music right now and am really impressed with the sound.  

My favorite thing about these Big Betsy baffles with the Lii Audio drivers is the efficiency.  It allows me to 'rock out' sort of speak with a 2 watt Zen amp in exactly the same way that the 94dB speakers did on the TORII or ZMA amps. Because it is the same, it is not the same.  It is far more satisfying to constantly remind yourself that this is happening with 2 watts than it is to know it's happening with 40 watts.


Steve

I can see where this odd shape would actually reflect all the internal waves to the center where the energy would be get canceled.



Very little would actually ever hit the back of the cone, which is what you want with any full-range driver.



Hey Bob, ever seen a wood veneer bent around an 1/8" radius?  

-Steve

Quote:


This got me thinking about telescopes.  Large observatory telescopes don't depend on huge primary single mirrors anymore like the Palomar but rather use arrays of smaller mirrors like the Keck.  I wonder if a driver surrounded by smaller baffles ...  

Here is another view of the foam block



Steve

Love the experimentation, Steve. It seems like it just keeps getting better and better. Can't wait for the next installment.

Steve, I'm envisioning a resonator box on the back of the baffle, ZOB-style, with the top surface covered in the same absorbing foam around the sound hole. A bass reinforcer. Thoughts?

Steve, I put thick felt all over the back of my Lil' Betsys a few weeks ago, and this has made a very definite difference. So much so that I have more felt ready to put on the new Crystal 10 baffles when they arrive.

Pal, I just ordered 3 or 4 (6 sheet pack) of 3/16” felt on amazon. Any thicker than that and it is hard to cut to shape. You will just have to figure the area to know how much you need. As big as the Big Betsy’s are, the reflection that is present now would be greatly reduced.

As I mentioned earlier in this thread, the frame of the betsy driver is the only problem with sound coming off the back of the Betsy Baffle, not the rear of the baffle itself.

As far as reflections go, any sound that hits the back of the baffle from room reflections, will reflect back away from the listener actually enhancing the ambience and have no effect on imaging focus except to possibly improve it.

The sound of these baffles is directly tied to the wood itself. Putting felt on it would be somewhat like putting felt on the speaker cone.  

None of this should be confused with the foam absorber placed on the base of the speaker. I would rather see people gluing felt to the walls of the listening room ; )

All of this is of course based on the assumption that a "live" baffle is going to sound better than a "dead" baffle. We sill need to make a co-mass-layer-dampened baffle to compare and see what happens, or de-couple the driver from the baffle or some degree of both to really find out.

I just don't want the 4700 lurkers of this thread to get felt happy without some degree of caution. The science is simple if you want to really find out.  It only take two speakers. You do something to one an not to the other and then objectively compare the two.  

Tweaking a stereo system is like going for a hike in the woods.  It is all to easy to make big changes without the comparisons and then loose track of where you came from and ultimately end up lost. This is what is meant when audiophiles who have been in it for 40 years or more say that they had it once or twice but lost it along the way and never got it back.  (Had it not been for Decware they would have died in the woods.)

Steve

So in marveling about the shape of the Betsy Baffle from Caintuck Audio which I scaled up to really understand -- and how it outperforms the same sized rectangular baffle that by the math isn't possible... you know when you hear this kind of bass coming out of a flat boxless device that looks this good it bends your mind pretty hard -- those curved sides and offset driver.... then it struck me!

It's an egg.

The driver is the yoke.

It's all starting to make sense now...  

Leave it to a hillbilly wood-butcher, to duplicate nature. I was trying to do it a year or two ago with the EGG omni speaker, and here were are once again, dealing with an egg. This one is flat and sounds round. The round one you expect to sound round. When the flat one sounds round, you wonder how.

Never underestimate eggs.

Steve

Any advice on finishing these baffles?  I usually just hit them with a dark (almost black) stain to cover my imperfections and let it dry and then a couple coats of poly.

I don't want to do a golden oak kind of thing.  I may want to leave them as natural as possible.  I guess I want to bring out the grain but not color them too much.

I have never worked with linseed or tung oils of any kind.  Any suggestions are appreciated.

Thanks Archie.  I think I will give it a try.  I loved that look on Steve's baffles.

Doesn't surprise me that the ZROCK2 ha a profound effect on the sound with these speakers.

I've been hamfisted with mine in both systems, and I get addicted to the creamy textures and body to the sound, making the small combo jazz I mostly listen to sound so full and rich and the instrumental images so vivid and closer to real.

I won't let mine loose and I'll have one more for my third system one day I'm sure. This device, along with the ZBIT, have changed the game in my istenening world.

Still digging the foam absorber.  Today I noticed another result from it.



All of these open baffles I spend some time listening to from the back side and comparing what comes out of that as opposed to the front side.  Not only frequency balance, but sound quality and imaging.

The frame design of the Crystal 10 is the best I have used. The way the spider comes to a seamless edge and the sound just rolls down the magnet cover is as diffractionless as a speaker can be made. And I have been noticing over the past weeks how good the Big Betsy Jr. sounds from the rear with this amazing driver.  It sparkles!  

Today I stood in the doorway behind the speakers and listened and it was truly spectacular, some would confuse it for the sound coming off the front. Identical sound in fact, just a tiny bit rolled in the rear. The foam really made things better from this perspective which is good since this is the sound that hits your walls and then hits your face. You hear it, believe me.

On a completely different note, I made an astounding discovery that confirms my suspicions about the wood becoming an transducer. In the picture above you can see the large cast iron handle. When standing with an ear biased to the front side of the cabinet at standing height, putting my hand on the handle makes an obvious difference in the sound of the high frequencies. The highs sound noticeably better with my hand off the handle. When the hand is on the handle the highs diminish from this extreme off axis perspective.  This is on the Big Betsy Jr., Crystal 10 baffle.

Steve

Quote:


Had to ponder this awhile.  As mentioned I did model this out of cardboard and it did have an additive effect like it does on the ZOB.  My thoughts are that on this baffle it really isn't needed and while it would likely increase the bass and texture it would really kludge up the design and as delicate as the sound is coming off the rear you have to ask yourself would you put a box just under the driver with a hole in it and foam in the front of cabinet?  Same thing.

I do have an idea for a way that it could be done that might work a lot better than what I did with the ZOB and be largely invisible.  To do it in hardwood would take a CNC machine, but layered MDF or plywood could make it possible to do with normal tools so we will see.  Right now it's just way less expensive and a cleaner look to just add a ZROCK2 which gives numerous other benefits beyond bass correction and is adjustable.

Steve

I finally got the lead shot installed at the base of my BBs.  I built a box with a 3 1/2"X1 1/2" piece of maple on the baffle side to act as a stiffener and I screwed it into the baffle.  Before doing that, I lined the free floating contact surfaces with cork.  I filled the box with 25 lbs (each) of lead shot and put a cover (edges also cork lined) on it.  My BBs now weigh about 105 lbs each!  I took them off of the isolation platforms since they couldn't take the weight anyway.

This sounds metaphorical but the sound now has a more solid bass to it.  Even without the isolation platforms I'm getting strong clean bass with a very hard hit and as much or more separation and detail up and down the scale.

I think my BBs are now closer to Steve's at the base although mine have more mass there.  I don't know what else I could do to these at this point so it's a good thing I'm happy with how they sound.  I researched hardwoods a bit and if I were ever to build another, better looking pair of BBs, I'd likely use 8/4 Hickory and follow more closely Steve's design.  Hickory is the hardest and densest American hardwood.

Here are a few pictures of my shot-box build.

Cork lining:

Box installed and filled with lead shot:

Box with cover -- all done:  (linseed oil finish, BTW)