Hi Guys, I am new to this forum. But, have been following since last year. I come from the other end of the spectrum with Maggies and Innnersound, high powered  SS amplification (plural), etc. My son grew up an audiophile. But, when he purchased his first home and was wanting to build out his first system. I suggested that he chose the opposite route and start with high efficiency speakers. He then set out to pick out his speakers, and was about to pull the trigger on them, when we came upon this thread. I woodwork for a hobby and said that I would make him the baffles. So, he ordered the F-15s and I ordered Steve's Z15M plans. I built his with 3/4"/18mm baltic birch (2 layers) and poplar base. They came out really nice. His wife really likes them as well. They sound so musical in both of our systems. Yes, they can handle a lot of clean watts too. I know have a new pair of F-15s, still in the office waiting as I decide on my next build.

Hi Tim,

Welcome the family!

Steve

Hi Donnie,  Don't forget about IDz (formerly RDz). I haven't programmed with these in 1/2 a dozen years or so. That's my sons setup. Now I work vicariously through him. Haha.    ...Tim

Hi all - I'm about to embark on the Big Betsy OB journey. I've ordered Lii Audio F15's which shouldn't be too far away. I have only read to page 12 of this thread so far, so I hope my questions haven't been answered in the remaining 20 or so pages - I'm considering constructing my baffles out of 40mm thick laminated bamboo panels which are often used for kitchen benchtops (unfortunately I can't include a link yet). Has anyone used this or similar for this purpose? Any gotchas or recommendations?
Cheers, Steve

Thanks Joespride

Thanks Archie - laminated bamboo panels appear to range from 750 - 1200 kg/m3 depending on construction methods, compared with maple at 620 - 750 kg/m3, so presumably lack of density is not an issue. It's probably also my most cost-effective option, because I am limited to handyman tools these days (plunge saw, router, etc). Is there any consensus regarding whether to mount the driver (F15 in my case) on the front or rear of the baffle? Recessed or surface-mount? What size should the cutout be for a snug fit?  Should I round over the opposing edge of the mounting cutout, and by how much? Any other guidelines I should know about (I'm hoping to have the baffles well underway by the time the drivers arrive )  Thanks so much for this resource, and for your advice!
Cheers
Steve

Excellent - thanks Archie!

Steve,

Steve D "intuited" the Big Betsy.  He basically scaled up Randy's Betsy baffle for the bigger driver.  So there isn't anything necessarily magic about the dimensions.  That said, I don't think 3 inches off of the width would be noticeable physically but it could be aurally.  No doubt these are big and imposing but if you have the room they look kind of cool.  The more you change the design, the more you'll wonder if you're getting the full effect.

You're right Archie - the less room for doubt the better.
Do you have the plan for the  ZF15L? I see you can purchase one for the ZF15M, but not the L?

@Joespride - do you use subs with your ZF15M's? I have a couple of sealed subs that I use with my Maggies, and I'm prepared to supplement the BB's bass with them if necessary. Do you think the difference in bass between the large and the mids, if running subs with them, is likely to be significant?
I know these are very subjective evaluations, but then so are most opinions in the hifi world  :)

Those look great!  Very impressive.  Did you mount them vertically?  If so, try a backward tilt of about 7 1/2 degrees and see what you think.

For me, some of the original magic had worn off and tilting them back brought it back.

Nice job on the baffles.  I have always wanted to make some bamboo baffles since I heard some at Axpona.  Where did you source your bamboo?

Palamino, Not just the same, but I saw some 44mm bamboo slabs at Lowes I have been considering.

Yes it wasn't cheap - I paid about $700 NZ delivered (about $450 US) but if you factor in planing, thicknessing, glueing up, etc it balances out somewhat. But no - definitely not a budget option

(That was for an 8'x4'x40mm sheet - did you like the mixed units? )

Looks like the ZEN / Lii F-15 are finally getting some press they deserve

https://www.youtube.com/watch?v=tZ7HznfA0YA&ab_channel=AndrewRobinson


Couple Caveats though: 1. you can use them in a smaller room, Mine is 13 X 16, and 2 Bass throw a PP 30ish watts at them and bass improves GREATLY

How far out from the wall are they?
Do you have a solid center image?

The speakers are out about 3ft from the wall. On some recordings the sound is brilliant. PF's 'Shine On...' was the best I heard. The music hanging in the air between the speakers, like they were not there at all. Or Dave Brubeck sound stage extending beyond the outside width of the speakers. Stan Getz sax on 'Girl from...' is that holographic sound that people talk about. I understand that the drivers could show up the weaknesses in the original recordings but having heard the same vinyl on cabinet speakers I know that the information is in the recording.

The ply sheets I used for holding the drivers was a first go. I am open to playing around with them. The inspiration for them came from this site;[ GlowintheDark Audio. com Lif15 ][Sorry I cannot post links]My version lacked the wings supports. I may try adding similar wings to extend the baffle and increase front/back separation. I note from this guy's final version of the speakers he left about 8 or 9 inches all around the driver.

Try pulling them out even more and tape cardboard to the baffle to make it bigger if you can.
Have you tried different listening positions?

Close but no cigar! F18's mounted on plywood. Brings to mind you get what you pay for!

John

I’m new here but not to audio or to woodworking.  I’ve now read through all 31 pages (phew!).  Thanks so much to Randy, Steve, and the all the rest who have built their own versions of Randy’s creation and posted their results.

Some posts have touched on my questions but not in any depth; I’m hoping that there is still more info/help out there to mine! As you will see from my questions, Randy and Steve might be in the best position to answer my questions.

(BTW, my room is very wide but not very deep. Setting up a listening position will be “interesting”.)

I love base but also am devoted to transparency and detail.  I ordered a pair of the new Silver-10’s; should be here any day.  I’m planning to build a ZC10M baffle or maybe one slightly scaled down like geno’s. I’m assuming I will want to augment the base and will decide between a ZRock or a 15W in a smaller baffle after the main’s are built.  May build the sub while waiting for the ZRock.  

Question 1: Anyone have experience with the Liver-10’s?

Question 2: Anyone  hhav experience with the 15W?

I’d love to make the bafffles out of live edge slab. (I’ve build numerous projects with live edge slabs before.) Yes, a blued up panel can be more stable but my source for slabs (Berkshireproducts.com) dries and sands them very well. In my experience they have been very stable. And very beautiful.

Question 3: has anyone tested the theory that building the baffles from boards of different widths helps the sound (perhaps by breaking up standing waves)?

Question 4: has anyone tested the theory that building the baffles from different species helps the sound?

This brings up the question of which species of wood to use.

I’m guessing that the wood characteristics that matter most are the A) specific gravity, B) Elastic Modulus, and C) Janka hardness. These data are available at

]wood-database.com[

I’m intrigued that there is an inverse relationship between the Elastic Modulus and a materials damping. Seems to me that the effect of this measure on the baffles might be very important and best determined empirically.

Steve, Randy, you have built and offer baffles in a viariety of woods. The characteristics of the woods you offer differ greatly. Have you compared baffles made from poplar (SG 0.4; EM 10.9; JH 540) to one made from Wenge (SG 0.72; EM 17.6; JH 1930)?

I would love to build baffles from 2 inch think slabs of English Elm. Berkshire has many beautiful slabs and the results would be stunning. My concern is that it has an elastic modulus of 7.1. So,

Question 5: although there are numerous comments about avoiding building baffles from softwoods, has anyone tried it? If not, I might be tempted to do so (wold be relatively inexpensive and an easier build) but I would have a hardwood baffle to compare it to.

And finally:

Question 6: any thoughts about using a 2 inch thick slab of English Elm with a relatively low EM?

BTW, I am clearly only going to make these for myself; I just find the questions interesting. (I’m a scientist if you haven’t guessed that already.) I also don’t have unlimited funds and a nice live-edge slab is not inexpensive so I don’t want to build more than one. (Unless Randy or Steve are so interested in getting systematic answer to some of these questions).

Thanks so much for any wisdom and knowledge you can provide. I will; of course, share my experience as it develops.

G

My first “Betsy sized” baffles holding Silver 10’s are built. I’m playing with placement, breaking them in, etc. Will be posting more about my odessey and experiments as I make progress.

For now a question: does anyone have experience with the Lii F-18? Very impressive on paper…

Thanks.  I’m playing with the Silver 10’s in Betsy sized baffles for now.  Great top end though a bit bright; using Roon I find a high shelf filter at ~1 kHz down 3 db or so improves the sound.  This may vary when bass is added and/or baffle size is changed.  We’ll see. Also, I don’t see how these can be run full range in an OB. Definitely has issues when tying to make low base.  QTs of the crystal wasn’t that much higher. So, despite the (understandable) desire to avoid crossovers, I think adding a base unit and a low pass filter might make a big difference.  Just riffing here; I’ve ordered the Dayton 100W plate amp and the w-15 so I will be trying this out.

The baffles are (unfinished for now) Sassafras. Very nice. I will be comparing these to same-sized poplar. I will post the thinking behind this and the results later.

I’d welcome all input.

Will post pictures after I meet my 2 post minimum if anyone is interested.