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SPEAKER FORUMS >> Betsy Open Baffle >> New - Magnum-8 baffles - New
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Message started by Randy in Caintuck on 09/05/21 at 18:58:55

Title: New - Magnum-8 baffles - New
Post by Randy in Caintuck on 09/05/21 at 18:58:55

There have been several recent requests for speakers with 8" drivers in the 1 1/2" thick baffles .....

Until now, I have not offered them for reasons explained on my website.

However, due to encouragement from a customer who visited me and has become an "audio buddy", I decided to build a pair using the Lii Audio Fast-8 drivers ..... thanks Doug .....

Much to my surprise and despite my previous thinking, these speakers pretty much blew my mind when I did the initial test run in my listening room .....

While the Fast-8 drivers sound very, very good in the 7/8" thick baffles, these speakers are audibly superior in every way.

The soundstage / image is larger ..... wider and deeper.
The focus and clarity of vocals and instruments is better, with more space between them.
The low level detail is greater ..... across the frequency range, but especially in the upper bass.

With the Lii Audio W-15 bass driver supplementing the low end, this is an amazing sounding system.

I have been listening to the Silver-10 baffles in my room for the past couple of weeks .....and while the flagship Silver-10 drivers are still "king of the hill", the Fast-8 drivers in the thicker baffles can hold their heads up with honor.

So, I am adding the Magnum-8 baffles to the lineup.

The website page can be seen here.

I will have a pair of the Fast-8 Magnum baffles at the 2021 Decware Audio Fest, as well as a W-15 Plus bass baffle for those who would like to hear them.

Happy listening,
Randy

Title: Re: New - Magnum-8 baffles - New
Post by Archie on 09/05/21 at 19:25:35

Interesting Randy. Any thoughts why this would be so? My initial thought would be that the heavier baffles changes the baffle/driver interaction in some way vibrationally. Whether this tunes a "sweet spot" or can be pushed even further with a stiffer, heavier baffle, I guess remains to be seen. Can someone try a baffle made out of granite? I have a stone fabricator friend but my "audio ears" aren't up to the task of testing this out.

Title: Re: New - Magnum-8 baffles - New
Post by Randy in Caintuck on 09/06/21 at 17:54:15

Hi Archie,

Good question .....

I think that you are correct. The additional rigidity and mass of the thicker baffles reduces the vibration / resonance. If you place your hand on the baffle while the music is playing, you can feel that the thinner baffle is "moving".
The thicker baffle is not ..... or at least not very much.
My initial reasoning was that the smaller drivers were not producing as much energy as the larger drivers, such as the Lii Audio F-15.
However, it seems that they are producing enough energy to make the thinner baffles vibrate or resonate a bit.

Make no mistake, the thinner baffles still sound good ..... very good.
However, the thicker baffles sound even better ..... at least to my ears.

There is a lot more material, time and labor involved in building the thicker baffles ..... but, for a music lover who has a very resolving front end and amplifier and who wants the last drop of detail and focus from their audio system, the thicker baffles are the best option.

Best wishes,
Randy

Title: Re: New - Magnum-8 baffles - New
Post by Archie on 09/06/21 at 18:13:02

Makes sense. I wonder where it ends though. How about a 4 inch baffle? Or 6"? My gut tells me that there is a sweet spot otherwise it'd be best to mount the driver in a block of concrete! It's easier to see how going the other way certainly doesn't work. Eventually you end up with no baffle and whiney little sound.

Title: Re: New - Magnum-8 baffles - New
Post by Steve Deckert on 09/08/21 at 03:16:31

It has been my observation that you want the baffle to move. It's going to move no matter what you do anyway. Even with a 3 inch driver, it will move, but the less the distance it moves the faster it will be. Thicker is stiffer.

Just like a woofer, the less it moves the more linear and clearer the sound. The thicker baffle which both raises the pitch and reduces the amount of movement by stiffening makes the movement faster. The faster the wood can respond to the vibration the clearer the midrange will become. However, you will eventually reach a point where the movement is so small it no longer effects the dispersion and sound of the driver.

Also, there is the shape of the baffle and the standing wave patterns at any given frequency which act like wave guides to disperse or focus the sound pattern.

I think you could watch the video below as an illustration of what I am talking about. When you watch the video, imagine the Randy's barrel shape and what the patterns might be like on that vs. a square board.

https://youtu.be/wvJAgrUBF4w

Also imagine that those shapes you see are not 2D like the sand, but 3D in so much as the air molecules stack so it probably stacks out to at least a few inches, creating a wave guide for whatever sound is coming off the panel at the frequencies between the patterns, which is the music. And interestingly, the pattern only manifests and changes in direct proportion the music content. So those patterns you see with the salt will partially manifest when those frequencies are active in the music.

Watch it here done with music instead of singular frequencies... https://youtu.be/Q3oItpVa9fs

This would be an interesting test to make by laying the baffle horizontally and energizing it with some salt before you cut the woofer hole. My guess is the different woods and thickness will create different variations of the patterns. For that matter you could also do this with the woofer installed, just be aware that if you're careless salt could go inside the woofer and wedge itself into the voice coil gap. Perhaps tape some plastic wrap over the woofer hole just to be safe.

I made many videos of this effect on the surface of a drop of water, called Decware Sound Drops: https://youtu.be/qk-v4yjlBO8

BTW, Those are some of the best looking baffles I've ever seen. And Fast 8 is my favorite 8 inch driver of all time so far, so I already know how good these sound. We will be excited to hear them at the fest.

Steve

Title: Re: New - Magnum-8 baffles - New
Post by Archie on 09/08/21 at 07:30:36

Agree. When I touch my baffles, especially with deep base, they are vibrating extensively. What I'm wondering though is where is the sweet spot WRT baffle thickness? Has anyone explored the upper reaches? I'd love to here a comparison between a 1 inch, 2 inch and a 4 inch thick baffle. I'm still intrigued with the idea of a 3 cm granite baffle. Or, what if the baffle were box like? High stiffness but low mass. Come on Steve, you know you want to try it! ;)

Title: Re: New - Magnum-8 baffles - New
Post by Steve Deckert on 09/09/21 at 02:54:28

What I want to try is one inch thick aluminum on Randy's baffles. I have a feeling about it. On the Zen Master Series, the aluminum would be 1.5 inch.

Steve

Title: Re: New - Magnum-8 baffles - New
Post by Archie on 09/09/21 at 06:25:19

That'd be a lot of aluminum! You might have to source it through a defense contractor.

Title: Re: New - Magnum-8 baffles - New
Post by maddog07 on 09/09/21 at 18:46:50

constrained layer damping maybe? alternate sheets of aluminum with other materials... cork, sorbothane, MDF/HDF, plywood.... endless combinations.. have seen this done on numerous turntable platters. Get that CNC plasma cutter fired up...! Q Acoustics does something like this with the cabinets in their Concept line. Wilson has been doing this for decades.
;D

Title: Re: New - Magnum-8 baffles - New
Post by Archie on 09/09/21 at 18:54:27

That seems like the opposite way to go if vibration of the baffle is necessary. A "deadened" baffle might suck the sound out of the driver. A TT platter needs to be dead so any vibration in the record gets damped out.

Title: Re: New - Magnum-8 baffles - New
Post by Donnie on 09/09/21 at 22:06:53

I'm thinking that perhaps a aluminum casting would be the way to go.

Stiff where you need it and a little more resonate in other areas.

Some serious FEA(Finite Element Analysis) would need to be ran to truly figure it out though.

Title: Re: New - Magnum-8 baffles - New
Post by Archie on 09/09/21 at 23:27:06

What would even be the design parameters? I have no feel for if light and stiff or heavy and stiff. I think stiff is probably good either way though. Lighter would give a higher natural frequency, so faster?