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Open Baffle Epiphany!

fjdds said:
Finally got around to completing these OBs, based on the Zenith 49-1045, two alphas per side, Eminence tweeter, and rear facing Realistic pod, out of phase. (Thanks PG!)

Couple of observations/comments:

-I agree with Mr. Glow in the Dark, they are more forward, not quite as warm as the 852s, but as he states, might be the limited hours on them. (These were actually NIB, never used. Note the immense magnets.)

-Allo Volt +D does a great job with them. Initially, I was disappointed, especially when compared to the 852s, but with time, the differences are diminishing, especially when I A/B the same material. In fact, the scale of the presentation is what is striking with this setup, as compared to the 852s, which, to me, are more intimate. Again, probably depends on the the material, my room, my ears/preferences, etc. I love them both, but the differences are obvious.
Next, to try them with the Magnavox amp.

-Using two plate amps (Yung SD100s) for the Alphas. Initially, I thought they were inadequate. Cranked all the way up, and still sounded anemic on the low end. Then, instead of streaming from my phone, I ran a cable from my DAC (Khadas Tone Board), to the FX, and wow, what a difference. Base deepened, soundstage expanded and more slam than I expected. The SD100 are more than enough to make those alphas flex.

-My woodworking skills are pitiful, so I went with a textured stone like spray paint. Covers a multitude of imperfections. Lazy I know, but I'm happy with the result. These are headed for the porch!

Your build came out great!
I could mistake it for the Master's (PG) work!
Congrat's!


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fjdds said:
Finally got around to completing these OBs, based on the Zenith 49-1045, two alphas per side, Eminence tweeter, and rear facing Realistic pod, out of phase. (Thanks PG!)

Couple of observations/comments:

-I agree with Mr. Glow in the Dark, they are more forward, not quite as warm as the 852s, but as he states, might be the limited hours on them. (These were actually NIB, never used. Note the immense magnets.)

-Allo Volt +D does a great job with them. Initially, I was disappointed, especially when compared to the 852s, but with time, the differences are diminishing, especially when I A/B the same material. In fact, the scale of the presentation is what is striking with this setup, as compared to the 852s, which, to me, are more intimate. Again, probably depends on the the material, my room, my ears/preferences, etc. I love them both, but the differences are obvious.
Next, to try them with the Magnavox amp.

-Using two plate amps (Yung SD100s) for the Alphas. Initially, I thought they were inadequate. Cranked all the way up, and still sounded anemic on the low end. Then, instead of streaming from my phone, I ran a cable from my DAC (Khadas Tone Board), to the FX, and wow, what a difference. Base deepened, soundstage expanded and more slam than I expected. The SD100 are more than enough to make those alphas flex.

-My woodworking skills are pitiful, so I went with a textured stone like spray paint. Covers a multitude of imperfections. Lazy I know, but I'm happy with the result. These are headed for the porch!




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I miss using four Alphas like you have which really add some nice bass weight. IMO your bass woofers on flat baffles have an advantage over H-frames in that they are not nearly as directional. Now that you've lived with your system for awhile do you have some more impressions to add? Did you use plywood or MDF? If MDF that stone spray worked well and looks great. I'm also curious as to the music you listen to with these OBs.
 
Poultrygeist said:
Wife says I have to make a choice. :eek:

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Oh Man!!! Probably is going to be a hard choice, except what you said that about the bass being more directional with the H-Frames might push edge the Lii combo into a narrow lead.
If you were in a building state of mind, you could go higher with a new baffle and add the other Alpha to the Lii party. I know, it is easy to dream up projects for others that will be responsible
for the brawn and $$ to make it happen:)
 
dfoulk said:
Oh Man!!! Probably is going to be a hard choice, except what you said that about the bass being more directional with the H-Frames might push edge the Lii combo into a narrow lead.
If you were in a building state of mind, you could go higher with a new baffle and add the other Alpha to the Lii party. I know, it is easy to dream up projects for others that will be responsible
for the brawn and $$ to make it happen:)
Click to expand...

The current Lii OBs are tall at 50 inches. I'd love to add another pair of 15 inch Alphas but that would require another 20 inches of baffle height. SLOBs ( slot loaded OBs ) would be a solution to add another pair of Alphas and I may try that in the future. Meanwhile I moved a huge pair of MLTL speakers to the garage so the wife seems ok with this as a compromise.
 
SLOBs

a16dcebf38a970fe38bfe6febc1f3253.jpg
 
Poultrygeist said:
The current Lii OBs are tall at 50 inches. I'd love to add another pair of 15 inch Alphas but that would require another 20 inches of baffle height. SLOBs ( slot loaded OBs ) would be a solution to add another pair of Alphas and I may try that in the future. Meanwhile I moved a huge pair of MLTL speakers to the garage so the wife seems ok with this as a compromise.
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I suppose going vertical (the ceiling) is off limits? Infinite baffle.
 
bingow said:
I suppose going vertical (the ceiling) is off limits? Infinite baffle.
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If you look at the SLOB bass woofer arrangement above it wouldn't be that difficult to fashion a flat baffle above leaving the slot open in the front. That way two drivers above wouldn't be unreasonably tall.
 
Here's a Nelson Pass slot loaded open baffle build. He uses six 8" bass woofers opposed and radiating into a smaller vertical slot which is open in the front.

images
 
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Poultrygeist said:
If you look at the SLOB bass woofer arrangement above it wouldn't be that difficult to fashion a flat baffle above leaving the slot open in the front. That way two drivers above wouldn't be unreasonably tall.
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Sorry, I meant are ceiling mounted speakers out of the question?
SLOBs: not familiar with them at all. A fascinating configuration that I'll need to do a bit of research.
 
bingow said:
Sorry, I meant are ceiling mounted speakers out of the question?
SLOBs: not familiar with them at all. A fascinating configuration that I'll need to do a bit of research.
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I would have to deal with the big overhead garage door but so far I've still got floor space.
 
Thanks all, for those enlightening tutorials; it's easy to be paralized by the possibilities. However, in my low-tech garage setup, I have tons of space: all overhead and none on the floor, so simple OBs seem my best solution. Update: my system is now complete except for making a solid sealed subwoofer box of the recommended size, vs the too small box out of foam. A proper sub box is in work.
For the Betsy's OBs, I replaced the hanging hooks (post 4928) with a 7' long cleat on the beam. That eliminated the gap while allowing the OBs to be slid horizontally for experimenting. In the photo below, they're butted, and sound better than with, say, a foot space between. Does that make sense?
DSCN4322 2.jpeg
 
Poultrygeist said:
I miss using four Alphas like you have which really add some nice bass weight. IMO your bass woofers on flat baffles have an advantage over H-frames in that they are not nearly as directional. Now that you've lived with your system for awhile do you have some more impressions to add? Did you use plywood or MDF? If MDF that stone spray worked well and looks great. I'm also curious as to the music you listen to with these OBs.
Click to expand...

Haven't been doing much of anything...Covid finally got me. Rough bout, still not quite over it.

These are plywood. Originally I thought I would try to stain/finish, but was just not coming out well. Was going to go the wallpaper route, then I saw this stuff. Worked out pretty well, and if I use it on a future project, probably will use MDF.

The bass IS more weighty with the four alphas, but to me, the H-frames seem a little more precise, tight. I usually park myself in the sweet spot when I'm listening critically.

On these OBs (four alphas), i've been going through the entire Chicago catalog, one of my favorites, and they really do sing. Some classic rock (Floyd,Who,Zep) and they show no signs of strain, even when I push them. Broad image/lots of slam. (Used your recommendation, Chocolate Chip Trip, by Tool to really push them. It really is a trip!)

The 852s/H-frames do a better job with acoustic, small ensemble, folk i.e. Krall, Methaney, Lightfoot. Sweet as can be.
 
fjdds said:
Haven't been doing much of anything...Covid finally got me. Rough bout, still not quite over it.

These are plywood. Originally I thought I would try to stain/finish, but was just not coming out well. Was going to go the wallpaper route, then I saw this stuff. Worked out pretty well, and if I use it on a future project, probably will use MDF.

The bass IS more weighty with the four alphas, but to me, the H-frames seem a little more precise, tight. I usually park myself in the sweet spot when I'm listening critically.

On these OBs (four alphas), i've been going through the entire Chicago catalog, one of my favorites, and they really do sing. Some classic rock (Floyd,Who,Zep) and they show no signs of strain, even when I push them. Broad image/lots of slam. (Used your recommendation, Chocolate Chip Trip, by Tool to really push them. It really is a trip!)

The 852s/H-frames do a better job with acoustic, small ensemble, folk i.e. Krall, Methaney, Lightfoot. Sweet as can be.
Click to expand...

Hope you continue to recover. Even after 2 shots and a booster I came down with Omicron in January. Sadly we're probably all destined to contract a variant.

So how do your OBs compare to box speakers you've owned?
 
Poultrygeist said:
So how do your OBs compare to box speakers you've owned?
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Completely different presentation. Much more engaging, although I frequently use the Bozaks (my avatar), which don't image nearly as well, but have other strengths. I'm currently doing a non-scientific listening comparison of my five systems (my shootout thread), to try and quantify what I'm hearing.

It's all so much fun. I'm no expert, but tweaking and learning as I go.
 
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Compared to the main amp that drives the HF speakers in a bi-amped OB system the LF plate amps rarely get the attention they deserve. I recently added this Dayton SA100 which drives two 95 db+ Eminence Alphas and am impressed with the bass produced. The Dayton makes 100 watts into a pair of Alphas wired in parallel and I like everything about it except for its weight and heat. In comparison the Yung SD100 is a class d, light as a feather, and never gets warm. The Dayton has better controls and may have an edge in accuracy but I'm not so fond of that big honking heat sink on top.

The Dayton has a plastic cover over the internals and can sit upright but I found some deep dish frames of different sizes at GW which work well. I connected the Dayton's black and red leads to the frame mounted RCAs so that it can use regular speaker wire connections.

P1010006 2.jpeg

This youtube video shows the same plate amp driving one W-15 bass woofer.

 
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