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Open Baffle Epiphany!

OK, two days ago I also jumped the wagon and ordered a set of Alpha 15A from PE since I want to see what's it all about.

At first I won't go the two way route of woofer and full range since I have a set of horns that I want to use on that project just to see what it takes to get this going.
I will build the baffle in a way that I can take out the horn section with the mid-range and tweeter horns and replace with a full ranger in case they just don't work out.
The horns are Foster FHT-2 and a Utah FHT-4 tweeter. Any opinions on them?

Baffle dimensions will be 24" by 40" since that seems to be a typical size for most of the projects I read about.
The crossover for first testing is also coming from PE and will cross at 800Hz and 5kHz. I'm pretty sure I will ad L-pads and maybe need to change the points but that should get me going at first.
 
Has anyone here built or listened to speakers that use an FR driver in an OB with a sealed or ported box woofer such as the Nomad Ronin, Sentinel or similar? Would this be a project worth pursuing?
 
tomlinmgt said:
I see that statement as an oversimplification that isn't a practical solution for some and really only addresses his designs. Sure, SL has figured out how to design a speaker that has less interaction with the room, but at the same time the design does have specific requirements regarding what type of room that design will work best in and how it should be set up in said room. I give the guy credit for giving the room as much consideration as he does because I feel it's largely disregarded by most on the manufacturer and and consumer side of things, but designing a speaker that can overcome room acoustics issues results in a design that is only a proper fit if certain circumstances are met. So, what about the folks who have a room that isn't a good fit for one of SL's designs? Are they SOL? Of course not...they just have to go with a different speaker design which brings a different set of concerns wrt addressing room acoustics. Just because his designs overcome many of the typical room acoustic issues doesn't mean he's solved the problem of room acoustics for everyone...or that he's reversed the laws of physics that dictate how a room responds to sonic energy. And his designs do nothing to eliminate the rear wall reflection issue I spoke of earlier...not to mention early reflections from side walls if they are within a given vector distance from the speaker/listening position.
Click to expand...

Clearly Mr Linkwitz lacks your depth of knowledge and experience with acoustics and is just fumbling around in the dark.

Art
 
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I can't comment on your design but it sounds very interesting.

darg said:
OK, two days ago I also jumped the wagon and ordered a set of Alpha 15A from PE since I want to see what's it all about.

At first I won't go the two way route of woofer and full range since I have a set of horns that I want to use on that project just to see what it takes to get this going.
I will build the baffle in a way that I can take out the horn section with the mid-range and tweeter horns and replace with a full ranger in case they just don't work out.
The horns are Foster FHT-2 and a Utah FHT-4 tweeter. Any opinions on them?

Baffle dimensions will be 24" by 40" since that seems to be a typical size for most of the projects I read about.
The crossover for first testing is also coming from PE and will cross at 800Hz and 5kHz. I'm pretty sure I will ad L-pads and maybe need to change the points but that should get me going at first.
Click to expand...
 
valvenator said:
Has anyone here built or listened to speakers that use an FR driver in an OB with a sealed or ported box woofer such as the Nomad Ronin, Sentinel or similar? Would this be a project worth pursuing?
Click to expand...



This is one of my favorite ways to listen to open baffles .... small subwoifer to fill in the
that lowest octave and a half....I have a little powered 8 inch yamaha powered sub just for this reason. It lets me dial in just a hint of sub bass
 
markus said:
This is one of my favorite ways to listen to open baffles .... small subwoifer to fill in the
that lowest octave and a half....I have a little powered 8 inch yamaha powered sub just for this reason. It lets me dial in just a hint of sub bass
Click to expand...

So the sub kicks in at about 120Hz? What type of OB are you using?
edit: Master Procrastinator huh? I think i come in at a very close 2'nd.
 
tomlinmgt said:
Harnessing the rear wave effectively and finding the optimum location to accomplish that is the fundamental difference between a dipole and monopole. Other than that the placement challenges for the two a similar, with dipoles actually being a little less influenced by the room than a monopole since they have less floor, ceiling and side wall interaction than a monopole that doesn't use some form of controlled directivity.
Click to expand...

My je labs open baffles always sounded best in HUGE rooms. .... when i was still married our sunroom was about 12 x 20, vaulted ceilings. ...all windows all around. .. they sound ed AMAZING. my favorite drivers in there were either 1962 rca 12 inch console woofers (they were really full range ) or ge built ampex branded 12 inchers. I dont like new drivers. :)
 
valvenator said:
So the sub kicks in at about 120Hz? What type of OB are you using?
edit: Master Procrastinator huh? I think i come in at a very close 2'nd.
Click to expand...


The little Yamaha has a variable crossover. .. I usually set it around 80 or 100 hz.... depends on the music. No crossover on the open baffle

As for the ob design its one of two choices:

Je labs open baffle or my diy klh line arrays:D
 
BHamm said:
I don't see how I can go wrong or be disappointed, especially after reading this thread and using an MJK design.
Click to expand...

Man the pressure .... two of my designs being built. Have fun, I am very confident you will be happy with the results.
 
tomlinmgt said:
^^^

Will this be the first time the TB 1808/15A design has ever come to fruition?
Click to expand...

I provided the design to a few people a number of years ago, never heard if it was ever built. There are many examples of two Alpha 15A woofers with 8" full range drivers but not sure if the TB W8-1808 was used.
 
For that price you could buy the components and the tools for a shop to build them in.
...plus free advice at AK from the man himself who designed them.
...am I right?
edit: reply to wsissons post #1294
 
wsissons said:
Mj I believe Grant Fidelity is selling that combo right now for 3500.00 plus......http://shop.grantfidelity.com/PureAudioProject-Trio15TB-Open-Baffle-Speakers-pair.html
Click to expand...

I've been studying the PAP OB design ever since I ran across it and think the modular system would be a very sensible design for me as I have a number of drivers and configurations with which I'd like to experiment. One thing that jumps out at me are the small air gaps that are created between the individual driver panels and I can't help but wonder what, if any, influence these air gaps have over the response of the drivers. :scratch2:
 
valvenator said:
Has anyone here built or listened to speakers that use an FR driver in an OB with a sealed or ported box woofer such as the Nomad Ronin, Sentinel or similar? Would this be a project worth pursuing?
Click to expand...


It goes slightly against the grain of this thread and the keep it simple concept of efficient fr speakers in an open baffle.

But, I have been curious about this and a few other things as well.

The golden age of infinity used sealed woofer enclosures and full dipole open baffle mid/tweet sections. They did this with elaborate crossovers and ultimately the speakers are very difficult to drive effectively (my speakers drop to 2 ohms and require some serious solid state power).

How do speakers like the old infinities or more modern jamo's (and others) compare to set/tube amps and efficient baffle mounted speakers? Is it all about low level listening or can they put out a strong 90db+? Those hawthorne speakers i linked a page or two ago looked amazing (96db 1w/m). But, it's just as easy to spend $5000+ on tube amps as it is solid state amps.

How does the linkwitz lx521 requiring 8-10 amps differ from say infinity gamma's with 2 high powered amps? Price with all given components seems like it would be similar.

I guess I just don't understand. Can someone explain the difference?
 
valvenator said:
Has anyone here built or listened to speakers that use an FR driver in an OB with a sealed or ported box woofer such as the Nomad Ronin, Sentinel or similar? Would this be a project worth pursuing?
Click to expand...

You see others going that route but I love OB bass too much to ever give it a try.

OB bass can be very natural sounding and it won't disturb sleeping family members.
 
I wonder how those $3700 Grant Fidelity OB's would compare to these which use the same drivers cost under $500 and are based on MJK's design.

P7040015.jpg
 
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