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Open Baffle Epiphany!

Far too much emphasis is placed on bass from open baffles.
OB has a wonderful, open sound free from box colouration.
It's been said before.
Many times.
Can't be repeated enough.

The sound lights up the room.
That's been said before as well.

Even quickly constructed, poorly implemented examples (like mine) are capable of delivering exemplary sound and a musical experience that is first rate.

It doesn't seem to be a real chore to coax enough bass from an OB to cover the musical spectrum.

I have yet to have the cuffs of my trousers flutter in the soundwaves from a contrabassoon or double bass at a live performance.
How much bass does one need?

I would post pictures of my temporary baffles but they are incredibly ugly at this point in time.

The only way I can bear to listen to them is with my eyes closed.


Art
 
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Mr. Pig,

I liked your summation. But I feel the OB brings strengths that outweigh the negatives versus some of the other big "OB's".

I lived for almost 15 years with Martin Logan electrostat's. I came to love the sound detail, stage depth and open character. Most of those years, it was with the big original Monoliths. The weaknesses mainly centered around the need for extreme power, the limited larger dynamic swings and the ported bass of the low end.

My OB answers these very well. I may give up just a little bit in flatness of response and clarity at some freq's with my short line of 8" Tang Bands with low augmentation from a line of 10"er's, but that's about it. I gain the ability to run them with almost any amp of my chosing. I have much better bass, even now with cheap bass drivers, and my dynamics are now very good!

The Carver Amazing is a similar comparison. It needs more than extreme power to do it's best. And the ribbon has a slight character (as does the big stat panel) that's always there. The Amazing has a higher output capability than I tend to want and I wouldn't get. But the freedom of amp choice is a huge difference for me.

I can run my mains with anything from a 2A3/300B, to SS. My currently hooked up are a pair of First Watt F1's giving me 4 channels of 10W each. That's more than I need for huge sound and all the bass you'd ever want starting to slope off as it enters the 20's. I have several decent examples of subs around and feel no need since I don't do any videos, only music.

It's really fun to see folks trying entry level with the simple cardboard attempts. Just wish more could hear the next steps up and how truely competitive they can be with anything, anything you can buy.

EV3
 
I'm sure many of you have read Linkwitz, co-inventer of the Linkwitz-Riley filter and expert in dipolar design and theory. In case you haven't here are just a few of his more interesting conclusions:

Open baffle speakers reproduce bass with less room interaction. It is more articulate than from box speakers.

If dipole behavior covers the full frequency range, then the room response becomes masked by the direct sound.

An open baffle circumvents the box problem of delayed radiation through cone and enclosure panels. They occur typically in the mid-frequency range and are difficult to suppress.

Large panel radiators or long line radiators suffer from severe lobing at high frequencies. It manifests in critical room and listener placement.

Realistic bass levels can be obtained from dynamic drivers in open baffles, not from panels. For extreme SPL requirements the number of drivers could get very large and therefore below 50 hz they are more economically replaced by seal box subwoofers.

Open baffles reach deeper into the room and are less subject to room response if their polar response is well behaved.

The room is rarely at fault. If it is comfortable for conversation and living in, then it is also suitable for sound reproduction.

Speaker placement to the inch based on some room acoustic calculation is nonsense.

Rooms should have lots of diffusive elements and not sound like a stuffed pillow if open baffles are used.

Placing absorbers at reflective points is the wrong approach. It only absorbs HF and increases the difference between the direct sound and the delayed room response. It works against perceptually masking the room response as merely a copy of the direct sound.

Equalization is fraught with serious problems. DSP can do many things, but which acoustic inputs to take and how to process them is still very much a research stage. It will change the sound you hear.

When I hear an unfamiliar loudspeaker in an unfamiliar room and it does not sound right, then I look for faults in the loudspeaker's design and placement long before I blame the room.

Conventional box speakers are always omni-directional at low frequencies and increasingly forward directional at higher frequencies and thus the room reflections color the sound.

Unfortunately, marketing departments and dealers think that bass and high frequencies need to be emphasized for products to sell.

Very few sales people of high end audio ever listen to unamplified life sound. They are highly susceptible to marketing department suggestions.

It is difficult to screw up an open baffle speaker design to where it sounds worse than your typical box speaker.
 
"lags behind in terms of transparency and low level detail"

Would depend on the full range drivers used and the strong suit of Fostex's, Tang Band's, Lowther's and many others.

I've found I get the most micro detail from drivers 8" and smaller whereas the larger drivers have that big fun factor going for them.
 
So the bottom line is that OB is his idea of perfect and everything else sucks.
Many other opinions contradict his but they're not valid.
 
Poultrygeist said:
"lags behind in terms of transparency and low level detail"

Would depend on the full range drivers used and the strong suit of Fostex's, Tang Band's, Lowther's and many others.

I've found I get the most micro detail from drivers 8" and smaller whereas the larger drivers have that big fun factor going for them.
Click to expand...

I agree with you on this. I'm finding the same results.

MK
 
kyle said:
So the bottom line is that OB is his idea of perfect and everything else sucks.
Many other opinions contradict his but they're not valid.
Click to expand...

As a speaker designer, it would be strange if Linkwitz didn't believe his design theories were correct. I'm not sure he has ever said "everything else sucks" even if he believes that to be true. :scratch2:

cubdog
 
Poultrygeist said:
"lags behind in terms of transparency and low level detail"

Would depend on the full range drivers used and the strong suit of Fostex's, Tang Band's, Lowther's and many others.

I've found I get the most micro detail from drivers 8" and smaller whereas the larger drivers have that big fun factor going for them.
Click to expand...

I can't argue with this. I have found that the little Fostex 126en's in my GHH's have great detail, speed, and cohesiveness. I also like the larger drivers for their dynamic qualities too.
 
Mister Pig said:
But this is just the opinion of a simple pig. If you want a second opinion go ask the cows for they are wise. Do not talk to the chickens as fowl are liars and they cheat at cards.
Click to expand...

:lmao:

What is the general opinion (if there is such a thing at this point) of OB Alpha 15A's vs H Frame Alpha 15A's?

I'm leaning more towards H Frame with OB on top rather than full OB.
 
MWalt said:
I can't argue with this. I have found that the little Fostex 126en's in my GHH's have great detail, speed, and cohesiveness. I also like the larger drivers for their dynamic qualities too.
Click to expand...

No wonder the Devore apes sound so good, MWalt....they strike a perfect balance with a 10".
 
Zolton said:
:lmao:

What is the general opinion (if there is such a thing at this point) of OB Alpha 15A's vs H Frame Alpha 15A's?

I'm leaning more towards H Frame with OB on top rather than full OB.
Click to expand...

I've found that using one Alpha per side gives a bit more room filling bass with the H-frames. But two Alphas per side on a flat baffle will yield even more.

MJK uses two H-frames per side which is a great solution but that takes up lots of real-estate. MJK must have a very understanding wife.
 
Poultrygeist said:
I'm sure many of you have read Linkwitz, co-inventer of the Linkwitz-Riley filter and expert in dipolar design and theory. In case you haven't here are just a few of his more interesting conclusions:


The room is rarely at fault. If it is comfortable for conversation and living in, then it is also suitable for sound reproduction.


Placing absorbers at reflective points is the wrong approach. It only absorbs HF and increases the difference between the direct sound and the delayed room response. It works against perceptually masking the room response as merely a copy of the direct sound.
Click to expand...

I have a ton of respect for SL and look at his designs and work with a great deal of admiration. However, I'd have to take him to task on the two comments above. I suppose "comfortable for living in" leaves him some wiggling room. Maybe he doesn't consider a room with flutter or slap echoes comfortable to live in.....but most people do indeed live in rooms with said conditions. And said conditions will indeed compromise fidelity. There's no way around this....it's simple physics. And I have watched a few of his video presentations and have heard him contradict the second comment.

SL's comments on room acoustics have to be taken in context as they're usually going to be made in terms of how his designs work with and around them.
 
Poultrygeist said:
I've found that using one Alpha per side gives a bit more room filling bass with the H-frames. But two Alphas per side on a flat baffle will yield even more.

MJK uses two H-frames per side which is a great solution but that takes up lots of real-estate. MJK must have a very understanding wife.
Click to expand...

He's also moved up the performance ladder wrt drivers in his side/side H-frames.
 
tomlinmgt said:
I have a ton of respect for SL and look at his designs and work with a great deal of admiration. However, I'd have to take him to task on the two comments above. I suppose "comfortable for living in" leaves him some wiggling room. Maybe he doesn't consider a room with flutter or slap echoes comfortable to live in.....but most people do indeed live in rooms with said conditions. And said conditions will indeed compromise fidelity. There's no way around this....it's simple physics. And I have watched a few of his video presentations and have heard him contradict the second comment.

SL's comments on room acoustics have to be taken in context as they're usually going to be made in terms of how his designs work with and around them.
Click to expand...

The Zu's sounded terrible in my 15X15 many windowed room but when I switched to simple OB's the difference was absolutely night and day. The room killed the Zu's but welcomed the OB's with open arms.
 
Poultrygeist said:
The Zu's sounded terrible in my 15X15 many windowed room but when I switched to simple OB's the difference was absolutely night and day. The room killed the Zu's but welcomed the OB's with open arms.
Click to expand...

Like I said, SL's comments regarding room acoustics have to be taken in context of his designs, and I suspect most OB designs, and how they work with and around room acoustics. I didn't remove any of my treatments when my OB's were in rotation and will definitely make it a point to "strip the room" next time I get them out. It's pretty high on my priority list, actually.
 
evsentry3 said:
Mr. Pig,

I liked your summation. But I feel the OB brings strengths that outweigh the negatives versus some of the other big "OB's".

I lived for almost 15 years with Martin Logan electrostat's. I came to love the sound detail, stage depth and open character. Most of those years, it was with the big original Monoliths. The weaknesses mainly centered around the need for extreme power, the limited larger dynamic swings and the ported bass of the low end.

My OB answers these very well. I may give up just a little bit in flatness of response and clarity at some freq's with my short line of 8" Tang Bands with low augmentation from a line of 10"er's, but that's about it. I gain the ability to run them with almost any amp of my chosing. I have much better bass, even now with cheap bass drivers, and my dynamics are now very good!

The Carver Amazing is a similar comparison. It needs more than extreme power to do it's best. And the ribbon has a slight character (as does the big stat panel) that's always there. The Amazing has a higher output capability than I tend to want and I wouldn't get. But the freedom of amp choice is a huge difference for me.

I can run my mains with anything from a 2A3/300B, to SS. My currently hooked up are a pair of First Watt F1's giving me 4 channels of 10W each. That's more than I need for huge sound and all the bass you'd ever want starting to slope off as it enters the 20's. I have several decent examples of subs around and feel no need since I don't do any videos, only music.

It's really fun to see folks trying entry level with the simple cardboard attempts. Just wish more could hear the next steps up and how truely competitive they can be with anything, anything you can buy.

EV3
Click to expand...

I certainly agree with your points, primarily that panel speakers are going to be more limited in terms of dynamic expression, and that they require robust and expensive amplification. That is just the nature of who they are, and if you want that sound that is the road you are going to have to travel. Yes, conventional speakers in an OB arrangement are more amplifier friendly, but there is an associated trade off in terms of low level resolution.

But some of this is about favorable equipment pairings. I have always believed that high efficiency speakers with SET amplification is capable of delivering electrostatic like resolution but with better macro and micro level of dynamics. In the past I have used a variety of single driver speakers as they are usually the most affordable way to do so. But my preference is for high quality horn systems, unfortunately I just cannot afford the good stuff at the moment. So when this used pair of OB speakers came available at a price I could swing, well I took a chance.

The problem I have with single driver speakers is that while they are authentic in the midrange, they tend to lack the harmonic density and proper decay patterns in the upper mids and lower treble. Music sounds proper in structure, but it doesn't have the texture that it should. The speaker I use has a coax driver, something along the lines of the Tannoy. Is it better? In most ways yes, but it is not quite as coherent as the Fostex 208 Sigma I have in my back loaded horns. Trade offs and priorities, there is just no way around them at the price points I can play at.

Now I have a couple of avenues to explore, and I intend to do them with these OB speakers. First, these drivers may not be as happy with a 300B SET amp even though they theoretically match up on paper. Or perhaps they will not perform in the way I think they should. I have a 33 WPC Class A battery powered amplifier coming, and in a few weeks I should have an idea of what it can do. I have heard this from Tannoy owners that their co-ax driver while theoretically efficient enough for SET prefers a bit higher power tube amps, or low power SS amps. The other option is to tri tri-amping them and getting rid of the passive x-over. With the battery powered amp in the house I can run it on the mids, the SET on the Radian horn driver, and the plate amps on the bass woofers. But I am going to have to source an electronic cross over and see how that pans out.

Lots of experimenting to do here, and I certainly do not have any definitive answers, nor are my opinions set in stone. All I have is my observations up until this point. I got my speakers on Dec 24, so I am very new to this arena. Needless to say, my opinions are subject to change.

Regards
Mister Pig
 
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Poultrygeist said:
I'm sure many of you have read Linkwitz, co-inventer of the Linkwitz-Riley filter and expert in dipolar design and theory. In case you haven't here are just a few of his more interesting conclusions:

Open baffle speakers reproduce bass with less room interaction. It is more articulate than from box speakers.

If dipole behavior covers the full frequency range, then the room response becomes masked by the direct sound.

An open baffle circumvents the box problem of delayed radiation through cone and enclosure panels. They occur typically in the mid-frequency range and are difficult to suppress.

Large panel radiators or long line radiators suffer from severe lobing at high frequencies. It manifests in critical room and listener placement.

Realistic bass levels can be obtained from dynamic drivers in open baffles, not from panels. For extreme SPL requirements the number of drivers could get very large and therefore below 50 hz they are more economically replaced by seal box subwoofers.

Open baffles reach deeper into the room and are less subject to room response if their polar response is well behaved.

The room is rarely at fault. If it is comfortable for conversation and living in, then it is also suitable for sound reproduction.

Speaker placement to the inch based on some room acoustic calculation is nonsense.

Rooms should have lots of diffusive elements and not sound like a stuffed pillow if open baffles are used.

Placing absorbers at reflective points is the wrong approach. It only absorbs HF and increases the difference between the direct sound and the delayed room response. It works against perceptually masking the room response as merely a copy of the direct sound.

Equalization is fraught with serious problems. DSP can do many things, but which acoustic inputs to take and how to process them is still very much a research stage. It will change the sound you hear.

When I hear an unfamiliar loudspeaker in an unfamiliar room and it does not sound right, then I look for faults in the loudspeaker's design and placement long before I blame the room.

Conventional box speakers are always omni-directional at low frequencies and increasingly forward directional at higher frequencies and thus the room reflections color the sound.

Unfortunately, marketing departments and dealers think that bass and high frequencies need to be emphasized for products to sell.

Very few sales people of high end audio ever listen to unamplified life sound. They are highly susceptible to marketing department suggestions.

It is difficult to screw up an open baffle speaker design to where it sounds worse than your typical box speaker.
Click to expand...

These points about a standard room free of treatments as adequate if not preferable as a listening environment is interesting. In some ways almost heresy to the grizzled audiophile. At a certain point I would want to believe it, but at a basic level this feels inherently wrong. Got any more information or link to why this would be the case?

Regards
Mister Pig
 
Linkwitz is a man we should listen to. He is an expert, a master!

I visited his room at an Axpona and spent as much time as I could. Very revealing speakers and I like them a lot! What I was listening to was what, maybe $20G system? Overall compared to many that's not too bad price point and for my tastes, beat most of them. But I'm just a working guy. I can't pop for his system unless I really worked at it.

But I've got maybe $1400 running now in 6 of the TB's and 8 of the modest 10's. No crossover elements in the way of the mains. Just line level for the woofers in an augment fashion. So line source (a short one) behavior with the OB freedom of sound. Seperate woofs from the mains so I can place both to best advantage. Much more freedom of amplification than the Linkwitz system and while with some performance differences would, IMHO, be comparable. Different but personal preferences differences, comparable.

BTW...bringing up Linkwitz. His sealed box Linkwitz transform is one low bass system that has the clarity and speed to work well with OB. When well built, it has a freedom of coloration and has the ability to blend in. But don't take that system on without being prepared to do it well or it probably won't accomplish it. But musical bass with superb dynamics is possible in that alignment. Don't do it though if for a movie system....just music.

I don't find the room requirements to be different with OB. Modest and proper treatment work required either way.

I spent time with the Zu approach and like them a lot. Bought a pair and still have them. They have strengths and I offer them great respect and love. They bring a small footprint and WAF and can be powered with about anything. When I brought them in and did a direct back and forth with the OB they were shamed and they had to leave with their tail between their legs. Not even close. I LOVE the dynamics and boxless presentation of the OB's in comparison!

EV3
 
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