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Hey all, I have several sets of dual concentric and point source drivers I've tested and played with over the years and want to try to build an open baffle for them to use in my listening space.
Has anyone ever done this?
Are there any tricks or secrets I should know about?
Ive got the following drivers to use
Tannoy 6"
Tannoy 8"
TB W8's
Dayton PS220's
Any help would be greatly appreciated
H-
I haven’t done them but have heard several at shows and read extensively about them. The one thing you’ll need is cone area and a relatively clean/uncluttered room for them to sound their best. Cone area because they don’t make as much midbass/bass as an enclosed driver and an uncluttered room so you don’t get a lot of waves bouncing around or you’ll get quite a bit of cancelation down low. For the midbass side, I’d try using multiple 8” speakers or step up to a 12” or even 15” midbass. The speakers I heard had dedicated high frequency drivers but I don’t see why you couldn’t build an open-baffle line array.
Danny Ritchie, GR Research is all things open baffle.
So what Id like to try is a single driver on a baffle to start then maybe expand to multiple drivers on a baffle if this works in the room.Quote:
Originally Posted by dgage
I have a 12” sub that will cover the lower octaves so if I can get down to 100hz that would be optimum I think. I know the Tannoy’s will do it easily it’s just making the proper baffle for it.
Sent from my iPhone using Tapatalk
Quote:
Originally Posted by dgage
To start off, I know this is a 4 month old thread. With that being said...
Hate to say it, but this is all pretty much incorrect.
Cone area for an open baffle design (OB) is the same as for any enclosed design, more efficiency, better power handling, and more overall output capability, and yes, but to a less degree, bass extension capability (as far as mid-bass reproduction is concerned. What helps for better mid-bass and/or bass in an OB is a lower FS, higher Vas, and a Qts closer to 0.60 or higher. And of course, a little extra Xmax than normal is a plus as well. The lower the FS is and the higher the Qts is, typically the less EQ is needed to reach a desired lower frequency. But above all of that, the larger (wider) the baffle is, the lower the driver will be able to reproduce bass before those low frequencies wrap around the baffle and start cancelling out the front and back waves. The smaller, a.k.a. - the narrower the baffle is, the higher that bass or mid-bass is going to start rolling off. Of course, for absolute bass reproduction, as with any design, more cone area the better. No replacement for displacement, unless of course you start talking about much greater Xmax capabilities.
As for the "relatively clean/uncluttered room"... Well, that's also not entirely true. With OB designs, they interact a whole lot less with the room than traditional enclosed loudspeakers, especially 90* off to either side of the baffle's plane, because that is where the cancellations are at their greatest, so there's very little sound output leaving the sides of the OB's and interacting with the side walls of the room they are in (this does NOT include about what happens in front of the baffle's plane between the loudspeaker and listening position). Also, OB loudspeakers do not "load" a room the same way as traditional enclosed loudspeakers do, so you don't have nowhere near the amount of issues of standing waves and such with an OB.
Of course, if you have a fairly acoustically lively room with hardwood or tiles floors and light furnishing, you will want to treat said room with some kind of acoustic treatments to get optimum performance from the loudspeakers and to minimize room interactions, but this goes for ANY kind of loudspeaker, whether it be an OB, sealed, ported, planar, omni-directional, whatever. All loudspeakers in any given room are going to have 1st and 2nd reflection points on the side walls in front of the speakers, between them and your listening position, as well as 1st point reflections on the floor and ceiling, again, between you and the speakers.
At a minimum, you will want to put down some kind of area rug that spans the distance between the speakers themselves, and between you and the speakers to help minimize that first reflection point on the floor. This is a cheap and easy solution that makes a big difference in the overall sound. This is exactly what I did in my room, and it immediately eliminated the "smearing" of vocals and instruments, improving the clarity dramatically. It also helped improve sound stage width and depth, as well as tighten up the imaging. And all of that from a $129 area rug that I bought at Lowes.
If you want to keep going from there, then you have to start looking at mounting acoustic panels on the side walls to treat those 1st and 2nd side reflections. Either use absorbing or diffusing panels, or a combination of the two. Going beyond that, you can also treat the front and rear walls, mount a "cloud" panel setup on the ceiling, place bass traps in all four corners of the room, and the list can easily go on and on, and costs go up and up.
Now on the other hand, if you have a fairly acoustically dead room, meaning wall to wall carpeting, curtains, heavy plush furnishing, then you may want to treat with just some properly sized and placed diffusion panels, and still use bass traps on all four corners of the room.
But now I'm going much further than this thread started out as, so I'll stop here. And again, yes, I know this thread is 4 months old already. I just don't like seeing ill-informed posts continuing to go on misleading people. I felt it my duty to correct a few things in this thread just in case the OP is still dabbling in this project and still had questions that may be answered in my post here.
With open baffle, you could have an issue with phase causing nulls in the bass region that you wouldn’t ever have to worry about with a sealed enclosure. So I’ll say you may be right but you also could be wrong depending on the setup and configuration of a particular room and speakers.
But then again, that is true about speakers in general, the room can greatly affect how a speaker sounds. But I still contend, placement of open baffle matters more than for enclosed speakers.
Quote:
Originally Posted by dgage
Again, this is incorrect.
1) Phase has nothing to do with it. With proper, capable drivers being used for bass reproduction, it's the limits of the size of the baffle that causes the limits to bass response. Simple as that.
Sealed, ported, bandpass, transmission line, horn, whatever it is... Enclosed bass drivers load and pressurize rooms and energize a room totally differently than an OB does. Those enclosed drivers are what excite room modes (peaks and nulls) which are different for different size rooms.
2) Not to sound arrogant, but I'm not wrong.
3) Again, wrong. As I said before, OB loudspeakers do NOT care about placement nearly as much as any other loudspeaker design. This goes for open baffle, magneplanar and electrostatic designs. Any enclosed design, room placement DOES matter a lot more.
If the front wave meets the back wave with (in)appropriate phase, there will be cancellation. This is how noise canceling headphones work. How do you figure open baffle is immune from this phenomena?
That is exactly what I said in my 1st post. However, it is NOT a "null" as you put it. It's just that the baffle doesn't support the bass at those frequencies.
A null is a dip in response, sometimes due to the crossover point or a room mode. What you're referring to is bass roll off. Totally different animal. So just choice of wrong word on your part. And that bass roll off has nothing to do with the room or its room modes.
So are we at least in agreement that OB needs larger midbass drivers to have the same amount of midbass as a non-OB comparable speaker. And if so, what is your thought on why that is required? If we don’t agree, we won’t agree as my performance requirements must be greater in my home theater.
.
SQ_Blaze is spot-on.
I also like to aim speakers 90-degrees away from the first side reflections on the walls, this way the side reflections are the 90-degree off-axis response which is essentially zero output, and this makes the walls disappear. I like that the speakers are less sensitive to the room in this way and I find them more accommodating to otherwise non-ideal rooms.Quote:
Originally Posted by SQ_Blaze
Also I find I want more cone area in the lowest frequencies because my baffle size is not large enough to keep the rear wave from interacting with the front wave at my listening position. So I'm using a pair of ported 12" subs in addition to the four 10" woofers on the towers in addition to the 8" midbass drivers.
I'm a bit of an open-baffle convert.
https://photos.smugmug.com/photos/i-.../i-9MW9zdG.jpg
I know I keep getting told I’m wrong but SQ_Blaze, what you’re telling me about Open-Baffle flies in the face of everything I’ve learned about audio. Phase isn’t involved. Placement doesn’t matter.
This guy might not be completely accurate either but most of his points checks with my knowledge of speakers and audio.
https://hometheaterhifi.com/editoria...ed-technology/
No.Quote:
Originally Posted by dgage
I feel that I'm repeating myself in this thread. The T/S parameters and baffle size are more important than the size of the driver where mid-bass is concerned. Also, the use of multiple small drivers works great as well.
I would go into more detail, but I'm on my phone and on break at work.
I agree.Quote:
Originally Posted by Justin Zazzi
Not everything that reviews said is accurate. I've been dealing with OB designs for 20+ years now and have consulted personally via phone or email with Danny Richie, Nelson Pass and Siegfried Linkwitz. In fact, I started out with Siegfried.Quote:
Originally Posted by dgage
Again, I'm no expert and always learning, but I'm 99.9% sure I haven't been wrong on anything I've posted thus far in this thread.
Maybe we are all right. What if we combine all these statements together:Quote:
Originally Posted by dgage
If the baffle is "small" relative to the wavelength of the frequency you're interested in (bass), then the open-baffle design will not have as much output as a similarly-sized sealed baffle. To overcome the lower output, you can increase the cone area.
If the baffle is "large" relative to the wavelength of the frequency you're interested in (midrange or treble),then the open-baffle design can have output similar to a sealed baffle around the same size.
The open baffle design will interact with the room in a few unique ways such as having zero output at 90 degrees off axis which can make placement more interesting in a room but it can also make nearby side walls less of a problem because you can eliminate the first side reflections. Open baffle designs benefit from being placed away from the rear walls and having a room of a certain shape/size but the same can be said about any speaker of any design.
I find the tradeoffs to be well worth it especially since I have the extra room and expertise to tinker with them. I'm also fortunate to have met Siegfried Linkwitz and demo'ed his LX521 at his home which is where I bought the plans for the ones I built, and I'm sad that he is no longer with us because he was a really wonderful person :)
My current system, running a pair of GR-Research X-Statik loudspeakers with highly upgraded crossovers per Danny Richie's recommendations. They use 6.5" drivers, all the same model, two in a sealed enclosure, and two on the OB. I've owned and used everything from big Martin Logan SL3's, NHT 2.9's, Klipsch Cornwall II's, Klipsch Heresy III's, several Monitor Audio models, a couple of Triangle models, several Sonus Faber models, a couple different Paradigm's, Quad ESL 63's, Carver Amazing Loudspeakers, and a few others I can't even remember, plus a plethora of DIY home builds.
Out of all of them, with the exception of one of my very huge (7 feet tall) and ugly DIY OB's, these are the best sounding speakers I have ever owned or used in my systems. They just do almost everything right, and take up just as much floor space as a typical tower speaker. I've had these for over 12 years, and no matter how much I spend on other speakers, I keep coming back to these. They're that good.
A few months back, we went to the Florida Audio Expo 2020. After listening to a good portion of the systems there, I came home to this system and feel that it holds its own pretty well to a lot of those super high dollar systems.
And yes, it is a definite shame that Siegfried Linkwitz is no longer with us. He was an absolute pleasure to talk with. I wish I was fortunate enough to have met him in person like you did.
https://charlest.zenfolio.com/img/s/...75922746-5.jpg
And I agree with this and more importantly this coordinates with the audio knowledge I (thought) I have. But SQ_Blaze mentioned open baffle wasn’t as sensitive to placement. I can’t imagine how an open baffle would work at my parent’s living room where he has book shelves behind his speakers. Whether front wave or back wave, audio waves will bounce off objects and change phase. Unlike normal speakers that only have one wave to worry about phase and phase coincidence, open baffle have two waves to interact with the room and other waves.Quote:
Originally Posted by Justin Zazzi
By no means am I trying to say open baffle isn’t good. I don’t have any real experience with them to make that statement and I absolutely can see some potential benefits as well. But my knowledge will absolutely not let me reconcile that open baffle isn’t subject to placement and it’s environment more than a normal enclosed speaker. We’re not getting any where and I don’t currently have the time or opportunity to work with open baffle so I will bow out of this discussion. You two obviously have more knowledge and experience than I do about open baffle speakers. Thanks for sharing.
And by the way, larger midbass drivers or multiple midbass drivers are synonymous to me. Both involve more cone area and displacement so at least my knowledge held up in one case. :)
If you ever travel to the Phoenix area I'd love to give you a demo.
Other than that, not sure how else to help.
Cheers.
Quote:
Originally Posted by dgage
As I've said several times already in this thread, OB speakers do NOT interact with a room the same way traditional speakers do. With OB's, there's a LOT less room interaction, and they don't load and/or pressurize a room like traditional speakers do. OB's with their very minimal sound output 90 degrees to the side of the baffles is a major part as to why they are not extremely sensitive to room placement. They can be positioned a lot closer to the side walls due to this very reason without the ill effects that traditional speakers pose in the same location.
If you still "can't imagine how", and you want to know how and why, then I urge you to get in contact with Danny Richie as he'll be able to tell you anything you want to know about OB's, and how and why they work the way they do.
Other than that, I don't know what else to tell you. And with that, I think I'm pretty much done with this thread.
Wasn't trying to be negative or minimize what you say but it is simply me not being able to process it. My issue. I already knew I had a ton to still learn in audio. I'll add this to the long list of items that I'll have a lifetime to never get through. Thanks for sharing and opening my eyes. I look forward to figuring out why and how it works one day.Quote:
Originally Posted by SQ_Blaze
To add NOTHING of value to this thread....
I have to agree with SQ_Blaze OVER Jazzie simply because i cant trust a man who sleeps with Mr Teddy after said bear had that much to drink
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