Like many of us i spent years studying and building all the TLs I had the time to make. The reason I did was because of the word on the street, and the reason I stopped is not because they don't sound good... Just an example..
Fs is only 40 hz, personally I go for fs in the 20’s area if deep bass is the goal.
Yes, I've done OB testing with dozens of drivers. The 15OB350 is easy to work with, well priced and sounds good. It will be used in a commercial design I'm working on.
Can anybody tell us what Toole (last edition) says about OBs?
Lots of people today think dipoles create a superior music listening experience. But important to identify the freq bands where OBs help or hinder. Beneficial north of 100 Hz. But is there "box sound"* from say 40 to 100 Hz?
Below that, where you get into the stupid zone where our drivers are resonating within the music passband, you get into all the inadequate tricks for housing them. So which inadequate housing to try? For sure, real low is no place for an OB, as Charlielaub says. I think a dipole per se, even if pushed hard with LT and EQ, doesn't bring anything useful to the sound spatially even if it does avoid inadequate box bass.
I sure wish people would stop shouting about some necessary theory of wave annihilation. In a room, with your panels a meter from the back wall, angled, various objects in the space behind the panels, the way the front and back waves interact is complicated. Of course there is some degree of cancellation and some degree of boost. For certain, it is nothing like the old diagram in Olson's textbook (if he had one) showing results for a circular baffle in infinite space. Like Einstein said, good to have simple theories, but not too simple.
B.
* not all boxes are boxy. 50 yrs ago, I used some Bozak speakers which had the whole insides filled with serious fluff but removed the backs. That's neither an OB nor a box. With all the wasted fuss about different shaped OBs, pity you don't hear about solutions like that which work quite nicely. Labyrinth (like my wonderful 17-foot sub) isn't too boxy.
Last edited:
Yes, I have yet to see a control room with open baffle speakers in it but most control rooms are really bad rooms for OB as they are usually small or at least narrow=hardly deep enough.
That said control rooms have acoustical treatment and the playback response is ideally pretty linear (in good studios at least).
Last studio I worked for had a set of huge Westlake speakers in the wall for general playback (2.5m-3m distance). Another set of Genelec monitors in ~1.5m distance and on the same stand another set of (you guessed it) Yamaha NS-10s.
I´m not sure it would make a difference in mixing&mastering if both systems (box/OB) would have the same frequency response in the listening spot (which usually is pretty much defined in any control room for critical listening at least)
For headphones there is no size or room constraints. Open back headphones are usually considered superior over closed. Im not sure if it’s comparable but worth to investigate. For PA we do see dipole pattern used, but with DSP rather than open baffle.
Linkwitz used 4 expensive but with very linear suspensions, 10”. SEAS woofers for his high end open baffle speakers, 2 per channel. And on his site points out that PV=NRT is only an approximation, and that air isn’t a perfect spring so a sealed box isn’t perfectly linear..
I hardly think he or Nelson Pass qualify as rank amateurs in audio! And sure some people go to open baffles because they don’t have a lot of time or perhaps lazy but moral judgements about others motive are kinda inflammatory! I do know many like them because they CAN sound very good! I think they are like most speaker approaches, they require knowledge and careful design, of the speakers and room size. In some ways open baffles are less affected by the room they are in than other designs.
Linkwitz speakers were/are? used in the recording control room of the San Francisco Symphony
I hardly think he or Nelson Pass qualify as rank amateurs in audio! And sure some people go to open baffles because they don’t have a lot of time or perhaps lazy but moral judgements about others motive are kinda inflammatory! I do know many like them because they CAN sound very good! I think they are like most speaker approaches, they require knowledge and careful design, of the speakers and room size. In some ways open baffles are less affected by the room they are in than other designs.
Linkwitz speakers were/are? used in the recording control room of the San Francisco Symphony
Last edited:
Can't say as audiophiles show any liking for recording studio speakers, even mega-dollar Meyers. Must be really hard for the determinedly engineering person who lives-and-dies by FR and polar response to explain that.
Not saying there's anything mysterious or beyond measurement. But frankly, I can't explain that either.
Not saying there's anything mysterious or beyond measurement. But frankly, I can't explain that either.
well the ruling fact is that the bass frequencies are all about the room dimensions. These waves down low get so long that they wrap around even fairly sizeable objects in the room which consequently have little effect; all has been discussed in multiple white papers in archive at JBL and other sites; also matlab scripted for multi-sub placements by Geddes etc. OB bass with cancellation has less left and may also be exciting the room somewhat differently as Linkwitz believed.
As mentioned I got the best result so far with a back loaded horn bass sub placed in a corner in an irregular shape space. The bass appears all present, not boomy and it cannot be located by ear. I am yet to get such a result in a different room though. As for those downplaying 40Hz bass and insisting on 20Hz: I listen to music from real instruments, not to electronically engineered earthquakes a.k.a deep house etc. so I probably do not qualify for a real bass head. Troels G. has a nice comment about dynamic bass from a large driver at 50Hzish only, still being able to communicate the musical drama to many a listener of real instruments.
As far as the modern "music" and the common recording practices there are interesting comments by musicians everywhere, e.g.:
Drop the Bass: A Case Against Subwoofers | Pitchfork
As mentioned I got the best result so far with a back loaded horn bass sub placed in a corner in an irregular shape space. The bass appears all present, not boomy and it cannot be located by ear. I am yet to get such a result in a different room though. As for those downplaying 40Hz bass and insisting on 20Hz: I listen to music from real instruments, not to electronically engineered earthquakes a.k.a deep house etc. so I probably do not qualify for a real bass head. Troels G. has a nice comment about dynamic bass from a large driver at 50Hzish only, still being able to communicate the musical drama to many a listener of real instruments.
As far as the modern "music" and the common recording practices there are interesting comments by musicians everywhere, e.g.:
Drop the Bass: A Case Against Subwoofers | Pitchfork
Last edited:
It seems OB studiomonitors exists.
Patented Baffle-free Reflector Audio studio monitors - Gearspace.com
I have seen them in the Gallery thread, but did not know it was studio monitors
Patented Baffle-free Reflector Audio studio monitors - Gearspace.com
I have seen them in the Gallery thread, but did not know it was studio monitors
I don't think anyone (who has a clue about OB/dipole systems) is denying that there is an increasing amount of cancellation at low frequencies.
Dipole bass works well down to some frequency, below which it becomes less and less workable due to increasing displacement requirements. If the listening space is quite large, this can be 25Hz or 30Hz. In a rather large rooms (like a large reception room) I have heard quite stunning OB bass that easily reached to 30Hz. But most people do not have such an environment in which to listen. Smaller spaces seem to suck the life out of dipole bass. So for DIYers in home environments, limiting the dipole bass to 80-100Hz and then crossing over to a closed box sub (or two) will most likely provide the most satisfying balance of bass presence and clean, uncolored midbass (and higher) frequencies.
There is nothing cult like about wanting your loudspeaker to sound good, and be free of coloration. But everything has its limit.
Yeah, I don't or didn't ever deny there were cancellations. Hardly cult like. What I do refute is the detractors who say how awful open baffle bass is and that it's a meaningless pursuit. All audio reproduction is a set of compromises and tradeoffs of some degree. Open baffle is no different.
Naturally a baffleless speaker will have a ton of cancellation, and one with a baffle will have less, and one in a box will have much less. Let's not pretend cancellations are solely the result of whether or not the backwave is taken into consideration. I've heard plenty of boxed rooms with huge cancellations and the sort that made the listening experience less smooth than some open baffle systems.
It's also like Coke and Pepsi. Some don't care either way. See like one or the other.
Naturally a baffleless speaker will have a ton of cancellation, and one with a baffle will have less, and one in a box will have much less. Let's not pretend cancellations are solely the result of whether or not the backwave is taken into consideration. I've heard plenty of boxed rooms with huge cancellations and the sort that made the listening experience less smooth than some open baffle systems.
It's also like Coke and Pepsi. Some don't care either way. See like one or the other.
Good ole Charlie !
There are OB fans, and then again there are cultists. I've read much, much more of the cultists diatribe than I have common sense, like yours, here, Charlie. I've even seen/and/read posts by the **nude driver only** crowd
(no baffle at all), making those wild claims about---"cleanest bass ever"
100 Hz di-pole is doable, I suppose, but still, the net result will be poor efficiency.
Long live Hoffman !!!!!
There are OB fans, and then again there are cultists. I've read much, much more of the cultists diatribe than I have common sense, like yours, here, Charlie. I've even seen/and/read posts by the **nude driver only** crowd
(no baffle at all), making those wild claims about---"cleanest bass ever"
100 Hz di-pole is doable, I suppose, but still, the net result will be poor efficiency.
Long live Hoffman !!!!!