You just agreed that it is a bad idea in a normal living room.
A normal speaker driver has a cone. The coil around a tube moves to and fro, pushing the cone and transferring vibrations to the cone surface. (It, of course, transfers vibrations to the "spider," to all other parts of the driver.) This cone surface has two angles, one acute and one reflex. Those angles go 360 degrees around the axis. Both sides of the cone vibrates, when electricity flows through the coil, making it a electro-magnet. Those vibrations create sound waves in the air, which your ear hears. Its your ears that matters, not the measuring instruments. (The measuring instruments help you with graphs and such like, but won't help with your hearing.) The cone doesn't just push air out, but vibrates all over its surface. And, that makes the sounds.
The front ot the cone is directed, while the back is not. The sound waves move out from the open back and hit any surface and bounce back, depending on the type of the surface and the angle of that surface. Someone here said that the OP's room is not good, the floor is not good and so on. There's no omnidirectionality of an OB speaker system, but hearing two types of sound waves, the directed one from the front and the reflected from many surfaces from the back.
Someone here said, take the OB speaker outside and take measurements. Good idea, for if you demolish the wall away from your apartment or house, you won't hear bounced sound from the back. No one is ready to live outside or break their walls, I believe.
Last edited:
You could use two monopoles back to back, but why do people use dipoles/OB anyway?
Whatever way, we fix the driver(s), the back surface of the cone won't stop vibrating, and issuing sound waves to the environment. In the back to back situation, they'd hit each other continuously and make a (terrible ?) mishmash.
Some listeners want heavy bass. cardioid bass feels so light after monopole, everyone might not love it 100%.
i think between monopole sub and OB 18" that steepness can be tuned with slope, i would start LR2
chdsl, I think that you are late for the show!
Many of us followers have extensive and long experience with dipole loudspeakers in normal rooms. Yes, they have their special features and problems, but they give different sound that many people like and find more "natural" even as stereo!
First electromechanical loudspeakers were open baffle or leaky boxes! Nothing new.
Many of us followers have extensive and long experience with dipole loudspeakers in normal rooms. Yes, they have their special features and problems, but they give different sound that many people like and find more "natural" even as stereo!
First electromechanical loudspeakers were open baffle or leaky boxes! Nothing new.
The thing is you are only thinking of the audio driver as a pistonic action cone that pushes air out, without the taking into account the vibrations of the cone surface itself. Also, that sound waves from the back bump off other surfaces of a given room. In other words, your OB in your room, won't sound the same in another room in your own house, or in someone else's room. The OB system that sounds quite nice in your room, won't sound that nice (or sound strange) in an indoor volleyball/basketball court, would it?
Yes, in breakup: See Why Pistonic Driver Cones Matter - YouTube (For what it's worth, you can stop listening after 4:33)
But in the pistonic range, I would doubt any reports as to the audibility of simple non-vibratory bending due to oscillating stress on the cone from the voice coil former.
Thank you for the link. Here's one too.
Anyway, sound is created by vibrations, and needs an element to move through. Around us it is the air. It is not the push of the air from the cone that makes the sound, but the vibrations of the cone and all other parts of the driver, including the coil itself. As some think, it is the push pull of air from the cone that makes the sound, just imagine air coming at you with the speed of 343 m/s. If air comes at you with that speed you'd be knocked off from the seat to the wall. Sound is an interesting thing. If you knock on a steel door, you hear sound, but with no movement of air.
Do you have any specific conclusions to point out from that?
Huh? The sound waves propagate toward you at that speed, but it's the alternating compression and rarefaction that makes the sound (*sound waves*), not wind. Who actually thinks that sound is made by airflow in and of itself?
Last edited:
Not sound waves, but air coming at you with that speed.
By the way, that guy in that youtube video should've tested with music on, rather than checking with specific frequencies. He would've found the whole Himalaya range in his "accurate" picture.
The sound waves are much faster in/through solids than in/through air. Here's list.
Last edited:
Do you have any evidence that cone (not surround) vibration modes can exist in any part of a cone's pistonic frequency band?Not sound waves, but air coming at you with that speed.
By the way, that guy in that youtube video should've tested with music on, rather than checking with specific frequencies. He would've found the whole Himalaya range in his "accurate" picture.
Thanks for the input!!!
I hadn't thought about the dip around 400Hz being a reflection, let alone it coming from the table. Great insight. Now the sim and measurements look more alike.
I guess your comments suggest crossing around 250Hz then. I think the limiting factor will be my midrange (B&C 8PE21), which I think will struggle reaching that low nude. In-room measurements are in post #38 in this thread, but outside measurements still to be made. Maybe 300Hz is doable.
I sent you a link. Read it through. Next good instrument is your finger. Touch the cone at different places when the driver is running.
Yeah, OK, I'm done.I sent you a link. Read it through. Next good instrument is your finger. Touch the cone at different places when the driver is running.
When you have time, please let us know, how the OB speaker sound, when you turn it towards the corner of the room, from your normal listening place. Thank you!
From the front, sound would hit the walls and reflect back to you, while from the back of the drivers, sound would fill the room. I've been testing this with one driver, but you have a full system.
You can do measurements in different conditions and look at responses with different manually set IR Window gating. In all angles of outdoor measurements the dip remains constant, that's one clue for me.
My AINOgradient's 12" low mid woofer sits on top of the bass box, but on the edge so frontal response is not badly affected by reflection. When the whole speaker system is done you should measure it also in normal "floorstanding" setup, at various distances to see what floor and front-wall backwave reflections do. Just remember that nulling shouldn't be eq'd with dsp/input, but with positioning excersices!
Crossing at 400-600Hz LR2 or LR4 to mid should be totally ok. LR2 is rather shallow and then directivity problems show up easier in multiway speaker's response. You must test also midrange's distortion in low end when considering xo. EQ with dsp before setting xo is easy, passive systems are not my piece of cake...
Last edited:
Like any other speaker
An OB/Dipole speaker will have less roominteraction than a normal boxed loudspeaker. Im not in love with OB. But for now it behaves better in my room. For the moment I have boxed reflex speakers (audiovector M3 Super), since my OBs are about to get ready for the finishing touch. It's quite obvious to me which sound less coloured (especially from low midrange and down). Maybe youl could create your own thread, for these kind of discussions?