Hey guys.
This is a fairly simple inquiry, for anyone who has some insight. I've been reading a lot about big open baffle speakers. In thinking about it (a dangerous endeavor) I've been wondering if most or all of the positive things about a big open baffle speaker would also hold true for a big infinite baffle array.
I've designed my media room with a cavity behind the front wall in the hopes of installing a couple of Ficar IB318s in it, however, what would the drawbacks be to designing the front main speakers in there as well?
Would that offer some of the same benefits of open baffle? I realize it won't be dipolar (unless I get really creative with the mounting), but aside from that, is this a terrible idea? In my head, it looks awesome, but before I get too far into putting it on paper or simming some crossover changes, has anyone done this to satisfactory or even awesome results?
This is a fairly simple inquiry, for anyone who has some insight. I've been reading a lot about big open baffle speakers. In thinking about it (a dangerous endeavor) I've been wondering if most or all of the positive things about a big open baffle speaker would also hold true for a big infinite baffle array.
I've designed my media room with a cavity behind the front wall in the hopes of installing a couple of Ficar IB318s in it, however, what would the drawbacks be to designing the front main speakers in there as well?
Would that offer some of the same benefits of open baffle? I realize it won't be dipolar (unless I get really creative with the mounting), but aside from that, is this a terrible idea? In my head, it looks awesome, but before I get too far into putting it on paper or simming some crossover changes, has anyone done this to satisfactory or even awesome results?
A cavity at the back will trap the sound coming from the rear and is in effect sort of an infinite baffle WITH the addition of some rear radiated sound that might need to be absorbed as it will be transmitted through the cone again. In an ideal infinite baffle the sound from the rear doesn't return.
In an open baffle the rear sound does interact with the sound from the front and will measure and sound different from an infinite baffle. The radiation pattern will also be different.
That said , it probably is a nice idea to have a rear cavity . It will mean less or no equalisation than a dipole at low frequencies. That gives you more headroom in the bass. Mids and HF have ripples in an open baffle . Here you will have just the regular speaker response and hence easier to work with.
Don't see why you are worrying about it.
It probably will not sound like an open baffle but it should sound good with good drivers!
In an open baffle the rear sound does interact with the sound from the front and will measure and sound different from an infinite baffle. The radiation pattern will also be different.
That said , it probably is a nice idea to have a rear cavity . It will mean less or no equalisation than a dipole at low frequencies. That gives you more headroom in the bass. Mids and HF have ripples in an open baffle . Here you will have just the regular speaker response and hence easier to work with.
Don't see why you are worrying about it.
It probably will not sound like an open baffle but it should sound good with good drivers!
There is a little overlap. IB, due to low box pressure and long distances, seems to allow for low box coloration similar to dipole. IB also limits dispersion to a hemispherical wavefront- meaning that you don't have the baffle step compensation dilemna. With baffle step compensation, you are increasing the on-axis sensitivity but also the overall radiated power, in the bass, meaning the power response gets tilted towards bass.
With an infinite baffle you don't need the compensation, which saves some sensitivity (3-6dB) and avoids the discontinuity between power response and axial response.
Related to that, the concern of baffle diffraction is effectively solved.
There's a LOT to be said for IB.
With an infinite baffle you don't need the compensation, which saves some sensitivity (3-6dB) and avoids the discontinuity between power response and axial response.
Related to that, the concern of baffle diffraction is effectively solved.
There's a LOT to be said for IB.
I've been considering Dayton RS-180s and B&G Neo3s, I guess somewhat like the Cryolite, but modified slightly for having a 10 foot baffle. I think I'm going to go floor to ceiling with a strip of wood that I'll flush to the wall.
The pic is how my cavity looks for now. I'm planning on eggcrate foaming it before any drivers go in.
Thanks for the input! I'm always a little apprehensive before I try something new and I like to make sure nobody says "OMG, I did that once and it was terrible!"
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Perfect. Looks like I need to make a trip up to Lowes again today
Realistically, the only crossover changes necessary might be relaxing or eliminating BSC as a starting point?
Cavity ? Wow that's a cavern ! I think some acoustic fiber sheets directly behind your driver would be sufficient.
Floor to ceiling panels ? Large panels vibrate unless they are pretty dense and/or thick. That adds to colouration. You might have to stiffen them if they are not very thick. I'm not an expert on US style plaster boards and walls.
So someone from there should comment on that.
Badman said that you will NOT have BSC with an IB . So you don't have to deal with it. Makes life easier !
I haven't looked up your driver specs. The bass driver better have a reasonably high Q ( like about 0.6 to 0.8 ). Otherwise you might have to use some bass boost ( a little bit ) . Hopefully it also has a low fs. Below 40 Hz for sure ! 30 Hz or lower would be fine.
Floor to ceiling panels ? Large panels vibrate unless they are pretty dense and/or thick. That adds to colouration. You might have to stiffen them if they are not very thick. I'm not an expert on US style plaster boards and walls.
So someone from there should comment on that.
Badman said that you will NOT have BSC with an IB . So you don't have to deal with it. Makes life easier !
I haven't looked up your driver specs. The bass driver better have a reasonably high Q ( like about 0.6 to 0.8 ). Otherwise you might have to use some bass boost ( a little bit ) . Hopefully it also has a low fs. Below 40 Hz for sure ! 30 Hz or lower would be fine.
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Well, what I'm planning is a 2 foot wide panel that goes floor to ceiling, which I will run 5/8ths threaded rod through, and then on the rear of the wall, 2x4 that are placed horizontal and the bolts tightened to them, so the wall studs are sandwiched.
Kinda like this: (pic)
Edit: On the driver Q, I'll be using them as main speakers with 4 subs, so I only ask them to go down to about 70 hz or so.
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I think this should work out quite nice ! Make sure the drivers are at the right height from the floor. Typically tweeter at ear level when seated. Guess you are using multiple subs. Helps to even out the bass response in the room. Cross over as low as you can to the sub. Below 100Hz for sure. Your driver has a Qts of 0.45 and Fs of 44 Hz. You can design a 2nd order crossover to match this and get an overall Linkwitz Riley 4th order response . Then crossover to the sub at that frequency using a LR 4th order LP filter for the sub. All active crossovers of course !
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My crossover to the subs is electronic cause it's part of my HTR, but the mains have a passive crossover.
My mains right now are ZX Spectrums. I might test this with them just for fun (I've built them with removable baffles), but in the long run, I do plan to buy new drivers.
I'm gonna go cut some baffles real quick and throw em in there and see what it sounds like
My mains right now are ZX Spectrums. I might test this with them just for fun (I've built them with removable baffles), but in the long run, I do plan to buy new drivers.
I'm gonna go cut some baffles real quick and throw em in there and see what it sounds like
cool project! Ive often dreamt of doing this, (i havdm a small apartment) there are some Mivoc kits available for in wall IB, though i have no idea of their sound. In my situation i have drywall and around 4 inches of batten depth, and i have thought of cutting in, then mounting the baffle on the surface anchored into the batten. Once i suss how to toe them in i may try it.
I thought about toe as well, as I usually have my mains ever so slightly toed in. I've had a couple of ideas on how to get it if not having it ends up sounding strange to me.
Perhaps something as simple as shaving down the baffle board into a wedge before mounting..
What's your opinion on this IB idea? Do you think it's a worthwhile thing to try?
Hi,
Bass down to 70Hz or so is easily doable from a decent sized dipole source.
It inevitably will be very different to IB wall loaded bass, as will dipole midrange
and IB midrange, its chalk and cheese regarding the dipoles ninety degree off
axis nulls and the total lack of such for IB wall mounting.
Both can work but will sound quite different.
rgds, sreten.
Bass down to 70Hz or so is easily doable from a decent sized dipole source.
It inevitably will be very different to IB wall loaded bass, as will dipole midrange
and IB midrange, its chalk and cheese regarding the dipoles ninety degree off
axis nulls and the total lack of such for IB wall mounting.
Both can work but will sound quite different.
rgds, sreten.
IB bass can be fine. IB midrabnge and upper octaveshave always sounds 2-dimensional and flat to me. Not my cup of tea. Positioning of the speakers is a significant factor in achieving "space". You don't have the option to move the speakers around with a full range IB system.
You are now getting into a should you or shouldn't you do your IB plan.
We've gone over the fact (many times!) that dipoles sound very different from IB's . They are harder to set up properly.......I think.
However you are making a home theater and not setting up a dedicated stereo music system. I would think the video based application ( unless it is mainly for music video's !) will work very well with IB's.
You do not have much to do to get your IB going. So do it ! If you find it great then stick to it until you get to hear a dipole and determine if that is required for your application.
Going dipole now when you are almost finished with the IB doesn't seem to make sense. Starting on dipoles will lead to much more time spent and MUCH more testing and added parts than what's going on now.
So I suggest you get your IB completed , enjoy it for some time and then you can start researching dipoles and IF you really need it for this application.
If you were just going in for a stereo music system then I'd say change course and do the dipole !
We've gone over the fact (many times!) that dipoles sound very different from IB's . They are harder to set up properly.......I think.
However you are making a home theater and not setting up a dedicated stereo music system. I would think the video based application ( unless it is mainly for music video's !) will work very well with IB's.
You do not have much to do to get your IB going. So do it ! If you find it great then stick to it until you get to hear a dipole and determine if that is required for your application.
Going dipole now when you are almost finished with the IB doesn't seem to make sense. Starting on dipoles will lead to much more time spent and MUCH more testing and added parts than what's going on now.
So I suggest you get your IB completed , enjoy it for some time and then you can start researching dipoles and IF you really need it for this application.
If you were just going in for a stereo music system then I'd say change course and do the dipole !
I can give you also an advice as I have both IB and H frames subs in the same room each fitted with 4 x 15" and the appropriate EQ + digital delay.
Whatever could be the respectable considerations of room modes and other coupling phenomenons, for what is simply earing, the IB kills the OB/dipole, not only because the power handling, the possibility of going eventually under the audibility threshold (means feeling the bass), but the sound quality is also much more clean and then realist. The restitution of the recording venue seems also more accurate when it's about huge volumes.
BTW, I finished by using all together in a kind of 2 ways sub. This compromise gives I think the best of both worlds.
Whatever could be the respectable considerations of room modes and other coupling phenomenons, for what is simply earing, the IB kills the OB/dipole, not only because the power handling, the possibility of going eventually under the audibility threshold (means feeling the bass), but the sound quality is also much more clean and then realist. The restitution of the recording venue seems also more accurate when it's about huge volumes.
BTW, I finished by using all together in a kind of 2 ways sub. This compromise gives I think the best of both worlds.
Let me clarify. Open baffle has a path for sound from front to back. If it is flat or folded into an open box, no matter. There is a path. IB there is NO path. Think of a speaker in the wall. If you put a speaker in a sealed box that is so large that it has no additional loading effects, then it behaves as an IB. The "cavity" if an OB is folded into a box does not have any loading effects, but it may change reflections and diffraction. Clue: "Infinite"
Their frequency response will be different, but the loading is the same. There is a big following for IB subs. Cult of the IB or something like that. More DIY folks. For OB work, go read Linkwitz and about the Orion.
Both have advantages, both have disadvantages. Both have their place.
Their frequency response will be different, but the loading is the same. There is a big following for IB subs. Cult of the IB or something like that. More DIY folks. For OB work, go read Linkwitz and about the Orion.
Both have advantages, both have disadvantages. Both have their place.
There is another issue with IB bass that should be considered. It is ofter discussed that OB bass, or dipole bass, doesn't excite room modes ascross the room or in the vertical direction. The thing is, that can be an advantage for a single woofer. But if you go IB and use 4 woofers you can (should, IMO) position the woofer so that two are 1/4 of the room height off the floor and two are 1/4 of the room height from the ceiling. In the horizontal direction there should be two woofers 1/4 of the room width from the left wall and two 1/4 of the room width from the right wall. In this manner many of the lower frequency modes in the vertical and horizontal directions will either cancel between woofers or not be excited at all. Axial modes in the lengthwise direction will, however, be excited to the maximum with wall mounted, IB woofers, but this can be countered by correct choice of seating position. But you are limited to a single row of seats for best bass.
Wow, that's a great and immediate insight on the subject.
It took me months to set up the best position, and indeed it's almost that : vertical and central IB array of 4 x 15" and the 4 OB on the sides. I say almost because of course I couldn't think of the rule of the 1/4.
Other confirmation, following the listening distance, there is indeed some irreductible perturbations. The worse being a 60 Hz dip measured from 10 meters. Only 1 meter closer and no more. If still closer, other perturbations appear.
I can add that with this optimal 9 meters distance, an other practical concern is the geometric alignment of the in wall IB with the OBs as the resulting arc of circle is quite cumbersome, with the OBs that can't be too close of the wall. All this needs space.
It took me months to set up the best position, and indeed it's almost that : vertical and central IB array of 4 x 15" and the 4 OB on the sides. I say almost because of course I couldn't think of the rule of the 1/4.
Other confirmation, following the listening distance, there is indeed some irreductible perturbations. The worse being a 60 Hz dip measured from 10 meters. Only 1 meter closer and no more. If still closer, other perturbations appear.
I can add that with this optimal 9 meters distance, an other practical concern is the geometric alignment of the in wall IB with the OBs as the resulting arc of circle is quite cumbersome, with the OBs that can't be too close of the wall. All this needs space.
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