I see the current of the tweeter goes trough the cap... but also trough the woofer, and that the current of the woofer goes trough the coil... but also trough the tweeter...
Isabelle
Isabelle
Hi,
The capacitor "shorts" the bass unit so all treble current goes through
the capacitor, and the same applies to the bass current, the inductor
"shorts" the tweeter preventing it passing any bass current.
At the c/o point of course the drivers do share the same current.
Used to be known as "quasi" second order filter as the bass unit inductance
now helps it roll off due to the shorting component. For the Vifa at resonance
a "shorting" component is better than a high impedance series component.
rgds, sreten.
The capacitor "shorts" the bass unit so all treble current goes through
the capacitor, and the same applies to the bass current, the inductor
"shorts" the tweeter preventing it passing any bass current.
At the c/o point of course the drivers do share the same current.
Used to be known as "quasi" second order filter as the bass unit inductance
now helps it roll off due to the shorting component. For the Vifa at resonance
a "shorting" component is better than a high impedance series component.
rgds, sreten.
I understand the first part, but then you lost me.
But if I understand it right, the value of the cap and coil is the same as with a parallel filter?
If that is correct, I can try both, do measurements and see for myself what the differences between series and parallel filters are...
Isabelle
But if I understand it right, the value of the cap and coil is the same as with a parallel filter?
If that is correct, I can try both, do measurements and see for myself what the differences between series and parallel filters are...
Isabelle
Good morning Isabelle,
I don't mean to interject here but I want to talk about that woofer with you. It is a wonderful product for it's size and I am very happy with mine but I strongly suggest you save your pennies and invest in a small plate amplifier for each of the FAST boxes. I have done something similar with two different speakers and am very happy with the results. Instead of padding down the FR units which in my estimation decreases the sound quality, you are simply adding to them with the woofers. Plate amps have the low pass XO built in and if you choose, you can use the built in XO for the high pass on FR's. It's so much nicer to have independent control over the woofers. Trust me, you won't be disappointed by the decision. I tried the other route and ended up crying in my audio soup until the light bulb came on and I moved ahead to a bi-amped system such as I am suggesting.
I don't mean to interject here but I want to talk about that woofer with you. It is a wonderful product for it's size and I am very happy with mine but I strongly suggest you save your pennies and invest in a small plate amplifier for each of the FAST boxes. I have done something similar with two different speakers and am very happy with the results. Instead of padding down the FR units which in my estimation decreases the sound quality, you are simply adding to them with the woofers. Plate amps have the low pass XO built in and if you choose, you can use the built in XO for the high pass on FR's. It's so much nicer to have independent control over the woofers. Trust me, you won't be disappointed by the decision. I tried the other route and ended up crying in my audio soup until the light bulb came on and I moved ahead to a bi-amped system such as I am suggesting.
Hi,
That just isn't an option if we want to keep things low-budget.
I think if we can't get it right without a dsp, we'd be better off resorting to an existing out-door set. But that takes away the spirit away from DIY...
We just don't want to spend to much money on a set that has to withstand all weather conditions to come to the conclusion it broke down because of those same conditions and have to start all over again... We just have too many other priorities first that will take up alot of money.
And afterall it's "only" meant to play at moderate volume levels with good sound, not to throw a party at high volume levels, but with equally high-end sound.... That's what our living-room set is for.
Xenia
That just isn't an option if we want to keep things low-budget.
I think if we can't get it right without a dsp, we'd be better off resorting to an existing out-door set. But that takes away the spirit away from DIY...
We just don't want to spend to much money on a set that has to withstand all weather conditions to come to the conclusion it broke down because of those same conditions and have to start all over again... We just have too many other priorities first that will take up alot of money.
And afterall it's "only" meant to play at moderate volume levels with good sound, not to throw a party at high volume levels, but with equally high-end sound.... That's what our living-room set is for.
Xenia
I agree on bi-amping being the better solution instead of padding down the more efficient drivers, but since these speakers will be mounted out doors, in rain, heat and wind, plate amps are not an option.
To bi-amp this speakers, I would need a pre-amp and 2 stereo power-amps (allowing me to ditch the passive crossovers and go fully active), but that's way over the budget we want to spend on this project.
These speakers will be powered by the B-channels of our home-audio amp (a vintage Technics SA-5460 for now, probably a Yamaha AX-497 later).
Maybe we will build a fully active system one day, but we won't "waste" that money and technology on a pair of outdoors speakers...
And that's pretty much the same thing as what Xenia already said in less words 😀
Isabelle
To bi-amp this speakers, I would need a pre-amp and 2 stereo power-amps (allowing me to ditch the passive crossovers and go fully active), but that's way over the budget we want to spend on this project.
These speakers will be powered by the B-channels of our home-audio amp (a vintage Technics SA-5460 for now, probably a Yamaha AX-497 later).
Maybe we will build a fully active system one day, but we won't "waste" that money and technology on a pair of outdoors speakers...
And that's pretty much the same thing as what Xenia already said in less words 😀
Isabelle
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Hi Xenia,
I totally forgot about the outdoor part of this but bi-amping isn't that expensive if you see below...
Hi Isabelle,
It's not necessary to purchase any more amps if you run the speaker level wires over to the plate amp. We could take this further but you have reminded me this is for outdoors so there's no need. Sorry about the intermission. 😉
Those plate amps cost some money too 😉
We will do something like this later, after we've built a nice set of home-audio 3-ways speakers (HiVi M8a, TangBand W4-1337 and Fountek NeoCD1.0 drivers are already on the shelf for this) and bought a new Yamaha amp (the vintage Technics will move to the bedroom together with the B&W DM2a's).
We have 2 Peerless 12" XXLS subs and 3 10" PR's laying around too and I still have a box I've started building for this, so one day, we'll finish that box, put those Peerless subs and PR's in it and use a Reckhorn amp to power those...
But for outdoors, we want to keep it simple, without having to compromise too much, that's why I'd like to use a F.A.S.T. setup for this: only 2-ways, but better bass-extension than a regular (midwoofer + tweeter) 2-ways setup.
Isabelle
A box that size should be happy with 15mm material, we've made them that size with (braced) 12mm multi-ply.
dave
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That's correct, I won't be using anything thinner than 18mm MDF.
You're talking to somebody that makes subwoofer boxes only out of 30mm MDF and has a subwoofer box of a discontinued project laying around made out of 30mm MDF with bracing and a full centimeter of fiberglass on top of it 😀
Isabelle
You're talking to somebody that makes subwoofer boxes only out of 30mm MDF and has a subwoofer box of a discontinued project laying around made out of 30mm MDF with bracing and a full centimeter of fiberglass on top of it 😀
Isabelle
One day she'll be taking over the world with her 30mm MDF, build a tank from them and blow over leopards and other heavy artillery😱😱😀
And silicone-kit😀
But you could use that as a sealant for the speaker cabinetss anyway😛
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Does everything have to go outdoors ? and is the size of the woofer really limited to 6.5" ?
There are many things that are nice to have, they may form the ideal solution on paper, but it maybe that the difficulty in finding a solution is because there are too many constraints and perhaps it's worth double checking that you can't relax some of them.
By the way, you could also pick up a used SS stereo amp off ebay which would be perfect for driving the woofers in a bi-amp configuration. It gives you independent volume control, plenty of gain and you could always take the lid off it and modify it to provide low pass filtering in the same box. This might not be 100% DIY but it has a chance of achieving excellent results within your budget.
There are many things that are nice to have, they may form the ideal solution on paper, but it maybe that the difficulty in finding a solution is because there are too many constraints and perhaps it's worth double checking that you can't relax some of them.
By the way, you could also pick up a used SS stereo amp off ebay which would be perfect for driving the woofers in a bi-amp configuration. It gives you independent volume control, plenty of gain and you could always take the lid off it and modify it to provide low pass filtering in the same box. This might not be 100% DIY but it has a chance of achieving excellent results within your budget.
Europe Audio have sale for Peerless 830946 SLS 6.5" drivers. See a ported box simulation for the drivers here:
http://www.diyaudio.com/forums/subw...ofer-using-peerless-830946-a.html#post1738156
b
🙂
I've looked at the SLS 6.5", but ported is not an option, since we want these speakers to play as low as possible, without bottoming out.
Since the size of the speakers is limited, a port that is tuned low enough would be ridiculously huge, so sealed is the only option here.
In a sealed configuration, the TangBand W6 (which is the same price as the SLS) is a better choice because of the higher x-max, allowing to put more power on them while playing very deep without bottoming out.
Isabelle
Since the size of the speakers is limited, a port that is tuned low enough would be ridiculously huge, so sealed is the only option here.
In a sealed configuration, the TangBand W6 (which is the same price as the SLS) is a better choice because of the higher x-max, allowing to put more power on them while playing very deep without bottoming out.
Isabelle
🙂
Do keep in mind that 20mm MDF is not as stiff as 15mm ply. So 15mm ply would be overdoing it in comparison to 20mm MDF (and won't have the energy storage issues). And 20mm ply ~ 30mm MDF (and you can actually lift it). Finese vrs brute force (which in the end doesn't work as well)
dave
oh dear, did Dave just (again) open the Pandora's box of MDF vs PLY debate?
Isabelle, another option to consider that was briefly mentioned earlier would be a product locally referred to as MDO Plywood - about as weatherproof as you can find a non marine rated plywood - the only surfaces you'd need to seal would be exposed cut edges
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