Hi there!
So I have this subwoofer box here, and I don't really know what type of box this is?
Is it a bandpass like it says in the PDF drawing? but that doesn't seem to match the illustration in WinISD.
Or is it just a normal vented enclosure with 2 woofers?
I've drawn blue circles around the vents in the front.
Also, my subs aren't loaded with JBL's, like stated in the drawing, but with Eminence Kappa-15LFA's
Thanks in advance!
So I have this subwoofer box here, and I don't really know what type of box this is?
Is it a bandpass like it says in the PDF drawing? but that doesn't seem to match the illustration in WinISD.
Or is it just a normal vented enclosure with 2 woofers?
I've drawn blue circles around the vents in the front.
Also, my subs aren't loaded with JBL's, like stated in the drawing, but with Eminence Kappa-15LFA's
Thanks in advance!
It's a king of Manifold/MTB design with dual driver. Band Pass 6th Order Parallel
https://www.diyaudio.com/community/...nifold-mtb-be-better-than-tapped-horn.391782/
https://www.diyaudio.com/community/...p-interpreting-impedance-measurements.392495/
You may find many other design options here to play with.
https://freeloudspeakerplan.rf.gd/
https://www.diyaudio.com/community/...nifold-mtb-be-better-than-tapped-horn.391782/
https://www.diyaudio.com/community/...p-interpreting-impedance-measurements.392495/
You may find many other design options here to play with.
https://freeloudspeakerplan.rf.gd/
Thanks for you reply!
Maybe I'm understanding this wrong, but shouldn't a 6th order parallel bandpass box have a chamber in front of and behind the woofer?
Because in this sub box, the front of both woofers is just facing 'outside air'.
The part that's marked blue here is the inside of the box
The part that's marked red directly touches the outside air, so there's no ports in front of it whatsoever.
The purple circles are where the ports are
I was wondering this, since in the PDF file for the MTP-246, both woofers have a seperate chamber, while here they're in the same chamber, and also they do not have any kind of port/chamber in front of them
Maybe I'm understanding this wrong, but shouldn't a 6th order parallel bandpass box have a chamber in front of and behind the woofer?
Because in this sub box, the front of both woofers is just facing 'outside air'.
The part that's marked blue here is the inside of the box
The part that's marked red directly touches the outside air, so there's no ports in front of it whatsoever.
The purple circles are where the ports are
I was wondering this, since in the PDF file for the MTP-246, both woofers have a seperate chamber, while here they're in the same chamber, and also they do not have any kind of port/chamber in front of them
I'd model it as an offset driver horn. That way, your horn parameters account for the shape of the chamber in front of the drivers, and you can still treat the rear chamber as ported.
That front chamber will create some gain, like the front chamber of a bandpass, but it will probably be at frequencies high enough that it doesn't really help the response in subwoofer territory (~160Hz as a first guess).
If you wanted to experiment with the design, you could even account for the fact that the front of the front chamber is slightly constricted by the front panels + bracing like this:
As drawn, I'm sure that would only make a small difference to the upper, out of band resonances, but it affords the option of playing with the overall mouth area to see if it makes any difference in-band.
That front chamber will create some gain, like the front chamber of a bandpass, but it will probably be at frequencies high enough that it doesn't really help the response in subwoofer territory (~160Hz as a first guess).
If you wanted to experiment with the design, you could even account for the fact that the front of the front chamber is slightly constricted by the front panels + bracing like this:
As drawn, I'm sure that would only make a small difference to the upper, out of band resonances, but it affords the option of playing with the overall mouth area to see if it makes any difference in-band.
Yes, and it has dual chamber, one in the back of the driver and one in front of the driver, and it's parallel because each chamber has an independent output.
The back chamber has a well defined port (purple) with a big chamber (yellow), the front chamber is flared and you can thing it has a very short port with the same cross sectional area of the chamber (very tricky).
Understanding this, the next step is how will you model the this box, and as David Morison pointed, it's better to model as Office Driver with ported rear chamber (OD), or even better, as a Compound Horn (CH1) and use the segment H4 as port (no end correction).
Hornresp is so flexible that you have many different options to evaluate the same box design, but each model will offer advantages and disadvantages in terms of accuracy that the user needs to balance the best trade.
In the website I posted to you and you can see below, you can download CAD files that export Hornresp data for you, and can play around with Manifold-MTB design to understand the model until you fell comfortable to implement a box with dual driver.
https://freeloudspeakerplan.rf.gd/
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I would call it a simple 4th order vented speaker, with some improved loading in the midbass range. upper and lower ports are identical so a single port resonance. the port end correction is fairly large to to the narrowly placed ports
Thank you all for your replies! Means a lot to me since I'm still learning a lot 🙂
I'll look into https://freeloudspeakerplan.rf.gd/ tomorrow or so
I'll try this hornresp Programm, I've only used WinISD up until now, but I don't think this sub box would be easy to model in there
Also thanks for the drawings! They also cleared it up a lot 😀
I'll look into https://freeloudspeakerplan.rf.gd/ tomorrow or so
I'll try this hornresp Programm, I've only used WinISD up until now, but I don't think this sub box would be easy to model in there
Also thanks for the drawings! They also cleared it up a lot 😀
For the stated purpose as a subwoofer that is nothing more than a bass reflex modified to be more compact. Any horn loading resulting from the V baffle will only affect frequencies outside the intended bandwith and are of no accoustic benefit.
