Thanks for the advice. Since I'm learning I hope I don't post to many stupid questions.
I have some slight constraints to size now that I'm getting closer to finishing the HT space. The depth of the area behing the screen is around 45cm max. So I was thinking of the following dimensions for the box.
42cm*80cm*80cm. This gives me a volume of 269Liters per box. The drivers would then have to be mounted on the 42cm side. When you say dual opposed what exactly are we meaning? Will one driver be mounted normally with cone facing outside and the other mounted with cone facing inside the box? If so I kind of like this since there is an element of aesthetics involved. The drivers are massive aluminum and look impressive so if one of them is mounted the other way around it will look impressive and looks can make thing sound better
The drivers are 4ohm and my class D amplifiers are 4ohm as well. I would have 1 module of 300w per woofer.
When we are talking sealed vs ported what is the determining factor on what to choose? Will sealed have better sound vs ported? I've seen a lot of threads regarding TH enclosures and it seems to be very popular. Should I lean in that direction now that IB is out and I want lots of output?
I have some slight constraints to size now that I'm getting closer to finishing the HT space. The depth of the area behing the screen is around 45cm max. So I was thinking of the following dimensions for the box.
42cm*80cm*80cm. This gives me a volume of 269Liters per box. The drivers would then have to be mounted on the 42cm side. When you say dual opposed what exactly are we meaning? Will one driver be mounted normally with cone facing outside and the other mounted with cone facing inside the box? If so I kind of like this since there is an element of aesthetics involved. The drivers are massive aluminum and look impressive so if one of them is mounted the other way around it will look impressive and looks can make thing sound better
The drivers are 4ohm and my class D amplifiers are 4ohm as well. I would have 1 module of 300w per woofer.
When we are talking sealed vs ported what is the determining factor on what to choose? Will sealed have better sound vs ported? I've seen a lot of threads regarding TH enclosures and it seems to be very popular. Should I lean in that direction now that IB is out and I want lots of output?
Dual opposed means you mount drivers on opposite sides of the box <||> as it were. So you mount one on the left side and one on the right side. Be sure to brace the large panels of the boxes, they will be large radiators of sound if not. Ill leave sealed or vented to the people with modelling software.
Is dual opposed different from the push/pull dual drivers? The write up on this page shows push/pull as one driver facing inwards and the other outwards.
Audio Innovation - by Dan Marx www.danmarx.org
Audio Innovation - by Dan Marx www.danmarx.org
In the pic below I've modeled the four drivers in the box volume you posted above, one ported one sealed, both using 500w. The sealed box is using a PEQ set to Fc =25Hz Q=1 Gain=6db. For the sealed box this is max output (123db at XO). For the ported box you could use 1200w but you would only get 4db more output.
Sealed has the benefit of ease to change the sound, and better group delay and transient timing. Since you have so much potential output (+120db) I'd keep things simple. If you were trying to get as much as you could out of these drivers you could use a TH which while larger than BR is more efficient, and BR is more efficient than Sealed. But since you can get more than you need for movies sealed... enough said.
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I think I will go with your suggestions to do sealed as a first box. I could of course change to more complex designs later is this is not enough. I'll try the below mounting mechanism.
Are he drivers supposed to touch each other? Or is there a small gap between them? Any good thread or link for good bracing/box design?
The magnets should not be touching the pole vent (the little hole on the back of the magnet) needs to breath. Bracing on the other hand is a tricky subject, I tend to go with long side bracing with side to side connecting braces, i'll attach a pic of an example (first and second pic). Some like shelf braces the last pic is an example from Speaker Building
edit: I labeled the number of braces wrong on some of the examples on the diagram with all the circles, it should have been number of open panel sections but I wrote it as the number of braces, oops.
edit: I labeled the number of braces wrong on some of the examples on the diagram with all the circles, it should have been number of open panel sections but I wrote it as the number of braces, oops.
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getting there
Hi all again,
Well boxes are now done and I'm getting closer to mounting them. I would need to complete the wiring before I proceed further. Could you please let me know how I should wire the dual woofers? Each one is rated at 4ohm and I will have a separate amp module for each woofer.
Will they both be wired identically?
Final dimensions are a bit smaller then originally envisioned especially since I reinforced the mdf at some places.
Internal dimensions are now. 69*38*78cm and thus 204 Liters. Then the cross bracing and woofers them self take away some additional volume. So one more question. Should I add some insulation stuffing to increase apparent volume?
Hi all again,
Well boxes are now done and I'm getting closer to mounting them. I would need to complete the wiring before I proceed further. Could you please let me know how I should wire the dual woofers? Each one is rated at 4ohm and I will have a separate amp module for each woofer.
Will they both be wired identically?
Final dimensions are a bit smaller then originally envisioned especially since I reinforced the mdf at some places.
Internal dimensions are now. 69*38*78cm and thus 204 Liters. Then the cross bracing and woofers them self take away some additional volume. So one more question. Should I add some insulation stuffing to increase apparent volume?
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