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post #1 of 8 Old 08-06-2014, 06:01 AM - Thread Starter
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Please read, unique box idea?

Hey all,
Along with a lot of others in my spot debating which sub enclosure to use, weather it be ported or sealed, I came across a thought, and then a product that further intreged my curiosity.
If I where to build a sub enclosure, could I implement both a sealed AND a ported design?
As in have the option of easily being able to there and then switch between the two? I saw the svs-pb13 ultra, and saw that it had both ported and sealed modes.
Can this be fairly simply implemented in a hand made box? Or would it play with the subwoofer in a negative way, or not allow for maximum sealed/ported benefits?

I guess to simply put it. Would it be possible to fairly easily produce a ported sub box that could be tweaked on the spot by sealing the port and have it sound like a well made specific sealed box? Or do I need a special amp or something like in the svs-pb13?

Thanks in advance
(And sorry if it turns out to be a noobish question)
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post #2 of 8 Old 08-06-2014, 11:35 AM
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yes, easily. However the size is the problem, generally you want either a small sealed box or a huge ported box. For a given box size there will be an optimal configuration, so in the end it's fairly pointless. There's always trade-offs. A big box will be better as ported, a smaller box better as sealed. You can play around in winISD with the models to see what happens.
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post #3 of 8 Old 08-06-2014, 08:22 PM - Thread Starter
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Originally Posted by Bassment View Post
yes, easily. However the size is the problem, generally you want either a small sealed box or a huge ported box. For a given box size there will be an optimal configuration, so in the end it's fairly pointless. There's always trade-offs. A big box will be better as ported, a smaller box better as sealed. You can play around in winISD with the models to see what happens.
Ahhh, how does the svs-pb13 work then? Or is it just advertising then excentuates the ability to have an effective sealed and ported mode?
And one more question, if I chose sealed only, should I include supports and have an extra layer on the front face to attatched the sub to, or will I be right to just screw the sub plate into the flat face?
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post #4 of 8 Old 08-07-2014, 07:44 AM
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ya the pb13 isn't 100% optimal for either configuration I don't think, but it's not bad. They probably have the driver specifically designed to be decent at both configurations, so it's probably like 95% performance in either configuration. In general for any sub, use double front baffle, and you need bracing inside too.
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post #5 of 8 Old 08-07-2014, 08:00 AM
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This can be simulated in order to figure out the solution to having a ported enclosure that has the option of having the ports plugged for a sealed mode configuration similar. I must caveat this statement by saying that you could possibly be sacrificing the optimal ported size and thus performance, but, here is what you need to do.

Download winISD Pro, and pick out the driver that you intend to use, which will hopefully be an 18" or at the very least, a 15" and start modeling ported enclosures that are around 5cuft to 6.5cuft. Then just play with the different ported & sealed variations until you find both a ported size that works well down to you required cutoff frequency while at the same time modeling a sealed enclosure of the same size that works well without being too big, which is why I suggested 5cuft to 6.5cuft as that is what I believe you will end up with as a compromise. Think about it, if the ported enclosure is 11cuft or even 8cuft then that would be too big for four sealed version, but at the same time, it would be optimal for your ported enclosure, and vice versa, if you build a 4 cuft sealed box it would be optimal for sealed but terrible for ported. It may end up being more compromises than it's worth, just in my humble opinion.
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post #6 of 8 Old 08-07-2014, 08:17 PM - Thread Starter
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Alright thanks, I have chosen to forget about the sealed and ported design and decided to chose a passive radiator design.
I'm not quite sure yet as to how to build it, but I am looking to use a 12" active front firing and two 12" Passive on alternative sides.
I have been doing a tonne of looking, and starting to get close. Although there is a huge amount factors I still have to work out haha. If anyone has any experience or knowledge on PR systems, it would be extremely appreciated!
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post #7 of 8 Old 08-08-2014, 03:00 AM
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Quote:
Originally Posted by simpko22 View Post
Alright thanks, I have chosen to forget about the sealed and ported design and decided to chose a passive radiator design.
I'm not quite sure yet as to how to build it, but I am looking to use a 12" active front firing and two 12" Passive on alternative sides.
I have been doing a tonne of looking, and starting to get close. Although there is a huge amount factors I still have to work out haha. If anyone has any experience or knowledge on PR systems, it would be extremely appreciated!

Have you modeled the drivers/passive radiators/enclosures yet? That should be your first step. No sense in purchasing the sub and passive radiators without knowing how they will perform. I am not sure if winISD will model PR designs as I have never tried or experimented with building one, mostly because passive radiators are much more expensive then a typical sealed or traditional ported design, but, if you are working with a small space, and WAF requires you to build something smaller and more astecially pleasing them PR designs are ok. Just keep in mind that you can get better performance than a PR at a much cheaper cost by going with a large ported enclosure.
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post #8 of 8 Old 08-08-2014, 03:14 AM - Thread Starter
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Originally Posted by Martycool007 View Post
Have you modeled the drivers/passive radiators/enclosures yet? That should be your first step. No sense in purchasing the sub and passive radiators without knowing how they will perform. I am not sure if winISD will model PR designs as I have never tried or experimented with building one, mostly because passive radiators are much more expensive then a typical sealed or traditional ported design, but, if you are working with a small space, and WAF requires you to build something smaller and more astecially pleasing them PR designs are ok. Just keep in mind that you can get better performance than a PR at a much cheaper cost by going with a large ported enclosure.
Yeah, I want to keep size as small as possible without compromising low end extension. And I also don't have the best carpentry skills to make extremely well made ported designs.
I have tried to model an enclosure on WINISD pro, but it doesn't seem I work properly, for some reason it seems to think my enclosure is tuned to something like 170hz!?
The main question I kind of have at the moment, is will two 8" radiators be enough to handle the 12" 300w sub, or should I go with a 15" radiator.
I am trying to keep costs down, and the 8" radiators are fairly cheap, but if I can't use them I think the next cheapest is a single 15".
Any thoughts?
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