Sub performance changes due to box shape.

[LorenC]

I once again find myself wanting to go a different route than the norm and search info to decide if I should, and this time it's about modifying an existing sealed, powered, subwoofer box since what I'm finding doesn't check the purchase tic boxes.
Preferences are <$500, 10 or 12 inch driver, high level outputs( just realized I mixed this in here while thinking about a planned purchase for the PC system), and it being a somewhat tall and thin box instead of basically square in shape. I'd like it to stand up in a corner. The sub I have my eyes on at the moment for this is the SVS SB-1000 or Pro.
Do any of you have any experience with moving all the components from an existing sub into a custom made box with in this case adequate internal bracing and equal volume?

The room is a 18' x 18' x 7', carpeted living room. Right now I'm using a NAD 4020 tuner, Nakamichi CA5 preamp, NAD 2140 amp with an Oppo cd player with Paradigm Monitor7 speakers. The video stuff is connected but not my focus. I also have a Nakamichi 420 amp I sometimes swap into use. I'm not a serious heavy metal guy but do enjoy a good amount some of it. Spectrum runs to bluegrass, blues, bossanova, and others.

 

[TLS Guy]

I once again find myself wanting to go a different route than the norm and search info to decide if I should, and this time it's about modifying an existing sealed, powered, subwoofer box since what I'm finding doesn't check the purchase tic boxes.
Preferences are <$500, 10 or 12 inch driver, high level outputs( just realized I mixed this in here while thinking about a planned purchase for the PC system), and it being a somewhat tall and thin box instead of basically square in shape. I'd like it to stand up in a corner. The sub I have my eyes on at the moment for this is the SVS SB-1000 or Pro.
Do any of you have any experience with moving all the components from an existing sub into a custom made box with in this case adequate internal bracing and equal volume?

If it was really tall, then you might have a standing wave problem.

If you are contemplating buying a sub and changing the box, that is just plain nuts. What you need to do is select a sub woofer suitable for the design you want and build the correct box. That will be far cheaper and you have both sealed and ported options.

 

[LorenC]

Seems like choosing, matching and sourcing the components would be better off left to those that know the business.

 

[ryanosaur]

It may help if you explained what your ultimate goal is with this concept. You seem to want to minimize the footprint?

I agree with TLS above, what you are talking about doing is not something I would ever recommend.

 

[LorenC]

If it was really tall, then you might have a standing wave problem.

If you are contemplating buying a sub and changing the box, that is just plain nuts. What you need to do is select a sub woofer suitable for the design you want and build the correct box. That will be far cheaper and you have both sealed and ported options.

What drives your opinion against my thoughts? Money, time spent, performance results, or what? I don't have any desire for a ported sub, so that "benefit" is out. The reason I was considering the SB1000Pro is the flat response down to nice, low levels. Seeing the graphs of several other subs outputs turns me away from trying to pick parts and assemble my own.

 

[TLS Guy]

Seems like choosing, matching and sourcing the components would be better off left to those that know the business.

I have been building and designing speakers for 68 years now. A sub design is actually something that is comparatively straightforward as far as speaker designs go.

I think there a some here who will tell if they think I know what I am doing. So what is your plan? Can you actually make a rough drawing, with the rough dimensions you require? Obviously the final box volume and dimensions are determined by the Thiel/Small parameters of the driver. But yes, I can predict exactly how your sub will perform, and give you an accurate model.

 

[LorenC]

It may help if you explained what your ultimate goal is with this concept. You seem to want to minimize the footprint?

I agree with TLS above, what you are talking about doing is not something I would ever recommend.

Footprint and available placement choices, mostly. What reason(s) put you against it?

 

[LorenC]

I have been building and designing speakers for 68 years now. A sub design is actually something that is comparatively straightforward as far as speaker designs go.

I think there a some here who will tell if they think I know what I am doing. So what is your plan? Can you actually make a rough drawing, with the rough dimensions you require? Obviously the final box volume and dimensions are determined by the Thiel/Small parameters of the driver. But yes, I can predict exactly how your sub will perform, and give you an accurate model.

Plan is to measure internal volume including bracing and duplicate that in the new shape. If it doesn't degrade the results then use HDF instead of what is probably MDF.

 

[TLS Guy]

What drives your opinion against my thoughts? Money, time spent, performance results, or what? I don't have any desire for a ported sub, so that "benefit" is out. The reason I was considering the SB1000Pro is the flat response down to nice, low levels. Seeing the graphs of several other subs outputs turns me away from trying to pick parts and assemble my own.

Why are you dead set against a ported sub? They are the best performers dollar for dollar. A sealed sub will need more power and Eq, but certainly possible. With your request for a tall sub an aperiodic transmission line sub, which would be the best design of all, might fit the bill very well.

Your original plan is just not sensible, mainly because it a terrible waste. You can do better for less. There are a lot of good sub drivers out there, and you can pretty much always select the optimal driver for a given application.

Lastly, it is an absolute fallacy that a sealed sub is "more musical" than a ported sub. That is complete and utter nonsense.

 

[ryanosaur]

First, if you buy a sub like the SB1000 Pro or even 2000 Pro... these have already been designed to perform at their best.
Then you want to take the driver and amp out and put it in an otherwise untested design... which by the way will not be cheap to build as last time I checked MDF is running over $70 per sheet in my neighborhood...
And throw away a box you already paid for.

TLS really does know what he is talking about and has even designed subs for other members here. The shape of the box can have a profound effect on performance, even for a Sub.

How low do you want this Sub to go? Why do you need high level output? What other components are in the chain? There are a lot of other things to ask...

But if you want the least expensive quality build, there are other things to consider. Among which is that a properly designed Ported Sub will pretty much always outperform the Sealed version.

There is also no reason to use HDF instead of MDF.

 

[LorenC]

I a

Why are you dead set against a ported sub? They are the best performers dollar for dollar. A sealed sub will need more power and Eq, but certainly possible. With your request for a tall sub an aperiodic transmission line sub, which would be the best design of all, might fit the bill very well.

Your original plan is just not sensible, mainly because it a terrible waste. You can do better for less. There are a lot of good sub drivers out there, and you can pretty much always select the optimal driver for a given application.

Lastly, it is an absolute fallacy that a sealed sub is "more musical" then a ported sub. That is complete and utter nonsense.

I haven't heard a ported sub I like yet. And if I was to use a donor unit the power would be already there.

 

[LorenC]

Ok can we get back to my original post and performance based results instead of preferences due to money and such? This isn't about me saving a couple hundred bucks or going the cheapest route to make it happen. This is about the physical obstacles and what it will be when/if it's finished.

 

[ryanosaur]

Tall, narrow boxes can have unpleasant resonance issues. That simple.
It just isn't a good idea.
Peace.

 

[TLS Guy]

I a

I haven't heard a ported sub I like yet. And if I was to use a donor unit the power would be already there.

That means you have never heard a properly designed ported sub. I can assure you that throwing away a cabinet is a complete waste of money. If you think that is a good idea, then you must have money to burn, other members don't. In sub design you can predict with extreme accuracy how a given sub will sound, as all significant parameters can be predicted beforehand. With speakers above sub range, things are a lot more tricky. But I have never owned a commercial speaker. I have always used my own designs.

When Stereophile ran a speaker design contest, which was blinded, this speaker won. It was open to all including professional designers. Both my sons have a pair in regular use.

 

[lovinthehd]

Why not an SVS ported column style sub as far as footprint goes?

ps no reason to avoid ported really. You could also build your own sealed tube shaped sub, too.

 

[TLS Guy]

Tall, narrow boxes can have unpleasant resonance issues. That simple.
It just isn't a good idea.
Peace.

That is why a TL sub might really fit the bill, when I see what space he has available. TL designs are in so many ways ideal for subs.

 

[LorenC]

The room is a 18' x 18' x 7', carpeted living room. Right now I'm using a NAD 4020 tuner, Nakamichi CA5 preamp, NAD 2140 amp with an Oppo cd player. The video stuff is connected but not my focus. I also have a Nakamichi 420 amp I sometimes swap into use. I'm not a serious heavy metal guy but do enjoy a good amount some of it. Spectrum runs to bluegrass, blues, bossanova, and others.

 

[LorenC]

Why not an SVS ported column style sub as far as footprint goes?

ps no reason to avoid ported really. You could also build your own sealed tube shaped sub, too.

Zero knowledge about it is why.

 

[lovinthehd]

Zero knowledge about it is why.

PC-2000 Pro Subwoofer | SVS

Cylinder subwoofer delivers massive output and subterranean deep bass extension while saving floorspace.

www.svsound.com

 

[LorenC]

The biggest reason for all of this is the major obstacle of working around the wife's constraints. Right now the best placement choice is in the corner behind the cabinet. It seems having the sub doing it's thing right beside the rest of the components is a horrible idea though.