[KerryEppes]

Hello, I am brand new to this and have been trying to learn about speaker building. This may seem like a dumb question, but the answer will help me understand more than I knew before :smile:

Would it be possible to not have an extra room, but just have a cylinder from each woofer go out through the exterior wall? You would have to have a filtering system to keep weather, bugs, dust, etc... out and not allow them into the house through these openings, but would that solve any issue of size and volume of free air to come into the sub-woofer system?

Thanks
Kerry

 

[GPM]

You could do it, but unless you live in the middle of a lot of acres to allow the sound to decay away, you'll be severely limited as to how loud it can be. Low frequencies [~1130 ft_sec./20 Hz = ~ 56.5 ft long WL] travel a long ways at high intensity and folks don't like having stuff rattle, upset pets, some children for no apparent reason.

GM

 

[Da Wiz]

The hole would have to be VERY short or it would have to be angled so that the outside diameter of the hole was 2 or 3 times larger than the diameter of the woofer in order for the pressure in the tube to not affect frequency response.

 

[GPM]

Unless quite long it will be so far above the sub's BW that it won't matter.

GM

 

[KerryEppes]

Thanks for the input. I did not realize the sound would also go outside. I think that tells me everything that I need to know about that setup. I just learned a bit more than I new before. Did I mention that I was brand new to this?

 

[GPM]

You're welcome! Yes, quite obvious!

GM

 

[KerryEppes]

Here is another round of questions concerning a IB Subwoofer ...
1. What would happen if you built a wall in front of one of the 4 walls in your room for an IB cavity and put 4 drivers on the wall (one driver in each corner of the wall)?
2. Also, can these drivers share the same cavity of air or do they need their own designated air space to work correctly?

 

[GPM]

It can work quite well as I proved to myself, others and a now long gone neighbor with four Altec bass horn drivers in his basement back in the early '70s as a ~substitute for a stereo pair of 20 Hz [sub] bass horns, though not in the four corners due to it being a too wide a wall for the listening distance [Lp] and 500 Hz/2nd order XO points.

In theory; one big space is fine assuming it's mono and the driver's specs are all very close together since whichever one is the current 'hog' as a single will tend to distort quicker from thermal power distortion [ AKA Lossy/semi- inductance], which in turn may/not cause itself to be 'noticed' when driven hard like when a BR vent 'chuffs'.

Anyway, there's a dedicated IB forum that has pretty much done just about every usable configuration and probably with just about every suitable 'sub' driver [still] available [at least here in the USA], so recommend you browse it for suitable drivers, 'fine tune' any questions you may have, read any 'stickys' re forum rules before joining as Tom is a no nonsense type: http://ibsubwoofers.proboards.com/

His "Twelve Shiva's Dancing Project" that jump started a resurgence of IB builds that petered out in the late '50s as amp power increased, 'subs' shrunk in size: http://ibsubwoofers.x10host.com/page13-12Shiva1.html

GM

 

[KerryEppes]

Hi GPM, thanks for the info!!! I have never built speakers, but keep thinking about it and think about possibilities of what I might do and keep coming up with different thoughts and then I get bogged down in paralysis analysis. It looks like you have given me a good link to just start reading and getting myself educated on this subject. Thanks for your help.

 

[GPM]

Happy Holidaze and all that jive!

You're welcome! Sadly, know the problem all too well. Regardless, please keep us updated if able to move forward.

GM

 

[KerryEppes]

Happy Holidaze and all that jive!

You're welcome! Sadly, know the problem all too well. Regardless, please keep us updated if able to move forward.

GM

I finally slowed down long enough yesterday to go to that website, but is is very overwhelming. Not sure where to start and where I did go, it was way over my head. Can you maybe give me at least the first 3 - 5 steps in the proper order that I should take to get me started? This feels like a dumb request, so I am sorry , but I am thinking you may understand my request very well?