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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => LAB Subwoofer Forum => Topic started by: Douglas R. Allen on November 24, 2011, 07:11:27 pm

Title: Small Tapped Horn?
Post by: Douglas R. Allen on November 24, 2011, 07:11:27 pm
While looking at different Tapped Horns I started to see very small designs. Like in the link below.

http://www.vtcproaudio.com/downloads/specsheet/els118.pdf

How can a small box like this have enough area to have the correct horn length? Have they invented something new? It seems by the graph that were not searching for the lowest freq. Not a lot below 40 hz but still it would seem it would require a somewhat longer horn length.

I am new to tapped horns so there may be a simple answer.

Whats your take on a 18 inch driver in a small tapped horn like this?

Thanks;
Douglas R. Allen
Title: Re: Small Tapped Horn?
Post by: Ivan Beaver on November 24, 2011, 08:54:06 pm
While looking at different Tapped Horns I started to see very small designs. Like in the link below.

http://www.vtcproaudio.com/downloads/specsheet/els118.pdf

How can a small box like this have enough area to have the correct horn length? Have they invented something new? It seems by the graph that were not searching for the lowest freq. Not a lot below 40 hz but still it would seem it would require a somewhat longer horn length.

I am new to tapped horns so there may be a simple answer.

Whats your take on a 18 inch driver in a small tapped horn like this?

Thanks;
Douglas R. Allen
You are correct it takes path length to get low freq in a horn-no way around it.

Overall the cabinet is not that small-when you look at total cubic footage.  It is fairly deep-and judging from the way the driver is mounted, my guess is that there are 2 layers to the horn-with it folding around.

Tom designed a cabinet like the one I described (and the way the VTC looks)-that never went into production (the prototype only gets used for my halloween display) called the twister.  While it worked well as far as performance, there were other issues that kept it from being produced.
Title: Re: Small Tapped Horn?
Post by: Art Welter on December 08, 2011, 02:21:26 pm
While looking at different Tapped Horns I started to see very small designs. Like in the link below.

http://www.vtcproaudio.com/downloads/specsheet/els118.pdf

How can a small box like this have enough area to have the correct horn length? Have they invented something new? It seems by the graph that were not searching for the lowest freq. Not a lot below 40 hz but still it would seem it would require a somewhat longer horn length.

I am new to tapped horns so there may be a simple answer.

Whats your take on a 18 inch driver in a small tapped horn like this?

Thanks;
Douglas R. Allen
Simple answer is the VTC ELS118 is 18.72 cubic feet compared to a DLS TH-118 at 14.84 cubic feet. It is not a "small" tapped horn, it is larger than a TH-118 and does not go as low.

Tapped horns require long path length to tune low, but do not require lots of volume to tune low.
That said, to go low and get loud still requires a big box even using TH design.