Front horn loaded bass reflex

Hey,

Panos tried to discuss this matter in 2005 in this thread:

http://www.audioheritage.org/vbullet...s-reflex/page2

Anyway I found this thread searching for info.

At the moment I am designing a midbass horn with small dimensions due to lack of space. I have a pair of 150Hz Lowther-style Tractrix-horns standing in my garage, the
are the same type as Bo Hanssons at Opus3:

Attachment 50034

I have also a few 414-8A in my stash to be mated to the horns and a bassreflex. Due to the Altecs qualities we shouldn´t expect to high upper rolloff. Shelving, like in a fullrange, shouldn´t be a problem as the BR only fills in just where the horn starts to fall.

The upper rolloff shouldn´t be a problem together with 2482 in these horns(note the driver at the bottom), also in the upper right corner you get a glimps of the midhorns:

Attachment 50033

This is a sim of the horn, box is 40dm3. Note, it will be big compromise even if the design could be bettered:

Attachment 50035

My friend Hoktuna has built 816´s and together with 416 he is quite satisfied with them used as mids down to 100Hz. Also with the same midhorns as I have.

Is there anyone except Panos29 who have tried the concept any tests? We can forget anything but midbass-systems.

I have some trouble understanding your intentions with porting the back-chamber.

Heja Johnny!

Where´s the trouble understanding this?

As I said in my first post floorsize matters. The tiny 150Hz horn with box will take you down to 100Hz. I know you are into tractrix so why not sim a 100Hz for size;)? The hornreflex will have a net volume of 70dm3. A 100Hz in the ballpark of three times at much.

Also try to make a horn with closed backchamber with a 414. One does not have to do much math to find out it will not work.

To sum it up: It´s about 414(yes, I like them) and space.

If your goal is simply to make it work with a smaller back chamber, then you should just try it. I would expect higher distortion from the horn with a ported chamber since you have no damping from the back chamber.

You cannot expect significant low frequency extention from a ported back chamber. The port output will not have attenuation, while the horn will attenuate.

Hej igen Johnny!

Quote:

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If your goal is simply to make it work with a smaller back chamber

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Where did I say that? Think you got it all wrong. You should think smaller horn and bigger (vented)backchamber. As I said in my previous post a 100Hz Tractrix will be ca 200dm3 net, while a 100Hz hornreflex is ca 70dm3.

Quote:

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You cannot expect significant low frequency extention from a ported back chamber. The port output will not have attenuation, while the horn will attenuate.[/

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So, how do you mean VOTT, 816 etc. works? Do some simming and you will see, try 816 or VOTT(828?) first. Use 416 like I do. Their sims don´t look pretty but you can see the way it works. Their problem is that the systems is tuned to low with to big backchambers. IRL 816 worksand sounds good as midbass though.

This is 816, first horn only and then combined with the ported backchamber.