Interesting Decware box design.

[Guest David H]

http://www.decware.com/newsite/Pro12.htm

Any thoughts on this design?

[Guest " "]

the specs peak at 80hz. so not much diff that a Heresy.

[IB Slammin]

the specs peak at 80hz. so not much diff that a Heresy.

...and a little harder to build?.......[8-|]

[dan4510]

Its a variation on the classic jensen/onken design.

Dan

[moray james]

Just my 2 cents worth here. The pipe is acting as a reflector or deflector of the back wave off the driver directing it to the side Onken style reflex vents. As such this seems like a good idea but you will likely find that this reflects upper range frequencies from the driver (which you want to be absorbed by internal cabinet damping) out into the vents. That means that you will now have two closely situated sources for these sounds (direct from the driver and secondary from the vents). Such issues cause confussion to your brain which is then trying to localize the image with multiple physical sources of the same sound. I suppose you could experiment with multiple internal drapes of 1/16 inch wool felt directly behind the driver to reduce the midrange energy output off the back side of the driver to help minimize this. You could also experiment with wool felt pads on the surface of the tube as well.

The Onken is a modified reflex design and like all reflex designs the vent is tuned to resonate in antiphase at the cabinet resonant frequency, this then loads the driver and provides acoustic control right where the driver lacks the ability to do so itself. I am not sure if the reflector (pipe) is going to help matters in any way. I would think that an internal cabinet design which provided smooth non turbulent air transfer from the vents into the box and back out would be the most productive measure to undertake regardless of what kind of reflex cabinet design you are looking at. Onken style cabinets can sound very good but they are not unlike any other cabinet in that they must be well designed for the intended driver to perform their best. Regards Moray James.

[Guest David H]

Very interesting, I will look into the onken design. I may build a pair of these cabinets for fun. I'll not be using the drivers or horns Steve chose.

Dave

[moray james]

There are a number of threads on Onken style cabinets over at DIY audio and GM is a wealth of design information on speaker. Dave at planet 10 hifi has also designed a number of Onken style cabinets. Please let up know how this works out. Would look very cool for your stretch Heresy. Best regards Moray James.

[djk]

http://www.ispra.net/audio/Onken/Audiophile_n2_dec1977/articulo-hiraga02.html#dix

[Al Klappenberger]

Dennis,

LOVE your avatar! [Y]

Al K.

[djk]

Thanks, just seemed appropriate for these times.

[brians7]

Here is a pic. of the speakers that i am working on. Your Eliptrac horns crossed over at 1000Hz with my Altec 902 would be Great. Brian

http://i292.photobucket.com/download-albums/mm24/brians7/Mobile%20Uploads/PART_1292894073213.jpg

[Guest David H]

Wow, that is a crazy looking box as well. Looks good.

Here is a pic. of the speakers that i am working on. Your Eliptrac horns crossed over at 1000Hz with my Altec 902 would be Great. Brian

http://i292.photobucket.com/download-albums/mm24/brians7/Mobile%20Uploads/PART_1292894073213.jpg

The Eliptrac is not ready but might work well.

Dave

[brians7]

The box is a Jensen Ultraflex / Onken built to the Jensen plans. The box is 13,300cu. and duct area 134cu. The plans call for the duct length to be 8" but I made it 10". I am using the Great Plains Audio 416-8C speaker. WinISD has the tuning freq. at 34Hz. Brian

Edited June 17, 2015 by brians7

[brians7]

So it's been raining so I drug these out of the closet and worked on them. There coming along nicely just need a gasket for the back's and build the crossover.