» Grund Audio GT-LPB-18c-H - Single 18" 800 Watt Subwoofer

[ashok]

Anyone come across this subwoofer. Looks like a tuned rear enclosure and the front looks a bit like a w frame dipole sub.
Quite high sensitivity and it is very narrow ( 17 inches) though the cross section sideways is large about 29x29 inches.
Is that their own driver ?

[ashok]

I found a URL with a clearer picture.

http://www.grundorf.com/index.php?Ty...el=GT-LPB-18CX

[ashok]

A little clarification.
I thought that maybe the frontal cavity would help lower cone resonance due to mass loading and affect the tuning of the rear chamber also. Net effect being that it can go down lower than otherwise possible. The band pass tuning helping in achieving a high sensitivity in a relatively (?) small box.

[djk]

Those are roughly one-half of these:

http://www.eaw.com/info/EAW/Loudspea...eet_Prelim.pdf

As you can see (from the unprocessed response), they have a bandpass cavity resonance up around 200hz.

Speakers are built like this to have a narrow footprint, little else.

[ashok]

Thanks Djk .
I wonder if reducing the frontal cavity will help. I'm looking at lowered Fs due to mass loading like a ripole and lifted low end due to a tuned rear box. Efficiency might go down but maybe one would require less equalisation at the lower cut off frequency.
A 'riplex' box ?

[freddi]

it might need lower tuning on the front cavity to limit peaking w/o eq - I get peaks around 200 or so with some Karlson.- Gregg over at the Karlson forum eyeballed cloned Metro's T15 which puts the rear wave vent more in series but used an Eminence and his vent was a smaller area tube - he didn't have good response nor Z graph to see whats happening
http://www.gainclone.com/E_Array_T15_Dimswc2.gif