My sub project is huge... should I build a riser for my sofa instead? (1 Viewer)

[Brae]

Gary, so what are you selling the Servo's for?

 

[Gary Griffiths]

Brae

I sold them for around £400 each (not including the x30 controllers), although one buyer pulled out when he actually saw the size of it. Strange, it's quite a bit smaller than my riser sub.

 

[Brae]

Gary, I wouldn't mind seeing an RTA of your riser DIY subwoofer. Also, you made a comment about the subwoofer being one-sided (lop-sided), which is something considering the traditional behavior of a subwoofer's function is to be non-directional.

Also, in you mention the use of Marchand Electronics BASSIS to boost the low-end. When I Googled 'Marchand Electronics BASSIS' it presents cabinetry. So, I am a little confused here. Are you using the entire 450L or are you using a Marchand Electronics BASSIS cabinet? Also, could you enlighten this poor stooge regarding the BFD (not quite awake yet this morning)?

As my theater itself will include a second-row riser, I have thought about the variety of uses for the volume it will create. But, I would have never thought of a 450L volume subwoofer housing as this is huge (why not infinate baffle?).

 

[Brian Bunge]

Brae,

The BASSIS can be found at www.marchandelec.com. It's basically an adjustable LT circuit in which you can adjust the Fb and Qtc of a sealed subwoofer.

Also, using a riser is an excellent way to get a large subwoofer enclosure when you aren't capable of doing an infinite baffle install.

 

[Gary Griffiths]

Brae,

Don't have the capability to do an RTA plot I'm afraid.

The drivers are mounted in the front face of the riser firing towards the screen. As you look at the riser from the screen the two Tempest drivers are mounted on the left half of the riser, the right half is empty at the moment (two sealed cavities). My sofa is a three seater, I sit in the central position which is in the center of the riser and can clearly hear that the bass is coming from my right when only the LFE channel is playing. When all channels are playing then it's not so noticeable that it's coming from the right.

The cavities are about 16^3 ft, 8^3 ft per driver so take a look at a Tempest in a sealed box with the Adire software to see what sort of a response you get.
www.adireaudio.com/Files/Adire.zip

The Bassis Linkwitz Transform helps it to go lower and bring up the Q to something less dry. The BFD (Behringer Feedback Destroyer) is just a stereo 12 channel parametric equaliser used to even out the frequency response, do a search on these forums to get more info.
www.snapbug.ws/bfd.htm

In a nutshell the bass is pretty impressive, certainly a better quality than I had with the dual Servo 15's and without the 'breathing' of the servo mechanism. However, it's addictive, I'm starting to think about a Tumult now so will probably post a separate query to get the opinion of the experts on the merits of the improved sound quality of the Tumult over the Tempest.

 

[Javier_Huerta]

I finally found a carpenter that would understand my requirements. So I'll post on Saturday about how this project finally ended.

 

[Javier_Huerta]

I just came back from the carpenter. He understands what I'm trying to do, but asked for some pictures of the building process (I told him about the rattles, liquid nails, clamps, etc.).

I already have a couple of images, but I was wondering, if you have a web site with pics of your sub's box while it was built, can you post them here? I'm looking for a simple braced box in the 200L region.

Thanks a lot for your help!

 

[Owen Bartley]

Mine was 210L gross volume, and I have some pics up on my (new) site. Should link from my sig.