Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems G68 bass management (yes, again)

I haven't found much discussion in the forums about the THX box on the bass management page in Mconfig.

First, does anyone know of any official THX Ultra 2 approved subs? According to M this means it's flat to 20Hz. Most subs (even very good ones) would not fall into this category without equalization of some type.

Also, if you check off your sub as being THX Ultra 2 approved, an option for Boundary Gain Compensation becomes available. The owners manual says very little about this except that it's meant "to reduce bass levels if listeners are close to wall". Does anyone know anything more about what exactly Boundary Gain Compensation does? Is anyone using it with noticable results?

A few of Velodynes range of subs are THX Ultra II certified. IIRC they are the HGS-15, HGS-18 and DD-15 & DD-18. Not sure of any other manufacturers' offerings, but you could probably find out from THX's web site.

HTH

Lee

Gain comp. rolls off the bass to compensate for room placement near a wall. Each wall is a gain of 3db and thus is why your bass is so strong in a corner. You have the floor, and two walls.

It attenuates the bass response. I don't use it.

There are a lot of Subs that have flat response to below 20Hz.

Ron

What does checking off "THX Ultra 2 approved" by itself (i.e. without selecting boundary gain compensation) do to the setup?

I don't think I tried that setting. I think what they wanted was when you have a THX Ultra 2 or flat sub down to 20 or lower it gives you the option for boundary Comp (bass attenuation). Switch off THX Ultra 2 and you can not select boundary comp. I just leave mine set for full frequency extension or THX. I don't think turning it off does anything different. Does any one know when it is off what it does? It may limit the low frequency output to protect a sub or compress it in some way. I just never tested it off to see what it did. I just know my bass is correct with THX Ultra two turned on. Sorry!

Cheers,

Ron

Is the Ultra 2 feature now in the 568.2?

I think JBL Synthesis are approved.

Ianh,

Yes the 568.2 has that feature. It seams the 568.2 has all features the G68 has minus MRC and extra inputs.

Ron