Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems Sub woofers, Sub Bass Systems and Crossovers....

Hi Steve,

The way Meridian works bass management is mostly as follows

small- allows you to select a cross over and the rolled off bass goes to the sub, or any speakers designated as large if there is no sub present.

large- no roll off at all. You can use the protection circuit for analog speakers. I believe the DSP speakers have a version of the protection circuit in it. what this circuit does is allow the full frequency range to be played- as volume increases, the circuit attempts to limit dynamic range (difference between loudest and softest moments) so as to protect the drivers in the speaker.

Mono sub- this means all the rolled off bass from any speaker designated as small goes here plus any LFE channel

LFE sub- only LFE goes to the sub- nothing else

No sub- rolled off bass from small speakers goes to any speaker designated as large. lfe goes to those speakers as well. no large speaker and no sub, I thnk then you lose that rolled off bass and I dont know where the LFE goes.

so how do we integrate the sub into your system.

First off, you cant do what REL wants since you are using digital speakers.

The Meridian website says the D5ks play down to 35hz. So I think there are a few ways to go. I think you have to give these all a try.

I think you might want to place the sub between the center and one of the mains (eg. Left......sub...center......right)

but room placement is always a tricky thing.

assuming all the speakers are D5ks (center, mains, surrounds)

I would start off with the D5ks set to small, and then pick a cross over frequency.

Configure the sub as mono for all options and then plug the sub into the analog sub output and there you go.

another way to try is
set the d5ks to large and then set the sub as an LFE sub only. Obviously this will only add the sub's output to movies or other sources with a LFE channel (DTS audio, DVD-A, SACD)

A kind of hybrid of this is to set all the D5ks to large except the center, and set that to small. set the sub to mono and then you can define the xover point for the sub- basically youre using the sub as an extension of the center channel and also for LFE. Since the center is critical for movies, and movie soundtracks do not contain bass exclusively in the LFE track, this might get you a good dynamic result.

Im not a big fan of having a sub just for LFE since LFE is so limited (120hz-20hz). and because the 120hz range is high enough for many people to "locate" the sub.

I think by putting it between the center and one of the mains- if you use it only for lfe, it might be easy to believe the bass is coming from one of the main speakers. this also goes for using a crossover in the small setting.

Almost forgot to mention what George said- turn off all the filters, etc in the sub!

George,
That might have been me. This is based upon the usual xover being 1st or 2nd order (6 or 12db/octave). I think M uses a 24db/octave digital xover so I think you can get away with an xover closer to the bottom limit of the D5ks in this case. I think I would try it around 50-60hz and go from there.

[This message has been edited by JerryL (edited 01-12-2004).]