Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems Lack of bass with Trifield??

Does anyone else notice a lack of bass when using Trifield or is it something I've set up wrong?

I'm using a 561 with crossover set at 80Hz and a REL Storm III subwoofer.

All speakers are set to small and I've calibrated the levels with a sound level meter.

I've noticed that all sources (CD,TV) have very little bass when in Trifield. If I switch to PL2Music or Stereo, the bass comes back again.

Anyone got an explanationfor this??

Thanks
Chez

How did you configure the center?
center / mono / lfe ?

I have mono for music/logic and lfe for movies.

mono for music/logic and lfe for movies!

as I say, the other presets are all fine, it's just Trifield!

Why have you got speakers set to small, if you are using a REL? Is the Storm not meant for bass augmentation?

REL suggest using it in conjuction with your mains set to large, yes. They also suggest that you should run one connection from your main L/R power amp AND a connection from the sub out of your processor. Even in this configuration, you would set the sub roll-off to such a level that the sub would not be reproducing any of the frequencies that your mains handle.

This didn't quite sound right to me.

At the end of the day, it's a subwoofer - I've got it connected to the subwoofer out of my preamp. If RELs could not be used in this way, anyone using monitor/satellite speakers (suck as M&K, whose entire range only go down to 80Hz) would have to buy M&K, velodyne or similar subs!

I don't think this is what's causing the problem though - if it was, I wouldn't be getting bass on any preset.

[This message has been edited by chez (edited 08-10-2003).]

[This message has been edited by chez (edited 08-10-2003).]

Just to add to my last reply - I have the subwoofer connected at Line Level ONLY (ie. direct from the 561).

Assuming I have my sub set-up correctly, the REL should be connected via both R/L amp outputs and LFE connections. The left and right speakers should be set to large, and the sub will effectively operate full range. For LFE and bass redirection from your centre and rears (anything other than R/L), the sub should obviously be line out.

Yes, Trifield is a bit thinner than music in the bass, but it shouldn't feel inadequate if the sub is set up right.

try taking the sub out of the system and playing some music at low-medium levels and see if the problem continues. if yes, then you know the issue is not with the sub. if no, then you know something about the sub (position, integration into the system)

now, I would use the speaker level connection to the sub as my last option- you may have overlapping bass, cancellation of bass, etc. with proper setup this can be avoided, but it is tricky. I would give all available methods a try though and see what works best. I found the best method when I used analog speakers was to tell the system I had no sub, and run the line level (balanced) to the sub, let the sub split the signal and then the split signal (high pass) went back to the speakers' amp and the low pass stayed with the sub.

have you calibrated your system using the test tones and a spl meter? if no- this should be done asap.

Hi JerryL

Thanks for your input.

I'm sure that the sub is corrected perfectly - if it wasn't surely there would be a lack of bass on all sound presets (not just Trifield)?

The speaker level splitting of hi/lo frequencies isn't an option as the RELs have no high pass filter.

I tried the sub with speaker level and line level and it didn't work (as you said, overlapping bass, bass cancellation etc).

As I said in my original post, I set the levels using an SPL meter and using the 561s built in test tones. I have also rune the sine wave and the response seems fairly even (my room has no acoustic treatments, so I would expect the odd dip/peak).

Also, just to clarify, the sub is working on Trifield, but it's output is considerably lower than on PL2/Stereo, which indicates to me that the 561 isn't passing all of the bass to the sub as it should be (with speakers set to small).

Chez,

How long did you give the speaker level connection a chance? This is one of the major benefits of the REL, and it can produce phenominal sound when done right. It took me a day or two to get it just right, but when I did get it, it was sublime. The bass is just so much smoother and more coherent to my ears.

I would still make a go of it telling your system all speakers are large and no sub and disconnect the sub to be sure. then play some music at a moderate volume and see if there is more bass there/ a more pleasing result. you could have a sub placement issue, speaker placement issue that Trifield is highlighting for some reason.

another way to try the setup is to use the speaker level setup with the processor configured to no sub, large with protection and then use the subs xover control to cut the bass where it naturally rolls off the mains. with all speakers set to small it means all the xovered bass is going to the sub and the sub location could be an issue. also, using the protection circuit is not like a crossover- based upon the values you put in it acts as a dynamic range limiter- so it will try to make sure you dont blow out a speaker from too much SPL. Ive found that its presence is very hard to notice.

[This message has been edited by JerryL (edited 08-10-2003).]

[This message has been edited by JerryL (edited 08-10-2003).]