Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems Enhanced Bass Alignment

Prompted partly by the "OK Computer" thread re bass distortion and room excitement I thought that EBA should be another route to cleaner bass (but not an alternative for the methods discussed there).

To oversimplify, we learnt from the "CES" thread that it comprises a sequence of retiming that changes with frequency and brings special benefits to bass quality and clarity.

Has anybody heard it? Anybody? Rick? Does it make a significant difference?

Meridian specify in their handbooks that this is an application for music but not for films. Why? Its not as though we can't change lip synch.

Hi,

I've loaded the v8 firmware into my 861v6, and I can see on my 861 EBA is only available for DIRECT mode, for the multi-channel presets it is omitted.

As my front two DSP's are 8000.2 which do not support EBA, I was not expecting to see EBA on the 861 preset menu at all, yet it is there.

Thus I believe that Meridian has just implemented a simple rule for EBA availability:
- 2 channel ok
- Multi-channel not ok

I feel this rule is too simplistic and that is should be based on what DSPs are configured into the system; so that on my system EBA should not be allowed on any preset mode. However, on say a 5.0 all 7k2 system then EBA should be available on all pre-sets.

Note: A 'Enhanced Boundary Alignment?' option is on the 7k2's config menu,
- 'N'o
- 'Y'es
- 'SL'

SL (SpeakerLink) allows the setting to be controlled by a suitable controller, such as the 861 Controller, via the SpeakerLink connection.

This if one had an all 7k2 system it is possible to override the 861 and just set them all to �Y�es.

Regards,
Carl

PS
Whilst EBA is available from the processor's DSP preset config, it is not available in Mconfig; which I find odd.
Yet the 'Centre Elevation' feature is displayed in both. I think Mconfig is still a WIP.


EDIT
Mconfig takes into account which speaker types are configured and adjust the EBA options for each preset accordingly.
See my second post below.

I thought so. The quality and apparent linearity in the typical hotel room was surprising.

It introduces a significant processing latency which means it will be out of synch with non-delayed speakers (fixable) and with video (difficult).

Carl

EBA is in MConfig, look in DSP presets tab then select direct in the left pane of the display and the properties window to the right of it should have EBA as an option?

Cheers

Russ

Hi,

Nope not in my setup but then I've got 8ks which don't support it.

Hmmmmmmmm...

As a test I have just deleted all my speakers and created a 5.0 7k2 system and the EBA option is available for all music preset but none of the movie ones.

Adding a SW600 sub, forces EBA to be off for all presets that use a sub.

So it looks like Mconfig does take account of speaker arrangements, but the 861v8 preset menu relies on the user knowing what they are doing (which I guess is fair enough).

IIRC EBA has a 40 mS latency, that's a lot but could be solved.
I guess for those that can and wish to, then just bypass Mconfig and set on v8 directly or set EBA=Y on the DSP themselves.

Regards,
Carl

Looking at my config file the EBA option is shown in direct and stereo presets but I can only change it in the direct preset, the stereo preset is greyed out - any ideas on this? Also note the default EBA appears to be off in the 861, in the 7200 the default is SpeakerLink. Therefore as part of the firmware upgrade, looks like you need to change the config file.

Is there a way of making changes done at the 861 using the function key stick without having to resort to config?

The centre elevation is very useful and works very well, a most useful change.

Speaking to the engineer at my dealer, he suggested that the new hardware change for the 7200's includes a new DSP board that has a higher numbers of MIPS available which gives room for further developments, anyone heard anything on this?

Thanks,
David

Further to my previous post, I can change the EBA on the stereo preset in the 861 using the function key and the remote but not in the Mconfig file? Is this an undocumented feature or user error?

See my previous comment.

Stereo uses your D2500 sub, which does not support EBA, so adding 40ms latency to the mains but not the sub would be a bad idea.

Regards,
Carl

I would think the 861v8 (possibly v6/v4/G6*, I forget it's limits) would know that and add appropriate delay.

You could probably simulate it by setting the 40ft (1 ft per MS if I recall) further than than it actually is

Personally this time alignment makes no sense to me. Real instruments produce multiple frequencies and are not "Time Aligned".

The only thing that makes sense is to correct for imperfections in crossover/drivers which has always been done in all the DSP Speakers (or most of them).

All this possible does is adjust the effective distance to the "instruments". All distances are "Correct".

Carl

thanks, moving the music profile to no-sub brings up the stereo EBA option as you outlined. Currently trying to assess if the 2500 adds anything to music, the EBA now gives yet another complication.

Note that the 7200HC has EBA in the speaker menu but there is no EBA option under the Trifield preset which is a shame as it is my main music preset Can't think of a reason why it should not work in Trifield.

Will probably leave the sub in as I have a phantom on the ID41 that is set to Direct so effectively turns off the sub while the original ID41 source does Trifield with the sub in.

Hi again,
It is the same reason, to use EBA ALL the speakers used by that preset must support EBA, so in this case it is your rear DSP5500's that veto EBA.

Regards,
Carl