Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems Discussion on effects of upsampling and apodising

I have nearly finished my room acoustic updgrade and WOW what a difference it has made.

My MS600 now has done things that have simply amazed me - the richness of the sound I am getting is quite remarkable especially since I am running it into an AV amp - which has also surprised me with how good it is - much better than I expected.

I will be running more measurements this weekend to see the extent of my room treatment but I am pretty sure I am hearing 95%+ my kit now rather than 75%+ the room.

Now the true analysis can begin of the sound quality of the Meridian Kit I own.

I have noticed something quite interesting and I want to see if its the same for other users.

When listening to certain band based music - when I track the drummer - I can clearly and perfectly hear the drummer go across the kit onto the cymbal - however the cymbal seems to not always properly tsssiing as I would expect it to as an instrument.
Now if I run the MS600 in direct I hear the tssining of the cymbals that I am expecting to hear - but the rest of the presentation is far worse and that lush sound is gone.
So its a no brainer as to what to have on.

I love what the upsampling is doing - however I am wondering if the apodising which is by my understanding a high freq filter of sorts is maybe having a slight negative effect on that particular element of sound?

Its not exclusively worse for all high pitched type sounds - flutes etc all sound far more realistic with x2 enabled but its the cymbals on certain songs where I have noticed it most

Has anyone else experienced similar or have similar or contrasting views

Hi EllisDJ

What exactly did you do to your room that has given you the WOW?

Cheers

Russ

To be clear, the apodising filter is a different corner frequency and function (in the mathematical sense) to M's ordinary anti-aliasing filter. It isn't a new filter in its own right.
EDIT: Hence the difference in sound, they both do the same job in different ways. The old filter goes higher and flatter than the new one, possibly has flatter group delay than the new one but adds unnatural pre-echo where the new one removes it from the original recording.

The apodizing filter is trying to correct the introduction of pre-ringing that using a linear filter creates in the music. Ayer also do this, and their paper on their work is here.

You'll find lots of other thoughts on the issue via Google.

Yes this is exactly what I experience and I don't like either M filter, especially the apodising upsample. It sounds very phasey and unreal to me. The non up-sample one is more real to me but lacks dimension big time. In fact it's so 2 dimensional it's driving me to look elsewhere for a music server system.
The only thing I haven't tried is the 818 as a preamp. I'm waiting for some new power amps to give that a go.

I hear the same differences between up sampling with apodizing filter vs. playing CD files in their native 44.1 kHz format. Highs are slightly rolled off with the apodizing filter plus I find it can make some CDs sound a little "muffled" or overly "mellow" and less "open" and "live". However, I agree that bypassing the up sampling/ apodizing filter, while improving high frequency extension, is not a better option sonically.

I used to have a choice of filters in my Marantz CD player, one of which was a filter designed to eliminate pre-ringing. It had a similar effect in that it rolled off the very high frequencies. I liked it for rock and electronic music as I found it weightier and more "direct".

Hey everyone!

Here is some good information regarding digital filters that might help.

Resonessence Labs - What are Digital Filters and why are they used in the INVICTA?

Wow I didn't expect so many replies so fast.

It's funny I was listening to Muse earlier on MTV Live HD on Virgin Tivo - just installed today and I was hearing something similar - which luckily I got to see the drummer.

He was doing the usual drumming - that you could track it's hard to put in words but hopefully you get what I mean.

Normally I would expect drum, drum, drum, drum, cymbal in like a rhythm.

However I was hearing the same sound at the end of the section instead of the cymbal - watching the drummer he was actually hitting another drum instead of a cymbal but one that has a much higher pitched tone, like a cymbal but nowhere near as zingy.

Maybe that is what I am hearing in the music, but am expecting the drummer to be hitting a cymbal which obviously sounds different.

I have got to say - the MS600 upsampling and apodizing has given me by miles the best sound I have ever had, and up there with the best I have ever heard.

I got to hear a very good system on a day at What HiFi a couple of months ago - however for solidity of image, richness and general enjoyment factor I think what I am hearing is better.
That system had much better depth of soundstage, every item had its own space in the sound stage so was much better there - but that was in an acoustically perfect room, with better speakers and a proper integrated amp. If they MS600 was on that system in that room it would have been something else - they was using a Cyrus CD6SE

A number of posts have been removed from this thread as they flouted forum policy.

Removal of pre-ringing (through the use of minimum-phase filters) is supposed to be most noticeable with high frequency instruments (cymbals, castanets, etc.). Are you comparing the apodized cymbal reproduction to hearing cymbals "live" or to your expectations based on listening to hi-fi? Bear in mind that before apodizing, every cymbal you have ever heard which has been through a digital audio process, you have heard with pre-echo.

That you can hear the drummer move suggests that something is very *right* with the filter. In fact, I would have expected the opposite based on certain commentary: that the linear phase filter led to better spatial awareness and that the minimum-phase filter led to better high frequency instrument reproduction.

I'm not claiming that Meridian's apodizing filter is infallible - in fact, at the moment, I up-sample using a simple minimum-phase filter that appears, at first glance, to have a very similar impulse response to that of the 808.2 (published by Stereophile). I do this because I want the freedom to try out different filters; something that Meridian does not offer. I have intended for some time to attempt to reproduce the Ayre "listen" filter using a derivation of the SoX utility, but I have other priorities at the moment. However, I got some great pointers from Charles Hansen of Ayre who gave me over an hour of his time on the phone to discuss this project.

I do believe that Meridian's "listening test" methodology is superior to the listening tests performed by most users at home: short-term and/or A-B type tests are completely flawed. On the other hand, I do believe that differences do reveal themselves both quickly and over the long term. Whether or not these differences are deemed better or worse is entirely up to the listener.

This is a very valid point, I have limted live drum listening experience so its very likely I am basing the sound I associate with the symbol from one form of digital playback or another.
I was debating that with myself yesterday - am I actually hearing it correct now? - and the comments I have made are disc dependant - other music I was listening to yesterday had clear cymbals that sounded more like how I expected.
Also with that fact - I have never once heard a drummer play in a studio i.e. good acoustic type environment - a lot of the cymbal hanging on sound that I associate with that instrument is probably reverb anyway - thats the part thats missing that may not be meant to be there in the first place, its actually an echo of the original sound.

The sound is very focused, maybe the old filter sounded more spacious I have no experience of it. I do find the sound focused but layered extremely well so it doesnt matter that the sound is focused as I feel I am still hearing everthing I should be and not missing anything.

Hi Russ,

Sorry I missed this post - apologies I have waffled on in other posts wiothout referring to this - sorry.

I have spent a lot of time reading and researching acoustically treating a room.
This was after I spent a day at What HiFi on the "Big Question" article in this months magazine. I am the bald one on the blue top - obviously the most handsome.

After hearing their hifi system in a perfectly and professionally acousticaly treated room I had to do it myself - the difference is absolutely huge. I had never heard anything like it - it blew me away

I have researched companies products - GIK Acoustics and Realtraps and there is tons online about what to do - apologies if you already know all this.

So Basically I have made my own acoustic absorption panels using Knauff 50mm RS60 fibreglass and wrapped in Camia Lucia fabric.

I have placed these at my speakers first reflection points on both walls (as best I can I have a door and sofa in way and the rear wall.

I also bought a new sofa and now sit in the middle ish of the room rather than on the back wall.
I know the middle is not a good place for bass but I am quite lucky with my bass response where I am.

I have put up 5 panels so far and I plan to make one more thicker one for bass to go on my front wall under my now all mounted tv.

I now sit much closer to my speakers - more equal distance away from them as they are apart.

The difference in all that I can explain technically if you would like or I can simply say I am now hearing my kit much more and not hearing my room any where near as much.

The difference to me was like spending another �5k on system components - for about �200.
However if I did spend �5k more on system components and still sat where I did before/ with no acoustic panels then I would not get the benefit of that upgrade as I wasnt even getting the full sound from my curent kit.

Big panels on the wall is not for everyone - my mrs doesnt liek them at all - but once they have been up for a while she will forgte about them as I will have done soemthing else form her to moan at me about by then - like probably buying a new amp - work permitting

This comment rings true to me (pardon the pun!). When I compared the Sooloos Ensemble's digital out (linear filter) to the MC200's digital out (upsampling apodizing filter) into my Simaudio 650D DAC, the former sounded much more open and live, with more decay and spatial cues. The latter sounded more direct, with less decay and a reduced sense of the recording space and a greater focus on body and tone. Of course some of these differences could be due to the pairing with the Simaudio DAC but I noticed that the same sonic traits of the MC200 filter when using the MS600 as the DAC.

Another thing I would add based upon my comparison of digital outputs between the Ensemble and MC200 is that the up sampling/apodizing filter in the MC200 does impose a strong sonic fingerprint on the digital output signal. This is not the case with the linear filter in the Ensemble. Using the digital output from the Ensemble, I was hard pressed to distinguish differences from CD play through the Simaudio 650d's on board transport. The Ensemble may have sounded a bit better specially and a tad smoother but it was a tough call. Digital output from the MC200's up sampling/apodizing filter sounded distinctly different than CD play through the 650d, however. Subjectively for me, the difference was not an overall positive one as it sounded like the MC200 was altering the music but I'm someone who likes the sound of the Simaudio stuff so it may just be my preference. The point is, though, that the Meridian filter does have a distinct impact on the sound in my experience. Whether that sound is for the better or not is up to the listener and probably depends on their associated equipment.