Room correction ?

I guess I stand corrected. No pun intended.

No computer needed in the living room for Linn's room correction, you just once upload the tune-demmed filter parameters to the DS and that's it.

Interesting post with a lot of useful information. I guess I am still nervous to apply some of these things, as I have a highly optimized setup. I will keep it in the back of my mind and hope the test it once.

In my opinion, room correction software is best used after acoustic room treatments have been used to eliminate the worst of the issues.  Most particularly LF absorbers (such as the BBC A10 for smaller rooms) can be used to damp the primary resonances of the room.  Room correction software can then be used to heal with the higher harmonics and higher room resonance modes.

Room correction software is a bit like a bandage on a wound, if you've got an arterial bleed it's worth sorting that out first!

what do you mean "again"?

The software developer uses this this term, so why should I use something different?

Of course is room correction "saying goodbye to bit-perfectness"!

No matter if it is done before playback or during playback, it is always a modification of your perfect bits with a set of "correction bits". What do you think it was?

To get some background about this you could read this http://www.audiovero.de/en/acourate.php and some threads about the product.

Dear Mr Wat, yes, Amarra iRC does work with DSD files. Quite what it does to them I've no idea but having recently aquired some DSD material I have listened with pleasure to it.

Do what you can with positioning, physically treat within domestically acceptable limits - then try.  The latter still provided a rather large improvement with no down sides for me.  Viewed this way it becomes icing on cake rather than plaster on open wound.

The physical treatments required to help with some of the rooms I've tried it in would be quite challenging to the eye of a user let alone partner.  When you see the graphs from different people's rooms, it's no wonder you get such disagreement over small changes in sound from similar kit.  Those differences are dwarfed by what the room is doing.

You can get a free demo copy of Amarra Symphony iRC, you just need a suitable microphone to go with it. I'd be happy to set it up for you using my kit Mr Wat, as long as you're not too far away.

I see that with AudioVero you can send them a couple of tracks and your room profile using some free measing software and they will create corrected files for you to evaluate.  Might be tempted to try this at some point. 

It's a bit of a faff to do as I will need to get a microphone etc but it does sound like there could be some significant gains to be made. I suppose it depends on how neutral the room is.

I like the idea of the NAS product Aleg uses, this allows the continued use of UPNP which for me just works. I suppose the downside is the need to recreate the files should anything change.

I wonder a room varies much when curtains are drawn, i.e. Would you need more than 1 profile?

Richard

Aleg - i wasn't having a dig at you - rather the product literature  which is what I had assumed you were referring to.. the 'again' reference was from other threads where some of us have had a dig at the marketing dept use of 'technical' language. 

I have been reasonably familiar over the last 12 years  with the DSP methods used for image and audio correction and accentuation  - what I do find interesting that much can be done in the real time now with quite cheap hardware. BUT as with all Convolution there are many considerations to maintain precision and thereby cause minimal  artefacts - I will look at the software notes you referenced to see if they describe what measures they use to reduce digital distortion.

Simon

Curtains may to an extent absorb some higher frequencies, but they won't affect bass at all.

H

That's why I suggested the BBC A10 design.

Huge, nice headsup thanks.. Some interesting reading on the research of different absorbers by the BBC,

http://downloads.bbc.co.uk/rd/.../reports/1992-10.pdf

Hmmf, not buying. It's not that I think it doesn't work, never having tried it. But there's something about 'correcting' the sound that sits wrong with me. I want my hi fi to produce the most perfect sound it can, the most faithful if you like, and play it. And the room's the room. It's what it is, and it's where the music gets played. Of course it affects the sound, but I don't want that corrected.

Also the room changes all the time. I envy people who can keep a pristine listening space, but I have two teenaged boys! And I don't always sit in the same place anyway.

Nope, I don't want my music corrected. It's an emotional thing. If feels like if you step in a puddle and your foot gets wet, the solution isn't to step in the puddle with your other foot to balance it up.

Solid

What do you think happens inside your 172. It has DSP to manipulate the sound. Surely if no manipulation of sound happened then all digital sources would sound identical

Foxman and DHT - You're absolutely right. Of course the sound is imperfect and adjusted, and there's not really any such thing as 'faithful'. But, like I said, it's an emotional thing, and I won't be using room correction. It wouldn't make me happy.

I've always built a system around a budget and a room, so very traditional. Works well until I have to move!

I'm open to the idea of room correction in the digital domain, up to a point. There's no way on earth my NAT01 is going through a digital process, likewise the LP12, unless it can be shown not to screw up the things that make these sources special in their own way.

Still, a Forum chum is heading that way and I'll be listening to the results at some point, so never say never...

I get some of the emotional attachment to signal purity, in theory at least.  Nobody is suggesting otherwise.  A well treated room physically or digitally is even more capable of diffentiating source changes.  The trick is well treated, there is a bit of experience and care to getting best results as in all things.

If we accept that our favourite sources are proving to be our favourite because we perceive them to be doing less to the signal than anything else, why let the room mask or distort what you have spent a lot on preserving?

Actually just getting a free demo and properly measuring your room is a very interesting exercise whether you then proceed to do something with it.  You can make some physical changes, or introduce acoustic treatment with a better idea of what you are trying to achieve for a start.

It's a nothing ventured kind of deal, I'm really glad I did even though the first couple of products I tried showed promise, they didn't completely cut it for me but the newer more complete mixed phase approaches I can't fault.

For example, Tony's big Naim active DBL set up was transformed to my ears, I think he always knew the room was compromised because like many of us he has other domestic considerations, but it was a very large bang for buck improvement.

Very good! Grazie

Hi Huge, out of this topics, I use flx slip 14/4 speaker cables in my current stereo system and I ordered SuperUniti now. I would like to keep my old cables with SU. I red that you use flx slip 14/4 with some ferrites. Would you kindly advice function of the ferrites and way how to install, please ?

Hi Crofta,

The ferrites are optional, the SU will work quite happily with the FLX SLiP in single wired configuration.  I did it because I already had the ferrites anyway.

I used a ferrite with a 10mm hole, 10mm long.  Take the Green & Black* through in one direction to the -ve side of the speaker connection and the Red and White through in the opposite direction to the +ve side speaker connection.  This creates a small differential mode inductance that increases from the near ultrasonic band increasing through to mid RF.  As this is next to the speaker terminals of the amp, it's 'seen' as a series inductor before the capacitance of the speaker cable, and can potentially reduce the effect of a decrease of the stability margin of the amp at low RF.

* nothing to do with chocolate!

Hi Huge, thank you for your reply. Do you know inductance and capacitance figures of FLX SLIP 14X4 ? I did not find the figures anywhere so far. Do you think that strongly recommended figures 16pF/m and 1 microH for Naim amps to be observed or Naim just joke with customers ?

Hi, the 16pF/m & 1μH/m are requirements for the Classic series power amps to maintain stability, and for these amps these requirements should be observed.

However for the Nait and Uniti series amps, these specifications are unnecessary.  The SU will work perfectly well with a wide variety of cables (this is explicitly stated in the manual, it just says that NACA5 is 'preferred', after all it is Naim's own cable!).  The only thing that must be avoided with the Naits and Unitis are high capacitance / low inductance types such as litz cables (for these the capacitance can be as high as 1000pF/m and the inductance as low as 50nH/m).

For the Classic series power amps the figures aren't a joke at all, for Naits and Unitis, the manual states they aren't necessary.