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Room correction
#21
Any news / progress on this one?
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#22
I do hope it is something that Devialet is seriously considering. My current rig is aging and not serviceable if something major fails and I've eyed Devialet as a potential replacement path. It would seem they have the processing power needed for implementation, any hesitation on the corporate end is probably related to the inherent difficulties/limitations in room measurement, coding a proper software interface and debugging it, and the tendency to endlessly tweak rather than listen. The latter in particular might be a disincentive for them since these units seem to be optimized for simplicity in operation, at least once initially configured.

I currently use a TacT Audio setup, it is digital throughout the signal chain. Input is PCM (optical, S/PDIF, or AES-EBU) up to 24/192. I use a modified Logitech Transporter as the source but just ordered an Aurender N10 to replace it. A TacT RCS2.2X is relegated to being a digital signal hub, measurement interface, and master volume control, all its processing is bypassed. The DSP is all performed in the four TacT S2150 amplifiers, each handles one driver group's crossovers, room/driver correction, target curve adjustment, and parametric EQ as well as time delay, phase, and gain matching in a horizontal quad-amp configuration; the specific filters for each amp are designed and programmed using (free) 3rd party TACS software. The outboard passive crossovers and electronic low pass sub crossover that came with my loudspeaker system are unused, rather the amps are directly connected to their corresponding driver groups. PCM>PWM conversion is performed at the final output with 150/300 watts into 8/4 ohm loads. Volume is controlled independently from the audio signal by reducing voltage on the output rails, so no loss of bits occurs. So basically, they are PowerDACs with variable output. The amps sounded excellent when new, and were further improved (substantially) by modifications including upgraded internal cabling, power supplies, and passive parts e.g. caps, inductors, and resistors... not surprising as they were built to a lower price point than the Devialet units. I have no doubt the Devialet amps would be significantly better.

Once one is accustomed to room/driver correction, there simply is no going back - physical room treatment can certainly help things in the reverberant range but does practically nothing in the modal range where all the bass problems occur. It is typical to see 20-30+ db swings over a few Hz in the low frequencies because of cancellation and augmentation effects determined by room dimensions, moving the speakers will change the frequencies of these nodes but not eliminate or significantly reduce them. Only with an infinite room - i.e. outdoor listening - do these issues vanish.
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#23
(06-Aug-2015, 16:49)ekovalsky Wrote:   It is typical to see 20-30+ db swings over a few Hz in the low frequencies because of cancellation and augmentation effects determined by room dimensions, moving the speakers will change the frequencies of these nodes but not eliminate or significantly reduce them.  Only with an infinite room - i.e. outdoor listening - do these issues vanish.

This is not quite right. The frequencies are determined by the room dimensions, so moving the speakers does not effect the room modal frequencies, but it does effect the extent to which they are excited. Correct positioning of the speakers to minimise excitation of room modes is very effective (but may end up with the speakers in a location which is not domestically acceptable).
The node is the location of the null point of a resonant mode, and the anti-node that of the maximum fluctuation.
Correctly placed Helmholz resonator absorbers can pretty well remove the effect of room modes, too, but they are very big, need skilful setup and may well not be very domestically acceptable either.

Personally I much prefer the passive correction to active, but it requires a lot more work and may not be very visually acceptable.
Devialet Original d'Atelier 44 Core, Job Pre/225, Goldmund PH2, Goldmund Reference/T3f /Ortofon A90, Goldmund Mimesis 36+ & Chord Blu, iMac/Air, Lynx Theta, Tune Audio Anima, Goldmund Epilog 1&2, REL Studio. Dialog, Silver Phantoms, Branch stands, copper cables (mainly).
Oxfordshire

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#24
That's true, f1eng.  Thanks for the correction.

In my previous house I spent many, many hours in a vicious cycle of moving the speakers and measuring.  Changing the position of the speakers and/or microphone most definitely changed the measurements but there was no position where they looked particularly good. The measurements and perceived sound did not necessarily correlate either.  I tried the 'golden ratio' and other favored placement strategies and ultimately wound up putting them where they struck a reasonable balance of aesthetics and acoustics.  I bought several Mondo bass traps and they did surprisingly little, at least in the bottom few octaves where the most aberrations were present.

Here is a photo I found of a very nicely done room incorporating Helmholtz resonator absorbers and diffusers - so it can be domestically acceptable.  If I ever build another house I will definitely consult with an acoustics specialist and try to do it right in the construction phase.  Retrofitting a typical home theater or other room is never easy.

[Image: imgext.php?u=http%3A%2F%2Fwww.engelholma...1e8542790e]

One major drawback to active correction is that its effectiveness is inversely proportional to the size of the 'sweet spot' - optimal correction is only possible at one specific position.  Also the ability to fix nulls is extremely limited, although they are not as audibly destructive as peaks that are easily handled.

I will say that measuring one's system for the first time is quite eye opening...  First time I did it I was stunned, after being accustomed to typical +/- the 3dB manufacturer plots which are taken near field in an anechoic chamber.
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#25
(27-Apr-2015, 23:22)markush Wrote: Didn't get this Informationen. Would ne Great if Otters could Write to devialet Support too!

I'd like to see Otters write to Devialet too.
JRiver v24 (Windows) >> 220Pro/CI >> Tellurium-Q Black >> PMC Twenty5.23 on Gaia III isolation feet. One White Phantom.
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#26
I just wrote to support about the current status of room correction, app update and providing upnp / dialog support for expert line. Let's see Smile
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#27
(12-Aug-2015, 13:24)JohnnySix Wrote:
(27-Apr-2015, 23:22)markush Wrote: Didn't get this Informationen. Would ne Great if Otters could Write to devialet Support too!

I'd like to see Otters write to Devialet too.

They would just ask for Electric Eels instead of mains leads Big Grin
UK kit - Technics SP10 - Technics EPA-501  - AT33SA - NUC5i3 - W10 - Roonserver - Roon AIR - Devialet 1000 Pro CI - Blue Jeans Speaker Cable (0.5 metre each side) - Magico S5

Spain kit - NUC7i5 - W10  - Roonserver - Roon AIR - Devialet D250 Pro CI - Blue Jeans Speaker Cable - Ergo IX speakers
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#28
They'd just get the usual weasel words in reply...
Roon (Mac Mini), Wilson Benesch Full Circle, Sonos ZP90 (Cullen modified), Expert 1000 Pro CI, Kaiser Chiara
Warwickshire, UK
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#29
So obviously also Devialet is aware that room correction is an important feature - part of the reply was:
==
Please feel free to stay in touche with us on these points, especially room correction as it is a well demanded feature now.
==
Was surprised though to read at:
http://www.hifisenses.com/showroom/devia...rview.html
where it says:
==
As far as I know there is no room correction feature planned as we speak.
==
The article is a quite interesting read overall.
Anyway - will stay in touch with the support team and hope to see some exciting improvements coming up soon.
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#30
I'm hoping to test a Trinnov Amethyst in my setup soon so will report back on its room correction capabilities (which are supposed to be best in class). As it is a UPnP streamer/renderer (among a million other things!) I will be able to feed it directly into the Devialet.

For those that aren't familiar with the Amethyst see this:

http://www.hifiplus.com/articles/trinnov...st-preamp/

I've heard some very positive reports across the Channel of others using the Amethyst with a Devialet. It's certainly got me very curious indeed!   

Guillaume
Industry disclosure: UK distributor for Shunyata Research

Absolare Integrated Signature v2, totaldac d1 server with additional external power supply, totaldac d1-seven, Echole PSU for Totaldac, Wilson Audio Sasha 2, Shunyata Research cables, Shunyata Triton v3 + Typhon QR + DPC-6 v3, Various Entreq ground boxes and cables, Entreq Athena level 3 rack, SOtM sNH-10G with sCLK-EX + 10MHz Master Clock input + sPS-500 PSU, i5 sonicTransporter w/ 1TB SSD

UK
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