Rodney_gold
R.I.P. 5 June 2018
Recently I bought 2 KrK VXT8 studio monitors and ordered a KRK ergo ( http://www.krksys.com/ergo/intro.php ) which is a room correction unit based on the Lyngdorf room perfect (Ex TACT).
Basically this unit can correct a 2 speaker setup or a 2.1 sub setup at freqs under 500hz It has 2 modes
1) Focus - where it uses 1024 FIR filters to correct at the listening position in the time and freq domain and then
2) Global , where it corrects the room to sound nice at positions away from the sweet spot - this is done only in the freq domain.
The unit is much more than that , it is a high end 24/96 DAC , is an AD , has an analog vol control , it's a preamp of sorts and has an excellent headphone amp , it is also a speaker/monitor controller (Can switch on and off A and B , or Sub and A - or any of em)
As you can see from the pics , it is not a huge unit at all , in fact the back is quite crowded thus it uses 1/4" headphone jacks instead of XLR plugs , it is a "balanced" unit and the leads I use are 1/4" to XLR (but more on that later)
It comes with a calibrated mic and the correct mic cable. It also comes with a Firewire Cable but its not suitable for a laptop , you have to get a 6 to 4 pin cable - available at all Apple shops (R90) - also comes with a 128mb mem stick with software and manuals.
The Process is to install the software , plug in the firewire cable to a laptop etc, the laptop finds the unit and the software guides you thru it all (idiot type guide - IE "The speaker button is not switched on - Switch it on" etc)
You tell it what you are running (IE 2 speakers or 2.1 sub system) and it prompts you to do the measuring.
The unit has to do at least one set of measurements on first run for sound to pass thru it.
It will always do one focus measurement with the mic at listening and then ask you to move the mic around to different positions for its "global" measurement. After 3 or so of em , the unit gets to above 90% of "room knowledge" and you can store the calibration in the unit - will never get to 100% , but the more measurements you do , the greater the "room knowledge".
The unit generates loud LF warble tones and then a 500hz warbly tone from each speaker to excite room nodes - a bit disconcerting first time you use it - it does NOT play both speakers together.
You then detach the mic , take out the firewire cable and the unit is now stand alone. You can store 2 different corrections , speaker A and Speaker B or 1 x speaker/sub.
You can listen to your setup in focus , global or bypass mode. It has analog inputs and a SPDIF input. Analog inputs will do a AD conversion - so I wouldn't and don't use em,
I have my squeezebox Touch feeding the ergo via SPDIF (which is 24/96 - so my HD music plays) I have my 2 speakers and sub attached to the back analog out of the unit.
You DON'T need balanced stuff to make this unit work , I used 1/4" to RCA adaptors and used its output with plain interconnects , so you can use this unit with a power amp and speakers unbalanced - it works. you can use it into a integrated too - into Cd or any other input , but then you get 2 vol controls , the Ergo's and the unit. It's basically a line driver.
So whats it sound like.
Well , lets start with the headphone amp - it is GOOD!! - REALLY good , Drives my Sen 800's exceptionally well , as good as my graham slee solo or better - I drove various headphone amps using RCA cables out of its speaker outputs (in Bypass - the head amp section of the Ergo is obviously not corrected and you cant correct headphones so using a corrected output signal is silly) and compared it with its own headphone amp - I was impressed, the bass was wonderful and the sound detailed and accurate and no sign of stress when driven hard.Had more clarity than the Solo.
Listening to the speakers , the sound in Focus mode initially sounded a bit bass light - but the clarity and air and speed was wonderful , the unit was limiting bass to delete a bass hump where I sit. I did another calibration and there was a little more bass, very difficult to position a mic without a mic stand or boom , used prestic on the listening chair , but it isn't ideal - will get a mic boom next week) After listening a while , the depth and speed of the bass was apparent and the sound grew on me big time. Changing to global gave more bass but at the expense of imaging , midrange purity , air and speed , bass was not as well defined but it was still great. Going to bypass mode was a revelation , the sound was thick and muddy and had terrible bass - however it must be said , I did NOT tune the sub prior to that , just stuck it on 80hz xover point and 1/2 volume - which was way too much to begin with.
The Ergo also corrects L/R inequalities in Focus mode , so imaging is a LOT better than in any other mode if there are inequalities between L and R chan.
As a DAC it beats the pants off my R20000 Logitech Transporter , has much more "air" , much better bass and does not sound cold and clinical like the Transporter does - as good as any high end DAC and better than some I have heard, albeit I havent tried many stand alone dacs - last one was the PS audio Perfect Wave. Anihilates the Touches internal DAC - dunno how it compares to some CDP's as I don't own one.
To repeat , you can use the unit as a one input PRE using its excellent analog vol control , you can have various flavours of room correction or bypass, you get a wonderful DAC , a wonderful headphone amp all in one - you don't however get SPDIF out , so you have to use it's own DAC... Works with balanced and unbalanced connections.
Typical audiophile setup would be CDP/Music streamer/soundcard SPDIF out to Ergo , Ergo to power amp (or active speakers or integrated amp) and ergo to Active sub.
Here are the tech specs on what is used inside the ERGO from the guy that designed it.
D/A converters - AKM AK4396. These were the top AKM converters when we designed the output stage on ERGO. Since then they have added the 4397 and 4399, however the 4396 is still a VERY good converter.
On the headphone D/A we use the AK4620 codec. It has a 115dB SNR. It's a pretty high end spec just for a headphone amp!
The A/D is the ADC portion of the AK4620. 114dB SNR.
SPDIF is also AKM (AK4122). AKM SPDIF has some of the best clock recovery and jitter specs for our application, which is why they were chosen.
Also the AKM DACs use FIR filters, so there is phase/frequency response is linear (no frequency dependent phase shifts that have to be accounted for). Architecturally things work well within ERGO.
After a relatively short time with the Ergo -- I think it's unbelievable value for money...gonna do a lot more comparing and experimenting with it , will use it on my Active ATC SCM50a's if I don't sell em.
Now the BEST part- The price - UNDER R5000!!!!!!
Agents are Tedelex Pro Audio in TVL
I bought mine from "the sound shop" , but I got a special deal as I bought a "package"
Sound shop has em advertised for R4999 - prolly get a discount on that
Online I seen em new at $499
Basically this unit can correct a 2 speaker setup or a 2.1 sub setup at freqs under 500hz It has 2 modes
1) Focus - where it uses 1024 FIR filters to correct at the listening position in the time and freq domain and then
2) Global , where it corrects the room to sound nice at positions away from the sweet spot - this is done only in the freq domain.
The unit is much more than that , it is a high end 24/96 DAC , is an AD , has an analog vol control , it's a preamp of sorts and has an excellent headphone amp , it is also a speaker/monitor controller (Can switch on and off A and B , or Sub and A - or any of em)
As you can see from the pics , it is not a huge unit at all , in fact the back is quite crowded thus it uses 1/4" headphone jacks instead of XLR plugs , it is a "balanced" unit and the leads I use are 1/4" to XLR (but more on that later)
It comes with a calibrated mic and the correct mic cable. It also comes with a Firewire Cable but its not suitable for a laptop , you have to get a 6 to 4 pin cable - available at all Apple shops (R90) - also comes with a 128mb mem stick with software and manuals.
The Process is to install the software , plug in the firewire cable to a laptop etc, the laptop finds the unit and the software guides you thru it all (idiot type guide - IE "The speaker button is not switched on - Switch it on" etc)
You tell it what you are running (IE 2 speakers or 2.1 sub system) and it prompts you to do the measuring.
The unit has to do at least one set of measurements on first run for sound to pass thru it.
It will always do one focus measurement with the mic at listening and then ask you to move the mic around to different positions for its "global" measurement. After 3 or so of em , the unit gets to above 90% of "room knowledge" and you can store the calibration in the unit - will never get to 100% , but the more measurements you do , the greater the "room knowledge".
The unit generates loud LF warble tones and then a 500hz warbly tone from each speaker to excite room nodes - a bit disconcerting first time you use it - it does NOT play both speakers together.
You then detach the mic , take out the firewire cable and the unit is now stand alone. You can store 2 different corrections , speaker A and Speaker B or 1 x speaker/sub.
You can listen to your setup in focus , global or bypass mode. It has analog inputs and a SPDIF input. Analog inputs will do a AD conversion - so I wouldn't and don't use em,
I have my squeezebox Touch feeding the ergo via SPDIF (which is 24/96 - so my HD music plays) I have my 2 speakers and sub attached to the back analog out of the unit.
You DON'T need balanced stuff to make this unit work , I used 1/4" to RCA adaptors and used its output with plain interconnects , so you can use this unit with a power amp and speakers unbalanced - it works. you can use it into a integrated too - into Cd or any other input , but then you get 2 vol controls , the Ergo's and the unit. It's basically a line driver.
So whats it sound like.
Well , lets start with the headphone amp - it is GOOD!! - REALLY good , Drives my Sen 800's exceptionally well , as good as my graham slee solo or better - I drove various headphone amps using RCA cables out of its speaker outputs (in Bypass - the head amp section of the Ergo is obviously not corrected and you cant correct headphones so using a corrected output signal is silly) and compared it with its own headphone amp - I was impressed, the bass was wonderful and the sound detailed and accurate and no sign of stress when driven hard.Had more clarity than the Solo.
Listening to the speakers , the sound in Focus mode initially sounded a bit bass light - but the clarity and air and speed was wonderful , the unit was limiting bass to delete a bass hump where I sit. I did another calibration and there was a little more bass, very difficult to position a mic without a mic stand or boom , used prestic on the listening chair , but it isn't ideal - will get a mic boom next week) After listening a while , the depth and speed of the bass was apparent and the sound grew on me big time. Changing to global gave more bass but at the expense of imaging , midrange purity , air and speed , bass was not as well defined but it was still great. Going to bypass mode was a revelation , the sound was thick and muddy and had terrible bass - however it must be said , I did NOT tune the sub prior to that , just stuck it on 80hz xover point and 1/2 volume - which was way too much to begin with.
The Ergo also corrects L/R inequalities in Focus mode , so imaging is a LOT better than in any other mode if there are inequalities between L and R chan.
As a DAC it beats the pants off my R20000 Logitech Transporter , has much more "air" , much better bass and does not sound cold and clinical like the Transporter does - as good as any high end DAC and better than some I have heard, albeit I havent tried many stand alone dacs - last one was the PS audio Perfect Wave. Anihilates the Touches internal DAC - dunno how it compares to some CDP's as I don't own one.
To repeat , you can use the unit as a one input PRE using its excellent analog vol control , you can have various flavours of room correction or bypass, you get a wonderful DAC , a wonderful headphone amp all in one - you don't however get SPDIF out , so you have to use it's own DAC... Works with balanced and unbalanced connections.
Typical audiophile setup would be CDP/Music streamer/soundcard SPDIF out to Ergo , Ergo to power amp (or active speakers or integrated amp) and ergo to Active sub.
Here are the tech specs on what is used inside the ERGO from the guy that designed it.
D/A converters - AKM AK4396. These were the top AKM converters when we designed the output stage on ERGO. Since then they have added the 4397 and 4399, however the 4396 is still a VERY good converter.
On the headphone D/A we use the AK4620 codec. It has a 115dB SNR. It's a pretty high end spec just for a headphone amp!
The A/D is the ADC portion of the AK4620. 114dB SNR.
SPDIF is also AKM (AK4122). AKM SPDIF has some of the best clock recovery and jitter specs for our application, which is why they were chosen.
Also the AKM DACs use FIR filters, so there is phase/frequency response is linear (no frequency dependent phase shifts that have to be accounted for). Architecturally things work well within ERGO.
After a relatively short time with the Ergo -- I think it's unbelievable value for money...gonna do a lot more comparing and experimenting with it , will use it on my Active ATC SCM50a's if I don't sell em.
Now the BEST part- The price - UNDER R5000!!!!!!
Agents are Tedelex Pro Audio in TVL
I bought mine from "the sound shop" , but I got a special deal as I bought a "package"
Sound shop has em advertised for R4999 - prolly get a discount on that
Online I seen em new at $499
