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For example, the design of and interaction between the hifi amplifier and its speaker load can and potentially will alter the sound balance of what you hear. To reproduce the sounds captured by the recording microphones, as Harbeth speakers are designed to do, you would naturally select system components (sources, electronics, cables and so on) that do not color the sound before it reaches the speakers.

Identifying components for their system neutrality should, logically, start with the interpretation and analysis of their technical, objective performance, as any and every deviation from a measurably flat frequency response at any point along the serial chain from microphone to ear is very likely to cause the total system to have an audible sonic personality. That includes the contribution of the listening room itself.

HUG specialises in making complex technical matters simple to understand, aiding the identification of audio components likely to maintain a faithful relationship between the recorded sound and the sound you hear. With our heritage of natural sound, HUG cannot be really be expected to guide in the selection, approval, endorsement or even discussion of equipment that is intend to introduce a significantly personalised sound to the audio signal chain. For that you should do your own research and above all, make the effort to visit an Authorised Dealer and listen to your music at your loudness on your loudspeakers through the various electronics offered there. There is no on-line substitute for that time investment in a dealer's showroom.

If you desire to intentionally tune your system sound to your personal taste, please consider carefully how much you should rely upon the subjective opinions of strangers. Their hearing acuity and taste will be different to yours, as will be their motives and budget, their listening distance, listening loudness and listening room treatment, not necessarily leading to appropriate equipment selection and listening satisfaction for you.

Alternatively, if faithfully reproducing the sound intended by the composer, score, conductor and musicians over your speakers is your audio dream, then understanding something of the issues likely to fulfill that objective is what this forum has been helping with since 2006. Welcome!"

Jan. 2018
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Adjusting room sound using DSP (not damping)

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  • #16
    Re: DSP Room Correction

    There are various DSP components available - TacT and Lyngdorf are a couple of the better known ones. So I would do a lot of research. I don't know of any that aren't fairly expensive; I bought my unit used to save a bit.

    Room/speaker interaction seems to be a funny thing. My M40s sounded at least good everyplace I set them up (even with the over-emphasised bass in a couple of places). Yet when I auditioned them in the dealer's room, they were disappointing. After all I had read, I knew that the room had to be the problem. Fortunately, he let me take them home on a trial basis, and I knew pretty much immediately that they would stay.

    One thing that helped in my room to get the best sound from them was to get them well off the floor. My stands are 25". If you have them much lower than that, you might want to try getting them up higher to see if that makes a difference.

    Good luck, Ned


    • #17
      Re: DSP Room Correction

      Hi Ned,

      I finally found my solution: Lyngdorf TDAI 2200 with RoomPerfect.
      It's just great! On the Lynkdorf page you'll find some reviews. There
      is also one from Peter Greene in "the absolut sound". The funny thing
      is, that Peter used the Lynkdorf with M40's.

      Ok, it's not cheap but probably the best investment that I ever made -
      sorry the second best - the best are the M40's.



      • #18
        Re: Adjusting room sound using DSP (not damping)

        Hi Thomas,

        Congratulations on getting the Lyngdorf. With that and the M40s you should really have a wonderful sounding system! Let us know how you do with it.



        • #19
          Re: Adjusting room sound using DSP (not damping)

          After 2 weeks with the Lyngdorf driving my M40s I'm
          even more sure that this is an ideal combination.
          In my opinion the Lyngdorf and the M40s love each other.

          The sound is still "Harbeth". Roomperfect doesn't seem to
          add or remove anything from this sound. It just removes the
          very bad influence of my room. The sound is very neutral.
          There is still a very deep bass but humfree. The stage is
          brilliant and voices are nailed on in their position. (This
          is of course the feature of the M40s but a bad room messes
          this up. )

          I never received a sound like this before in any room,
          at any speaker position with any speaker.

          With Roomperfect you also have to forget what you learned
          about speaker position and stand height. Normally you would
          put the speakers more far from the back walls. Especially
          with the M40s you would also choose some higher stands to
          remove some of the bass. But you would also like to have
          the tweeter around ear height. This requires high listening
          chairs :-)

          Lyngdorf recommends to put speakers closer to the back walls
          to have a better impulse characteristic and to let
          Roomperfect do the job of reducing the bass. That works perfect!
          This could also help to reduce the stands height for an optimal
          tweeter height. (Has also a higher wife acceptance factor)

          Another thing to mention is that the TDAI 2200 is a fully digital amp.
          It has anolog and digital inputs. Fortunatelly my CD player has
          a digital output and the result seems to be better than using
          anolog input. Another good thing: I'm now out of the discussion
          about the best NF cables ... Good digital cables are cheap.

          I would really like to know what you think about the Lyngdorf
          compared to your DSP solution. You could walk into a hifi shop,
          borrow the thing and give it a try. But be warned - it will stay!



          • #20
            Re: Adjusting room sound using DSP (not damping)

            Hi Thomas,

            I'm really happy to hear that your experience with the Lyngdorf has turned out to be so positive! With my TacT, I've been able to do exactly what you've done - put the M40s closer to the wall behind them and then let DSP deal with the peaks in the lower frequencies. The bass response is absolutely solid and clean. But also in the upper frequency range, there is a clarity to the sound that isn't there when the DSP isn't engaged. I can only think that in time anyone seriously concerned about achieving good sound from his/her system will put DSP at the top of the list (just after Harbeth speakers!).



            • #21
              Lyngdorf Roomperfect (RP-1 or TDAI 2200) with Harbeth

              Anyone else using Lyngdorf Roomperfect (RP-1 or TDAI 2200) together with Harbeth? What is your experience?


              • #22
                Re: Adjusting room sound using DSP (not damping)

                Has anyone tried any software based room correction? Like accourate, audiolense or Inguz audio?


                • #23
                  Re: Adjusting room sound using DSP (not damping)

                  Greetings all.

                  Firstly I'm not a Harbeth speaker user - sorry. However I would like to offer my views on room correction - I hope it's helpful.

                  I note that Tact and DEQX have been mentioned; these cost around ?5,000 and ?3,000 respectively. I've not used these but in my research on the internet I came accross the Behringer DEQ2496, a digital equalizer. These cost around ?200. Add microphone and microphone stand and it totals around ?300.

                  I needed some sort of room correction as I'm using a small room (13' x 8') as a dedicated listening room and when trying speakers that sounded good in my dealers place they were most unsatisfactory here, no matter what placement I used. Principally they were too boomy. My dealer suggested some sort of bass damping and whilst researching this came accross the idea of digital equalizers. Eventually I invested about ?1,000 in Auralex foam products and as a result got quite a dead sounding room.

                  I read about Tact and DEQX but was reluctant to spend that sort of money when I didn't really understand it all, so I thought I'd buy a Behringer and learn with that - if it worked I could reconsider the Tact or DEQX. Well it takes alot of learning but after a few months and some good advice on the internet, I was very happy with the sound I got. I still haven't heard what the others do and feel no need to find out!

                  Now I'm like some religious fanatic! I consider the Behringer to be the most important part of my system (the rest cost around ?25,000 in total!), and along with the foam, I recommend it to anyone who will listen. It does so much more then any cable upgrade, perhaps any upgrade for that matter.

                  By the way, whilst the Behringer includes an Analogue to Digital, and Digital to Analogue Converters, I use it mostly in digital. I have a seperate CD Transport and DAC, so the signal route is, CD Transport to Behringer to DAC to amp. This is what seems to be recommended but I do occassionally use vinyl and then I feed my phono stage into the Behringers analogue inputs but use my DAC - this works quite well. I should also point out that the Behringer only uses XLR inputs and outputs (no RCA) but you can get suitable RCA to XLR cables.

                  If anyone wants more advice on the Behringer I'm happy to give it.


                  • #24
                    Re: Adjusting room sound using DSP (not damping)

                    Thanks for your post on DSP, Hipper. I've been using a TacT unit for some time now and agree that DSP is a tremendous step in achieving good sound in one's room. (Needless to add, room treatment to the extent practical should be the first step). Unfortunately - I think - it seems that many listeners would rather buy and install various interconnects and amplifiers than invest in something that actually makes a substantial improvement in sound. As you've pointed out, while the TacT, Lyngdorf, etc. are fairly expensive (I purchased mine used), something like the Behringer is much less so and achieves much the same result (I'm assuming from your observations). Congratulations on your venture into DSP (as you say, there is a learning curve involved) and happy listening!



                    • #25
                      "KRK Ergo" - inexpensive room correction that works?

                      Hi everyone
                      I recently bought and have installed a KRK Ergo as a stand alone Pre/Dac/Room correction device and thought to post about my experiences.

                      My hi fi was Squeezebox3 (SB3) via spdif - Lavry DA10- LFD Zero- C7's. Now it is SB3 via spdif- KRK Ergo - LFD - C7's.

                      First off a little background. I rent an apartment in Sydney so cannot muck around with the room too much. I had copious room treatments up - mainly various foam combination's - front wall absorption, side wall absorption, rear wall diffusion and corner tx - bass traps & 8th Nerve Adept triangles. They worked to control the bass but killed room dynamics. Like weeding with a shovel.

                      All well and good and I would probably have left it there?.but SWMBO said "get rid of the foam" so off it went to a buyer and I had my acoustically challenged room back. It?s small (4.5mL x 3.4mW x 2.8mH), it?s bright (painted plaster over double brick and concrete slab floor with carpet), opens up to the kitchen, entrance foyer and hallway and save for the Adept triangles was suddenly untreated.

                      The furniture is leather and reflective (our cat dictates no soft furnishings) and the telly has to live between the speakers. Not a pretty picture acoustically.

                      I have been interested in DSP for a while but did not want to spend $$$ on the Lyngdorg/TACT stuff on the off chance I might like it (it is expensive here). Enter the US$599 (ebay) KRK Ergo. I?m no purist who says it?s heresy to muck around with the digital signal ? after all you should see what happens in a mixing studio?.so DSP makes sense to me.

                      This little device is intriguing. First it is made by a pro audio company (KRK) so doesn't have an audiophile price tag. Secondly it uses under license the Lyngdorf Room Perfect software to 500Hz (where 90% of room issues are). Thirdly it uses the AKM4396 delta sigma dac chip (as used in the Logitech Transporter) but too my ear has a nicer output stage (I had a Transporter and didn?t like the analogue out). Fourthly it has a very accurate analogue volume control (ie can be used as a Pre) and lastly has a separate headphone amp.

                      Righto onto using it. First complaint - setting it up was a pain. The Ergo whilst a stand alone unit once calibrated needs a computer with a Fire Wire interface for set up ie to run the calibration software.

                      No worries - I bought a $25 PCI Fire Wire adapter and hooked up the Ergo to my htpc to run the software and install the drivers. And?.Nothing. OK helps to read the instructions. Or not as it turned out. First off the instructions are woeful. You need to start the software install and then follow the order KRK tell you to in the software load to get the drivers loaded: run the software, plug in the Ergo when the software tells you and only then point Windows at the drivers. Of course you have to work this out yourself.

                      Ok that bit over out I went and bought the connectors I needed. I needed some 1/4 inch Phono to 3 pin XLR connectors to hook up the Ergo to my LFD (I already had some special XLR to RCA connectors that enabled me to use the XLR output from my Lavry into my LFD) and a 5m microphone cable and a boom stand. About $80 all up.

                      ]Next up room calibration ? all you need to do is to follow the software instructions. You set the volume as directed. Next you stick the mic where you listening position will normally be and take your first measurement. A series of tones are emitted that would, I imagine, make Dick Cheney proud. Pleasant it was not. Oh well only 4-5 more to go.

                      You variously move the mic around to 4-5 random positions at least 3 ft apart to build a 3D sonic image of the room (how it does this is beyond me - I'll leave it to the PhD's).

                      The software tells you at what % your room is "read" - anything above 90% you are good to go. I stopped at 95% (5 readings).

                      Ok - usefully you have 3 settings:

                      1. Focus ? gives a 3ft cube around your primary listening position
                      2. Global ? best for listening out of that 3 ft cube
                      3. Bypass ? no room correction.

                      So how did it sound?? Well before I get onto that I want to quote Erik Kosnar, KRK National Product Specialist

                      "In response to the type of correction being done with Ergo, I will say that it should be a subtle effect. If it does something really crazy then it's probably wrong, although I've never seen this happen. Now, with that in mind, it is doing these subtle corrections with a phase accurate filter system consisting of 1024 bands. It's also only working in the 20Hz to 500Hz range. Most room modes are stronger in the sub 500Hz range, and those are what will mess up the way in which you interpret bass in your mixes. What it is doing can also be done with some proper testing equipment and other forms of EQ, as it has been for years. Ergo just does it automatically for you.

                      KRK is definitely not trying to make any outrageous claims with Ergo. It is a great piece of hardware with top notch electronics and a great room correction algorithm. Most people will notice a benefit from what it does in their room. ?

                      There is a distinct and audible improvement using the Room Perfect correction software. It appears to work exactly as it says it does.

                      These are my thoughts:

                      1. It does not completely remove the need for room treatments, and is designed to be complementary rather than substitutive.

                      2. In my room at volume I could still use some bass traps or specific freq Helmhotz resonators. There are still bass issues but much less so.

                      3. It?s effect on my music is very positive. The bass tightens up and gets deeper and more focused. The mids are sharper and there is better separation and imaging. Highs seem crisper (weird I know).

                      4. Their goal is to let you hear accuracy for mixing. I would say the Ergo has very accurate converters and is a step sideways from my Lavry DA10. I prefer the Ergo AKM 4396 implementation. It makes up abit for the rolled off tweeter in the C7?s.

                      5. The volume control is precise and very sensitive.

                      6. The headphone amp is good. Not great but good.

                      7. It can control the integration between 2 sets of speakers or 1 set and a pair of sub's. Helpful it you run stereo subs (I don?t) or want to A/B different speakers.

                      8. Overall a remarkable bit of kit. I know nothing at it's price point that is close and can be used in a stand alone analogue system.

                      To me it?s a no brainer. I have sold my Lavry DA10.

                      So in summary what you get for US$599 odd is a stand alone dac (once you have set it up via fire wire):

                      ? with the same chip as the Logitech TP and a better output stage to my ears;
                      ? with balanced and unbalanced connections (via adapters)
                      ? with room correction to 500Hz using the Lyngdorf tech (probably the best out there)
                      ? separate headphone amp with it's own volume
                      ? a Pre Amp?.in that it has a very good analogue volume control...
                      What is missing??
                      ? spdif or other digital out (grrr grrr)
                      ? a better output stage (it?s no slouch however in stock form)
                      ? multiple digi in (it?s a pain swapping sources).
                      ? an internal re -clock (I don't think it has one but instead uses the ubiquitous CS8414 for PLL duties)?which means your source is crucial to control jitter (or you have a Altmann JISCO or Apogee Big Ben to deal with jitter issues). No problem if you have an excellent transport. For instance I had a Meridian 508.24 over here and used it as a transport with great results ? it has superb jitter suppression. My SB3 sucks. I have a Altmann JISCO on the way.

                      Ok..more to follow after I have lived with it for a while.

                      (Note from Administrator: An excellent and complicated post, edited for emphasis)


                      • #26
                        Re: "KRK Ergo" - inexpensive room correction that works?

                        Thanks for your post, Tricka. I've been wondering how well the KRK Ergo works since seeing it advertised. Sounds like a big plus. I've had a TacT unit in my system for some time now and agree completely with your main points. Namely, best to do as much room treatment as you can before going to DSP, and that the results will probably be subtle but absolutely audible and distinctive.



                        • #27
                          Re: "KRK Ergo" - inexpensive room correction that works?

                          Hi everyone.

                          Thanks for your feedback Ned. I have been playing around with it some more and discovered 2 things - one it works better with the C7's close to the front wall and two it works better with a good transport (d'oh).

                          I have cut and pasted a mostly relevant post I made on an Australian forum about the KRK.

                          "I just have a/bed the Logitech Transporter AKM 4396 with the KRK Ergo 4396.
                          This was with the room correction bypassed obviously. I chose 2 pieces of music:


                          Felix Mendelssohn / Symphonies No.3 ''Scottish'' & No.4 ''Italian'' -Chicago Symphony Orchestra - Sir Georg Solti

                          both just 16/44.

                          So without any blind testing I would say there was very little difference between:

                          1. TP spdif KRK Ergo; and
                          2. TP analogue

                          That is the implementation of the AKM 4396 each sounded very very similar with the TP being used as a spdif transport.

                          Perhaps at a reach I might say the KRK was less strident, had better instrument separation and better control over the bass but you had to listen for it. I didn't like either very much. Both felt clinical and non involving.

                          Switching on the room correction (TP spdif KRK) made it more listenable - imaging improved, sound stage grew and the bass was more pronounced and tight. But still didn't make me tap my toes so to speak.

                          Hmmm that is interesting I thought.

                          What about a/b with my modded SB3 I thought? Ok abit trickier as the KRK only has one spdif in - I suppose I could feed the TP analogue into the KRK but that involves another AD step so seemed abit unfair. It does have 2 sets of analogue out so that is a little easier. Oh well let's see what happens. First off in bypass mode:

                          1. OMG - what a difference - the modded SB3 was head and shoulders above the TP as a transport - suddenly the music returned to my system - the highs were clean, extended but not strident, the notes had body and bass was clean tight and fast.

                          Righto maybe it's the extra AD let me try TP spdif out vs SB3 spdif out - listening to one track and then listening again..this is what I heard:

                          1. In all tracks listened to the modded SB3 was a better transport than the stock TP with spdif out.
                          2. The music had more body, flesh and delineation with the SB3, had less harshness and "digititis" than when using the TP as transport.
                          3. There was better instrument separation, the high frequencies had better extension and clarity and bass was well defined and tighter.
                          4. Localisation within the sound stage improved.

                          Turning on the Room Correction made the differences stand out like the proverbial.

                          So what is going on here?

                          You may remember I said I thought the KRK sounded better than the TP. At the time I theorized that the KRK had a better implementation of the AKM4396 ie shorter signal path's and a better designed output stage. Now I am not so sure.

                          Yes the KRK when fed spdif from the TP may perhaps sound cleaner than the stock TP analogue out... but there wasn't much in it and both were to my ears un-involving. No I would say the big difference lay in the transport used.

                          When I switched to my modded SB3 the whole game changed, just as it did when I went from my modded SB3 to the Meridian 506 as a transport. Everything got, well, better - plain and simple.

                          The modded SB3 has a pulse transformer to clean up EMI. EMI induces jitter, along with clocking, PLL's and ps. I've borrowed this explanation:

                          "Jitter is a kind of vibration - and the thing that vibrates is the time an event happens, that you expect to happen at a specific time.
                          So, if you have a girlfriend that you expect to see every day after work at 7.00pm you know, what jitter is: Sometimes she comes at 6.30, sometimes at 7.23 and sometimes maybe the next day. The time of arrival of your girlfriend then jitters.
                          If you then observe these irregularities in arrival time over a longer period, you will learn more about the kind of jitter.
                          The latest arrival time minus the earliest arrival time during the observed period of time is called the "peak to peak jitter amplitude".
                          The "jitter-amplitude" is the expected time minus the time of arrival. So jitter-amplitude can have positive (early) or negative (late) values.
                          You can build the average over a larger number of jitter-amplitudes, if you want to know the time your girlfriend may most likely arrive. Then you may see, if the distribution of the arrival-times is completely random (random jitter) or depends on other events (correlated jitter).
                          Correlated jitter is, when you know that on Thursday she comes later, because she has to look after her mother.
                          If you got it to this point, you are already an expert concerning jitter."

                          So I can only put down the vast improvement in sound quality I heard from going from the TP to the modded SB3 to the Meridian as a digital transport to jitter suppression.

                          I await with interest the arrival of my Altmann stand alone JISCO to see if any further advantage is to be had. As an aside the JISCO uses the inherent properties of the ubiquitous clock extraction PLL phase loop to shift jitter to MHz freq where the receiver chip (usually the ubiquitous CS8414) and strongly attenuate it. Smart cookie this Charles Altmann.

                          So far I would say that the KRK Ergo, when partnered with a good transport, is one of the best single pieces of audio equipment I have bought to date.

                          It certainly has breathed new life into my Harbeth's.



                          • #28
                            Re: "KRK Ergo" - inexpensive room correction that works?

                            Yesterday was a fun day.

                            I took my magic black box around to a mate's place (Ian). We were joined by a mate of mine (Matt).
                            Ian was particularly interested to see if the Ergo would help with his sub integration, which by domestic necessity is placed in a corner and not between the monitors.
                            Ian has a Logitech Transporter - Supretek Pre- Passlabs 150- SF Cremona Auditors - REL sub.
                            I have never really loved Ian's system - the bass is missing and incoherent when present, the mid's are nice but the HF are very strident and pinchy = fatiguing. Ian is a classical pianist so values accuracy beyond all.

                            This is what we found:

                            1. The Ergo improved the quality and quantity of the bass and allowed the sub to be usefully integrated - it "fleshed" out the notes and was clean-esk (as clean as you can get with a single sub). Ian felt the bass went from a "5" to a "8" in his room. I would agree.

                            2. The Ergo Dac is very good when coupled with a low jitter transport. The Transporter analogue out via XLR (as opposed to my earlier reports which reported on the unbalanced analogue out) gave superior highs - more "air" if you will. Ian felt his HF extension went from a 9.5 to a 9. I would agree. But both Matt and I preferred the Ergo dac with the highs - it being a little less pinchy to our ears. Ian was absolutely the reverse - which goes to show we all have different tastes.

                            3. The modded SB3 was preferred to the TP as a digital transport with the Ergo without the Supretk Pre in the chain. It was cleaner, more resolved and had greater clarity and less harshness. It's not all 0's and 1's....and the transport definitely matters.

                            4. The Supretek Pre was in all cases preferred in the chain. While extremely resolving both the TP and to a lessor extent the Ergo feed from the SB3 lacked emotional content and "body" to the notes. Ie we all like tubes in the path in Ian's system (which is unsurprising given the nature of the Passlabs X150).

                            5. The headphone out drove Ian's HD650's very nicely if not especially loudly. Loud enough for me to get a pair.

                            6. Our conclusion was that the Ergo was an amazing piece of kit for USD599 - it has a top quality dac when fed with a good transport, excellent headphone amp and the really wonderful Lyngdorg DSP to 500Hz.

                            I am sold on DSP. Whether TacT, Lyngdorf or DEXQ I feel it offers substantial room enhancement.


                            • #29
                              Re: "KRK Ergo" - inexpensive room correction that works?

                              I've added an Altmann JISCo and am running both it and the KRK off 12v Li ion Battery packs...whoaaa...suddenly a whole dimension is reached.

                              Highly recommended


                              • #30
                                Re: "KRK Ergo" - inexpensive room correction that works?

                                Does this little box of tricks have the option to use manual EQ?

                                Not keen on auto systems as they can't really get to grips with the complex mix of direct and reflected sound.