Jump to content


  • Content Count

  • Joined

  • Last visited


About mitchco

Recent Profile Visitors

26,439 profile views
  1. Several near field monitors are active and typically already have digital XO's and if lucky, time aligned/linear phase operation. Genelec, HEDD, Adam, Neumann, PMC, Fostex, Amphion, are just a few brands that come to mind. JBL larger speakers like the M2 and Cinema speakers like I have require external XO and amps. So there is no passive XO network. For other speakers that say they are biamp-able, it usually is indeed still passing through the legs of a passive XO... One has to look really carefully as a "real" biamp scenario is where the amps connect directly to the drivers. I am a diyAudio guy and have built/modified speakers and have either unhooked the passive XO and ripped it right out, depending on whether reselling or not. That's another possibility... As soon as I get some time, I will start looking into this deeper...
  2. Hi @TooSteep Thanks for your kind words. That’s a great question! Before getting into the specifics of a particular loudspeaker, there are three approaches: Audiolense can apply an overall time correction (using TTD) to an existing loudspeaker that is not time aligned. Assuming a 2-way design, the caveat is that the z-offset between the drivers needs to fall within the time correction window. It is likely for most desktop speakers that this would work. One would have to measure the step response and evaluate the sonic result to see if it is time aligned/phase coherent enough… You could download a trial version of Audiolense XO and try it on your existing speakers. I think the trial version corrects for 90 seconds. A second approach is to biamp a two-way so that one could use Audiolense linear phase digital XO and the software would automatically time align the drivers and apply an overall time correction. This is the approach I chose for the article and my preference. Finally, acquire a set of time aligned speakers for the computer desk. I have not looked into this much Vandersteen makes a time and phase coherent smaller speaker the VLR Wood. I have not seen any measures or listened to the product. Green Mountain Audio is another… Plus there are dozens of near field studio monitors, some of which are time aligned/phase coherent... Again, great question/suggestion. I will start looking into this more and see what I can come up with… Kind regards, Mitch
  3. Not at this time... But a good question for Martijn @mensink
  4. Thanks @m3lraaHnevetS Let me look into it...
  5. Thanks! Here is Martijn's (the designer of the 8c's) explanation from Gearslutz: "The tweeter and midrange on the 8c's are acoustically aligned. They are both delayed to be aligned with the subs, so you get what is often called a virtual point-source. The two subs get the exact same signal. The bass works best when the 8c is placed relatively close to the front-wall. Then the wall and the speaker become a single system, with a hemispherical radiation pattern (this matches well with the cardioid radiation pattern above 100 hz). When the 8c is placed right up against the wall, the 'reflection' against the wall is not really a reflection, it is perfectly coincident with the direct sound from the drivers. When there is some distance between the 8c and the wall, the acoustic center of the combination of the woofers and the wall (the point from which the sound appears to emanate) shifts a little towards the wall. With the presets we add a little more delay to the tweeter and midrange to again align them with the bass, so the result is still a virtual point-source with both flat amplitude and phase." If you look at the near field measurements I took of the 8c's in the Objective Measurements section, one can see that indeed the direct and reflected sound are coincident. The result is a virtual point source with both flat amplitude and phase, as shown by my measurements. Hope that helps.
  6. @M DeBoard Thanks for your comments. I know it is counter intuitive, but if you look back in the Setup. Config and Calibration section, you will see a slide entitled, "Perceived versus measured spectral balance." What it is showing is while the steady state, in-room measurement is a sloping or tilted response from 20 Hz to -10 dB at 20 kHz, is actually perceived by our ears/brain as a "flat" or neutral response. If you follow the links in that section to Dr. Sean Olive's and Dr. Floyd Toole's research, there is quite a bit of science behind this, which correlates this perceived versus measured spectral balance. This research has been repeated several times, with many participants in controlled subjective listening tests, and the results are consistent. As noted in the slide, a measured flat in-room response is not the preferred target. Our ears would "perceive" that is way too bright. I have tried that a number of times and would agree. I have a drum kit in the same room as the speakers and often play along. With the speakers calibrated to sound perceptually flat (i.e. in-room measured response from 20 Hz to -10 dB at 20 kHz). The spectral balance sounds tonally neutral to my ears, not too dull, not too bright, but just right 🙂 While most speakers can't match the sheer output of a live acoustic drum kit, the cymbals do not sound rolled off at all and match the tonal balance when I put sticks to cymbals on my kit. In the listening results section, I wrote a couple of paragraphs on this comparing to a recordings of cymbals and bells. Definitely does not sound rolled off. Hopefully that reconciles the discrepancy between the measured in room response versus what our ears/brain perceives.
  7. @heycarlos Thanks for your kind words. It was a long time ago... At that time, most studios had a soffit mounted pair of Urei 813 time aligns or Westlake's were very popular. For near fields, Yamaha NS-10M, JBL's of all sorts from 4312's to 4401's to 4406's to 4311's and on it went - it was all West Coast sound where I was... I had Tannoy NFM-8 which were really nice, but they still had not worked out the odd midrange bump of their dual concentric design. Auratones (horrortones!) were everywhere and far from being fidelity - used to check how your mix would sound over a car radio 🙂 Relative to the nearfields back in the day, none compared at all to the 8c's. Nearfields sitting on the mixing bridge were typically free field and always lacked bass. Also the industry was just catching on how controlled dispersion was a big deal as most speakers from that era had narrowing directivity as frequency increases. So during final mixdown, the artists and producer would take turns sitting in the mxing chair as that was the only place where to top end balance was correct... Really wish I had the 8c's back then!!
  8. Hey Mike, thanks for the comment. I am a Windows PC kind of guy, so probably not much help to you here... The only thing I can think of is running BruteFIR on a raspberry pi... Here are a few examples: https://github.com/TheBigW/DRC and https://community.roonlabs.com/t/guide-high-quality-room-correction-with-raspberry-pi-roon/15306 and http://edoc.sub.uni-hamburg.de/haw/volltexte/2018/4193/pdf/thesis.pdf might give you some ideas... Good luck! Mitch
  9. Thanks Juergen! I appreciate you giving my articles a read and your kind comments! Yes, I am amassing a nice little library of in-room measurements. There are some interesting correlations... In the end, it is all about how speakers sound in a home environment. More to come... Thanks again. Cheers, Mitch
  10. Peter, as you may or may not know, I am big into digital room correction. You will find four articles here on CA, plus a book. I understand what you are saying. Based on the directivity and voicing of the 8c's, I would say that super smooth, tilted response would sound similar to the Revel Salon2's. If one overlaid the frequency responses measured at the LP, they are quite alike... The issue is that many speakers are still voiced using a flawed approach, as mentioned in the soapbox section and elsewhere. Sean Olive and other studies have shown that there is no correlation between price and frequency response. When it comes to speakers, frequency response is the determining factor for our subjective opinion of sound quality. This makes it harder to compare to other speakers...
  11. Just following up and posting the RT60 or REW decay time for my room. This is with 4 x 2' x 4' broadband absorber panels on the back wall, 2 more on the left side wall, that you can see in the room pic. 2 x bass traps on the left, in front of an unused fireplace. Keeps the metal from rattling and the cavity from resonating. Heavy 20 oz velour acoustic curtains. Thick carpet with double underlay between the speakers and couch. While I get a nice flat response for reverb/decay time, it is at the top range of recommended reverb (i.e. decay) time for my room. volume. Top range is 400 ms. Meaning, while the room has an even decay time over a broad frequency range, it is still a lively room. You can hear it on the sub recording above in Rihanna's voice about 3 seconds before the video ends...
  12. I am glad you liked it! The packaging is excellent, double thick cardboard boxes with foam inserts that float the speaker. I believe there is a dealer network, but, it is unlikely that the whole speaker would need to be shipped back to the Netherlands unless there was physical damage to the cabinet or drivers. The electronics panel has 6 screws on the bottom and 3 cables to unclip to be able to remove the panel and ship. So in the unlikely event that the loudspeaker needs servicing, it is more likely that it would be the electronic panel that needs shipping, which is small and weighs less than 5 lbs.
  13. Good quetion for Martijn @mensink Yes the fan kicked in, but I never heard it from the listening position. I could barely hear it with my ear right by the speaker/stand with no music playing. It is very quiet.
  14. Thanks! Given that the subs output 100 Hz and below to the front wall, whether it is glass or drywall will make little difference. Well, wrt room treatments, it depends. The lower the frequency you go, the less room treatments have an impact, unless you stuff the room. So really, for all intensive purposes with these speakers you don't need bass traps. Depending on how lively your room is will depend on whether you ditch the room treatments or not. In the article, I reference industry guidelines for studio control rooms and critical listening rooms, which there is a spec for decay time based on the volume of the room. Mostly it is a range. Even with a few broadband absorbers on the back wall and heavy acoustic drapes on the front wall, my room is at the upper limit of the spec for being almost too lively, but the response is smooth across the frequency range. It's late now, but I will post the decay time of my room tomorrow.
  15. @Emlin Ah, I see what you are saying and understood. I am hoping that Martijn @mensink can drop by and comment on the roadmap for the user interface. I know he was on his way to Beijing, so maybe a bit before he can comment... @Em2016 Thanks! Good question. Yes, I understand Roon integration is being developed, but I am hoping like above, Martijn can join the conversation and comment on the streaming roadmap...