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Everything posted by MartinC

  1. Any chance of 'You Tube' in the thread title being changed to 'YouTube' as one word? Probably just me but I keep having to remember it's written as two separate words when searching for this thread...
  2. This escalates... (Lots of good but less silly videos on the channel too.)
  3. Which isn't at all concerning .
  4. Sound like it's expecting a stereo input then? So more like a soundbar than center channel (which would be mono)?
  5. Please re-read my long post from this morning, and earlier posts in this thread. I'm not going to keep repeating myself.
  6. With apologies to @flak monkey if you feel this is derailing your thread, but let me have a go at quickly proving what I've said to try to wrap this up. As a very quick demonstration, here are measurements of each of my main speakers individually (run full range rather than with a subwoofer): Below is a comparison of what I get if I measure the two speakers simultaneously in black, compared to what I get by calculating the sum of the two individual measurement in red. To achieve this I used the acoustic timing reference option in REW which is good enough that the sum is very accurate for all but the highest frequencies, where frankly there is no point looking at the sum anyway. (@Camverton note that this is a demonstration for an asymmetric setup, as shown by the different responses for the two speakers.) For the sake of demonstration I then produced an EQ filter based on the calculated sum, targeting a flat response below 200 Hz at 78 dB. Measuring the result of applying this filter to both speakers, with both speakers playing together, I got the result in purple below (with the uncorrected combined response in black for reference). Finally, here's what the left and right speakers measured individually with the EQ applied look like. Note that the individual responses are far less flat below 200 Hz than the combined result above is.
  7. What are you attempting to demonstrate with the RMS average there? It does not represent the response for the two speakers played at the same time.
  8. Yes, which is absolutely key to what I posted above. My whole point revolves around the phase response being affected by the room, not just the amplitude response.
  9. Lots of people appear to advertise both CDs and vinyl at what seems distinctly optimistic pricing; I'm guessing just in case someone is actually prepared to pay it. Adverts don't necessarily reflect what items actually get sold for...
  10. The result will be the same no matter what the layout, provided the same and accurate timing reference is used for both measurements, and the sum is the (mathematically) complex sum rather than simply adding the amplitude responses. In practice for most it's probably simplest to just measure the two playing together though.
  11. Two products you could consider to demo would be a NAD C658 or miniDSP SHD.
  12. If you use the same time reference for both, you can measure each speaker response separately and then calculate the sum in REW. I'm somewhat wondering what you are describing as a hypothesis though so let's break this down... Do you understand and agree with my key point? This is, if you were able to EQ the amplitude response of each speaker at the listening position to be identically smooth (flat or whatever shape you want), the sum would not be flat if there were differences in the phase responses of the two. This is mathematical and therefore acoustical fact, not a some sort of hypothesis. To take an extreme example just to maybe help explain the point - if you have an equal amplitude from each speaker but they end up being perfectly out of phase at the listening position, then they will sum to zero. Consider panning the signal level from all on the left, through equal on each channel, to all on the right. What would be heard at the listening position would be that the sound level will start at one level and gradually drop as the signal moves to the center, and then rise again as it's moved to the right to get back up to the starting level. For the low-bass frequencies I'm talking about this is purely a level change, not something that affects the direction the sound appears to be coming from. You very likely don't normally look at the phase responses but for info. when the measured amplitude responses for the two speakers are different it is basically guaranteed that the phase responses will differ too. It's a consideration I've likely looked at more as it affects my choice of crossover frequency between main speakers and subwoofer. I first realised the issue when considering EQ for my own speakers but then switched to using a subwoofer which removed the complication . For clarity let me also stress that I have not dogmatically said something like 'everyone must EQ low-bass based on the sum of left and right speaker signals'. What I've done is explain that there is reason to consider both the individual and summed signals. The nature of low-bass signals in I suspect most recordings does though make me lean towards prioritising using the combined response. What this certainly means is that I won't pronounce as 'wrong' someone who does this and likes the result. I'm afraid what I've shared above has come from my own brain, based on application of my own knowledge and experience rather than something that I can point you to some particular source for.
  13. This is absolutely the right thing to do .
  14. Let me restate my point. If you EQ the amplitude response of each speaker individually to be flat but they have different phase responses, then the sum will not be flat. Your mono signal would be the summed situation. For signals that are predominantly 'mono' you are therefore arguably better off EQing the summed signal. I would only consider EQing the sum in the region where the sound could not be localised though, not at 200 Hz.
  15. Two thoughts: Other types of music are available . I'm not sure what sort of microphone techniques are typically used for live classical recordings but I wouldn't be surprised if the low bass (let's say < 100 Hz) is generally of a pretty equal level on both recorded channels? Note that any localisation of where double-basses will be down to higher frequency content (harmonics or higher notes). Human hearing is not capable of localising the frequency range I've been focusing on. You might but there is no universal 'we' here. For info. I believe* Dirac Live factors in both the individual and summed response although quite how the balance is weighted when deciding on what adjustments to apply I have no idea. *Edited as checking quickly I can't actually find anything to prove this. I thought it was referred to in a changelog but I can't find it. Possibly I'm mistaken on this this point...
  16. Devil's advocate - lots of remasters are worse than older versions too.
  17. Thinking about it, one other way that music streaming importantly differs from 'renting' in general, is that the music files aren't somehow degraded by previous use by others.
  18. Do you think some users of streaming services are under the impression that they do 'own' anything? I'd suggest few if any do. Rather than renting I view cloud-based music streaming services like vast libraries that I'm paying for access to, like you conceivably could to access a physical library of books. What I pay in a particular month is for access in that month - nothing more or less. The huge benefit over ownership is that I have access to pretty much whatever I want in any given month, rather than having a choice largely restricted to what I may have previously bought. Are there albums that I bought 20-30 years ago that I still listen to occasionally? Yes. But the vast majority of what I listen to is actually music I've 'found' much more recently. I assume you realise that you could stream high-res. content from Qobuz for just £10.83 per month (if you pay for a 1 year subscription)?
  19. That does make more sense . I'd guess downloads aren't used too much by most, but you make a fair point regarding saved favourites or playlists. I wonder if there's a simple way to save/export these at all as a backup actually.
  20. Good point, I imagine if you measure the response at a null point it will think there's no problem whereas if you measure at the peak it will maximise the eq. Even when optimising for a single listening position it still makes sense to base EQ on some sort of average over a range of positions. Most listeners have two ears that are not at the same location for starters . My personal experience is very much that EQ can do an excellent job at enabling a full-range sound in a modestly sized room without boomy room mode issues.
  21. You would presumably be switching to another service that provides this access though? Not sure what your point is...
  22. Might be worth adding 'speakers' to the thread title .
  23. At a single listening position, that I'd agree with .
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