rcohen

JRiver has lots of clock options, and you also can tune the audio/video delay offset to compensate for latency in your display and your receiver.

If you are using JRiver, that is one of the options you can select. It prevents doing any signal processing on the PC, though.

Following up on this thread, the approach of zooming in on the right side of the graph and extending the EQ window as shown in post #13 gave me great sounding results that I was very happy with.

I have used Dirac Live and Audyssey XT32 (normal and Pro). Dirac Live was definitely an audible improvement. I did the free trial and didn't want to go back. If you're not sure, it's definitely worth the time to try the trial. There is some technique to finding the right target curve, but I thought it was fun. Of the ones you listed, I understand that they get harder to use in this progression: Audyssey, Dirac, Audiolense, Acourate That said, Dirac is easy to use.

I guess I should have said that while it's possible the default target curve will work best for you, in many cases it won't, and the ability to tune the target curve is extremely useful. The default curve is clearly based on studies of the preferred curve in average home listening rooms, but here are reasons one curve doesn't fit all: 1) The reflectivity of the room has a big influence on the preferred frequency response. That's why different default target curves are used for homes, theaters, studios, and outdoor venues. They have very different acoustic properties. Different home listening rooms can have quite different acoustic properties - easily enough that many will want to change the curve to have perceptually neutral sound. 2) The distortion produced by speaker drivers will influence your ability to tolerate loud sound. For example, some tweeters sound nice with a flat response, while some sound much better rolled off. Some are somewhere in between. 3) The dispersion characteristics of speakers will influence how 1 & 2 interact. 4) People honestly have different taste. I like a bit more bass than the default curve. It would be nice if there was just a ground truth with frequency response, so we could all hear what the artists intended. Unfortunately, it's more complicated than that. Dirac's default curve is a good start, and a good end for some. But just because it was perfect for you doesn't mean it will be perfect for all people, all speakers, and all rooms. Even given all these variables, good room correction is quite valuable and worthwhile, IMO.

IMO, it's not possible to get quality room correction with a predefined target curve. The right target curve is highly dependent on the room, speakers, and personal taste. With the upgrade, the XMC-1 has great potential.

That's exciting to hear. I love Dirac's sound quality and iteration, and still using it happily. I do wish it had more flexibility like Audiolense XO, though. Specifically, I wish I could measure and insert filters into the JRiver DSP chain, to take advantage of 64-bit floating point processing, to eliminate dynamic range issues I'm struggling with when doing bass management post-Dirac with high efficiency speakers. Alternately, if JRiver's flexible bass management, active crossover, and channel distribution features were built in to Dirac, that could accomplish the same thing, especially if more channels were available. Atmos decoding is another problem, since that is currently only available inside pre-amps. Audiolense has this same issue, though. It would be REALLY compelling of there was a good room correction/EQ solution that worked with Atmos for prices within reach ($2k, not $20k).

10-4. When I measure from the speakers, I actually have often found some subtle FR differences between amps and DACs, despite the common evidence that they are all the same. These are generally small - in the <1.0 db range. Audibility is subtle and dependent on the content. The small differences are easily compensated for by room EQ software without side effects, though, assuming you remeasure through the equipment. After remeasured EQ, I can't hear the difference. I'm actually experimenting with JRiver vs pre-amp bass management now. Pretty confusing actually, with some clipping problems coming up with doing it in my pre-amp, and it's tricky to get Dirac set up right with doing it in JRiver.

It makes sense that differences would be smaller if you are already close to where you want to be. It can also be easy to chase your tail with psychological tricks. There have been times that I've found myself imagining differences when Dirac was actually off. My perception of the sound changes with fresh ears in a new session. Also, every recording is different, so it's not like there's a single perfect answer that applies to everything. Still, I found that after multiple sessions of tweaks, I was able to dial it in to a sound that I was happy with...right as I got new speakers and had to start over.

There's a crossfade region between the gold dot and the orange dot. After the orange dot, nothing gets changed. Still, if everything to the left of the orange dot gets lowered, that's the same as a spike to the right of the dot. The tilt on the default curve for speakers with extended treble past 20khz creates this condition.

Did you rerun the measurements when comparing the e28 and the Integra? I typically find that the differences between DACs and amps disappear when I rerun measurements and room correction on them. Also, sometimes the differences between microphone positions will cause a greater difference than the DACs themselves. I assume you aren't using subs?

BTW, this is another example of Dirac spiking the treble on the right side of the graph. It creates a FR with a nice tilt, but that puts the measured treble over the line and spikes it where the filter rolls off. This sounds edgy and fatiguing to me. You can flatten it out by zooming in, but it's strange default behavior for a speaker with good treble extension. Why not a shelf filter? Regarding clipping, a Clip Protection option similar to the one in JRiver would be nice. That automatically scales down the volume when clipping is detected. No clipping is really what you want, but it's easy to get clipping and bad sound if you're not paying attention. It sounds like it's not so straightforward on Macs. Too bad everything doesn't standardize on double-precision floats. I've actually been struggling a lot with clipping in different parts of my system, especially since introducing a some high efficiency speakers to the mix.

Regarding the BBC dip, I think that depends heavily on speakers. It's probably best to use the standard response of the speakers as a guide, but you can go with whatever you prefer. I prefer it without the dip, myself.

I'm basically talking about rounding out that left upper-left corner on your first graph a bit, to see if it improves your impulse response. The idea is that a filter is getting generated based on the difference between the measured curve and the target curve. Filters with high amplitude steep slopes may introduce ringing. Sometimes, though, this ringing can cancel out ringing from your room, and actually fix ringing from the listening position. Either it will sound better, worse, or you won't be able to tell the difference, and you should go by that.

LBob, a couple suggestions based on my experiments. YMMV, so see if this works well for you: 1) On the left side, avoid that sharp right-angle change in slope between the measured response and the target curve. The difference between the two curves is the correction filter. When the correction filters have steep slopes with high magnitude, that causes ringing. This is most audible with the bottom frequencies as blurring out fine details. Instead, try to smoothly transition from the measured response to the target curve. This may help with the impulse response. 2) On the right size, when the treble angles up like that, it can sound harsh. Try zooming in around the right side of the graph, dragging right-hand limit beyond the rolloff point of the measurements, and create a target curve where the treble tapers down very slightly to the limit, rather than shooting up. Find the shape that sounds detailed and natural, but without harshness or fatigue. This side of the curve can be very sensitive to small changes, and the sweet spot varies depending on speaker and room.