REW interpretation help

[Keith_W]

I use an old recording of Kathleen Ferrier because I love her voice.

When I say "small", I mean "focused". Imagine this: if you toed your speakers out a ridiculous amount until they were pointing directly at the wall, the centre image of a mono recording will sound diffused, as if she was smeared in front of you. As you start to toe them in, the image will become more and more focused. Do it too much (say speakers pointing at each other) and it will start to become diffuse again.

The problem is that tonality also changes with toe-in. You have already indicated you don't like too much toe-in, because it sounds too bright. This is why we DSP, you can obtain centre focus AND maintain a pleasing tonality.

 

[Deepinton]

Here are toe in experiments at 5, 10, 15, 20 and 30 degrees. Only R speaker to save space. Just eyeballing seems to suggest 20 yields the best measurements. But the drop is there even at 30 degrees which is straight at my ears, so something is up. I will leave them at 20 for a few days and see/hear. Who knows, maybe the data tricks my mind into hearing different and liking it

 

[Keith_W]

There is only one measurement in that MDAT, at 30deg. It doesn't look too bad, I could happily live with that.

 

[Deepinton]

I use an old recording of Kathleen Ferrier because I love her voice.

When I say "small", I mean "focused". Imagine this: if you toed your speakers out a ridiculous amount until they were pointing directly at the wall, the centre image of a mono recording will sound diffused, as if she was smeared in front of you. As you start to toe them in, the image will become more and more focused. Do it too much (say speakers pointing at each other) and it will start to become diffuse again.

The problem is that tonality also changes with toe-in. You have already indicated you don't like too much toe-in, because it sounds too bright. This is why we DSP, you can obtain centre focus AND maintain a pleasing tonality.

Thanks for the track! While I can't, or rather shouldn't, DSP my turntable, i do have options to tweak the sound with the C55's 8 band analog equalizer. Would that help any? My wiim ultra, which I use for streaming has a built in parametric equalizer, but i have not used it much. Does DSP cause any other detrimental sonic effects?

 

[Deepinton]

There is only one measurement in that MDAT, at 30deg.

ah sorry, my bad. Heres an updated file

 

[Keith_W]

I don't know what a "C55" is. If it's a graphic equalizer, you could certainly play with it and see what result you get. It won't be particularly precise though.

DSP is a very powerful tool, and like any powerful tool it can do immense harm if it's not used properly. In the same folder that you can find my REW eBook, you can find some Acourate eBooks. Those are more like recipe books. I make no attempt to explain what you should DSP and leave alone in those books, I assume that the reader has an idea and needs to know the procedure in Acourate to accomplish their goal.

That latest set of measurements shows what I would expect - more toe in, more treble. You can see and hear for yourself how such a minor adjustment / tilt in the frequency response can affect the tonality in such a profound way. Imagine what DSP can do. There are dozens of DSP threads on ASR, I suggest you go through them and see how people are using it.

And yes, you can DSP your turntable. It is possible to dispense with your phono stage altogether and perform RIAA equalization entirely with DSP.

 

[Deepinton]

I don't know what a "C55" is. If it's a graphic equalizer, you could certainly play with it and see what result you get. It won't be particularly precise though.

DSP is a very powerful tool, and like any powerful tool it can do immense harm if it's not used properly. In the same folder that you can find my REW eBook, you can find some Acourate eBooks. Those are more like recipe books. I make no attempt to explain what you should DSP and leave alone in those books, I assume that the reader has an idea and needs to know the procedure in Acourate to accomplish their goal.

That latest set of measurements shows what I would expect - more toe in, more treble. You can see and hear for yourself how such a minor adjustment / tilt in the frequency response can affect the tonality in such a profound way. Imagine what DSP can do. There are dozens of DSP threads on ASR, I suggest you go through them and see how people are using it.

Sorry, the c55 is a McIntosh pre amp with a built in 8 channel analog equalizer. And yes, I will dig into DSP. Thanks!

 

[Deepinton]

.

That latest set of measurements shows what I would expect - more toe in, more treble. You can see and hear for yourself how such a minor adjustment / tilt in the frequency response can affect the tonality in such a profound way. Imagine what DSP can do.

Should I still be concerned about that drop around 1.5khz?

 

[Keith_W]

Should I still be concerned about that drop around 1.5khz?

As you can see, once you toe it in a bit the 1.5kHz step disappears.

 

[LSPhil]

ah sorry, my bad. Heres an updated file

I took a look at the RT60 measurement, and I'm fairly confident that there isn't much indirect (reflected) sound being generated in your room. It might be worth experimenting with those settings to see how they affect the results.
I'd also be very interested in seeing a direct measurement of the tweeter.

 

[Deepinton]

View attachment 537437

As you can see, once you toe it in a bit the 1.5kHz step disappears.

What smoothing did you apply to get this?

 

[Deepinton]

I took a look at the RT60 measurement, and I'm fairly confident that there isn't much indirect (reflected) sound being generated in your room. It might be worth experimenting with those settings to see how they affect the results.
I'd also be very interested in seeing a direct measurement of the tweeter.
View attachment 537440

Yes, my room was practically dead when I started on this journey. 2" polyester wool padded side/back walls, acoustic tiles on the ceiling, carpet, etc. I added some diy curved slat panels on top of hardboard to the rear half of both side walls, added hardboard panels to the back wall, and got rid of the heavy curtains on the window. These changes got my REW rt60 measurements up a bit but still under my target of 250, but they made a big difference to the sound. Any suggestions on how to get the number higher (other than ripping out all the beautiful side wall treatments)? The rear of the entertainment center you see in the picture is about 3' away from the actual hidden front wall. That space was acting as a resonating chamber, so I removed all the doors from the entertainment center and put in lots of glass wool panels in front of the actual front wall to tame the bass a bit.

 

[Deepinton]

What smoothing did you apply to get this?

NM, I see it's 1/2. But the downward slope after 1.5khz still shows. Or am I reading this wrong?

 

[Deepinton]

any idea why the L+R measurement shows ups and downs around 4khz?

 

[Keith_W]

It's usually an artefact from an improperly centred microphone. It will disappear if you do an MMM. Hopefully!! If it doesn't, you have a problem!

 

[Deepinton]

It's usually an artefact from an improperly centred microphone. It will disappear if you do an MMM. Hopefully!! If it doesn't, you have a problem!

You are right. An RTA measurement shows none of those gyrations.