Magic Beans And Measurements

[@joentell]

To be clear, bass can be EQ'ed, and should be, from the main listening position in the farfield. The higher frequencies should be corrected for in the nearfield. The reason being that for the frequencies above the transition region in the room, some people refer to it as the Schroeder frequency, what we perceive is the direct sound and we can separate out the reflections that occur thanks to our binaural hearing and our brain's ability to distinguish between those sounds. A single mic placed at the listening position is already affected by nearby reflections at the listening position, as well as reflections from the walls, floor, ceiling, and nearby surfaces and it becomes impossible to separate out the room effects on the measurement. There's air attenuation in the higher frequencies which is distance dependent. That, the speaker's directivity and reflectiveness of thr room affect the high-frequency roll-off. In most popular room correction software, they're mainly just guessing what the roll-off should be.

[@juliangst]

But why should you correct anything above the Schröder frequency at all? Getting linear and smooth directivity speakers in the first place is not that expensive nowadays.

[@joentell]

​@@juliangstif you have speakers with good directivity and are already flat on-axis, then you probably don't need any EQ above the transition region. Some speakers have decent directivity but maybe the treble is too high due to the crossover design. There are various reasons why someone would want to EQ the upper frequencies. Just consider if you were the speaker designer and had access to DSP. You would likely use it to optimize the linearity of the speaker response if you had the option. We have that option, so why not use it?

[@kejar31]

what about ~200 to 500 or 1K?

[@kejar31]

Also what about speakers that require a decent distance for the tweeter and mid-range to summize? Would near-field not show a dip in the transition freq?

[@joentell]

@@kejar31 yes, that likely right where the transition region starts and can be EQ'ed based on the nearfield measurement

[@sudd3660]

i would say that every speaker need eq when placed in a room. and the last part of the eq is done by ear at listening position(assuming 2 channel one listener). then we need to pick the speakers, room and room treatment so that it matches what we want, so that we need at little eq as possible. all these recording engineers, music producers, drivers, speakers, designers, try to make things after their goals. and i think that the end sound is perceived as about equally loud at all frequencies. so then you know that any tone made in that song is coming across to you about as loud and any other nearby tone and you won't miss anything or have a loud peak somewhere. i wrote this to leave room for any kind of audio taste and preferences.

[@joentell]

Most recording engineers listen nearfield where most of the sound you hear is based on the direct sound of the speakers. In other words, they're in the direct dominant field. Most people listening to speakers in their home are beyond the critical distance (where the direct sound and reflected sounds are equal) and they are usually in the reverberant field. Bass should be corrected for in all situations. My argument is that the higher frequencies should be EQ'ed based on the direct sound and not based on what's measured in the farfield response.

[@sudd3660]

@@joentell good recording engineers mix in one place like the ones you said, then test it in another environment and often in many. they should now about all the effects. some mix in home room like environments also. we can only hope the music we listen to is done to sound the best in the playback listening environment we use. the room effect on the sound still has to be tuned by ear so that a large or tiny room does not add up to peaks that wont show up on simple measurements. think we view audio the same way, and hopefully magic bean get more people interested how this all works and they can chime in how it sound in the end, and the effect audio enjoyment :)

[@MrOkcyurwin]

I read about and listen to a lot of different spaces to understand room acoustics (just a hobby). Room acoustics and speaker acoustics are simply two different things. A speakers can be built to pressurize air in a certain way to optimize the audio frequencies but that's only near field. Once those same frequencies start reflecting of solid objects, floor, ceiling, walls, that same frequencies/pressure is now a product of the room acoustics and NOT the speaker. Correct placement of speaker in room; best MLP in conjunction of where the speaker has been placed; correct volume/pressure for the room; the correct acoustic treatments; and finally room EQ (Ideally below 500hz- stereo). The AV industry (folks that have something to sale😉) will sing about room EQ software is the answer to your poor sounding TV room. This false narrative is why we can argue over which room eq software is better than the other. A polished bit of poo will still smell of poo. Room eq is just polish. If you do everything stated above first then room EQ can be missed out and you should still have a decent sounding stereo system. 5.1 and above is a whole different level of problems but again start with the basics. Don't see room eq as the ear of god👂😊👍🔊🔊

[@joentell]

I agree with pretty much everything that has been said above. EQ is not the answer to all the problems. Buy good speakers, place them properly, use treatment, and ensure you're not sitting in a null. That will go a long way. EQ can be helpful when you are missing some of those things. Lots of home theater systems require compromising on some of the things mentioned and EQ can help. I just came back from NAMM a few weeks ago and got to meet some famous recording engineers. The good thing about their setups is they start with good speakers like Genelecs or Neumann for example, which already utilize some of the DSP techniques I'm advocating for (correct for the direct sound so that the response is linear) and they do use EQ for the bass in-room. Unfortunately, there are some mixers using speakers that are known to measure poorly and some really don't know as much about audio as one might expect. It just depends on who you talk to.

[@TokeBoisen]

Most talk I've seen on DIRAC especially has concluded that you shouldn't force a flat response for your speakers unless you know they're both flat and have good dispersion characteristics, at which point they should measure rather flat to begin with, but DIRAC have struggled with the EQ being a little bit aggressive instead of trying to align with a speaker's natural response. Unless you know what your speakers measure like, using Dirac to EQ to flat is generally not recommended

[@JS-dh9wh]

Does this work with Lyngdorf RoomPerfect?

[@DailyHiFi]

It depends on whether you are able to create your own target curve or not.

[@Linkone7]

Does Magic Beans work with Anthem AVM90?

[@joentell]

I haven't tried the Anthem, but it looks limited. I don't see a way to import curves.

[@Linkone7]

​ appreciate the reply... looking forward to seeing it finally launch

[@joentell]

​@@Linkone7thanks! I wish there was a way to import curves into Anthem. Even PEQ import would be fine. I think you can draw in a curve which you could do, but it's a bit of extra work for the end-user.

[@Linkone7]

@@joentell I'm going to sing up for your beta...maybe I can test that on the AVM90 😉

[@michaelwyckoff7593]

Hey fellas😊

[@joentell]

Sup!

[@JohnSmith-qi6co]

Assuming there is a great target curve for my brain, room and equipment. Why is the one MB comes up with, that curve?

[@DailyHiFi]

Joe here. The effect of the room can be measured as well as the output from your equipment without the room's effect. Many years of research from Harman have shown over and over that we can consistently predict what most people like. The predicted response matched up to listener's preferences 95% of the time, but let's just say 90% to be safe. What people like is an accurate sound reproduction. This makes sense if we're talking about Hi-Fi since the goal is accurate sound reproduction. In other words, what goes the frequency response that goes into an amplifier should be the same as what comes out, just louder. The same applies to speakers. It's possible you're in the 5%-10% of people who prefer something that isn't accurate. That's fine. You can still use tone controls. But accuracy is the correct starting point.

[@JohnSmith-qi6co]

@@DailyHiFi So if as you say "the frequency response that goes into an amplifier should be the same as what comes out, just louder. The same applies to speakers." Shouldn't that mean that I want what's going in to be what ARRIVES at the MLP? That would mean we are back to measuring at the MLP rather than near field. Hmmm...I'm trying to understand. I think we need a simple statement like "This is the true target curve we want MB to come up with because it [[...fill in the blankk...]]"

[@JohnSmith-qi6co]

I should add that I'm worried that if I merely get real accuracy only near field, my crappy room might do somehting horrible to the sound by the time it gets to the MLP.

[@DailyHiFi]

That comment about wanting a flat response at the MLP is not correct, but a common misconception. When a guitarist plays an acoustic guitar and sings in your room from 10ft away, you don't want it to sound as if your ear was as close to their mouth as a mic would be. You would expect to hear the interaction with your room and your brain is smart enough to distinguish the direct sound from the effects of the room. What you want is the speaker itself to reproduce the sound accurately. So from 10ft away, it will have a similar interaction with the room as the live performer and the tonality from that distance will be nearly identical. Here's the statement you want: the True Target curve is that which the nearfield response of each speaker is as neutral as possible taking into account the nearfield effects of nearby surfaces. This pertains to the frequencies above the transition region where direct sounds and reflected sounds are distinguishable. Below the transition region, the room and speaker become indistinguishable and the True Target curve is determined by the room response and the ideal target is that where all the speakers follow a smoothed version of the room response.

[@DailyHiFi]

Your "crappy room" will affect all real world sounds, and yet you're able to determine what sounds real vs fake in your room. Our brains are amazing. That's why I think it's very important to not only study acoustics, but psychoacoustics which takes into account how we perceive sounds.