Why is "beating speaker frequency response into submission" via EQ a bad thing?

[SkizeR]

We'll talk about it tomorrow. It's hard to type out

Sent from my SM-G975U using Tapatalk

[Jdunk54nl]

This is semi embarrassing to even post.....but for the sake of learning I am going to.

I don't have REW graphs but will just to check them out but I was paying attention to the Helix RTA graph and didn't notice anything really weird on it. I am guessing something will show up on REW when I check speaker pairs but will post again once I get the chance to get those graphs. I want to know if something would have shown up on REW...it should when playing pairs.

I threw my 3 way together, spent about 10 minutes waving a microphone in front of my face using the helix auto rta. I did left side together, right side together, sub, then everything together. I never checked individual speakers/pairs or did anything beyond that. I changed my process and didn't do other necessary things with the new process. According to the Helix RTA, my speakers summed greater than the separate sides.

Nick (skizer) got into my truck this past weekend and nearly instantly said your midbass and midrange are out of phase. He pulled up the helix software and went through flipping polarity and he was definitely right. It should have been an easy test and is normally in my tuning routine with REW. But the RTA didn't show anything weird and I didn't have the time to check. I should have known something was out of phase. Every time something is, my ears get the clogged feeling from listening to out of phase stuff.

Point is, check speaker pairs (by ear using mono/correlated pink noise) and....just because on the RTA it is louder...doesn't mean you don't have phase issues....

[jtrosky]

This is semi embarrassing to even post.....but for the sake of learning I am going to.

I don't have REW graphs but will just to check them out but I was paying attention to the Helix RTA graph and didn't notice anything really weird on it. I am guessing something will show up on REW when I check speaker pairs but will post again once I get the chance to get those graphs. I want to know if something would have shown up on REW...it should when playing pairs.

I threw my 3 way together, spent about 10 minutes waving a microphone in front of my face using the helix auto rta. I did left side together, right side together, sub, then everything together. I never checked individual speakers/pairs or did anything beyond that. I changed my process and didn't do other necessary things with the new process. According to the Helix RTA, my speakers summed greater than the separate sides.

Nick (skizer) got into my truck this past weekend and nearly instantly said your midbass and midrange are out of phase. He pulled up the helix software and went through flipping polarity and he was definitely right. It should have been an easy test and is normally in my tuning routine with REW. But the RTA didn't show anything weird and I didn't have the time to check. I should have known something was out of phase. Every time something is, my ears get the clogged feeling from listening to out of phase stuff.

Point is, check speaker pairs (by ear using mono/correlated pink noise) and....just because on the RTA it is louder...doesn't mean you don't have phase issues....

So your midrange and midbass speakers were physically wired differently in terms of polarity? Is that why they were out of phase? Or was it a setting within the DSP that caused them to be out of phase?

Just curious how you got to that point.

I have one of those polarity-checking tools - very nice to have to make sure polarity is correct - but you really only need it when you physically mess with the speaker wiring - otherwise, you can check phase settings in the DSP. But for $10 off Amazon, it's a nice-to-have.

[Jdunk54nl]

So your midrange and midbass speakers were physically wired differently in terms of polarity? Is that why they were out of phase? Or was it a setting within the DSP that caused them to be out of phase?

Just curious how you got to that point.

I have one of those polarity-checking tools - very nice to have to make sure polarity is correct - but you really only need it when you physically mess with the speaker wiring - otherwise, you can check phase settings in the DSP. But for $10 off Amazon, it's a nice-to-have.

I have the polarity app which does the same thing and everything is electrically correct from that. Also every wire in the car for speakers is aftermarket and is easy to tell which is the positive side and which is negative. In other words, it is not an electrical issue but I do not know what would cause it. Someone that has more knowledge than me can chime in.

[Jdunk54nl]

I am actually willing to bet that I have had phase issues more often than I think. I am really starting to realize that when phase is good in my truck, I have ZERO issues with my ears (like right now). When I do have phase issues or am checking phase, my ears always get a clogged feeling.

I remember quite well many times when my ears would get this clogged feeling and I could never figure out what the issue was so I just re-did everything. I would bet money it was a simple phase issue now knowing what I know.

[subwoofery]

Seat at equal distance from 2 speakers playing the same music - everything is coherent and in phase

Seat closer to the left one and both speakers are playing the same music - you now have a timing issue and a level issue
Both equals to phase problems.

Starting with the correct polarity helps but is not the remedy to a phase problem. In a car, you rarely if ever seat at equal distance from both speakers. To make the matter worse, you have 5, 7, 12, 15 speakers playing different frequencies, some louder, all with added refletion, etc...

I get the same feeling when something is out of phase (clogged ears)

Kelvin

[jtrosky]

Seat at equal distance from 2 speakers playing the same music - everything is coherent and in phase

Seat closer to the left one and both speakers are playing the same music - you now have a timing issue and a level issue
Both equals to phase problems.

Starting with the correct polarity helps but is not the remedy to a phase problem. In a car, you rarely if ever seat at equal distance from both speakers. To make the matter worse, you have 5, 7, 12, 15 speakers playing different frequencies, some louder, all with added refletion, etc...

I get the same feeling when something is out of phase (clogged ears)

Kelvin

But isn't that what time alignment is for (the speakers being at different distances)? I'm sure he had time alignment setup (and I'm assuming correctly since he didn't mention having to change that).

Although - @Jdunk54nl do we know exactly what was changed to "fix" the phase issue? If so, that would probably tell us what the problem was.... :-)

[Jdunk54nl]

Polarity was swapped in the dsp software for midbass. Beyond that I am not 100% sure what Nick changed.

yes time alignment was set via tape measure.

[jtrosky]

I'm really curious to hear if anything else was changed. I can't think of any reason why a complete polarity flip on the DSP would fix the issue unless the midbass speakers were physically wired with the opposite polarity of the midrange speakers - but you mentioned that they were definitely wired the same... I'm really curious to find out if anything else was changed to fix it - as well as how to easily identify the issue to begin with (which was the main point of your post).

[Jdunk54nl]

I'm really curious to hear if anything else was changed. I can't think of any reason why a complete polarity flip on the DSP would fix the issue unless the midbass speakers were physically wired with the opposite polarity of the midrange speakers - but you mentioned that they were definitely wired the same... I'm really curious to find out if anything else was changed to fix it - as well as how to easily identify the issue to begin with (which was the main point of your post).

It was easy for me to hear when you played pairs of speakers with correlated/mono pink noise. Nick picked it up without even doing that. I think it was the "lack" of midbass he noticed. I know he did do some further EQ work, but you could tell a HUGE difference just by flipping the polarity of the speakers.