Should you make a different EQ for both of your speakers or have them both use the same?

[PingWine]

I know that this is a silly question but the reason I ask this is that one of my speakers is against a wall and another is in a corner. Should I measure them together and apply the EQ for both or should I measure them one by one and correct them one by one too?

It would seem logical to do them separately so that you wouldn't notice bass difference on either sides (I know you can't locate low bass but I counted low mids to this too as well as those are also effected by walls and such. )

On the other hand It'd be logical to measure them both together because in the end THAT'S the frequency response you're gonna hear - not two individual flat eq'd speakers.

Thanks in advance!

 

[MZKM]

Unless I’m wrong, EQ can add delay around those frequencies effected, which can cause phase mismatch, so even if both are EQ’d flat in one region, they won’t sum together and be flat.

So, it’s better to EQ together. However, if your layout isn’t symmetrical and there are large bass differences, then tame those separately.

 

[PingWine]

Unless I’m wrong, EQ can add delay around those frequencies effected, which can cause phase mismatch, so even if both are EQ’d flat in one region, they won’t sum together and be flat.

So, it’s better to EQ together. However, if your layout isn’t symmetrical and there are large bass differences, then tame those separately.

Would it be sensical for example counter the bass boost by already lowering the bass on speaker acoustic controls? Before even measuring anything

 

[Sancus]

Unless I’m wrong, EQ can add delay around those frequencies effected, which can cause phase mismatch, so even if both are EQ’d flat in one region, they won’t sum together and be flat.

So, it’s better to EQ together. However, if your layout isn’t symmetrical and there are large bass differences, then tame those separately.

I've never seen any room EQ system that EQed channels summed together so I don't see how it could be correct to do so.

If you are using one channel to correct for discrepancies in the other then surely it will sound wrong moment input stops being identical as is very common in stereo.

The only time it makes sense to me to EQ a sum of multiple channels is when the input is identical as in the case of multiple subs.

 

[PingWine]

I've never seen any room EQ system that EQed channels summed together so I don't see how it could be correct to do so.

If you are using one channel to correct for discrepancies in the other then surely it will sound wrong moment input stops being identical as is very common in stereo.

The only time it makes sense to me to EQ a sum of multiple channels is when the input is identical as in the case of multiple subs.

Now that you put it that way: it makes perfect sense, too

 

[QMuse]

Unless I’m wrong, EQ can add delay around those frequencies effected, which can cause phase mismatch, so even if both are EQ’d flat in one region, they won’t sum together and be flat.

So, it’s better to EQ together. However, if your layout isn’t symmetrical and there are large bass differences, then tame those separately.

Phase mismatch is caused by difference in phase response coming from different positioning of the speakers, not because of filters. Speakers should be measured and EQ-ed separately but response of both speakers should be measured in the 20-100Hz range to check if they sum up properly.

 

[edechamps]

The only time it makes sense to me to EQ a sum of multiple channels is when the input is identical as in the case of multiple subs.

It is of course possible to use a single EQ for multiple subs, but that's missing out on the potential for multi-sub optimization (a.k.a "sound field management" a.k.a "spatial equalization") to further improve the results

 

[edechamps]

Unless I’m wrong, EQ can add delay around those frequencies effected, which can cause phase mismatch, so even if both are EQ’d flat in one region, they won’t sum together and be flat.

I was under the impression that, since modal resonances are typically minimum phase, EQ'ing them away (with an equalizer that is itself minimum phase, as typical IIR "PEQ" filters are) actually makes the system more time-aligned and thus more likely to sum properly, not the opposite. I'm not entirely sure I understand the underlying reasoning though, maybe @JohnPM can pitch in.

 

[Sancus]

It is of course possible to use a single EQ for multiple subs, but that's missing out on the potential for multi-sub optimization (a.k.a "sound field management" a.k.a "spatial equalization") to further improve the results

Yeah subs get more complicated, as far as I understand there's 3 common approaches that I know of:
1) Measure each sub individually, EQ each individually(pre-bass module Dirac does this, afaik)
2) Set level and delay separately, but measure and EQ together(Audyssey does this)
3) Measure both separately and together, and EQ separately *to target* a flat response when measured together. As far as I understand, this is the MSO approach and also the Dirac bass module approach, it's the best but the most complicated.

 

[Lorenzo74]

On the other hand It'd be logical to measure them both together because in the end THAT'S the frequency response you're gonna hear - not two individual flat eq'd speakers.

Thanks in advance!

measure both and equalizing both makes no sense. If you have the possibility to eq separately best is to use it.
look at what dirac live or DEQX do. Each channel has a different interaction in the room ( except for perfect symmetry in room and speaker placement

then you might measure again with each individual correction applied and tune the stereo system if interaction between the two has affected the overall frequency response.
MY best
L.

 

[ernestcarl]

Well, you could apply the same general "house curve" EQ as a secondary layer to quickly alter the tone of the system as desired -- that is, after individually EQ'ing each speaker first, of course.

I have saved 3 house curve PEQ presets for my Sceptre S8 monitor + sub system -- well more likely two as the third one is just really a minor modification of the natural default curve, just in case... I've labeled these presets "forward" (for critical listening & most blu-ray movies) and "relaxed" (for most music, streaming, & TV watching) and then use my miniDSP remote switch to change settings as needed. The latter preset being what I'll be using probably ~80% of the time.

 

[Jon AA]

Certainly EQ each separately, aiming for the same curve. However, I do think it's a good idea to measure them together afterward and take a look at the bass region. Since the bass in much music is mono anyway, you want to know if a problem shows up when the two are played together--or if each speaker doesn't have a perfect response individually, they might give a smoother response when played together that will make you feel better.

 

[Hipper]

I look at it this way.

When we listen our left ear hears the left speaker plus some sound from the right speaker (called interaural crosstalk). Of course your right ear does the equivalent. If everything in your room was symmetrically arranged and each speaker produced the same signal each of your ears would hear an identical signal. This is correct. If however your room is not symmetrical each ear would hear different sounds from the speakers. This will need correcting so that they sound the same. Very rarely is a room perfectly symmetrically set up.

Therefore it is correct to equalise each speaker separately, at least for the low and mid bass.

Having an asymmetrical set up though will make it more difficult to get the correct stereo phantom image because reflections, something EQ can't do much about, will not be correct. The best way to deal with that would be to use some room treatment.

The ideal of course would be to start with a symmetrical speaker arrangement and I would put as much effort into this as you can before using EQ or room treatment.

 

[Karu]

In a 2.2 crossover setup, when you equalize each sub separately, how do you set the target level for each sub so that the combined final level of both subs matches with the level for the mains?

 

[JohnPM]

I was under the impression that, since modal resonances are typically minimum phase, EQ'ing them away (with an equalizer that is itself minimum phase, as typical IIR "PEQ" filters are) actually makes the system more time-aligned and thus more likely to sum properly, not the opposite. I'm not entirely sure I understand the underlying reasoning though, maybe @JohnPM can pitch in.

If a filter is exactly matched to the resonance the filters zeroes will be on the resonances poles, cancelling them, so the decay in that region is replaced by the decay of the filter's poles. There is a bit more on that in the REW help.

 

[dasdoing]

what's our base here?
if we take a utopical perfect room with utopical perfect speakers and those speakers are perfectly flat meassured seperated, would they be perfect meassured together?

 

[Tim Link]

I'm jumping in this thread late to talk about another reason to EQ speakers separately - making them match more perfectly for improved stereo imaging. I've had a problem with my sound stage extending further to the right than it does to the left. I finally got serious and accurately measured each speaker's response separately, moving them each to the exact same position close in front of the microphone. This is not to correct the speakers in absolute terms, but just to make them match each other. I happen to use 3 speakers in my setup so I found that 2 of them matched very closely while the 3rd was off in some areas by a few dB, suppressed in the midrange and a little higher above 10k. I used REW to divide one response by the other, which gave a difference curve. The EQ feature in REW then gave me the parameters to flatten the difference curve and thus optimally correct the speaker to match the others. After applying the calculated EQ to the errant speaker I measured and the match was super close. The imaging is at last balanced!