Are peaks more offensive than troughs?

[Digby]

Obviously, we all want a flat speaker, but do you find peaks in response more annoying than troughs? Personally, I can listen to a speaker than is somewhat dull and enjoy it, but any speaker that has something "extra" going on (an obvious peak) will annoy far quicker and is more likely to be turned off.

What is your experience and is there any research into which is the worse of these two aberrations?

 

[TheBatsEar]

Can't say it does to me.

I have a feeling i acclimate to any speaker after some time, as long as distortion is below a certain level and directivity is fine, frequency response flaws (peaks, shelfs) don't seem to matter much.

 

[wwenze]

Consider a chord of 6 notes. It is hard to notice a single softer note. But easy to hear a single louder note.

 

[DVDdoug]

Peaks are probably worse, especially if we are talking about a narrow band. And the resonances that cause peaks also tend to cause ringing.

But if a dip or trough is caused by standing wave cancellation it can take "infinite power" to correct it, especially in the bass. A bump is easier to correct.

 

[anotherhobby]

I think peaks are worse because they are an excess of sound pressure, so you can hear/notice them. Luckily they are much easier to fix too. It's very hard to hear nulls/dips since they are the absence of sound pressure, and as such I think they are mostly only offensive if you know you are supposed to be hearing something. If they are very wide, they can become more noticeable, but I think it's still harder to "hear" them. Nulls are very depressing to see on a graph though.

 

[Pogre]

Nulls are very depressing to see on a graph though.

Ha! That's so true!

Nulls are less offensive but much harder to deal with.

 

[Matias]

Nulls are less offensive but much harder to deal with.

I would say try to EQ them and measure again. No harm trying and checking.

 

[Pogre]

I would say try to EQ them and measure again. No harm trying and checking.

Oh for sure. I don't just throw my hands up in the air. Some nulls can be EQ'd, yes. Standing waves tho...

*Edit: I also always start with cutting peaks first. Sometimes when you get your peaks cut down those nulls don't look as bad and can be dealt with.

 

[mightycicadalord]

I definitely find peaks more annoying, alot of the time you can listen with nulls and not even know it.

 

[Trif]

Consider a chord of 6 notes. It is hard to notice a single softer note. But easy to hear a single louder note.

This is in line with an early object lesson for all musicians. The wrong note at the right time is a lot less embarrassing than the right note at the wrong time!

Seriously, I gotta ask where? What frequency? A peak in the highs that only makes cymbals sound sizzlyier isn't so bad. A peak in the mids that makes singers sound nasally won't be tolerated for long. Dips are generally less noticeable, though again, in the speech range we're so much fussier.

Overall, I guess I vote for peaks.

 

[Soundmixer]

I would say try to EQ them and measure again. No harm trying and checking.

It is useless to EQ a null, as the more equalization you add, the deeper the trough becomes. You EQ peaks, and ignore troughs. You can't hear them anyway.

 

[Matias]

It is useless to EQ a null, as the more equalization you add, the deeper the trough becomes. You EQ peaks, and ignore troughs. You can't hear them anyway.

Not all troughs are nulls ime and can be equalized, confirmed by measurements and heard.

 

[kongwee]

Just reposition the speakers, I do that very often.

 

[Soundmixer]

Not all troughs are nulls ime and can be equalized, confirmed by measurements and heard.

Show me those measurements. Nulls cannot be treated with EQ, it just makes the problem worse. Nulls can be treated with acoustical treatments, by moving the MLP or the speakers. It can also be treated with acoustical panels like bass traps as they eliminate the reflections that cause the nulls in the first place. Using equalization to fill a null does two things. It does not fix the problem, but it does push the amp and the speakers harder which can lead to distortion.

A trough is a deep null, unlike a small wiggle in a speaker's frequency response which can be equalized.

 

[anotherhobby]

Show me those measurements. Nulls cannot be treated with EQ, it just makes the problem worse. Nulls can be treated with acoustical treatments, by moving the MLP or the speakers. It can also be treated with acoustical panels like bass traps as they eliminate the reflections that cause the nulls in the first place. Using equalization to fill a null does two things. It does not fix the problem, but it does push the amp and the speakers harder which can lead to distortion.

A trough is a deep null, unlike a small wiggle in a speaker's frequency response which can be equalized.

He didn't say nulls were treatable with EQ. He said toughs might be, and I agree with him. I think we just have different definitions of trough. My understanding of trough when referencing response curves is how Amir uses it in this post:

That EQ system made things worse by applying a further dip in those frequencies causing a nearly 5 dB trough around 2 KHz.

On a room response curve, I would not call a 5 dB dip a null, but it's a bad dip and I'd call it a trough like Amir did. It's how I hear dips of that size frequently described. If you are doing room EQ, it's possible that it's somewhat or completely fixable with EQ depending on your situation, so it's worth trying. I'm not saying the situation in Amir's post is fixable, I'm just saying that troughs, as described, frequently are.

It's possible Amir, myself, and Matias are all using that word incorrectly though. If not, then you are.

Or maybe you disagree that 5 dB dips are correctable? If you don't think so, I do have graphs.

 

[dc655321]

Show me those measurements. Nulls cannot be treated with EQ, it just makes the problem worse. Nulls can be treated with acoustical treatments, by moving the MLP or the speakers. It can also be treated with acoustical panels like bass traps as they eliminate the reflections that cause the nulls in the first place. Using equalization to fill a null does two things. It does not fix the problem, but it does push the amp and the speakers harder which can lead to distortion.

A trough is a deep null, unlike a small wiggle in a speaker's frequency response which can be equalized.

Consider a xover that is not quite right and leaves a substantial phase difference between drivers. This can result in a trough or even a null if out of phase by pi. It’s also easily correctable. As with peaks/troughs from driver resonances too.

A trough below Schroeder may be due to room modes and so not solvable short of changes to listening or source positions, as you said. Room treatment at low frequencies is not typically a viable option (< ~100Hz). Peaks in this region are easy to solve with signal processing.

 

[Soundmixer]

He didn't say nulls were treatable with EQ. He said toughs might be, and I agree with him.

Trough is a point in the cycle where minimum amplitude exists. In another way, it is a point on the negative side of a wave where minimum amplitude exists.

minimum amplitude is not a slight dip in frequency response, it is a deep dip. It is not wise to try and fill in deep dips in a frequency response of a speaker/room interaction. It is better to move the speaker, the MLP, or use bass traps or acoustical panels to eliminate the reflection pattern that creates it. Using EQ for this purpose is not wise, and can create more problems than it solves.

If you are doing room EQ, it's possible that it's somewhat or completely fixable with EQ depending on your situation, so it's worth trying.

You can try, but filling in dips (depending on how deep they are) is not wise as it puts more stress on the amps and the drivers themselves. We know that for a fact, so it may not even be wise to try.

It's possible Amir, myself, and Matias are all using that word incorrectly though. If not, then you are.

It is also possible nobody is using the word incorrectly, but differently. When I think of minimum amplitude, I don't think of a slight dip in frequency, I think of a deep one. I would not touch a 5db dip with EQ, especially if it is a high Q dip.

If this is the example you are pointing to

The deepest dips in this example are what I would call troughs. The five deepest dips I would not touch with EQ but would pull the peaks down instead. Even the lesser dips I would not touch with EQ, as that would be about 5db of boost for each. This is where absorption would be more effective than EQ.

Consider a xover that is not quite right and leaves a substantial phase difference between drivers. This can result in a trough or even a null if out of phase by pi. It’s also easily correctable.

The only way you could correct this is not with EQ, but by making a new crossover. A null cannot be corrected unless you move out of it.

 

[dc655321]

The only way you could correct this is not with EQ, but by making a new crossover.

That is what I was getting at.

A xover need not be physical, of course. It can be of the same stuff as other EQ components.

 

[Pogre]

I call the not so bad ones "dips" and the bad ones are what I call "nulls". Dips can be eq'd and nulls can't.

I don't know if that's right terminology, it's just my colloquial Pogre-ese way of looking at it.

 

[Soundmixer]

That is what I was getting at.

A xover need not be physical, of course. It can be of the same stuff as other EQ components.

You are correct. But passive speakers require a properly well-designed crossover, and the majority of the speakers in homes are passive ones.