An interesting perspective from a Zaph Audio blog:
"March 31, 2011
The old worn out flat response debate...
So far every hobbyist speaker forum I've looked at has had a discussion recently about whether a flat frequency response is a good design goal for a speaker system. Unfortunately, the phrase "frequency response" is too generic to be answered without some serious qualifiers. Less experienced speaker designers are unaware of the qualifiers. The two primary qualifiers are Where and When. "Where" has everything to do with off axis response and placement in a room, and "When" has to do with reflections. Each of these can be broken down into pages upon pages worth of data and knowledge with much of it getting into physcoacoustics - way beyond the scope of a simple blog update.
A lot of things are important considerations of shaping a frequency response. Harmonic distortion, power response, room placement among other issues all factor in. But make no mistake that none of those considerations are more important than flat on-axis response. That's what hits your ears first, and that's what means the most to your brain. Start there and you are already off to a great start. Then deviate from flat as required to resolve other issues.
The other consideration is "What". What are you listening to? Rock CD's from the late 80s? Recent Telarc Classical CD's? It is true that sometimes 2 wrongs can make a right. Back in the 80's, most music was mixed for vinyl and then dumped onto CD without adjustment. The result was a horrible, piercingly bright tonality particularly with pop and rock. Badly mixed and mastered CD's like that can indeed sound better with a downward slanted frequency response. The type of music plays a part also. For amplified music, there really is no wrong response curve. There is only what the recording engineer prefers, and if you don't like that, it's not wrong to change it. There's a reason why subwoofer setups tuned by ear are generally set 5-10 dB higher than the mains - because people are listening to amplified music, and that's what they like. Unamplified music is different however. There is a standard to be met, and that's a 7th row, center reproduction of concert hall reality. And if you want that to sound as real as possible, you had better design for accuracy.
I have one concept to present in regards to speakers and music: Plan for the best, EQ for the rest. The best is well recorded acoustic music and the rest is amplified music where the proper tonality is subjective. Don't read that as "Rock music is not the best". I personally have more of that in my collection than anything else. What I'm getting at is that tone controls are not evil. In fact I will say that a system without tone controls is a seriously flawed one. Those with high end amps or preamps having only input and volume controls are going to scoff at that one, but it's true.
This is just a little input from your truly on this subject. I could go on forever, but I have a pretty busy schedule these days."
George
"March 31, 2011
The old worn out flat response debate...
So far every hobbyist speaker forum I've looked at has had a discussion recently about whether a flat frequency response is a good design goal for a speaker system. Unfortunately, the phrase "frequency response" is too generic to be answered without some serious qualifiers. Less experienced speaker designers are unaware of the qualifiers. The two primary qualifiers are Where and When. "Where" has everything to do with off axis response and placement in a room, and "When" has to do with reflections. Each of these can be broken down into pages upon pages worth of data and knowledge with much of it getting into physcoacoustics - way beyond the scope of a simple blog update.
A lot of things are important considerations of shaping a frequency response. Harmonic distortion, power response, room placement among other issues all factor in. But make no mistake that none of those considerations are more important than flat on-axis response. That's what hits your ears first, and that's what means the most to your brain. Start there and you are already off to a great start. Then deviate from flat as required to resolve other issues.
The other consideration is "What". What are you listening to? Rock CD's from the late 80s? Recent Telarc Classical CD's? It is true that sometimes 2 wrongs can make a right. Back in the 80's, most music was mixed for vinyl and then dumped onto CD without adjustment. The result was a horrible, piercingly bright tonality particularly with pop and rock. Badly mixed and mastered CD's like that can indeed sound better with a downward slanted frequency response. The type of music plays a part also. For amplified music, there really is no wrong response curve. There is only what the recording engineer prefers, and if you don't like that, it's not wrong to change it. There's a reason why subwoofer setups tuned by ear are generally set 5-10 dB higher than the mains - because people are listening to amplified music, and that's what they like. Unamplified music is different however. There is a standard to be met, and that's a 7th row, center reproduction of concert hall reality. And if you want that to sound as real as possible, you had better design for accuracy.
I have one concept to present in regards to speakers and music: Plan for the best, EQ for the rest. The best is well recorded acoustic music and the rest is amplified music where the proper tonality is subjective. Don't read that as "Rock music is not the best". I personally have more of that in my collection than anything else. What I'm getting at is that tone controls are not evil. In fact I will say that a system without tone controls is a seriously flawed one. Those with high end amps or preamps having only input and volume controls are going to scoff at that one, but it's true.
This is just a little input from your truly on this subject. I could go on forever, but I have a pretty busy schedule these days."
George
Since our hearing does not work like a microphone and a dsp can not compensate for a poorly designed loudspeaker or room acoustics, it is there for a must to do it right in the speaker and the room
Is there really any such standard for acoustic music? I find that the low freq response in recordings to have very different qualities and levels that a such standard is hard to believe! I have even limit the low freq reach in my speakers cause there is just to many recordings with no low freq control at all.
Agreed. High frequency response is very different, too. Listen to 10 different Bach violin Sonata BWV1001, some are much brighter than the other! Well, orchestral music is a bit more consistent, maybe...
I've gravitated towards wide baffle speakers because a directivity shift in the upper mids or treble sounds bad imo. Its the overall power response that matters. Also there's often extra energy right before a driver starts beaming and this can be hidden by a flat response
