Will a perfectly flat playback system always sound good?

[WXfreak]

I have a beginner question. In theory, will a completely flat playback system always sound good if the music was properly recorded and well mastered? Are there situations where an accurate and flat playback system might not sound as good as another playback system, even when the recordings are high quality, well produced, and well mastered?

 

[Philbo King]

It can be perfect out on the lawn AND deeply flawed inside (due to room reflections causing standing waves and bass nodes/antinodes). The acoustics of the room have an (arguably) much bigger effect on the sound than does the speaker performance.

 

[Chrispy]

Define completely flat system first. Definitions/understanding varies. Preference varies as well.

ps As far as differences between well setup systems most likely in the speakers and/or room.

 

[Jim Taylor]

I have a beginner question. In theory, will a completely flat playback system always sound good if the music was properly recorded and well mastered? Are there situations where an accurate and flat playback system might not sound as good as another playback system, even when the recordings are high quality, well produced, and well mastered?

"Sounds good" is an expression of preference. Never confuse a system that provides accurate playback with a system that fits your preferences.

Accuracy is measurable. It is a gauge of how well the transducers and electronics work. It has no bearing on how well you like the result, and it's based on data.

Preference, OTOH, is a unique personal comment regarding how well you like a result, and it's based on emotion. It's an expression based on your subjective value system as to how well something aligns with your personal likes and dislikes. It has no intrinsic connection with accuracy.

So what you're really asking is whether your personal preferences can differ from a system that functions accurately.

It's very possible ... but only you can know whether they do or not, and to what degree.

 

[dualazmak]

My simple answer is "essentially no!".

So many factors, including your music preference, room acoustic mode, your hearing ability in high Fq zone, etc., etc., affect and contribute (positively or negatively) "subjective sound quality" at your listening position, and hence your optimal Fq response should be established in your own room environment and with your own audio setup to be fit for your own subjective music listening preferences.

And, you need to understand that the Fq-SPL curve is only one of the so many factors for nice sound quality for you.

I assume you may understand what I mean by looking/reading through my DSP-based multichannel setup case, for example;
- The latest Fq-SPL (re-confirmation) of multiple amplifiers SP high-level output signals and that of room air sound at listening position: all measured by “FFT averaging of recorded cumulative DSP-processed flat white noise” (as of June 8, 2025): #1,009
where I wrote as follows under the below spoiler cover.

Spoiler

I well understand, however, my Fq-SPL measurements and the results in this post would not fully represent/re-confirm the following aspects of my audio setup in my acoustic environments:

1. 0.1 msec time alignments among all the SP drivers (ref. #493, #494, #504, #507)
2. transient (kick-up and fadeout) behavior/characteristic of SWs and WOs (ref. #495, #497, #503, #507)
3. presence and extent of sound reflecting wall(s) and possible reverberation thereof (ref. #498)
4. pros of relative gain (tone) controls in analog domain (ref. #438, #643)
5. favorable effects of wide 3D reflective dispersion of high-Fq ST sound (above ca. 7 kHz) using random-surface hemisphere hard-heavy crystal-glass (ref. #912, #921, #926, #927, #929)
6. size of the “sweet sphere” around my listening position (ref. #926, #927, #931)
7. subjectively felt amazing disappearance of SPs (ref. #520, #687)
8. importance of excellent reproduction of 15 Hz - 40 Hz zone low Fq sound in some (many) music tracks (ref. #782, #588, #591, #641, #650, #63(remote thread) )
9. etc., and so on...

I have already objectively and/or semi-objectively measured and discussed above aspects/features in each of the attached reference posts.

If you would be further interested, please find the latest system setup of my DSP-based multichannel audio rig here in post #931 on my project thread.

 

[dualazmak]

Also,,, I highly recommend you establishing/preparing your own consistent "Reference/Sampler Music Playlist" consists of various genres of music based on your own preference before going into your possible fine tunings of your audio rig.
Just for example, in my case, you can find "it" on my dedicated thread;
An Attempt Sharing Reference Quality Music Playlist: at least a portion and/or whole track being analyzed by 3D color spectrum of Adobe Audition

 

[pablolie]

personal listening habits are also a key element here.

 

[terryforsythe]

I have a beginner question. In theory, will a completely flat playback system always sound good if the music was properly recorded and well mastered? Are there situations where an accurate and flat playback system might not sound as good as another playback system, even when the recordings are high quality, well produced, and well mastered?

The room in which the speakers are placed has a huge impact - room size, decay time, reflections, etc.

In a room with reflective side walls, linear off axis performance also is important. More thorough speaker reviews, such as those Amir presents herein and those at Erin's Audio Corner, will include a plot of the estimated in-room response. The general concensus is that it should be linear (though there may be some that will disagree). In a room with sound absorber on the side walls, horizontal off-axis linearity becomes less important. If you have a speaker that is flat on-axis and has a linear estimated in-room response, it likely will adapt better to different room environments in comparison to a speaker that also may be flat on-axis, but is more non-linear off-axis.

I encourage you to watch some of the audio educational videos Amir has made:

Speakers:

Power Amplifiers:

Distortion and Noise:

Pshychoacoustics:

Also, this playlist at Erin's Audio Corner has a number of educational videos pertaining to audio:

Understanding the Measurements

In this series I discuss the different data sets I provide in my reviews and explain what they each mean and how they are important to you.

www.youtube.com

 

[kemmler3D]

I'll go as far as saying a perfectly flat system in the colloquial sense of being neutral, flat on axis smooth off axis etc. will sound good more often (in more rooms) than a significantly not-flat system. All else held equal you probably don't want the speaker changing the frequency response of the music any more than necessary. But as others have said there are other important factors, the room dominates, and preferences are the ultimate measure.

To put it another way, nothing will "always" sound good but you don't help your odds by adding coloration out of the box.

 

[Sokel]

I suppose we're talking "flat" as of no significant resonances, etc.

But what flat? Natural flat, forced flat?
Cause the later posses a lot of culprits if not done carefully, force flat declining highs for example.

And then is the room.The better the room the better the chances.
So...

 

[thewas]

LLM summary of above:

• 00:00–00:46 — Speaker measurements in anechoic (reflection-free) conditions may sound “flat,” but that doesn’t reflect (pun intended) how they behave inside your room.
• 00:46–01:29 — People often dislike “flat” sound not because of the speaker, but because of how the flat response interacts with their own room. Research generally shows listeners prefer speakers with a flat on-axis response.
• 02:06–02:44 — A sine sweep is used to test speaker response: it has equal amplitude across frequencies, letting you measure the speaker’s true (anechoic) frequency response.
• 02:44–03:49 — As frequency increases, a speaker’s radiation pattern becomes more directional. At low frequencies, sound is omnidirectional (spreads in all directions); at high frequencies, it focuses more forward.
• 04:22–05:20 — Using a near-field scanner (instead of a large anechoic chamber), you can measure a speaker’s anechoic response — what the speaker itself does, independent of room reflections.
• 05:20–07:00 — Inside a typical room, bass waves “stack up” (standing waves), while high frequencies scatter more. This leads to room-induced changes in the frequency balance vs anechoic measurement.
• 07:00–08:09 — The result: a speaker that measures flat in anechoic conditions will often have boosted bass and rolled-off highs when placed in a real room.
• 08:45–09:23 — If you try to EQ (equalize) your in-room response to make it completely flat, you might end up boosting highs a lot and cutting bass – creating a harsh, fatiguing sound.
• 10:03–10:40 — The “correct” in-room response depends on your room: above ~400–500 Hz, the speaker largely dominates the sound; below that, the room dominates.
• 11:09–11:46 — EQ should be used carefully: correct problematic peaks below ~500 Hz, but don’t try to flatten everything. Nulls are best handled with acoustic treatment, not EQ.
• 12:15–12:48 — Buying speakers based on their anechoic measurements is useful, but don’t ruin a good speaker by forcing a flat in-room EQ. Let the speaker’s natural tonal balance—plus modest correction and room treatment—shine.

 

[DanielT]

I have a beginner question. In theory, will a completely flat playback system always sound good if the music was properly recorded and well mastered? Are there situations where an accurate and flat playback system might not sound as good as another playback system, even when the recordings are high quality, well produced, and well mastered?

It is partly (or for the most part) based on taste and preference. Most people seem to like a smooth FR however. It varies, some people want more bass than others. For example,Wiim RoomFit , their automatic EQ room correction feature, has three different target curve choices: "Flat," "Harman," and "BK." BK, for example, I think means more bass boost (I haven't tested it). Flat is flat and Harman is:


I alternate between Flat and Harman. Haven't really decided yet ( with my current speakers) which one I like best.You have to experiment to find out what you like.

Another example, some people find it nice to have bass and treble boost when listening at low volume. Others don't mind it that much:

Should you use Fletcher-Munson loudness compensation?

I know many are familiar with the Fletcher-Munson or equal loudness curves. In a nutshell: “The Fletcher Munson Curve contains a set of graphs that show that when you listen to music at a lower volume, mid-range frequencies will be sound more prominent, whereas high and low frequencies will be...

www.audiosciencereview.com

Then everything in addition to FR that can affect the perceived sound; I mainly think about distortion levels and reverb in a listening room. Too much or too little attenuation gives a rather dull and/or strange sound. Extreme example of this:

It should be:
Lagom (pronounced [ˈlɑ̂ːɡɔm]) is a Swedish word meaning 'just the right amount' or 'not too much, not too little'.

Lagom - Wikipedia

en.wikipedia.org

The importance of EQ in the bass range has been emphasized in the thread and I really agree with that.
Plus if you want EQ higher up in frequency, the speakers should be EQ friendly. That is: On and off axes should follow each other. Otherwise, the EQ operation will be no good.

Edit:
SPL level (seen in relation to compression/distortion) and how far down in frequency you want the speakers to go are also factors that determine whether you think it sounds good.
Another matter of taste is the dispersion pattern of the speakers.

 

[dualazmak]

Hello again, OP @WXfreak...

If you can use PC (Windows or Mac) and music player software as your local and/or streaming "music source", you may tentatively "test and try" the benefits of DSP software (like EKIO for Windows which I have been using all the way through) even with single stereo USB-DAC, single stereo amplifier and ordinary 2-way or three-way passive speaker having passive LCR crossover network in it. By "benefits of DSP software", I mean various crossover configurations for multiple Fq zones, group delay, relative gain tuning/simulation between the SP drivers, phase/polarity inversion(s), various EQs, and so on.

I call such (tentative) test/evaluation setup as "Quasi/Sham-multichannel" audio setup (ref. here); I believe my simple diagram tells well the setup configuration;

Even though many people criticized me that such quasi/sham-multichannel setup would be quite unusual, useless and out-of-the-scope and very-much-outlaw from true active multichannel multi-amplifier approach, I actually and intensively tested and evaluated this preliminary approach prior to going into my "royal road" towards multichannel multi-amplifier fully active exploration (ref. my project thread here); I have learned a lot from such preliminary primitive studies and experiences.

By the way, what would be my almost completed/established PC-DSP-based multichannel multi-SP-driver multi-amplifier fully active 5-way 10-channel audio setup after about 5 years of exploration? If you would be interested, please visit my post #931 and #1,009 on my project thread.

 

[Roland68]

I have a beginner question. In theory, will a completely flat playback system always sound good if the music was properly recorded and well mastered? Are there situations where an accurate and flat playback system might not sound as good as another playback system, even when the recordings are high quality, well produced, and well mastered?

There are a few points that many, even experienced users, don't understand.
1. 90% of recordings (more or less) aren't well mastered, but rather heavily dynamically compressed and adapted to the mainstream.
2. Among the remaining 10% of recordings (more or less), you'll find everything from quite good to excellent.
3. A so-called remaster, digital remaster, 20th Anniversary remaster, etc., isn't necessarily better than the very first vinyl version; sometimes it's even much worse.

If you say "accurate and flat playback system," then I'm assuming a high-quality and transparent system (which doesn't have much to do with the price) that's calibrated to the room using DSP, and the room itself represents a good compromise.

Then the question is easy to answer with a clear yes and no!
Personally, I actually prefer this approach because I want to hear what's on the recording.
Incidentally, in over 35 years, I've never encountered a well-recorded piece of music that didn't sound good to me.

In my experience, most people don't even know what they prefer.
So it's entirely possible that it doesn't sound good to you personally. But a large part of it is also a matter of habit, like almost everything in life.
If devices/speakers are colored or emphasized in any way, then that will naturally always affect all the music played, whether for better or worse. Therefore, I think an uncolored system is always the best starting point, unless you know your own preferences.