BRZ EQ Settings - Frequency Response Curve Test

[avholic]

Coincidentally, Subaru BRZ's OEM audio system's frequency response curve behaves like it's torque curve - there is a dip around 350 Hz (3500 rpm for the torque). I tweaked the EQ settings today, hoping to avoid upgrading the sound system and save a few bucks.

Below are my settings:






Below is the resulting Pink Noise frequency response curve. My goal was not to make it flat, but to make my BRZ sound like my home audio system with warm sound, clear mids, less harshness on high end, to minimize listening fatigue on long drives.




Here is a quick test of the resulting frequency response:

[ame="http://www.youtube.com/watch?v=Qc3H__y_aW4"]2013 Subaru BRZ EQ Settings - Frequency Response Curve Test - YouTube[/ame]


Edit: Also try R2 fader setting as suggested by Spaceywilly.

[GregV]

So for us non audio engineers who have no idea what that video is showing us, these settings will make the factory stereo sound better?

[avholic]

It sounded better for me for general listening and different genres. Try using OEM flat or any of the preset settings. The vocals sound tiny, and the high frequencies are ear-splitting. By the way, that setting is for CD and Ipod inputs. I didn't even try tweaking for satellite, Siruis/XM sound horrible.

[Spaceywilly]

Just tried out those EQ settings, and it sounds great. I changed mine to R2 since I prefer a little more punchy bass, but overall it's a huge improvement in sound over what I was using before (basically same bass settings but more treble/midrange). I might have to pick up one of those sound analyzers... looks like a fun toy.

[avholic]

Glad you like it. I've had that device for a long time. Comes in handy whenever I have a new car, or when I add/change an audio component.

[chandz05]

Thanks I've been looking for something like this! I didn't like any of the preset EQ settings, and I'm definitely not an "audio" guy, so me playing around with it probably made it sound worse. Definitely gonna try these settings out today.

[wheelhaus]

Originally Posted by GregV

So for us non audio engineers who have no idea what that video is showing us, these settings will make the factory stereo sound better?

An "ideal" audio system is one that can reproduce the original recording exactly as it was recorded. This means it produces a flat frequency response, so the speakers are actually producing measurably even response across the 20-20000Hz range in the environment. Most albums are mastered in a recording studio for perfect balance and sound quality, but not many people have a studio, or a dedicated listening room that has perfect acoustics and sound reproduction. Most listeners don't want a perfectly flat response, they want the music to have a little color, as the OP stated, warm, rich sound isn't perfectly flat.

Cars are high on the list of terrible listening environments. Aside from engine and road noise, cars have awful acoustics (control of how the sound moves around the space) lots of hard surfaces for reflection (such as glass) and very poor listener positioning (sitting off-center). The speaker positions are also screwy, with the mid-woofers and tweeters all being in different locations, and EVERY one being a different distance from the listener. What you normally end up with, is just sound mixed with noise. A lot of the "noise" is the sound you want to hear, just not exactly when/how you should be hearing it. You may be able to hear the music clearly, but probably not at high volume levels for very long, because it causes psychological listener fatigue. So you switch tracks, listen to another artist, or just turn it down.

By using the EQ, you have some control to achieve a flatter frequency response. This is always a goal of any audiophile (as a starting point). A flat frequency response could be very difficult to achieve in a car, especially with a typical OEM system. The speakers themselves probably don't produce a flat response, let alone in a screwy acoustic environment that affects frequencies even more. What you end up with is a system that has big spikes and dips from an audio analysis as shown above. Even if the processor says it's using a "flat" EQ curve, it's referring to the source signal, not the environment and the actual resulting sound quality. (Imagine listening to a perfectly adjusted high end stereo system through a cardboard tube on your ear. Sounds like crap, right?)

White noise and pink noise are both randomly generated "noise" that covers the entire spectrum from 20-20000Hz. This noise is used by analysis tools to measure what's being produced by a system. White noise uses even energy across the spectrum, whereas pink noise lowers the energy at higher frequencies (reduces 3dB per octave). Our ears hear sound logarithmically (on a curve) and are more sensitive to mid-range and high frequencies, so to the ear, a 100Hz bass tone at 70dB wouldn't sound as loud as a 4000Hz squeal tone at 70dB. White noise would sound level and even to a microphone, but pink noise would sound level and even to a human ear. With pink noise, that 4000Hz range would be about 15dB quieter, and it would sound about the same level as the 100Hz tone to the human ear.

By measuring what the stock system is actually doing (not just what it says onscreen) you can see what your ears are hearing, and you can make adjustments to fix some of the issues mentioned above. Hopefully for most, this does the trick and you've just improved your sound and saved a bundle on a bunch of audio stuff you don't need.

However, if you still need more, there's two key points to consider beyond amps and speakers if you're looking to make improvements. 1- sound deadening- (improving acoustic control of the environment). 2- time alignment- Time alignment is a critical step to make the sound appear accurate to the driver's position. This adjusts when the signals are sent to each speaker by adding a slight delay (sometimes only a few milliseconds) to the speakers closest to you. The goal is to get the sound from each speaker to reach your ears at the same time, with proper EQ and volume level. Many DSPs (digital signal processor) and some high end head units can use a calibrated microphone that will make this time adjustment automatically, and can also EQ each speaker individually in ways inaccessible to the user. What you end up with is a system that sounds clean, clear and accurate to your ears, like you're watching the performance happen right in front of you. Hardcore car audiophiles will also get into custom speaker placement and enclosures, but that's another topic.

[S2kphile]

Originally Posted by wheelhaus

An "ideal" audio system is one that can reproduce the original recording exactly as it was recorded. This means it produces a flat frequency response, so the speakers are actually producing measurably even response across the 20-20000Hz range in the environment. Most albums are mastered in a recording studio for perfect balance and sound quality, but not many people have a studio, or a dedicated listening room that has perfect acoustics and sound reproduction.

Well-said

And me let add this because this is, imo how music is produced today and it shouldn't be.

Music isn't supposed to be bass heavy. It is supposed to be a base for the rest of the music to be supported upon, this is why if you listen to music on a small radio you hear mids and highs and it sounds ok for what it is, but put a full range speaker system in it's place and suddenly the music truly comes to life. The opposite of this is the 'norm' in today's hifi world where bass is overdone to the point where the bass takes over and doesn't let the music breathe. The pursuit of a balanced sound is what audiophiles are after. Clear and present bass, but balanced against warm, smooth mids and sparkling transparent highs. If these are all proportioned correctly you get something in the realm of magic.

To OP: I thought music is suppose to come from the front not the rear?

[ngabdala]

I tested these settings today. They are great

[jpit]

As mentioned before an auto is a poor listening environment if you are looking for a flat response. I did some comprehensive testing with a sound level meter in the BRZ
and I could get over a 12 db change just by moving the microphone a couple of inches. The problem I found with the stock speakers is a harshness that didn't seem to be correctable with the equilizer and a very narrow sound stage. There are many audiophiles that believe sound should only originate from the front. Several years ago Bose did some comprehensive measurements in a concert hall and discovered that 89% of the sound flowing to the ears was reflective and that's what helped give it depth. Have no idea what those measurements would be in a car, however, I feel that having ambient sound coming from the rear (adjusted properly) does add some depth to the sound. Whatever sounds best to the listener is the most important criteria.

[GregV]

Tried the settings in the OP and does sound noticeably better. I tried R2 as SpaceWilly suggested and I prefer that over the R4.

[avholic]

@S2kphile, Yes the sound image should be on the front stage, and the sweet spot should be on the driver's side. But I couldn't eliminate the harshness as what jpit mentioned. Hence I went for the rear-bias (as the rear speakers have better mid-range), but not too far to keep the vocals up-front. The db sensitivity of the front speakers appear higher due to glass reflection. So it doesn't hurt to have rear-bias. You may adjust the fader to R2 like Spaceywilly and GregV did. That option will also improve the bass response as the door-mounted mid-sub is considered front component by the fader.
@jpit, @wheelhaus, good info, thanks for sharing.

[Spaceywilly]

Originally Posted by jpit

Several years ago Bose did some comprehensive measurements in a concert hall and discovered that 89% of the sound flowing to the ears was reflective and that's what helped give it depth..

I think several years ago might be a stretch, they started doing this back in 1968 with their 901 speakers which have 8 speakers facing the rear and 1 facing the front

[jpit]

I was trying to keep my age under wraps as I had a pair of the original 901s. Nine 6" speakers on a pedestal with an equilizer.