testing how "flat" the TSX head unit's preamp outs are...
#1
testing how "flat" the TSX head unit's preamp outs are...
Gents,
We have had several discussions about the preamp outputs on the TSX, with many (including myself) questioning how flat the signal produced is, with treble=0, bass=0.
I have run some tests and found that the HU is overall pretty flat...especially at higher volumes...Results were dissappointing at lower volumes.
My car is a 2004 non-Navi TSX.
I burned an Audio CD with 16bit 44.1kHz White noise sample and capture the output from the preamp outs at various volumes...10, 20, 30, 40. I have spectrum analysis diagrams posted for each volume...
original clip (direct analysis):
http://rockenbach.homeip.net:8080/sh...actualclip.JPG
volume set to 10:
http://rockenbach.homeip.net:8080/sh...X_HU_vol10.JPG
volume set to 20:
http://rockenbach.homeip.net:8080/sh...X_HU_vol20.JPG
volume set to 30:
http://rockenbach.homeip.net:8080/sh...X_HU_vol30.JPG
volume set to 40:
http://rockenbach.homeip.net:8080/sh...X_HU_vol40.JPG
On all the capture clips, you can see the HU rolls off the high end at about 20kHz. That's no problem, as most of us can't hear very much above that anyway. What's a little dissappointing, as you can see, is the highs are noticably and audibly peaked when the volume is around 10 (probably gets worse between 0-10), and there is a nice little dip in the mid range. The curve starts to flatten out around 20 (50% volume), but still has a slight peak on the high end. Above 20, its really pretty flat.
I would suspect its better than many average OEM HUs. I was hoping to see flatter response in the 0-20 range, as this is where most listening is done, unless you don't like your hearing too much![Smile](https://acurazine.com/forums/images/smilies/smile.gif)
So, there's my analysis.
If anyone wants to do their own analysis, the white noise clip is available at:
http://rockenbach.homeip.net:8080/sh...e_st_20sec.wav
I would be very interested in seeing a similar analysis of a NAVI Head Unit. Any takers?
-mark
We have had several discussions about the preamp outputs on the TSX, with many (including myself) questioning how flat the signal produced is, with treble=0, bass=0.
I have run some tests and found that the HU is overall pretty flat...especially at higher volumes...Results were dissappointing at lower volumes.
My car is a 2004 non-Navi TSX.
I burned an Audio CD with 16bit 44.1kHz White noise sample and capture the output from the preamp outs at various volumes...10, 20, 30, 40. I have spectrum analysis diagrams posted for each volume...
original clip (direct analysis):
http://rockenbach.homeip.net:8080/sh...actualclip.JPG
volume set to 10:
http://rockenbach.homeip.net:8080/sh...X_HU_vol10.JPG
volume set to 20:
http://rockenbach.homeip.net:8080/sh...X_HU_vol20.JPG
volume set to 30:
http://rockenbach.homeip.net:8080/sh...X_HU_vol30.JPG
volume set to 40:
http://rockenbach.homeip.net:8080/sh...X_HU_vol40.JPG
On all the capture clips, you can see the HU rolls off the high end at about 20kHz. That's no problem, as most of us can't hear very much above that anyway. What's a little dissappointing, as you can see, is the highs are noticably and audibly peaked when the volume is around 10 (probably gets worse between 0-10), and there is a nice little dip in the mid range. The curve starts to flatten out around 20 (50% volume), but still has a slight peak on the high end. Above 20, its really pretty flat.
I would suspect its better than many average OEM HUs. I was hoping to see flatter response in the 0-20 range, as this is where most listening is done, unless you don't like your hearing too much
![Smile](https://acurazine.com/forums/images/smilies/smile.gif)
So, there's my analysis.
If anyone wants to do their own analysis, the white noise clip is available at:
http://rockenbach.homeip.net:8080/sh...e_st_20sec.wav
I would be very interested in seeing a similar analysis of a NAVI Head Unit. Any takers?
-mark
#3
VP Electricity
Join Date: Jun 2004
Location: Portland OR US
Age: 58
Posts: 4,617
Likes: 0
Received 8 Likes
on
1 Post
And in looking at that curve it doesn't look like the highs are peaked, it looks like the mids are dipped. The absolute HF level is the same, isn't it?
Since Pink Noise is random, what kind of averaging were you using on the audio analyzer?
Since Pink Noise is random, what kind of averaging were you using on the audio analyzer?
#5
VP Electricity
Join Date: Jun 2004
Location: Portland OR US
Age: 58
Posts: 4,617
Likes: 0
Received 8 Likes
on
1 Post
I will measure my car again today... but I suspect you are seeing an "auto-loudness" feature.
http://www.webervst.com/fm.htm
And I run my system above 30 frequently - and once I've installed a new amp, I control how loud that actually is with my gain settings, right?
http://www.webervst.com/fm.htm
And I run my system above 30 frequently - and once I've installed a new amp, I control how loud that actually is with my gain settings, right?
#6
Originally Posted by jlukja
![Sad](https://acurazine.com/forums/images/smilies/sad.gif)
-mark
#7
Originally Posted by elduderino
I will measure my car again today... but I suspect you are seeing an "auto-loudness" feature.
http://www.webervst.com/fm.htm
And I run my system above 30 frequently - and once I've installed a new amp, I control how loud that actually is with my gain settings, right?
http://www.webervst.com/fm.htm
And I run my system above 30 frequently - and once I've installed a new amp, I control how loud that actually is with my gain settings, right?
As far as spectrum analysis algorithm used...I am using the spectrum analyzer in Sonic Foundary Sound Forge, set to logorithmic view. The algorithm they use is Blackman-Harris alg.
-mark
Trending Topics
#8
Originally Posted by elduderino
Any way to show db ranges? It's very hard to see the actual amount of variation...
-mark
Last edited by mpeteritas; 07-29-2005 at 11:42 AM.
#9
Team Owner
Originally Posted by elduderino
And I run my system above 30 frequently - and once I've installed a new amp, I control how loud that actually is with my gain settings, right?
![EEK!](https://acurazine.com/forums/images/smilies/eek.gif)
jlukja, who's volume control doesn't venture past 20 much at all.
#11
Ok, the normalized spectrum analyses are at:
vol10:
http://rockenbach.homeip.net:8080/sh...vol10_norm.JPG
vol20:
http://rockenbach.homeip.net:8080/sh...vol20_norm.JPG
vol30:
http://rockenbach.homeip.net:8080/sh...vol30_norm.JPG
vol40:
http://rockenbach.homeip.net:8080/sh...vol40_norm.JPG
Also, the captured wav clips are at:
http://rockenbach.homeip.net:8080/sh...X_HU_vol10.wav
http://rockenbach.homeip.net:8080/sh...X_HU_vol20.wav
http://rockenbach.homeip.net:8080/sh...X_HU_vol30.wav
http://rockenbach.homeip.net:8080/sh...X_HU_vol40.wav
and again the original clip is:
http://rockenbach.homeip.net:8080/sh...e_st_20sec.wav
-mark
vol10:
http://rockenbach.homeip.net:8080/sh...vol10_norm.JPG
vol20:
http://rockenbach.homeip.net:8080/sh...vol20_norm.JPG
vol30:
http://rockenbach.homeip.net:8080/sh...vol30_norm.JPG
vol40:
http://rockenbach.homeip.net:8080/sh...vol40_norm.JPG
Also, the captured wav clips are at:
http://rockenbach.homeip.net:8080/sh...X_HU_vol10.wav
http://rockenbach.homeip.net:8080/sh...X_HU_vol20.wav
http://rockenbach.homeip.net:8080/sh...X_HU_vol30.wav
http://rockenbach.homeip.net:8080/sh...X_HU_vol40.wav
and again the original clip is:
http://rockenbach.homeip.net:8080/sh...e_st_20sec.wav
-mark
#12
Team Owner
Good work Mark,
Now that I'm home I can see the graphs. Interesting. I thought loudness was the artificial boosting of bass at low volume. The graphs would seem to indicate that the bass isn't boosted at low volumes relative to the high freq.
Makes me wonder if using less efficient speakers would help. The logic being that a comfortable volume would be achieved at a higher pre-amp output (and thus flatter frequncy response curve). Well, at least for those of us who are less interested in volume and more interested in SQ.
Now that I'm home I can see the graphs. Interesting. I thought loudness was the artificial boosting of bass at low volume. The graphs would seem to indicate that the bass isn't boosted at low volumes relative to the high freq.
Makes me wonder if using less efficient speakers would help. The logic being that a comfortable volume would be achieved at a higher pre-amp output (and thus flatter frequncy response curve). Well, at least for those of us who are less interested in volume and more interested in SQ.
Last edited by jlukja; 07-29-2005 at 09:39 PM.
#13
Originally Posted by jlukja
Good work Mark,
Now that I'm home I can see the graphs. Interesting. I thought loudness was the artificial boosting of bass at low volume. The graphs would seem to indicate that the bass isn't boosted at low volumes relative to the high freq.
Makes me wonder if using less efficient speakers would help. The logic being that a comfortable volume would be achieved at a higher pre-amp output (and thus flatter frequncy response curve). Well, at least for those of us who are less interested in volume and more interested in SQ.
Now that I'm home I can see the graphs. Interesting. I thought loudness was the artificial boosting of bass at low volume. The graphs would seem to indicate that the bass isn't boosted at low volumes relative to the high freq.
Makes me wonder if using less efficient speakers would help. The logic being that a comfortable volume would be achieved at a higher pre-amp output (and thus flatter frequncy response curve). Well, at least for those of us who are less interested in volume and more interested in SQ.
-mark
#16
Originally Posted by I'm Batman
Were you sitting in the car while running the tests?
-mark
#17
VP Electricity
Join Date: Jun 2004
Location: Portland OR US
Age: 58
Posts: 4,617
Likes: 0
Received 8 Likes
on
1 Post
I didn't have time on Saturday... I might on Monday - I'm cracking the dash open to install an Icelink anyway.
When I had the JL 300/4 under the seat, I could reach under there are grab an RCA easily.
Now that we have the DLS CA41 under there, the RCAs are on the end, under the seat rail, so it's impossible to grab them there without pulling the seat. SO I get to pull the dash for the umpteenth time, so I might as well put in the Icelink when I do : )
When I had the JL 300/4 under the seat, I could reach under there are grab an RCA easily.
Now that we have the DLS CA41 under there, the RCAs are on the end, under the seat rail, so it's impossible to grab them there without pulling the seat. SO I get to pull the dash for the umpteenth time, so I might as well put in the Icelink when I do : )
#18
VP Electricity
Join Date: Jun 2004
Location: Portland OR US
Age: 58
Posts: 4,617
Likes: 0
Received 8 Likes
on
1 Post
At low levels (up to 20) the Nav HU tests out the same. I hadn't had it that low when I tested it before because my amp gain is low and because I was mostly verifying that there wasn't a high-pass "subsonic" kicking in at higher volumes.
But for kicks, I connected the RTA to a Nakamichi CD-400 and turned the "Loudness" control on and off. WHen Loudness was ON, the EXACT same contour appeared in the midrange as mark has posted.
So it seems pretty obvious that this midrange dip is an auto-loudness feature of the preamp IC that was used.
But for kicks, I connected the RTA to a Nakamichi CD-400 and turned the "Loudness" control on and off. WHen Loudness was ON, the EXACT same contour appeared in the midrange as mark has posted.
So it seems pretty obvious that this midrange dip is an auto-loudness feature of the preamp IC that was used.
#19
Burning Brakes
Join Date: Jun 2005
Location: Georgia
Age: 59
Posts: 761
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by jlukja
Good work Mark,
Now that I'm home I can see the graphs. Interesting. I thought loudness was the artificial boosting of bass at low volume.
Now that I'm home I can see the graphs. Interesting. I thought loudness was the artificial boosting of bass at low volume.
The graphs would seem to indicate that the bass isn't boosted at low volumes relative to the high freq.
Makes me wonder if using less efficient speakers would help. The logic being that a comfortable volume would be achieved at a higher pre-amp output (and thus flatter frequncy response curve). Well, at least for those of us who are less interested in volume and more interested in SQ.
#20
Originally Posted by elduderino
At low levels (up to 20) the Nav HU tests out the same. I hadn't had it that low when I tested it before because my amp gain is low and because I was mostly verifying that there wasn't a high-pass "subsonic" kicking in at higher volumes.
But for kicks, I connected the RTA to a Nakamichi CD-400 and turned the "Loudness" control on and off. WHen Loudness was ON, the EXACT same contour appeared in the midrange as mark has posted.
So it seems pretty obvious that this midrange dip is an auto-loudness feature of the preamp IC that was used.
But for kicks, I connected the RTA to a Nakamichi CD-400 and turned the "Loudness" control on and off. WHen Loudness was ON, the EXACT same contour appeared in the midrange as mark has posted.
So it seems pretty obvious that this midrange dip is an auto-loudness feature of the preamp IC that was used.
Now we know where to target our listening volumes, eh? 20+ seems to be the ticket (for those who have amp gain to control the perceived volume).
-mark
#21
VP Electricity
Join Date: Jun 2004
Location: Portland OR US
Age: 58
Posts: 4,617
Likes: 0
Received 8 Likes
on
1 Post
I'd still say this about the auto-loudness and sound quality:
1) It's generally accepted that gentle variations in freq response over a few octaves are far less objectionable than spikes or holes in the response.
2) The spikes and holes created by the speakers interacting in the car are far, far worse than anything the auto-loudness control creates.
So when you actually ACHIEVE this curve as an ACOUSTIC response instead of a SIGNAL response, I would start worrying about volume levels. Until your speakers are close to this curve in actual miked-and-measured playback, I will continue to believe that your listening issues are speaker related, not signal contour related. In other words, you are absolutely right about the loudness contour feature, but I believe that until you have a VERY advanced amp-and-speaker playback system, you're close to the mountain-from-a-molehill on this being the cause of anyobjectionable sound.
I recently delivered a BMW X5 using the OEM audio system and summing the various channels together. We got this thing to sound INCREDIBLE with Dynaudio speakers, Genesis amps, and a DLS sub.
But our signal response wasn't anywhere NEAR as smooth as this one. The various bands were fighting each other in their stopbands due to phase effects of the filters. Still sounded great, though.
Or as MJ said, "It's not the shoes".
1) It's generally accepted that gentle variations in freq response over a few octaves are far less objectionable than spikes or holes in the response.
2) The spikes and holes created by the speakers interacting in the car are far, far worse than anything the auto-loudness control creates.
So when you actually ACHIEVE this curve as an ACOUSTIC response instead of a SIGNAL response, I would start worrying about volume levels. Until your speakers are close to this curve in actual miked-and-measured playback, I will continue to believe that your listening issues are speaker related, not signal contour related. In other words, you are absolutely right about the loudness contour feature, but I believe that until you have a VERY advanced amp-and-speaker playback system, you're close to the mountain-from-a-molehill on this being the cause of anyobjectionable sound.
I recently delivered a BMW X5 using the OEM audio system and summing the various channels together. We got this thing to sound INCREDIBLE with Dynaudio speakers, Genesis amps, and a DLS sub.
But our signal response wasn't anywhere NEAR as smooth as this one. The various bands were fighting each other in their stopbands due to phase effects of the filters. Still sounded great, though.
Or as MJ said, "It's not the shoes".
Thread
Thread Starter
Forum
Replies
Last Post
mada51589
3G TL Problems & Fixes
79
05-03-2022 08:54 PM
Soul_Deamon
Audio, Video, Electronics & Navigation
7
11-13-2018 04:44 PM