Head unit frequency output Please help!!!!!!!

[sacd]

View attachment 26544964View attachment 26544965View attachment 26544963View attachment 26544962View attachment 26544961I'm not sure if this is normal or not. I have a pretty high end unit that plays dvd and sacd disks. it has 6 rca outputs 2 front 1 center 2 rear and a sub out. when I run the rca's directly into my sound card this pnk noise graph I get. I have all of the settings I can think of off and yet my 100hz is 18 db above 10000hz coming directly from the head unit. I'm getting the rockford fosgate 3sixty.3 to try and correct but is something else wrong. I have the eq off as well as all filters on the unit. I have included response for four speakers and the sub. I have a good unit but I'm kind of new to all this. Thanks for yourtime. I know everyone is busy but you will really save me some headaches!!!!

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[Side Show 10+ year member]

what is the question?

 

[mat3833 10+ year member]

View attachment 26544964View attachment 26544965View attachment 26544963View attachment 26544962View attachment 26544961I'm not sure if this is normal or not. I have a pretty high end unit that plays dvd and sacd disks. it has 6 rca outputs 2 front 1 center 2 rear and a sub out. when I run the rca's directly into my sound card this pnk noise graph I get. I have all of the settings I can think of off and yet my 100hz is 18 db above 10000hz coming directly from the head unit. I'm getting the rockford fosgate 3sixty.3 to try and correct but is something else wrong. I have the eq off as well as all filters on the unit. I have included response for four speakers and the sub. I have a good unit but I'm kind of new to all this. Thanks for yourtime. I know everyone is busy but you will really save me some headaches!!!!

ummmm, i think thats "correct" considering most songs peak higher in the lower frequencies. your pink noise track might be jacked tho.

Matt

 

[sacd]

i would think that pink noise coming from my head unit would be flat?

 

[mat3833 10+ year member]

im not sure. never really messed with pink noise. why dont you do an RTA sweep from 20hz to 20khz and check the response against pink noise. i beleive pink noise is a representation of "average" musical output.

Matt

 

[keep_hope_alive Premium Member]

pink noise is equal energy per octave. white noise is equal energy per Hz.

do an octave band view and it will flatten out.

also depends on what exactly is being done to that image.

 

[keep_hope_alive Premium Member]

here is some RTA testing i did with one of my head units. in this manner, i can measure flat response out using 1/24th octave resolution

Data was taken by using the SoundDevices USBPre line level rca input from the Alpine CDA-9887 output directly. Levels are relative. Autosound 2000 Track 18 (un-correlated pink noise) was used as the source.

I am using the Alpine DRE-A200 as a crossover between my tweets and mids off the Front outputs on the 9887. you can see the 12dB/oct slope of that crossover.

There is the same consistent drop at the crossover frequency (6 and 12 are the same, 18 and 24 are the same at the xover point). Certainly, when choosing crossover slopes and points, the drop at the crossover point should be taken into consideration - resulting in some overlap with the crossover points.

4kHz crossover point, slope varies 6 to 24dB/oct. Front output of 9887

1kHz crossover point, slope varies 6 to 24dB/oct. Front output of 9887

200Hz crossover point, slope varies 6 to 24dB/oct. Rear output of 9887

50Hz HPF, 250Hz LPF, slope varies from Full to 6, 12, 18 & 24dB/oct. Rear output of 9887

Then i played with the mic for a bit. Played with crossover settings. I had the laptop in the passenger seat, mic at my head (moving around to average out peaks/valleys). This is the front stage only (no sub). Crossover points are:

Midbass: no HPF (Full), 315Hz LPF 18dB/oct

Mid: 250Hz HPF 18dB/oct, 3.5kHz LPF 12dB/oct

Tweet: 3.5kHz HPF 12dB/oct

One line is measured 1/24th oct, the other line is a smoothed version of that line.

naturally, with the subs the low end is (much) higher, but I wasn't running the sub during the RTA testing today and was more interested in midbass response.

here are individual graphs of crossover slopes. This is what i've been listening to, set by ear. It is close to what I expected, though i'm more then 3dB down at the xover points.

 

[mat3833 10+ year member]

i quit. KHA is in the house and anything i say from here on out will probobly be pointless. lol

Matt

 

[sacd]

Just wanted to say thank you so much for taking the time to reply to my question. To give you a lil more info since I have time. I have sony's mexdv2200 which is their older super audio dvd audio player. I have prosumer speakers n amps infinity kappa 4x6's in the front and their 6x9's in the rear and a 10" pioneer sub in the rear.These prob aren't the best but I don't listen to loud music and I listen mostly to 5.1 channel recordings. I really didn't know much about rating a system but figured I would jump in. The head unit sends all my signals out at full range when playing sacd's and bypasses all of it's eq settings as well as filters and time alignment settings which would be great if I was in a perfect listening environment but I'm in an old caddy so I need to adjust my source to compensate. I guess I will run traight out of the3sixty.3 into my computer first to make sure everything is flat using pink noise then put my mic at head level and adjust from there.Do you generally do each individual speaker then do the fronts then rears then sub then the full system? I rarely listen to stereo recordings so each speaker is important to me?I'm using visual analyzer 2011 as my program for analyzing the signals. Thanks again for taking the time to comment on my thread.

Best Regards,

sacd

 

[keep_hope_alive Premium Member]

When I use my RTA i will do each speaker separately to evaluate response (before and after crossovers). what you are interested in is the response you get at the headrest, which will be different than what you get on-axis and in a proper enclosure.

this is what I did with speakers in an 1990 DeVille:

http://forum.sounddomain.com/ubbthreads.php/ubb/showflat/Number/1431119/page/0/nt/2/fpart/1

it's, meh. given the chance, i would do a 3.5" and 1" plate up in the dash and make 6.5" midbass enclosures for the doors.

listening to 5.1 doesn't make much sense when you don't have a dedicated center. did you put a 4x6 in the center of the dash?

 

[sacd]

dude that's crazy!!! I have a 1990 coupe deville!! That's what this is for. Do you like your 6x9's with free air in the trunk mine have the factory enclosures on them but not sure if they hurt or help?

 

[sacd]

View attachment 26545029View attachment 26545030View attachment 26545026View attachment 26545027View attachment 26545024View attachment 26545025View attachment 26545028ok here are the new pics wew!!!!!