the12volt.com spacer
the12volt.com spacer
the12volt.com spacer
the12volt.com spacer
icon

Using Test Tones or SineSweep


Post ReplyPost New Topic
< Prev Topic Next Topic >
FreakypervSD 
Member - Posts: 22
Member spacespace
Joined: February 09, 2005
Location: United States
Posted: April 29, 2005 at 10:30 AM / IP Logged  

Ok Lets say I play a  Test Tone Cd or Sine Sweep from 20hz to 20khz...NOW WHAT? Oh I forgot mention I dont have one of those fancy  Oscilligimeisters...soooo....what to do....I think im suppose to use it to set my Gains?  find  Slope/Frequency??  If any great minds out there can  give me some Idea  on how to get the most out of or use the Tones (Without the Oscilligoogleplex ;) I would really appreciate the help.

Also I have a SUV and when I play the Sine Sweep sound, the Low Frequency  starts from the back and I can actually hear it travel all the way to the front as the frequency gets higher....I dont want it like that right?? PLEASE HELP!!

Oh I did Download this cool Program called TrueRTA a real time audio spectrum analyzer...lol but trying to learn how to use it. It also has a built in Oscilloscope...:p .

stevdart 
Platinum - Posts: 5,816
Platinum spaceThis member has made a donation to the12volt.com. Click here for more info.spaceThis member has been recognized as an authority in Mobile Audio and Video. Click here for more info.spaceThis member consistently provides reliable informationspace
Joined: January 24, 2004
Location: Pennsylvania, United States
Posted: April 29, 2005 at 12:26 PM / IP Logged  

When the sine sweep reveals a sweep from back to front in frequency that means that the sub is set a little too high in frequency response and also that the front midbass are either nonexistant or are set too high...or that you need bigger midbass sound in the front.  Or, that the sub could be positioned better.  Ideally, when playing a sweep, you will first feel a rumble then a deep rising bass felt and heard throughout with no apparent source... and as the freqs rise the sound will come from the front.  All the sub bass should be felt and heard throughout the vehicle.

For setting crossover settings, I prefer to use individual tones at frequencies that are close to each other, such as a 75Hz, then an 80, then 85 etc.  You'll hear the volume slightly drop off when the crossover is set at your desired point.

Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
FreakypervSD 
Member - Posts: 22
Member spacespace
Joined: February 09, 2005
Location: United States
Posted: April 29, 2005 at 1:27 PM / IP Logged  

Thanks stevdart, exactly what i wanted to know for that sine sweep....now If I have a stronger midbass up front that should bring the subs up alittle more??

On the individual tones. Its alittle difficult to for me to understand on this part... but when u say  I should hear  the volume drop off at the desired point...did u mean at each tone frequency the sound gets softer or attenuates or levels offs...im sorry its just hard for me to picture how sound should sound..lol unless I actually hear it and and someone points it out.....

thanks for you response btw

5150azn 
Silver - Posts: 584
Silver spacespace
Joined: June 21, 2004
Location: United States
Posted: April 29, 2005 at 2:47 PM / IP Logged  
When you play a sine sweep usually the loudness of the tones rise and fall. This usually means certan frequencies are not being reproduced properly. When you got through a sweep the sound should not fade in and out. Loudness should stay the same. So when that happens you may need to adjust your crossover to help boost those frequencies that are fading out.
Tell the Snap-On guy I'm not here!
stevdart 
Platinum - Posts: 5,816
Platinum spaceThis member has made a donation to the12volt.com. Click here for more info.spaceThis member has been recognized as an authority in Mobile Audio and Video. Click here for more info.spaceThis member consistently provides reliable informationspace
Joined: January 24, 2004
Location: Pennsylvania, United States
Posted: April 29, 2005 at 11:36 PM / IP Logged  

When I set crossover points for lowpass and highpass on the amp, I play the volume very softly...just enough to hear.  If 80 Hz is what I want (usually) to cross both the LP and HP points at I'll start with the sub tones and play each tone one at a time and adjust the crossover so that 80Hz is slightly attenuated compared to 75Hz.  Then double-check to see that 75 and 70 both sound about the same volume.  With the tones playing very softly it's easy to tell a 3db difference, whereas when loud it's harder because you won't be able to trust your ears.

Picture a crossover setting to look something like this:

Using Test Tones or SineSweep - Last Post -- posted image.

...where the red line would indicate about 75Hz and the orange would be about 85Hz.  The crossover setting of 80Hz is in the middle and will be played by both the sub and the mid driver so that it's volume is relatively just as loud as either freq to its left and right.  The straight lines would represent amplitude, or volume.  This is the picture you're making when you set those xover points.

Do the same thing with the HP, but in reverse.  There I'll be looking for 85 and 90 Hz to sound the same volume but both be louder than 80Hz.  After that, it's a matter of tweaking slightly while listening to a good song track with prominent drums.  I want to feel the kick of the drums in the front and i'll know I have the HP crossover right.  At the same time you don't want to know the sub bass is coming from behind you.  Good (and plenty of) damping in the doors or wherever your front midbass drivers are will help greatly with the front bass response.  That damping even helps bring the actual sub bass forward even though the front speakers are attenuated at those low freqs.

And as posted above, you are also looking for even volume relative to the drivers producing the freqs.  The lows should be the same volume as the mids and highs.  Adjusting deck controls or gains will accomplish this.

Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
FreakypervSD 
Member - Posts: 22
Member spacespace
Joined: February 09, 2005
Location: United States
Posted: April 30, 2005 at 12:09 AM / IP Logged  

Thank you  thank you thank you! I know it's not rocket science but totally felt like it was for a bit there....Whoever thought Radio Installation is a snap, maybe to hook up the wires but to actually get down and dirty fine tuning the system (i know this is only touching the surface) .It definitely takes time and patience to learn and know this stuff...Thank you again really...And anymore tips or advice on tweaking the  system would be welcomed. 

Oh Stevdart, I actually was picturing spotlights (like the ones on Stage )as a crossover model :) great drawing ;)

stevdart 
Platinum - Posts: 5,816
Platinum spaceThis member has made a donation to the12volt.com. Click here for more info.spaceThis member has been recognized as an authority in Mobile Audio and Video. Click here for more info.spaceThis member consistently provides reliable informationspace
Joined: January 24, 2004
Location: Pennsylvania, United States
Posted: April 30, 2005 at 12:30 AM / IP Logged  

Heh heh, spotlights would do it too.  Glad to be of help and I know you'll get it right.  You have a big advantage over me with that True RTA software, though.  When I saw you post about it I looked it up and remembered that I had downloaded it several months ago.  So when I looked at it again I still don't know how to open it or make it work.  Not trying hard enough, I suppose.  But anyway I learned a lot from this forum and following links, so I've written alot in this forum, too.  It's all in Car Audio.  Type in stevdart for author (search) and you could have a few weeks of reading to do, but you'll know all the tips I've passed on (or invented!).

Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
FreakypervSD 
Member - Posts: 22
Member spacespace
Joined: February 09, 2005
Location: United States
Posted: April 30, 2005 at 4:29 AM / IP Logged  

U must really Love the audio bcuz you weren't kidding about the advice and help you've been giving...Your one of the few that I look for advice from. (and i know alot of other people think that too.) Im one of those people that is a forever tweakmeister cuz it's alot more satisfying and rewarding knowing I can do or make something sound better than b4.

Francious70 
Silver - Posts: 629
Silver spacespace
Joined: July 26, 2004
Location: United States
Posted: May 02, 2005 at 12:25 AM / IP Logged  
Usually the ones with the higher post counts are people you'll get priceless advise from. That's not to say all the people with high post counts, but most.
Paul
KarTuneMan 
Platinum - Posts: 7,056
Platinum spaceThis member has made a donation to the12volt.com. Click here for more info.spaceThis member consistently provides reliable informationspace
Joined: December 14, 2004
Location: Isle Of Man
Posted: May 23, 2005 at 11:08 AM / IP Logged  
You can also use the sweep to find rattles and noise in different parts of the car. Helps you make a quiet stage for your music. Different materials "buzz" at different frequencies.....when your listning to your favorite song, youll here a rattle or somthing, but you cant seem to put your hands on it to find out where its comiong from, use the sine sweep!!

Sorry, you can NOT post a reply.
This topic is closed.

  Printable version Printable version Post ReplyPost New Topic
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot delete your posts in this forum
You cannot edit your posts in this forum
You cannot create polls in this forum
You cannot vote in polls in this forum

  •  
Search the12volt.com
Follow the12volt.com Follow the12volt.com on Facebook
Monday, April 12, 2021 • Copyright © 1999-2021 the12volt.com, All Rights Reserved Privacy Policy & Use of Cookies
Disclaimer: *All information on this site ( the12volt.com ) is provided "as is" without any warranty of any kind, either expressed or implied, including but not limited to fitness for a particular use. Any user assumes the entire risk as to the accuracy and use of this information. Please verify all wire colors and diagrams before applying any information.

Secured by Sectigo
the12volt.com spacer
the12volt.com spacer
the12volt.com spacer
Support the12volt.com
Top
the12volt.com spacer
the12volt.com spacer