• Angry
  • Awesome
  • Hungry
  • Secret
  • Page 1 of 3 123 LastLast
    Results 1 to 10 of 22

    Thread: Interpreting Response Graphs - Speakers

    1. #1
      Reboot
      Curiosity killed the cat;
      Insecurity killed the man
       
      Hungry
       
      Mi10's Avatar
      Join Date
      Oct 2010
      Location
      Chennai
      Posts
      4,909
      Blog Entries
      2

      Post Interpreting Response Graphs - Speakers

      So you decide to get a Brand new Component speaker system from the Brand of your Choice. As soon as you open the packing you find a slew of papers - Manuals, Warranty Information, Specs Sheets, Ads sheets and maybe Stickers. Typically, in Indian scenario;
      80% of the people dont even bother to have a look at them.
      15% of the remaining give a glance inside before throwing them out
      About 3% remaning, try to make sense of various specifics describing the Speaker, but give up when it comes to hardcore parameters like T/S or the Frequency response Graph.
      Only 2% can make sense of the Response Graph, but not on all aspects mentioned in the same.
      The last 1% are the ones who really understand in and out of a response graph.


      Why is Response Graph important ?

      Frequency response curves, tell you a lot about the nature, character and sound of a loudspeaker. Response Graphs when understood properly give a quick, but extremely effective way of describing various aspects related to a Speaker.


      A Typical Response Graph

      A typical response graph is one which is a computer generated graph between a parameter in Vertical axis and another Parameter in Horizontal axis. The vertical axis is usually the sound level in dB. Louder sounds are higher up, while quieter sounds are lower at any given frequency. What is important in a frequency response curve is not what the actual numbers are, but how much they vary from frequency to frequency.
      To understand this we need to understand a bit about the dB or "decibel". The dB uses a logarithmic scale since this correlates fairly well with human hearing. As a rough rule of thumb, a change of 3 dB at 'mid' frequencies is just noticeable by the average person. Now some people are either trained themselves or have gifted ears to hear much more subtle differences. typically, a well trained audio engineer or audiophile can detect subtle differences in frequency response as small as 1 dB at certain frequencies. However, the average person will probably not notice changes until they are atleast around the 3 dB different point. This ability to detect differences gets worse for everyone at both low and high frequencies.

      Most folks get confused with interpreting change in db. A larger change on the order of 10 dB is needed for something to sound "twice as loud" at mid frequencies. This gets more and more when it comes to low and High frequencies. The way it is this way is becasue the ear / brain combination interprets sound very differently.
      For example if i want my sound system to play twice louder and buy a 200 watt amplifier to replace my existing 100 watt amplifier, it will not be twice louder at all, Infact i wont even be able to notice much of a difference at all as the level increase is just 3 dB. In order to get the sound system to sound twice as loud, I would have to buy a 1000 watt amplifier to replace the original 100 watt model which will then contribute to a 10 dB increase in level.

      Note that the important thing on the vertical axis is not how much the curve appears to go up and down, but the number of dB it goes up or down. Be careful when comparing curves to look at the dB scale. If no dB scale is given, then the curve is close to be termed meaningless.



      The next thing to look at is the horizontal axis that shows the frequency. The usual numbers given for the range of human hearing is from 20 Hz to 20,000 Hz (20 kHz). This range can be expected to hold true for healthy young people who have not been exposed to excessively loud sounds. Most of us lose some of our hearing starting at the frequency extremes as we age. An average human would be able to hear frequncies from 30hz to 17Khz well.

      The Key aspect to look for in this axis is the Range. A Typical Sub would cover freq below 400 hz well. A typical Midbass would cover freq from 80 Hz to 5Khz well. a Typical Tweeter will cover freq above 4Khz pretty well. However there are quite a number of exceptions to these stated numbers. Most High end Woofers take down from 700 hz also. Few Competition grade Midbass do an easy 60 Hz to 5Khz. Few High end tweeters take things from as low as 1khz all the way beyond the 20khz range !
      A Typical Response Graph looks like this;

      Name:  80_dB_range.jpg
Views: 544
Size:  32.5 KB


      On Axis, Off Axis Response:

      Every audio device has its own "color" and "texture" which the skilled engineer uses to produce a pleasing result. Ofcourse ultimatley a flat and linear curve is what would be an ideal scenario. But then in reality it is quite impractical to get a perfect flat line. Second, most frequency response curves are only of the response directly in front (on-axis or zero degrees) of the device being tested. Even if the on-axis frequency response were flat, that would not tell us what the response was like at different angles. Most loudspeakers will have very different responses at different angles. The minimum set of curves needed to characterize a microphone's variation in frequency response and level at different angles is on-axis, 90 degrees off-axis (directly to one side), 60 degrees off-axis (angled to one side), 30 degrees off-axis (steeply angleed to one side)and 180 degrees on-axis (directly to the rear).

      Remember with each type of axis, you will find the response not only varying in db but sometimes in range also. It is important you understand what axis is the response curve measured at before arriving at a final conclusion.

      Sometimes, an impedance graph is also represented along with the freq range graph. The sudden peaking of the impedance in a response graphs is the Resonant Freq of the Driver.


      Listed Below are Few of the Response Graphs of popular Drivers and Speakers.

      DLS Scandinavia 6 Midbass

      Name:  DLS6.JPG
Views: 583
Size:  46.5 KB


      Dynaudio MD142 Mid Range

      Click image for larger version. 

Name:	DynMD102_graph.JPG 
Views:	94 
Size:	66.5 KB 
ID:	59971

      Morel CDM 88 Mid Range

      Click image for larger version. 

Name:	CDM88 Graph.JPG 
Views:	98 
Size:	159.3 KB 
ID:	59970

      Seas Reference RT27F Tweeter

      Name:  f_seas_lotus_reference_l0004_06s.jpg
Views: 376
Size:  63.0 KB


      Focal PolyGlass V30 Components

      Click image for larger version. 

Name:	PolyglassV30_Graph.JPG 
Views:	90 
Size:	74.7 KB 
ID:	59968


      These curves help a lot when it comes to positioning of tweeters. So, the next time around, do understand the graphs before making a buy. Happy reading

      Cheers
      Mi10
      RIP Penguin May 2013 - Dec 2015

    2. #2
      People asking for status
      update
       
      Awesome
       
      Pr_007's Avatar
      Join Date
      Jul 2010
      Posts
      1,545
      Super Thread Sir!!!...I used to look at a lot of graphs and some I understand but there are a lot I did not. This is an extremely valuable thread. Thank you.

    3. #3

      !
       
      Awesome
       
      Vinosh Sam's Avatar
      Join Date
      Feb 2011
      Location
      chennai
      Posts
      809
      Blog Entries
      1
      Thank You!!!!....Now I need a rewind button to start from scratch on my ICE setup...But wait, why do i need to learn all these when I have you and GH
      Last edited by Vinosh Sam; 29th Nov 2011 at 19:41.
      I am responsible for what I say; not what you understand.

    4. #4
      Stark Industries
      Opinion are like Assholes,
      Everyone has one
       
      Hungry
       
      IronMan's Avatar
      Join Date
      Sep 2011
      Location
      Chennai
      Posts
      2,265
      oh my god so much info for ICE... now am freezed
      Alto --- Lets Go.... but where ???

    5. #5

      Up and Running
       
      Awesome
       
      matbhuvi's Avatar
      Join Date
      Dec 2011
      Location
      Bangalore
      Posts
      2,677
      Got a question. Many graphs show a second smooth curve..what is that?


      Click image for larger version. 

Name:	Unity.JPG 
Views:	37 
Size:	95.7 KB 
ID:	62966

      Also, in x-axis, the units are not charted in a consistent manner. The space between 100 to 200 is same as 1000 to 2000. Why is that?
      Last edited by matbhuvi; 26th Dec 2011 at 10:39.

    6. #6

      not aware that he can set his status here!
       
      Awesome
       
      Gilead's Avatar
      Join Date
      Mar 2010
      Location
      Chennai
      Posts
      4,887
      Quote Originally Posted by matbhuvi View Post
      Also, in x-axis, the units are not charted in a consistent manner. The space between 100 to 200 is same as 1000 to 2000. Why is that?
      It's a log scale.
      I don't know what's gonna happen man but I wanna have my kicks before the whole shithouse goes up in flames

    7. #7

      Up and Running
       
      Awesome
       
      matbhuvi's Avatar
      Join Date
      Dec 2011
      Location
      Bangalore
      Posts
      2,677
      Quote Originally Posted by Gilead View Post
      It's a log scale.
      Makes sense.

      Wiki helped me on the smooth curve. It is impedance curve. It gives the resonant frequency of the speaker.

    8. #8

      not aware that he can set his status here!
       
      Awesome
       
      Gilead's Avatar
      Join Date
      Mar 2010
      Location
      Chennai
      Posts
      4,887
      Found some interesting figures for the Dynaudio MD142 and Morel CDM88 mid range speakers.

      MD142
      Resonant Frequency: 475 Hz
      Frequency Response: 700-6000 Hz

      CDM88
      Resonant Frequency: 280 Hz
      Frequency Response: 450 to 7000 Hz

      It looks to me (depending on the XO) that vocals may jump between the mid woofer and the mid range in the Dynaudio component system.

      EDIT: karanbhatia do you have the passive XO points of your 3 way?
      I don't know what's gonna happen man but I wanna have my kicks before the whole shithouse goes up in flames

    9. #9
      Reboot
      Curiosity killed the cat;
      Insecurity killed the man
       
      Hungry
       
      Mi10's Avatar
      Join Date
      Oct 2010
      Location
      Chennai
      Posts
      4,909
      Blog Entries
      2
      Quote Originally Posted by Mi10 View Post
      Sometimes, an impedance graph is also represented along with the freq range graph. The sudden peaking of the impedance in a response graphs is the Resonant Freq of the Driver.
      Quote Originally Posted by matbhuvi View Post
      Wiki helped me on the smooth curve. It is impedance curve. It gives the resonant frequency of the speaker.


      Yes, its impedance - The peak is where your Resonant freq is (Its already given there )
      RIP Penguin May 2013 - Dec 2015

    10. #10
      Reboot
      Curiosity killed the cat;
      Insecurity killed the man
       
      Hungry
       
      Mi10's Avatar
      Join Date
      Oct 2010
      Location
      Chennai
      Posts
      4,909
      Blog Entries
      2
      Quote Originally Posted by Gilead View Post
      Found some interesting figures for the Dynaudio MD142 and Morel CDM88 mid range speakers.

      MD142
      Resonant Frequency: 475 Hz
      Frequency Response: 700-6000 Hz

      CDM88
      Resonant Frequency: 280 Hz
      Frequency Response: 450 to 7000 Hz

      It looks to me (depending on the XO) that vocals may jump between the mid woofer and the mid range in the Dynaudio component system.

      EDIT: passive XO points of your 3 way?
      HPF 900 Hz @ -6 db octave to LPF 3.5khz @ -6 db for the Midrange (Guess so !)

      Do check out Legatia L3v2
      RIP Penguin May 2013 - Dec 2015

    Page 1 of 3 123 LastLast

    Thread Information

    Users Browsing this Thread

    There are currently 1 users browsing this thread. (0 members and 1 guests)

    Similar Threads

    1. In need of speakers..
      By Satish Bhat in forum ICE and Gadgets
      Replies: 9
      Last Post: 24th Apr 2012, 22:39
    2. Speakers wanted.
      By agn in forum ICE and Gadgets
      Replies: 6
      Last Post: 23rd Jun 2011, 23:47
    3. Best Component Speakers !!! help???
      By raman in forum Equipment & Install Queries
      Replies: 54
      Last Post: 16th Feb 2011, 16:18
    4. Better speakers for Scorpio
      By Dev in forum Equipment & Install Queries
      Replies: 2
      Last Post: 22nd Sep 2010, 23:59

    Bookmarks

    Posting Permissions

    • You may not post new threads
    • You may not post replies
    • You may not post attachments
    • You may not edit your posts
    •