Page 1 of 6 123 ... LastLast
Results 1 to 15 of 89

Thread: Frequency Response

  1. #1
    Administrator Mr. Widget's Avatar
    Join Date
    Apr 2003
    Location
    San Francisco
    Posts
    9,981

    Frequency Response

    In an effort to put my money where my mouth is, instead of diverting yet another thread OT, I am starting this one inspired from a post elsewhere. We were discussing the 2397 horn with the 2441 driver and I posted the graph below which inspired this post:

    Quote Originally Posted by hapy._.face
    Hey Widget-

    In the range where it matters- that graph isn't nearly as contrasting as I would think it SHOULD be considering the price of the 4001. Does look a little smoother...
    The information that a frequency response graph gives us is limited. There have been many discussions around this topic with the posting of RTA curves, but I don't think the topic has really been covered. An MLS plot created by a system like CLIO with a calibrated mic gives us a bit more info, but it, like the RTA plot is really only an indication of performance. Primarily what you can get from looking at a curve like this one is an idea of a speaker's tonal quality. If you see a serious peak or dip you can infer that there may be a resonance issue or other problem, but realistically all we can tell is if the speaker will sound bright or dull, honky or more neutral... it really isn't nearly as all encompassing as so many seem to think.

    When I posted this plot comparing the JBL 2441 and the TAD 4001, I said that the differences were "subtle and quite possibly not worth the big coin if cash is tight, but the inner detail and sense of dynamics is just that much better and they are slightly smoother." Tonally the two drivers were remarkably similar. You would gather that from looking at the plot. What you can't see is the way the 4001 with it's larger magnet and beryllium diaphragm has greater resolving ability which is quite audible. It also sounds slightly smoother and less fatiguing, but these differences are much more subtle.

    The bottom line is that while a frequency response plot is helpful, don't put too much importance on it. Distortion and impedance plots are also useful, but as we have said countless times our own ears are the ultimate best judges of sound quality.

    Widget
    Attached Images Attached Images  

  2. #2
    Senior Member
    Join Date
    Nov 2003
    Location
    Toronto
    Posts
    1,115
    Hi Widget, does a TAD bolt up the same as a 2441?

  3. #3
    Administrator Mr. Widget's Avatar
    Join Date
    Apr 2003
    Location
    San Francisco
    Posts
    9,981
    It does. It is essentially Bart Locanthi's attempt at taking the 375/2440 and improving on it. It has similar geometry and is essentially the same design that Mr. Lansing himself created decades earlier. Bart increased the magnet and changed the diaphragm material. It even has the same roll surround as the 375/2440, not the diamond surround that JBL developed later.


    Widget

  4. #4
    Administrator Mr. Widget's Avatar
    Join Date
    Apr 2003
    Location
    San Francisco
    Posts
    9,981
    This is posted elsewhere on these threads, but here is a JBL published comparison between the 2440, 2441, and the 4001. The discussion is about the mass break point and it's effects on HF response of compression drivers. For this discussion it is interesting to see how a different horn, in this case a JBL 2350 radial horn will have a dramatic effect on the FR curve of a compression driver.

    Widget
    Attached Images Attached Images  

  5. #5
    Senior Member
    Join Date
    Jan 2006
    Posts
    814
    Quote Originally Posted by Widget
    snip....In an effort to put my money where my mouth is...
    I think you put your mouth where your money is...hell, who doesn't !?


    Quote Originally Posted by Widget
    snip...as we have said countless times our own ears are the ultimate best judges of sound quality.
    ....little wonder why some of that older (imperical) JBL sounds so good- even today.


    Quote Originally Posted by Widget
    An MLS plot created by a system like CLIO with a calibrated mic gives us a bit more info, but it, like the RTA plot is really only an indication of performance
    I know it is elsewhere in this forum, but I'm glad you posted this again to put some fresh paint on it. I'm sick of hearing about the graph as the "end all". Sure, an RTA gives us insight to a driver's Fs and overall performance- but it won't tell you squat bout how it sounds!! Thanks!


    Quote Originally Posted by Widget
    Bart increased the magnet and changed the diaphragm material. It even has the same roll surround as the 375/2440, not the diamond surround that JBL developed later.
    Flattering.

  6. #6
    Senior Member
    Join Date
    Feb 2004
    Location
    Central Coast California
    Posts
    9,019

    It would be instructive...

    ...but nearly impossible to see how my receptors stack up to these transducers. It'd also be instructive to see how these transducers function in a real world environment.

    This kind of solid work in understanding the subtleties of the interaction of magnet, diaphragm, horn, et al is the foundation to understanding the sonic characterisitcs of a system in a (more or less) standardized procedure.

    I think we tend to like to do it so much because it's manageable, repeatable, consistent, comparable from unit to unit, etc. Plus we get to use really neat equipment. I admire those who have more skill, better equipment, and more dedication to this endeavor than I.

    Thanks, Widget, for sharing this.

    Widget's assertion that the ears are the ultimate judge is irrefutable and shows that he's both a man of science and of common sense--a useful commodity indeed.
    Last edited by Titanium Dome; 03-02-2006 at 03:24 PM. Reason: everyone's just too damn uptight--my bad
    Out.

  7. #7
    norealtalent
    Guest
    Quote Originally Posted by Titanium Dome
    ...
    If the LH weekend happens this summer, maybe I'll invite an audiologist to offer hearing analysis for attendees. That should be an eye--and ear--opener! Maybe it'll finally reveal what I've suspected all along about those who prefer horns...but I'm getting off thread here.
    Whatdyashay? Speak up sonny, I can't hear ya!

  8. #8
    Senior Member edgewound's Avatar
    Join Date
    Jun 2005
    Location
    Southern California
    Posts
    2,672
    Quote Originally Posted by Titanium Dome
    ...

    If the LH weekend happens this summer, maybe I'll invite an audiologist to offer hearing analysis for attendees. That should be an eye--and ear--opener! Maybe it'll finally reveal what I've suspected all along about those who prefer horns...but I'm getting off thread here.
    What is it that you suspect? That horn-preferers have some sort of physical defect? Boy oh boy... you set yourself up for this one. Some listeners...probably most listeners... will prefer the system that sounds best to them....I've heard both....and I like both if they're respectivley done well. Your agenda is showing .
    Edgewound...JBL Pro Authorized...since 1988
    Upland Loudspeaker Service, Upland, CA

  9. #9
    Senior Member
    Join Date
    Jan 2006
    Posts
    814
    Quote Originally Posted by Titanium Dome
    ...but nearly impossible to see how my receptors stack up to these transducers. It'd also be instructive to see how these transducers function in a real world environment.
    It would, indeed.


    ....maybe I'll invite an audiologist to offer hearing analysis for attendees. That should be an eye--and ear--opener! Maybe it'll finally reveal what I've suspected all along about those who prefer horns...but I'm getting off thread here
    Good idea! I worry about your iPod's ill effects on YOUR hearing! (insert a big smiley face here)

  10. #10
    Administrator Robh3606's Avatar
    Join Date
    Apr 2003
    Location
    Rocinante
    Posts
    7,984
    Since this is a forum about Lansing Heritage, it's obvious we'll spend most of our energy on the speakers themselves. However, we do neglect our rooms and our ears to a great degree.
    Why would you think that???? Anyone who is serious about this hobby tends to be more careful than most about what they will expose their hearing to. Especially as you get older where it's only a matter of time that age takes it toll. Last thing you want to do is help it along!

    If the LH weekend happens this summer, maybe I'll invite an audiologist to offer hearing analysis for attendees. That should be an eye--and ear--opener! Maybe it'll finally reveal what I've suspected all along about those who prefer horns...but I'm getting off thread here.
    Your kidding right??

    Rob

  11. #11
    Senior Member JBLnsince1959's Avatar
    Join Date
    Dec 2003
    Location
    KC - land of ahhhhs
    Posts
    1,795
    Quote Originally Posted by edgewound
    What is it that you suspect? That horn-preferers have some sort of physical defect? Boy oh boy... you set yourself up for this one. Some listeners...probably most listeners... will prefer the system that sounds best to them....I've heard both....and I like both if they're respectivley done well. Your agenda is showing .
    Yeah that would be first for Dome wouldn't it...

  12. #12
    Senior Member jim campbell's Avatar
    Join Date
    Nov 2005
    Location
    Winnipeg ,Siberia
    Posts
    1,167
    many years ago someone showed me a graph comparing a very expensive studio tape recorder ($150,000.00) and a mass market cassette deck valued at about $300.00. the studio machine did not even note frequency response above 15khz.the specs on the cassette deck were actually better than the studio rig.some time later a friend with a frequency generator showed me just how fast sounds roll off above about 12-14khz.after that i always put very little stock in graphs and spec sheets and believed my ears.

  13. #13
    Senior Member DavidF's Avatar
    Join Date
    Apr 2003
    Location
    San Jose CA
    Posts
    918
    Quote Originally Posted by Giskard
    After five years on this forum I'd put very little stock in most of the ears here.

    Well, ok, maybe a wee bit - after all, you all seem to be able to tell the difference between an Altec or JBL and everything else.
    Say what? My ears are very discriminating. They just don’t always like what they see.

    Davidf

  14. #14
    Senior Member Ian Mackenzie's Avatar
    Join Date
    Apr 2003
    Location
    Australia
    Posts
    7,127
    Widget,

    Is it possible to post a near field unsmoothed response comparison and also distortion curves for the respective drivers?

    Ian

  15. #15
    Administrator Mr. Widget's Avatar
    Join Date
    Apr 2003
    Location
    San Francisco
    Posts
    9,981
    Near field... these were taken at 1m on axis with 1/12th octave smoothing. This level of smoothing removes very little information. The main reason that they look fairly clean is that they are time windowed which eliminates all of the hash that you normally get with a pink noise curve. I should have placed the horns higher from the floor (I have slightly over 10' ceilings) to extend the time window. With this window the information below about 800Hz is meaningless.

    Since I no longer have either the 2441s or the 4001s... had to sell them to try other items, I can't make the other measurements. Sorry.

    The point of this thread was to explain that a simple FR plot really doesn't tell that much of the story. Impedance plots and distortion curves will get you another 10% there, but you are really still way off in the dark.

    Widget

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. Is it sacrelege? Am I evil? (long) - 4343 xover mods
    By 4343mod in forum Lansing Product DIY Forum
    Replies: 63
    Last Post: 05-11-2010, 03:20 AM
  2. frequency response 2450 and 2450sl
    By Jakob in forum Lansing Product Technical Help
    Replies: 2
    Last Post: 02-21-2006, 07:35 AM
  3. Frequency Response Testing on the W15GTI
    By toddalin in forum Lansing Product Technical Help
    Replies: 0
    Last Post: 01-12-2006, 05:46 PM
  4. Does Ti Increase UHF Response?
    By Mr. Widget in forum Lansing Product General Information
    Replies: 9
    Last Post: 01-25-2005, 01:33 PM
  5. 2435HPL vs. 435Be
    By jim henderson in forum Lansing Product Technical Help
    Replies: 67
    Last Post: 08-12-2004, 12:24 PM

Posting Permissions

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