Good Audio Frequency Sweep Program?

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TonyPTX
TonyPTX Posts: 545
edited June 2003 in Troubleshooting
OK, I'm looking at optimizing some speakers (or speaker internals I should say) and was wondering if anyone knows any good (preferrably freeware) software that will help me plot out SPL based on a frequency sweep from 20 kHz to 20 Hz.

Thnx,
Tony
Damn....8 lines...I've gotta put my sig on a diet now....
Post edited by TonyPTX on
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  • GuitarheadCA
    GuitarheadCA Posts: 400
    edited June 2003
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    I would also be interested in any answers to this question, as I have a Computer tied connected to my system and a fairly nice stage mic connected to it.
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  • Dr. Spec
    Dr. Spec Posts: 3,780
    edited June 2003
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    http://www.markfitzsimmons.com/gomer/1-12octave.zip

    http://www.nch.com.au/tonegen/index.html

    http://www.snapbug.ws/sinewaves/

    These might help, but might not get you all the way to 20 kHz.

    Doc
    "What we do in life echoes in eternity"

    Ed Mullen (emullen@svsound.com)
    Director - Technology and Customer Service
    SVS
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  • TonyPTX
    TonyPTX Posts: 545
    edited June 2003
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    Good stuff Doc. It's a start.
    Damn....8 lines...I've gotta put my sig on a diet now....
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  • GuitarheadCA
    GuitarheadCA Posts: 400
    edited June 2003
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    Man, I can only hear from 30 to 17k:( I was hoping for 20 to 20.

    But thanks doc, it's fun stuff and appreciated. Anything you know of that can use a computer and a Mic for a SPL meter?
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  • GuitarheadCA
    GuitarheadCA Posts: 400
    edited June 2003
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    Actually light on, I did the test on my RTi38, so I may actually be able to hear lower than 30. But I'm still ticked because my roomate can hear 18,000 and I cant.
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  • TonyPTX
    TonyPTX Posts: 545
    edited June 2003
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    I can't hear anything past 16k. Live with it. At least I can say my name isn't FIDO.
    Damn....8 lines...I've gotta put my sig on a diet now....
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  • Dr. Spec
    Dr. Spec Posts: 3,780
    edited June 2003
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    To me, nothing is more fun that running the 1/12 octave sub sweeps.

    When my PB2+ gets here in a week or so, I'll be running six different tune sweeps on it.

    I've even got custom unweighted correction factors for my SPL meter, since the RS Correction Factors don't work for my meter.

    Guitar - I think there are software programs out there that will allow a good mic to be used for spectra analysis, but I'm not sure where to find them.

    Doc
    "What we do in life echoes in eternity"

    Ed Mullen (emullen@svsound.com)
    Director - Technology and Customer Service
    SVS
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  • TonyPTX
    TonyPTX Posts: 545
    edited June 2003
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    Peter,
    A nice program is called SpectraPlus which is available here. Down side is that it's only good for 30-days and I installed it a while back and am now up the creek without a paddle.

    Doc,
    I know you have a much better SPL meter than the regular ole' RatShack, but I remember reading a post somewhere of how someone had mod'ed their RatShack SPL meter (replacing a few caps and resistors) to get it to work w/o the need for correction factors. Ever look into this?
    Damn....8 lines...I've gotta put my sig on a diet now....
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  • Dr. Spec
    Dr. Spec Posts: 3,780
    edited June 2003
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    Originally posted by TonyPTX
    Peter,
    A nice program is called SpectraPlus which is available here. Down side is that it's only good for 30-days and I installed it a while back and am now up the creek without a paddle.

    Doc,
    I know you have a much better SPL meter than the regular ole' RatShack, but I remember reading a post somewhere of how someone had mod'ed their RatShack SPL meter (replacing a few caps and resistors) to get it to work w/o the need for correction factors. Ever look into this?

    http://www.gti.net/wallin/audio/rsmeter/33-2050/33-2050.html

    The difference between my meter and the RS meter is that mine follows the C-weighted curve faithfully, and the RS meter does not.

    The RS Correction Factors are a combination of error correction, and conversion to an unweighted response.

    "My" correction factors are only for conversion to an unweighted response, and contain no additional error correction.

    The above link mods correct for both the RS error AND the c-weighted curve down to 20 Hz. Below that, I'm not sure.

    Doc
    "What we do in life echoes in eternity"

    Ed Mullen (emullen@svsound.com)
    Director - Technology and Customer Service
    SVS
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  • GuitarheadCA
    GuitarheadCA Posts: 400
    edited June 2003
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    Well I checked out that program Anthony recommended. First time I've had my hands on something like that, and I'm having alot of fun. So this is a pretty rough (very far from perfect testing environment) analysis of my RTi38's connected to an Onkyo 8211 (usining a $50 Audio Technica Mic).

    I'm not quite sure how to explain the VERY strong low end, perhaps my desk is resonating, or there's a low hum from an air conditioner or something. I think the dip at 700hz is kinda interesting too. I'm sure the dipping off at 18k is most likely due to the mic's upper limit, as it's way below what the Silk Domes are supposed to be able to do. Okay, so it's no Sound and Vision Test, but I still found it really interesting. Any Comments?
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  • GuitarheadCA
    GuitarheadCA Posts: 400
    edited June 2003
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    Okay, didn't have the tone controls to flat before (duh), The bass was boosted pretty high. Here's a better curve (yes, the scale is a little different, but it's still a better run). Now I would attribute most inconsistancies to not being able to hold the mic steady for a full minute.

    Oh, and I called on the price of the program (thinking I might actually like to have it around) - $795!!! GOODNIGHT! Let's just say if I had $800 I'd spend it on speakers or music, not the the program to measure them.
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  • TonyPTX
    TonyPTX Posts: 545
    edited June 2003
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    Originally posted by GuitarheadCA
    Oh, and I called on the price of the program (thinking I might actually like to have it around) - $795!!! GOODNIGHT! Let's just say if I had $800 I'd spend it on speakers or music, not the the program to measure them.

    Holyshiznit....time to search your favorite alt.bin newsgroups.
    Damn....8 lines...I've gotta put my sig on a diet now....
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  • jkratzer
    jkratzer Posts: 148
    edited June 2003
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    Guitarhead,

    If I'm reading your chart right, then the RTi38 is weak below 90Hz on the low end and above 12KHz on the high end. I would have thought that the RTi38 would have a wider range than that.
    My 7.1 setup consists of:
    Denon 3803
    Panasonic DVD
    RTi70s front
    CSi40 front center
    RTi28s side surround
    FXi30s back surround
    PSW202 Subwoofer - Hey, it's my first sub!
    RCA 46" 4:3 RPTV
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  • GuitarheadCA
    GuitarheadCA Posts: 400
    edited June 2003
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    Yes, you are reading the chart right.

    However, I believe the dip above 12 khz is due to the mic. The low end I think is pretty accurate though. You're right it starts dipping at 90 hz. However at 90, it's still +6 db (assuming the -20 line is a good measure of the average.) It goes all the way down to 50hz before it's -6 db, which isn't that far from what polk quotes. in regards to the mic: it's a pretty good mic, but it is a stage mic, and stage mics are taylored to the frequency that voices can produce (I bought it so I could record some guitar riffs and songs I made up on a multitracking program I have on my computer). And I believe the mic's range is about 25-16k.
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  • GuitarheadCA
    GuitarheadCA Posts: 400
    edited June 2003
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    Oh, and I did a little research, and found some consumer Specturm programs (the $800 one is obviously geared toward commercial use).

    http://www.trueaudio.com/rta_abt1.htm

    http://www.audio-software.com/

    Both having trial downloads, and with both, the top of the line package is $100. Much more affordable, I think I'm going to buy the $69 package from the top link. They're real easy to use if you have a mic connected to your comp.
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  • dthomps
    dthomps Posts: 352
    edited June 2003
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    Guitar-
    Do you use high speed internet?
    Do you use Kazaa or WinMX or anthing?
    No, I am not suggesting pirating, thats illegal...:D....Right?

    Just a completely off topic question.


    Interesting results, I wish I had a mic capable enough to use with one of these programs. Looks like its a little bit of fun.
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  • gidrah
    gidrah Posts: 3,049
    edited June 2003
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    I know I've seen (and will try to find) a mod for these that uses a different mic. If I remember correctly it does entail some inside work and replaces the housed mic with a jack. The suggest replacement is a Panasonic. Supposedly it puts this meter within the range of pro as the mic is the lacking portion. Gimme some time and a few beers.
    Make it Funky! :)
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  • GuitarheadCA
    GuitarheadCA Posts: 400
    edited June 2003
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    dthomps,

    Did you think I pirated the commercial Spectrum analyzer I used? I wish my friend, because it is a sweet program. I have that on a 30 day trial; that's why I was doing additional research on other analyzers. I think I might actually have to buy one too, because no one has a key on Kazaa;)
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  • dthomps
    dthomps Posts: 352
    edited June 2003
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    Nah I knew it was the unregistered version, just saying you might not need to go out and buy one.

    Too bad I checked out Kazaa too and found nothing.
    Have fun though, and let us know how the program you end up with is.

    Send me an email, you have it disabled through the forum, I have something for you :D

    surfbum72@worldnet.att.net

    Mike
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  • TonyPTX
    TonyPTX Posts: 545
    edited June 2003
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    Hey now, don't leave me outta the loop.....it's my damn thread to start off with!! :D
    Damn....8 lines...I've gotta put my sig on a diet now....
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  • GuitarheadCA
    GuitarheadCA Posts: 400
    edited June 2003
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    lol, no worries Anthony, I'll let you know if it's anything good ;)
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