# Test Tones



## tomacco (Dec 8, 2007)

Hello: Are there any circumstances where the use of a signal generator would be preferable to a test CD?

Best Regards
Eric G.


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## jerome (Apr 24, 2007)

Yes, I personally think so. A (sinus) signal generator will give your the possibility to cover a large range of frequencies as you measure real-time SPL (with REW for instance) without changing tracks every time.

In my opinion, this tool is very useful to find peaks and valleys very quickly: keep looking at your real-time SPL measurement while you cover the frequency range you're interested in. You can easily go back and forth, adjust the speaker placement, level and phase.

One other problem with a test CD is that, by definition, it cannot reproduce all the frequencies and every track is time-limited. You don't have these problems with a signal generator.

Hope this helps !

Note: REQ also includes a very complete signal generator and it's very easy to use


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## tomacco (Dec 8, 2007)

jerome said:


> Yes, I personally think so. A (sinus) signal generator will give your the possibility to cover a large range of frequencies as you measure real-time SPL (with REW for instance) without changing tracks every time.
> 
> In my opinion, this tool is very useful to find peaks and valleys very quickly: keep looking at your real-time SPL measurement while you cover the frequency range you're interested in. You can easily go back and forth, adjust the speaker placement, level and phase.
> 
> ...


Hi: Yes this helps. I was thinking if you got into a problem at a particular frequency, just stop the sweep, and fine-tune, or do whatever clever test you had up your sleeve.

Thanks
Eric G.


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## jerome (Apr 24, 2007)

tomacco said:


> I was thinking if you got into a problem at a particular frequency, just stop the sweep, and fine-tune, or do whatever clever test you had up your sleeve.


Yes, I agree with you.

That's how I have learnt how to do it:
1) Run a full sweep with REW. Stop here if you're happy with the results 
2) Find the frequency that needs to be corrected
3) Generate this frequency and modify placement, phase, gain, etc in order to suppress the problem
4) Go to 1


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## tomacco (Dec 8, 2007)

jerome said:


> Yes, I agree with you.
> 
> That's how I have learnt how to do it:
> 1) Run a full sweep with REW. Stop here if you're happy with the results
> ...


Thanks Jerome: Sounds like a concise procedure.

Eric G.


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## jerome (Apr 24, 2007)

You're welcome ! I'm just happy to let you know how I got it from the guy who owns this one:








Useless to say that he is very good at calibrating a system with many subwoofers.

Yeah, I know it's crazy. He runs the system in 5.8 mode .... :surrender:


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## tomacco (Dec 8, 2007)

Hi Jerome: I think that picture belongs in some kind of BFD Hall of Fame.

Eric G.


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## atledreier (Mar 2, 2007)

Isn't that 'Flageborg's' setup? Sure looks like it.


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## jerome (Apr 24, 2007)

atledreier said:


> Isn't that 'Flageborg's' setup? Sure looks like it.


Yes, it is. But nobody knows who Flageborg is on this forum :shh:

I had the chance to attend one subwoofer course where he helped a lot. Quite a guy :bigsmile:


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## Bob_99 (May 8, 2006)

I'm not being critical, but I would think some room treatment would really make it sound a lot better.

Bob


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## tomacco (Dec 8, 2007)

jerome said:


> You're welcome ! I'm just happy to let you know how I got it from the guy who owns this one:
> 
> 
> 
> ...


Hi Jerome: Can you provide the URL for that picture or site - I just can't read it from the picture.

Thanks
Eric G.


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