# Subtesttones



## l´Blundt (Jul 6, 2006)

Hey.

I´m the happy new owner of a old pci 20-39 SvS(used).
When i play testtones, 20 to about 25hz, there is this air sound coming from the driver itself. Is this normal? Or is the driver maybe a bit damaged?
Other than that it plays superbly

l´Blundt


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## Sthrndream (Apr 21, 2006)

Hello,

First, please remember that you can EASILY damage a subwoofer by playing test tones at loud volume levels. This is particularly true with sine waves. Instead of test tones, try a few bassy DVDs with strong 20-25hz content. do you hear any audible distress from the subwoofer?

Tom V.
SVS


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## Malice (May 1, 2006)

or try using the REW software and do a log sweep of frequencies. It's quick, it's accurate and induces less stress on your sub and on the nerves of "she who must be obeyed" (assuming you have one!!).

Bob


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## l´Blundt (Jul 6, 2006)

Thanks for replying.
I dont think theres anything wrong with it. When playing movies or music with deep bass there is no audible stress.
I am just wondering if it is normal? Maybe its the suspension that can be heard working? When i hear it the driver is not moving more than a couple of mm. each way.
By the way it is Bass Mekanikz vol.5 im playing them from. Maybe its the disc?

Do anybody know where one can download a couple of testtones? Or anytheng like that.

l´Blundt


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## Otto (May 18, 2006)

> Do anybody know where one can download a couple of testtones? Or anytheng like that.


Check out download.com and search for tone generator. Most of them are free for a while, and should be able to accomplish what you're looking for. Start with that volume knob low.....


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## Otto (May 18, 2006)

Duh.... Well, of course, REW can do this for you as well. Available right here at the HTS. Assuming your system is connected, or can be connected, to a PC of some sort.


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## l´Blundt (Jul 6, 2006)

Thanks. I´m looking into the tonegenerator-stuff right now.

I can connect to my pc yes. But what is REW if i may ask?

l´Blundt


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## Otto (May 18, 2006)

REW is Room EQ Wizard, a program created by HTS's John M. It's a powerful tool that will measure your sub's frequency response (or, in general, any speaker's FR). It can then interface with a variety of EQ devices (the most popular being the Behringer Feedback Destroyer Pro). The EQ is generally applied on your sub's signal path to get it as close to your target response as possible, be it flat or some other "house curve."

Check out the links at the very top of these HTS pages in BIG letters -- "BFD Guide" and "Room EQ Wizard". They are excellent resources and will answer many questions about measuring FR and applying EQ.

Happy reading!


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## l´Blundt (Jul 6, 2006)

Many thanks. I´ll look into that tomorrow.

l´Blundt


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## lienly (Sep 4, 2006)

just quickly read those 2 links, seems they are very handy tools!:jiggy: 

BTW, what sub do you use, Otto? didn't find it in your photo album.



Otto said:


> Check out the links at the very top of these HTS pages in BIG letters -- "BFD Guide" and "Room EQ Wizard". They are excellent resources and will answer many questions about measuring FR and applying EQ.
> 
> Happy reading!


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## Otto (May 18, 2006)

Hi Louis,

I'm using an infinite baffle sub that I put together last year. You can check out my thread here.

Yeah, REW and the BFD can be very powerful tools for equalizing a sub. Just pick up an SPL meter and measure first to see if you need a BFD.


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