# sweep or sine wave ?



## Guest (Nov 20, 2006)

Hey Folks

What is the right way to measure ? Sweep or Sine wave ? Because I always thouhgt that the right way was sine waves. But then yesterday I read the help file completly one more time, and saw that the suggested method was sweep. How coluld i not have seen that in the first place  So I tried sweep, and that made a hell of a difference. + my room doesn´t seem to be that "acoustic good" :crying: 

So what is the most right way ? 

I´ll try to post some graphs soon. So u guys can help me :daydream: 

And 1 more thing. My soundcard doesn´t have line-in. But it has wave, mic, stereo mix, and one more thing I don´t remember right now. (It´s a labtop i borrow from someone, and i brought it back again)

Which one is the right one to use then ?


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## brucek (Apr 11, 2006)

> So what is the most right way ?


Sweep..............



> Which one is the right one to use then ?


You need a line_in. This a standard problem with a laptop. Most people with a laptop must get an external sound card driven from the USB port.

brucek


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## Blue Dude (Oct 19, 2006)

Would one of those cheapie $5 USB keychain sized sound cards be suitable for this use? My laptop has a similar input limitation and needs a workaround.


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## Guest (Nov 21, 2006)

brucek said:


> You need a line_in. This a standard problem with a laptop. Most people with a laptop must get an external sound card driven from the USB port.
> 
> brucek


Can you recommend an external soundcard ?


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## brucek (Apr 11, 2006)

> Can you recommend an external soundcard ?


Just about any soundcard that is full duplex and had line-in and line-out connections will work. Any inadequacies are compensated for in REW after you carry out a soundcard calibration (the first part of REW setup).

Several members here use the Soundblaster Live! 24-bit USB. It works fine with REW.

brucek


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## Guest (Nov 22, 2006)

I have ordred a Soundblaster Live 24 yesterday. So I´ll post some graph this weekend hopefully.


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## brucek (Apr 11, 2006)

> I have ordred a Soundblaster Live 24 yesterday


Be sure to read this thread...............


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## Guest (Nov 22, 2006)

brucek said:


> Be sure to read this thread...............


I´ll do that.

And I´ll need two y-split cables mini-jack (stereo) -> RCA for this soundcard setup right ? 

1 from SPL -> soundcard
1 from soundcard -> A/V processor


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## brucek (Apr 11, 2006)

Not really a Y-split (which implies mono), but a (stereo mini-plug to two mono plugs) adapter.

The soundcard line-in and line-out jacks are both stereo and require a stereo plug (of which you'll only use the right channel).










brucek


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## Guest (Nov 22, 2006)

brucek said:


> Not really a Y-split (which implies mono), but a (stereo mini-plug to two mono plugs) adapter.
> 
> The soundcard line-in and line-out jacks are both stereo and require a stereo plug (of which you'll only use the right channel).
> 
> ...


My bad. That was actually also what I ment. But I just named them wrong. :duh: 

So 2 of thoose will do ? Also just the right one to my A/V processor ? Does that make a different ? 

I´m getting my soundcard tomorrow. :bigsmile: So I´ll be tweakin´ the whole weekend 

Is it not good to use the sub to tame a peak ? Because I think I have a large one at around 50 hz :demon:

Sorry for all the questions. But I would like to make it right this time


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## brucek (Apr 11, 2006)

> So 2 of thoose will do ? Also just the right one to my A/V processor ? Does that make a different ?


Yep, two of those will do.

Yeah, you send the right channel from the soundcard to the A/V processor, but many people at that point split the signal (with a splitter) to feed both the right and left CD or AUX input, so when you add the mains after equalizing the sub, you get a right and left channel mains to check the interaction at the crossover...

Use REW with the sub only to setup the BFD filters. Then, when finished, add the mains and do a response to check the interaction at the crossover for any further tweaking...

brucek


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## Guest (Nov 23, 2006)

Performing a sine wave sweep is a tricky matter, you have to remain very still and quite as the wave or tone will be disturbed by any movement as the sound bounces off of you!

It’s better to be on the outside and while the tone goes though from 20Hz to 20KHz you can later analyzer the data on the pc.

All the fronts should have the same tone at the same spot, but often this needs addressing by an equalizer, the manual touch makes it more personal, you’re setting it to what is written down on paper you setting it for a flat response at the sweet spot and that’s all that can be done it’s not possible to have it the same throughout the whole room, and that would be very ideal but it’s not possible.

Once done check it out with some music and some film material to see what else is left, often a few more tweaks here and there across the fronts. You’ve got to have the right amount to cater for the ear not to bright and not too boomy, that’s mostly down to the reproduction of the CD or the films soundtrack.

To compensate for are own hearing loss at different frequencies is pointless, as friend might point out, “it’s too bright what on earth have you done here?” And being too bright will result in failure of the HF on one or more of the fronts if the films soundtrack level goes why too high, and with the boosted high frequency on your home cinema set-up, well you can say good bye to the HF!


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