How to EQ HiFi speakers to be closer to true flat audio monitors

[lollielala]

I want to do some home recording & I

have a set of no-name boomy speakers that produce

sound that is far from what I think it should sound like

 

My ears are ok at but can't recognise & distinguish all various audio frequencies (yet)

 

Are there any noteworthy sound designer test CD's out there?

 

Does any software exist that can listen & analyse sound

& tell me what frequencies need to adjusted to make a more flat true?

 

Links welcomed but please No Copy & Paste Answers

- thank you

 

[stejorge]

Maybe you could try audiolense from juice HIFI. It's not the cheapest of SW, but in my opinion it the best for the job. You would need a mic/pre to be able to record the sweep's.

You could download a trial version if you are just intrested in the sweep result, and are not intrested in the correction file.

 

http://www.juicehifi.com/index.html

 

[blueixus]

I started this thread of test tracks a while back, there is some good info on downloadable stuff.

 

http://www.computeraudiophile.com/content/Audio-Test-Tracks

 

[Shadorne]

You do need good speakers too. The cheapest option is a pair of used Yamaha NS10. These speakers are good for mixing everything from 60 Hz and up - provided you work at low background levels and very close to the speakers (nearfield). Then all you need is to find a friend with an expensive system to conduct some bass checks for the lowest octaves and try it in another friends car system.

 

The key to this speaker is the time domain response or waterfall plot. Although the frequency response is not very flat it is outstanding in the the time domain. It also shines a lens on your midrange (no flattering BBC dip on the NS10) - and if you get the mids right in your mix then the rest will sound great.

 

This is a brutally unflattering speaker. Like a high quality lens - the photograph shows every wart pimple and blemish and so does this speaker. By listening very close at low levels (nearfield) you also eliminate the major issues of the control room response.

 

What is odd is that few people pay any attention to waterfall plots - most people look at frequency response to judge speaker performance and this is one of the biggest myths in the industry.

 

If you ever wondered why Quad made waves with their ESL 57 - it is ALL and ONLY because of a superlative waterfall plot (no ringing and ultra rapid decay means a clarity that is unsurpassed - with an NS10 you hear the timbre that is on your mix rather than a sugar coated timbre imposed by the speaker)

 

Good luck.

 

[Nyal Mellor]

You are not going to get very far EQing a generic set of speakers. The sound quality is not just related to the frequency response but also the distortion, time domain performance, off axis performance, etc (most of which you can't fix by EQ).

 

You would be better off saving and buying better speakers.

 

Otherwise you could experiment with the EQ in iTunes. Note that a flat FR is not necessarily what you should aim for anyway.

 

[esldude]

Pretty simple for basic useful EQ work are warble tones. Stereophile Test CD 2 has some good tones for your purpose. You can order from here.

 

http://ssl.blueearth.net/primedia/product.php?productid=5&cat=0&page=2&featured

 

These tones sweep 1/3 octave at a time. This comes reasonably close to breaking up the sound into bands similar to what your ear processes subjectively. The back and forth frequency sweep mostly eliminates bad room resonances from clouding the results to let you hear what the speakers are doing. Combine this with the Radio Shack sound level meter for measuring and you can get a pretty good handle on what is happening. Set the RS SLM to C weighting slow response. While not a lab grade sound level meter this one is flatter than most speakers.

 

At one time Audacity would generate warble tones though recent versions do not.

 

http://www.speakerworkshop.com/

 

The free Speakerworkshop software is said to generate warble tones, though I haven't used it myself.

 

Another possible route is to generate some peak noise with Audacity, then filter it into 1/3 octave bands. Generate the pink noise, then under effects select 'equalization', then choose the 'graphic EQ' radio button. Pull all sliders down to a minimum except the band under test which you will push up to a maximum. Fortunately the EQ effect in Audacity has sliders for each one third octave. While not optimum this and a sound level meter should be workable also. You will need to generate 31 tracks tracks to cover all the test bands.

 

Having done this with a number of speakers, I know this can be very helpful. Sometimes pretty mediocre speakers can be made to sound fairly good.

 

A few things to keep in mind. Like someone said, you don't want truly flat. You can play around with it, one good approach initially is flat to around 2 khz, then a two dB per octave slope. Even that might sound a bit bright. Another thing to keep in mind is dips in the response often cannot be EQ'd out. Your room may have a suckout there, and no matter how much power you push into that zone you just don't get much output. You can blow speakers or amps being too aggressive there. I would not boost a dip more than 6 dB no matter how deep, and maybe not that much if the dip is below 200 hz. Peaks can be tamed pretty well, and often are more subjectively noticeable anyway. Rooms cause the most problem at 500 hz and below. Speakers are often not too bad above 500 hz. Moving your speakers to different locations can alter the response below 500 hz, especially below 200 hz. So some low frequency problems can be made better that way before you do EQ.

 

[wgb113]

Your cheapest option is Rives Test CD2 and a Radio Shack sound level meter. The RS meter isn't perfect but the Rives disc contains tones that compensate for the inaccuracies of that particular meter.

 

That will tell you where the problems of your speakers & room interaction are. Whether or not you want to attempt to fix it with EQ is up to you. It could possibly make things worse.

 

You also may find yourself not liking a flatter sound. I would start by making sure you're not currently using any EQ, bass boost, or other sound enhancement and then trying pulling those "boomy" speakers out from the wall as far as is reasonable.

 

My best advice is experiment to your ear's content but in the end only worry about what sounds good to YOU.

 

Bill