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Forums     Plugins     CurveEQ HarBal

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I am new to this foum and to the world of audio processing, so please bear with me.

Having just purchased the mastering suite (and convolution suite) including curveEQ based entirely on reviews in this forum and in the music publications such as SOS etc, I was wondering how similar curveEQ and HarBal are.  HarBal is getting very good press and in the latest SOS, Martin Walker says "Harbal is a considerable improvement over....  Voxengo's CurveEQ".  This appears to be because HarBal uses loudness compensation?  Are there plans to upgrade CurveEQ in this respect?

Clearly the authors work very hard to keep these tools updated and as a software developer myself, I say well done - I support you.

Many Thanks

The only advantage that loudness compensation gives, is that it allows before-and-after judgements to be quickly and easily made -- Harbal simply uses an "A-weighted" curve to change the overall volume of the EQ'd file so that it has a similar overall volume to the original file.  It makes no difference to the final sound you get.

With CurveEQ you can can easily change the overall volume of the EQ, so you can get pretty much the same functionality with only a little extra effort.

Thanks very much for the prompt reply.

I didn't get where I am today without a little extra effort!  If only I could get back to where I started..

As far as I know Har-Bal isn't a plug in yet so it works as a standalone EQ.  Also the version I have doesn't display a real-time spectrum although someone said that was either implemented or will be shortly.

I'd have to read the article (I'll find it today I'm sure) but I'm not sure I'd make a one is better than the other comparison.  In other words today I have to rebalance a stereo track, one channel is bass heavy so I have to do a stereo split in Sonar3 and seperately EQ each channel again then rebalance the stereo field.  I'll be using CurveEQ on each track as an insert plug for the EQ and something else to rebalance the stereo field (maybe soniformer2 or wideboy, etc).

OK - I've got it.  The SOS excerpt is:

"Harbal is a considerable improvement over other similar products I've reviewed in the past including Steinberg's Freefilter and Voxengo's CurveEQ, because it incorporates A-weighted compensation for perceived loudness changes."

I guess that statement could be made for any plugin that alters the loudness or rms of an audio file be it EQ, compressor, etc.  That's cool of HarBal to re-normalize the wave for you automatically.  With CurveEQ I'd have to watch the rms meters on something like Inspector and compensate by hand.

Actually I just skimmed the article for now - it looks very nice as I'm quite interested in such things and respect SOS opinion more or less.  This particular article seems to mention CurveEQ as a name-dropy kind of thing as opposed to a serious feature-by-feature comparison, just to make a point that most EQs don't auto-normalize but HarBal does.  CurveEQ just happens to be one the readers are familiar with from past reviews.  As with any good auto-feature you would also need a switch to turn it off - hehe.

With CurveEQ you may match the spectrum against the idealistic a-weighted curve.

Here's the spectrum file:

I think the rebalancing result should be very close to that you get with HarBal.

Moreover, A-weighting is a 'scientific' approach.  None of the plug-ins can follow the real a-weighted curve since the actually-perceived sound level should be known, and this is impossible without scientific measurement environment.  Not speaking about the fact that a-weighted curve changes dramatically with the perceived level meaning an equalization which changes in time should be used.

Aleksey, I think you are misunderstanding what HarBal is using an A-weighted curve for.  AFAIK it's doing an A-weighted RMS analysis of the whole file pre-EQ and post-EQ, and then changing the overall volume of the post-EQ file to equalise their A-weighted RMS values.  Nothing more than that.  It's true what you say about the A-Weighted curve, it's a pretty loose approximation of the ear's frequency characteristics, there are much more sophisticated models available, though it should be more accurate than an unweighted RMS reading.

Andrew, CurveEQ spectrum matching does pretty the same thing (maybe using other words in description).  The only difference to HarBal is that in CurveEQ you can choose any weighting curve (which actually resembles the destination spectrum).  Tell me if I'm wrong.

The A-weighted stuff in Har Bal has nothing to do with spectrum matching directly.  Har Bal doesn't match anything to an A-weighted curve -- it's just using an A-weighted analysis to ensure the output file has a similar perceptual loudness to the input file.  It's only purpose is to make pre- and post-EQ comparisons easier.

In any case I still think it uses spectral matching.  Actually, an a-weighted analysis of both sources followed by the spectral loudness correction (i.e. not a global volume gain) is the same as spectrum matching.  Otherwise I don't understand the purpose of HarBal at all.
This topic was created before release of the latest product version, and it may contain details irrelevant to this version.  Replying is disabled for this topic.