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Old 20th October 2006, 12:28 AM
Ianm2 Ianm2 is offline
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Default signal processors...

having been listening to tuners, its become apparent how much radio stations use compressors to give music punch and loudness.

and it sounds terrible, thin and lacking and transistory sounding.

one option I may experiment with one day, is an expander, this is the opposite of a compressor.

some japanese companies actually made these apart from pro audio arena where they are used a lot, but the jap ones used them for records, where, according to some blurb, can actually improve vinyl, and even make it sound like cd, which is obviously a bit of anathema, but its an area to experiment one day.

they never caught on, but can be picked up cheap, anyone experimented?
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Old 20th October 2006, 05:33 PM
G.Axiom G.Axiom is offline
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Default Re: signal processors...

There is a lot of interesting gizmos in the pro side to play with. Some of them might even make use in our efforts.

Tried shortly the following gadget at my place, with certain records ( =worst, neither old or otherwise faulty, specially if compressed to death) it was actually pretty useful. Will try more formally it again later.
With good recordingds it was pretty useless, if not harmful.
AFAIK it is very basic tool at any recording studio.

Edit:seems to be another good Chilean opened here, so:
Hereby I reclaim I must not be held responsible of any of my sayings later today

EditII: due the time table problems the previous observations was made with CD only, had not enouhg time to play it with LP, but my guess is that it is another story.

Last edited by G.Axiom; 20th October 2006 at 06:31 PM.
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Old 21st October 2006, 03:06 PM
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petercom petercom is offline
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Default Re: signal processors...

But that Apex device, which is similar in principle to the Aphex aural exciter used in some '70s and '80s recordings, is a phase shifting EQ device. What Ian was talking about was a dynamic expander.

As all recordings are compressed to some lesser or greater degree it might be fun to try out a dynamic expander. The problem is that you don't know how the compression was applied and therefore cannot map the expansion correctly.

There used to be a compander/expander available for pro use called dbX. This was principally developed to overcome tape noise etc., rather like a non-frequency selective version of Dolby NR, however some demo records were made using it in an effort to put a wider dynamic range on vinyl. You can still find dbX expanders on the secondhand market, and similarly some tape recorders which have it incorporated.

The trouble is that a dynamic range of more the 40dB brings remarks from most listeners that the 'quiet bits are too quiet and the loud bits too loud'. Classical recordings are therefore compressed to a dynamic range of less than 40dB, whilst pop CDs usually have less than 12dB dynamic range and pop singles or tracks dedicated for radio or iPOD listening are usually compressed to less than 1dB.

Too much expansion of commercial recordings could sound very strange. The criticism poked at dbX was that you could often hear dynamic 'pumping' where the expander reduces the level just as a 'loud' transient occurs and the expander reacts too late in following the dynamic envelope. That's why Dolby took the studio world by storm as the recording and playback levels were closely matched by setting up the Dolby reference level accurately for all recording and playback devices and the compression and expansion levels were fixed for defined bands of frequencies.
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Old 21st October 2006, 06:30 PM
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slowmotion slowmotion is offline
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Default Re: signal processors...

My old cassette player has dbX. As far as I remember ( haven't used it for many years), on some music it worked ok,
but on for instance solo piano you could clearly hear the noice level change.
Very distracting.

I've been thinking off and on about an expander myself,
but never got around to do anything about it.
Might be easiest to test a digital device.

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