The No.1 Website for Pro Audio
Digital Limiter Quality Test
Old 16th February 2019
  #1
Digital Limiter Quality Test

Want to participate? Download the .wav file in the attachments, run it through your limiter(s) at +10 dB gain and post the resulting WAV file.

tl;dr Good choices: Limiter No.6 (free, but not the easiest interface), Acon Digital Limiter, Waves L3 (budget choice if it's on a sale sale and you don't push too much low end into it), UAD Precision Limiter, Fabfilter Pro-L2 (if you use the right settings -- good luck), IK Multimedia Stealth Limiter (don't push it), Avid Maxim (on the fence due to IMD).

In this thread, I want to find out which digital limiters can actually limit a signal in a clean way. I created a simple file that consists of three sine waves (100 Hz, 1 kHz, 10 kHz) at -10 dBFS and 0 dBFS each. I then applied +10 dB of gain, hoping to see a flat line.

This is what the signal should look like after limiting:



Next, I create a spectrum plot of the signal after limiting to visualize distortion. This is what the spectrum should look like:



Here are the limiters that I have so far:

Jünger d02 (with gain and limiter)



Fuzz box. Clean without the compressor gain and limiter.

LoudMax



Not bad for free, but introduces short-term squashing, traces of aliasing, slow release.

Sonic Anomaly Unlimited



Didn't really bring the signal up to 0 dBFS, short-term squashing, slow attack and release, slight 3rd harmonic.

SPL Loudness Maximizer



Soft/Hard -9 is clean, anything else not so much. Reduces the volume of the wave prior to the jump in volume. Distortion mostly 3rd harmonic. Do not use the "Boost" button. +10 dB is not +10 dB

Limiter No.6



Also introduces short-term squashing. Very fast release however.

Acon Digital Limiter



Super clean. Also reduces the volume of the wave prior to the jump in volume, but better than the SPL.

Waves L2



Does some very subtle rounding of the waveform at 100 Hz, introducing odd harmonics. Decreases the volume prior to the volume jump in the 1 kHz and 10 kHz steps. Not bad for something that's around 20 years old.

ToneBoosters Barricade 4



Not sure I understand what's going on here. This was in Auto: Clean mode. There is a DC filter somewhere. The waveform itself looks very good though.

eaReckon FR-LIMIT 87



Squares the waveform off quite a bit. 500 ms release is rather slow. Does not increase the volume so a gain after it is required (weird). Download at eaReckon - FREEBIES.

iZotope Ozone 8

Ozone 8's Maximizer is a bit more complicated so here is a quick summary of my findings:
  • The Maximizer tries to reduce the volume of the audio prior to the jump, except that it does that for a bit too long.
  • The "character" control should really be called "distortion" and the range inverted. It has something to do with the limiter release but any value other than 10 allows for distortion. At 0, you basically allow a lot of distortion. I wouldn't use any value below 8.
  • The IRC IV "transient" mode is absolute garbage and can't be made to not distort.
  • The "classic" and "modern" settings of IRC IV are good.
  • Stay the **** away from IRC III, it's horrible.
  • IRC I and II are useable, for what it's worth.



IRC IV "transient" mode with character at 0.



IRC IV "transient" mode with character at 10. Better but not clean.







IRC IV "classic" mode with character at 10. You should be using this mode or the modern mode if you want a jumpier release.

Ozone 8 also has a "Vintage Limiter" that's also quite capable as a limiter and, in my limited tests, it's probably just as good but easier to use than the Maximizer.



The "Tube" () mode is probably the cleanest of the three modes but it's so slow, the limiter acts more like a leveler.



The "Analog" ( ) mode is quite clean and only introduces low-end squashing which we've seen before. Mids and high end and done rather well. I haven't checked a value other than character 10.



The "Modern" ( ) mode is a little bit dirtier and looks like what the "Transient" mode above is doing. The release is very fast (looks exponential) though.

NUGEN Audio ISL2



NUGEN ISL2 is either very clean in "Auto" mode, but with a horribly long (> 1 s) release or...



...distorting.

Waves L3



You can tell that L3 is based on L2. It has a similar behaviour around the volume jump but seems to do slightly weirder things to the waveform. It does the volume very well though so if you want to use Waves plugins, L3 is probably a better choice than L2.

Plugin Alliance bx_limiter



bx_limiter always distorts the 100 Hz sine, even if enough headroom is present (this was made with the XL overdrive disabled). 1000 Hz looks good. bx_limiter tries to decrease the volume of the signal prior to the jump and does that rather well. Still, obvious distortion in the low end.

IK Multimedia Stealth Limiter



Gets the volume right (I.e. no visible release), at the cost of squashing and at times squaring half of the wave -- barely visible as distortion in the spectrum. Probably okay if you don't push it too hard (but who does?).

IK Multimedia Brickwall Limiter



Very visible squashing of the signal. It really looks like the wave hit a, ahem, brick wall. Some distortion visible in the spectrum.

PSP Xenon



Squashes the wave prior to the jump. The wave after the jump looks very good but the spectrum shows visible distortion and also high-frequency IMD.

Aom Invisible Limiter



This limiter does very unnatural things to the signal, including introducing what I would call a phase-shifted copy of the signal. Other modes completely clip the signal. It also introduces intermodulation distortion. It passes the volume test but the IMD is not acceptable.

Kuassa Kratos2 Maximizer



Soft clips the waveform and produces slightly square tops. It passes the volume test but introduces just too much distortion.

Avid Maxim



This is the first limiter that visually does a perfect job. The waveform looks super natural and you couldn't tell anything ever happened. It passes the volume test but seems to introduce some IMD in the high end -- the spectrum of the distortion looks like there is some shaping going on.
Attached Thumbnails
Digital Limiter Quality Test-original.jpg   Digital Limiter Quality Test-limiter-test-edit-1_junger-d02-preset-4-gain-10-compressor-2.0-limiter-on_take_1.jpg   Digital Limiter Quality Test-limiter-test-edit-1_loudmax_take_1.jpg   Digital Limiter Quality Test-limiter-test-edit-1_sonic-anomaly-unlimited-character-0.0-response-1.0_take_1.jpg   Digital Limiter Quality Test-limiter-test-edit-1_spl-loudness-maximizer-10-9-10_take_1.jpg  

Digital Limiter Quality Test-limiter-test-edit-1_track-limiter-6-brickwall_take_1.jpg   Digital Limiter Quality Test-acon_digital_limit.jpg   Digital Limiter Quality Test-limiter-test-edit-1_waves-l2_take_1.jpg   Digital Limiter Quality Test-limiter-test-edit-1_toneboosters-barricade-auto-clean_take_1.jpg   Digital Limiter Quality Test-limiter-test-edit-1_eareckon-fr-limit-87_take_1.jpg  

Digital Limiter Quality Test-limiter-test-edit-1_ozone-8-maximizer-irc-iv-classic-character-10_take_1.jpg   Digital Limiter Quality Test-limiter-test-edit-1_ozone-8-maximizer-irc-iv-transient-character-10_take_1.jpg   Digital Limiter Quality Test-limiter-test-edit-1_ozone-8-maximizer-irc-iv-transient-character-10_take_1-waveform.jpg   Digital Limiter Quality Test-limiter-test-edit-1_ozone-8-maximizer-irc-iv-transient-character-0_take_1.jpg   Digital Limiter Quality Test-limiter-test-edit-1_nugen-audio-isl2_take_1.jpg  

Digital Limiter Quality Test-limiter-test-edit-1_nugen-audio-isl2_take_3.jpg   Digital Limiter Quality Test-limiter-test-edit-1_waves-l3-multimaximizer_take_1.jpg   Digital Limiter Quality Test-limiter-test-edit-1_plugin-alliance-bx_limiter_take_1.jpg   Digital Limiter Quality Test-limiter-test-edit-1_ozone-8-vintage-limiter-modern_take_1.jpg   Digital Limiter Quality Test-limiter-test-edit-1_ozone-8-vintage-limiter-analog_take_2.jpg  

Digital Limiter Quality Test-limiter-test-edit-1_ozone-8-vintage-limiter-tube_take_2.jpg   Digital Limiter Quality Test-tr5-stealth.jpg   Digital Limiter Quality Test-xenon-limiter-fast.jpg   Digital Limiter Quality Test-tr5-brickwall.jpg   Digital Limiter Quality Test-avid-maxim.jpg  

Digital Limiter Quality Test-kratos2-all-fast.jpg   Digital Limiter Quality Test-aom-suppress.jpg  
Attached Files

limiter-test-24bit.wav (775.4 KB, 2394 views)


Last edited by johannburkard; 13th April 2019 at 05:12 PM.. Reason: Defining "flat line"
Old 18th February 2019
  #2
Nobody on Gearslutz uses digital limiters?
Old 19th February 2019
  #3
Gear Addict
 
saagedal's Avatar
 

Quote:
Originally Posted by johannburkard View Post
Nobody on Gearslutz uses digital limiters?
Attached is the result from Acon Digital Limit (part of our Mastering Suite and Acoustica) on that test file.

Best,
Stian
Attached Files

acon_digital_limit.wav (775.4 KB, 2275 views)

Old 19th February 2019
  #4
Thank you @ saagedal , I added it. Very well done.
Old 20th February 2019
  #5
Gear Addict
 
saagedal's Avatar
 

Quote:
Originally Posted by johannburkard View Post
Thank you @ saagedal , I added it. Very well done.
Thanks! It's actually possible to pass your test with close to perfect results if you use the so called analytic signal. Unfortunately, that method only works well for sine waves and fails miserably e.g. a square wave test signal. That's why we use the look-ahead to smoothly change the gain in advance (you can control this using the look-ahead time). The variable gain signal should only contain low frequency content to avoid distortion.

Best,
Stian
Old 20th February 2019
  #6
Quote:
Originally Posted by saagedal View Post
Thanks! It's actually possible to pass your test with close to perfect results if you use the so called analytic signal.
I started to think that what I did was not "surprising" enough. But looking at the waveform immediately showed me how limiters react to jumps in the signal ("transients").
Old 14th March 2019
  #7
Added Waves L2 and ToneBoosters Barricade 4.
Old 14th March 2019
  #8
Added iZotope Ozone 8 and eaReckon FR-LIMIT 87.
Old 15th March 2019
  #9
Gear Addict
 

Great work, thank for this!

Daniel.
Old 17th March 2019
  #10
Added NUGEN Audio ISL2.
Old 23rd March 2019
  #11
Gear Maniac
 
Ted brenn's Avatar
Quote:
Originally Posted by johannburkard View Post
Added NUGEN Audio ISL2.
Thanks for the test,

It's very difficult to choose a limiter to get the max loudness.

I have lot's of limiter, nearly all those you tested.

Actually I have a very powerful result with the new VELO 2 (Soundspot)

Could you test it ?
Old 23rd March 2019
  #12
Quote:
Originally Posted by Ted brenn View Post
Actually I have a very powerful result with the new VELO 2 (Soundspot)

Could you test it ?
How about you test it? It's totally easy. Just download the .wav file linked above, add 10 dB of gain on the limiter and post the result.
Old 29th March 2019
  #13
Added Waves L3.
Old 6th April 2019
  #14
Added Plugin Alliance bx_limiter.
Old 9th April 2019
  #15
Forgot about the Ozone 8 Vintage Limiter so I added that.
Old 10th April 2019
  #16
Gear Addict
 

Great post!,

Wonder about the old good Sonnox Limiter.

Best,
Daniel.
Old 10th April 2019
  #17
Lives for gear
 

Thanks for this, it’s very interesting.

I’m wondering about Voxengo Elephant. I’ve been using Toneboosters Barricade. The Barricade spectrum is confusing, I don’t understand what I’m seeing there. I think I’d like to try another limiter, I like Acon Digital stuff, that looks like the best choice for me so far, but I’d like to know about the Voxengo plugin.
Old 10th April 2019
  #18
Quote:
Originally Posted by Danielbest1 View Post
Wonder about the old good Sonnox Limiter.
If you have it, help me out. Instructions in the first post.
Old 11th April 2019
  #19
Gear Addict
 
dione's Avatar
Are these done with True Peak/ISP on or off ?

Also, so much settings possible, i don't know where to start

I have Pro-L2, Limitless, Elevate, FG-X and some you already tested.
Old 11th April 2019
  #20
Quote:
Originally Posted by dione View Post
Are these done with True Peak/ISP on or off ?
Off because I'm not interested in what happens after D/A.

Quote:
Originally Posted by dione View Post
Also, so much settings possible, i don't know where to start

I have Pro-L2, Limitless, Elevate, FG-X and some you already tested.
Try to get it as clean possible: Run Voxengo SPAN alongside. Use maximum lookahead if available. Start with single-band.

From what I can tell, all digital limiters can do nasty and at times unmusical things to a signal. All I want to document is with what limiters you can avoid that.

Last edited by johannburkard; 11th April 2019 at 12:53 PM.. Reason: Tpyo.
Old 11th April 2019
  #21
You like your limiters, @ dione , don't you?

BTW: Using a long release kind of defeats the purpose of a limiter.
Old 11th April 2019
  #22
Gear Maniac
IK Multimedia Stealth Limiter

IK Multimedia Stealth Limiter (Infrasonic Off, Mode Tight, ISPL 4x)
Attached Files

TR5-Stealth.wav (1.51 MB, 1356 views)

Old 11th April 2019
  #23
Gear Addict
 
dione's Avatar
Quote:
Originally Posted by johannburkard View Post
You like your limiters, @ dione , don't you?

BTW: Using a long release kind of defeats the purpose of a limiter.
I like it loud

In the case of Pro-L2 and Limitless i used the release settings of the presets.

And like you said, try getting it clean as possible, which in some of limiters means long release times as automatic or short release in UAD, SB and Elevate caused immediate audible side-effects so i tried longer releases to see how transparent they could get.

And ofcourse : this test still doesn't really say everything about what the limiter in question can really do, since 10 db gain change is not something that's done on a daily basis and it's not a test on real music.

Elevate and FG-X have settings for transients, clipping and dynamics etc, all stuff that has a drastic effect on a couple of sine waves but can sound awesome on real music. So i'm not taking those results too serious.

But, since no one else is posting anything i thought i'd get things started
Old 11th April 2019
  #24
Thanks so much @ dione , I've now added your results.
Old 11th April 2019
  #25
Thanks @ waltercruz , I've added it.
Old 11th April 2019
  #26
Gear Maniac
Quote:
Originally Posted by johannburkard View Post
Thanks @ waltercruz , I've added it.
Nice! Two more for collection: PSP Xenon (Fast Limit preset) and the old IK Brickwall Limiter
Attached Files

TR5-BrickWall.wav (1.51 MB, 1381 views)

Xenon-Limiter Fast.wav (1.51 MB, 1364 views)

Old 11th April 2019
  #27
Lives for gear
 
GJ999x's Avatar
No sonnox yet?
Old 11th April 2019
  #28
Quote:
Originally Posted by waltercruz View Post
Nice! Two more for collection: PSP Xenon (Fast Limit preset) and the old IK Brickwall Limiter
Sorry but both of those are empty for me.
Old 11th April 2019
  #29
Gear Maniac
Quote:
Originally Posted by johannburkard View Post
Sorry but both of those are empty for me.


my fault!

sent the correct files now (double checked this time!)
Attached Files

TR5-BrickWall.wav (1.51 MB, 1344 views)

Xenon-Limiter Fast.wav (1.51 MB, 1354 views)

Old 11th April 2019
  #30
Thanks @ waltercruz , I've added them. From your limiters, I would prefer the IK Multimedia Stealth Limiter, it really did a good job.
Post Reply

Welcome to the Gearslutz Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and Reverb.com listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.


 
 
Slide to join now Processing…
Thread Tools
Search this Thread
Search this Thread:

Advanced Search
Forum Jump
Forum Jump