Ask HN: Seeking device to normalize audio output for consistent volume levels

[ghoomketu]

Hello hn. I'm looking for a device that I can insert between the audio output and speaker to normalize the audio.

The goal is to ensure that sudden loud noises don't become overwhelming and quieter parts sound reasonably the same.

My reason for doing this is because it's so hard to watch movies these days because of the inconsistent volume levels (2x harder at night).

Any suggestions or recommendations on specific products or solutions would be greatly appreciated! Any DIY suggestions are also welcome too.

[shadyfroyo]

You’re looking for a compressor.

Lots of pro audio boxes out there.

A MiniDSP box where you can implement a compressor is fun, you can also tune just about everything else with it.

https://docs.minidsp.com/product-manuals/flex/dsp-reference/...

[mcallaster]

Seconded on MiniDSP being a great solution.

You can have four different presets for different signal processing. The important part is that you can set them up how YOU want. Proprietary black box DSP parameters labeled as “night mode” or “movie mode” are hardly descriptive enough for my taste.

It is also worth mentioning that if you decide to get a Dirac model/license, it is locked to the device instead of the purchaser. This is big deal for resale value, as many receivers lock licenses to the purchaser (and aren’t readily transferrable to new gear).

I am a big fan of what they are doing in the space. I recently purchased a HTX from them for my living room and I have been as happy as a clam.

[neuralRiot]

I used to love MiniDSP but now it uses “Dirac” so you need 2 accounts one in dirac and another in MiniDSP, install 2 different softwares that work together(?) you get the download links (drivers and software) for the products you purchased from your account. Too cumbersome and time-wasting for pros.

[madphilosopher]

A compressor is the right answer. If you lean toward more old-school audio engineering, I would recommend one of these compressors:

* Alesis 3630

* DBX 166 or 266

* FMR Audio Really Nice Compressor

Explore the various demos on YouTube to see what these are about. The compressor goes between your audio source and your amplifier. I personally use the Alesis 3630 for normalizing the audio in my ham radio transceiver setup.

[not_your_vase]

1 - Get an amplifier that has a "Night Mode" function. It has been a basic function on most AV-receivers in the past decade+, assuming you don't buy the most pedestrian model. It compresses the dynamic range of the sound, to avoid the loud parts waking up the neighbors while you can also hear the conversations. Of course here you are looking for an investment of between $350 and $inf. Buying secondhand can save big bucks.

2 - Use a PC for your video needs. Most video players support the same function (VLC, GOM player, Kodi... look for "dynamic range compression" and similar options). A 10 years old mid-tier machine will play everything including UHD, so this solution is fairly cheap. If you get a cheap IR-USB remote, you won't even have to mess with keyboard and mouse.

[rollcat]

> 2 - Use a PC for your video needs.

I would like to second this recommendation. I've put my work desk in the living room; the 43" screen doubles as a (non-smart!) TV; instead of futzing with remotes I have a wireless mouse, an on-screen keyboard, and a macOS/iOS shortcut to switch the display between 2x (couch mode) and 1.5x (desk mode), which could also take care of audio routing, DND, lights, etc.

Using a real mouse + virtual keyboard is so much faster than ANY remote I've ever used, and if you're not into clicking, you can type with a "real" wireless keyboard[0]. Another upside, is you get to watch things in the browser - with a proper ad blocker - instead of half a dozen confusing TV apps. Setting everything up takes a bit more effort than plugging a stick into an HDMI port, but it immediately starts paying off.

[0]: https://www.microsoft.com/en-us/d/microsoft-all-in-one-media... via friend's recommendation, they have a very similar setup with a projector and MS Windows.

[diggan]

> 1 - Get an amplifier that has a "Night Mode" function

Well, or get a compressor/limiter that you can jank into any signal chain, so you don't have to buy a whole new amplifier. You can find cheap compressors/limiters for like under $100 I'm sure.

[randomfinn]

If your source is Dolby Digital, you may not need anything new - just adjusting your settings. Dynamic range compression is a standard feature, and the bitstream should already include the necessary metadata for the decoder to implement this.

It's been a while since I looked into this in detail, but iirc the decoder must automatically enable dynamic range compression when it's set to two channel output. So avoid configurations where you first convert the audio to 5.1 channel PCM or analog, and then apply downmixing or virtual surround.

If you're using a surround system, most receivers have a night mode as mentioned by others already. Some have also an adaptive system that adjusts the dynamic range based on your volume setting - turn it up and you get the full dynamic range, turn it down and the dynamic range is compressed more as you set the volume lower to try to keep the dialog audible. Many receivers include a microphone for automatic settings, and after calibration know the actual output level. The Dolby Digital bitstream (and I think DTS) include a flag to indicate the overall dialog level, and based on these a receiver can do quite a good job. Some I think go only by the DD metadata, others have a compressor that can be applied to any input.

[shermantanktop]

FYI, the place to put such a device is definitely not between the amplifier and the speaker. You want it on the audio input to the amplifier.

Unfortunately modern receivers have preamps that do a ton of digital decoding, input switching and other stuff, making the audio signal between the preamp and the amp impossible to get to. That leaves you with receiver features like night mode, as suggested by others.

[marssaxman]

This kind of device is called a "compressor", and they are ubiquitous in recording studios. They can get very expensive and complicated, but for your purpose something like this may suffice:

https://www.amazon.com/rolls-SL33B-Stereo-Program-Limiter/dp...

Specifically what you want is a "stereo compressor" or "compressor/limiter"; if you want something more sophisticated than the device above, there are many 1U rack options available for ~$200 (dbx is a good choice), or used on reverb.com more like $70-$100.

[ghoomketu]

Thank you. Appreciate the reply. These gadgets are rather costly tbh. I did some digging around on YouTube for the compressor and I found this:

https://youtu.be/d3XxckqoeXE

Is it doing the same thing? Seems rather easy and cheap to make.

[neom]

And just in case for fun, you want to know about the other end of the spectrum from the recommendations you'll likely get, here is the Rolls Royce version of what you're asking about: https://teenage.engineering/store/tx-6

[alexjplant]

At the risk of sounding like a hater there is _nothing_ "Rolls Royce" about a six-channel digital mixer that sells for $1200. No mic pres, tiny unlabeled controls, and six channels of God-knows-what conversion tied together with rudimentary functions implemented in a decade-old $15 DSP SoC is a toy. This is a device for generating Instagram likes, not a serious piece of A/V or music production gear. Under no circumstances should OP buy this.

At least the Pocket Operators are reasonably priced and the OP-1 has some quirky uniqueness to it. The TX-6 is a brazen cash grab on par with their $1600 Ikea table [1].

[1] https://teenage.engineering/store/field-desk

[TylerE]

No, that’s the Tesla Ctbwetruck version. TE is ridiculously overpriced and form over function. You can get way better compressors for a couple hundred bucks

[pimlottc]

When it comes to hifi audio, $1,000 doesn't get you the Rolls Royce version of /anything/

[ajb]

This can be done in software, eg https://askubuntu.com/questions/31580/is-there-a-way-of-leve... for linux.

I guess that you're asking for hardware because the source device is not under your control. In theory you could use any device with a line in to process the audio. However for watching movies that may be suboptimal as any significant delay would cause lipsync issues. That's probably something you need to check for in any solution.

[diggan]

Not that OPs use case seems latency sensitive, but it can be good to know for others. If you go this route, you'd have to set things up very carefully as latency balloons up quickly if you pipe things outside>computer>outside. If you're just looking for reducing the dynamic range, cheap compressor for sub-$100 would do the trick without adding much latency.

[idontwantthis]

Instead of customizing this, I would buy a nice sound bar for your TV. I have the Samsung HW-Q990 and it is probably the one piece of technology I have absolutely no regrets for buying. Sound quality is better than most movie theaters, and I have no problem hearing dialogue. It has multiple settings including night mode and voice booster.

Sorry this sounds like an ad, but I would recommend buying any consumer soundbar with good reviews (I used rtings) before I would recommend installing custom audio equipment.

[atoav]

What kind of device do you use, what kind of speakers? If I were you¹ I'd first look for a software fix (dynamic range reduction or compression). If you really want to go for a device I would skip all musician-advice and buy some sort of DSP like the t.racks DSP 4x4 Mini Pro that has compressors, equalizers and delay compensation on board and is programmable via a GUI.

But already over-compressed stuff like music will sound worse that way, so in your position I'd prefer a software fix that is limited to movies.

¹: I am not, I like dynamic audio

[NDizzle]

Maybe it's because I'm a bit older school, but I turn these kind of things off traditionally. In my experience they degrade sound quality. There might be higher end (or the technology made its way down to affordable) that don't degrade the quality, but I'm not taking any chances with the amount of coin I have put into my setup.

[bestham]

VLC used to have a built-in compressor as a plugin by default. Try it and see what you think.

[bmcahren]

Your TV, amplifier, or sound bar should have a night mode that does this for you.

[msephton]

I'd be surprised if your setup didn't offer this already. Both my Apple TV and surround sound speakers system offer it. My TV, too but I don't use that for audio out.

That said, at night I simply use headphones.

[butterknife]

The stations should have this on their end really.

https://www.ebay.co.uk/itm/285621756629

[lvkh1]

What about a simple software equalizer?

[bookofjoe]

https://imgur.com/a/FVjuLtz

[bbstats]

Many modern TVs and sound bars do this, and many of those sound bars are cheaper than a MiniDSP box

[ulnarkressty]

I have the same issue with late night talk shows / live comedy shows where the audience cheering is way louder than the host's voice. At some point I tried an AI model to detect and lower the volume of these parts, but didn't get that great detection with the limited training dataset that I labeled manually. IMO Youtube or other streaming platforms should offer this option.

[jitl]

AppleTV has a seeing to do this if you’re using one of those.

[tikkun]

Yes, "reduce loud sounds"

(Works okay, but not great)

[brudgers]

A limiter limits the maximum power. Some are hard and will clip. Some are soft and will produce a milder distortion.

A compressor compresses the dynamic range. They reduce the sounds about a selectable threshold with variable ratios and envelopes. Usually they have various other features.

This compressor/limiter/gate/expander/de-esser has more features than you are likely to use soon (side chaining) and will almost certainly sound good enough (despite what people may comment in response) [1].

https://www.sweetwater.com/store/detail/MDX2600--behringer-c...

Good luck.

[1] If it doesn't you can spend more later if it solves your problem. The nice thing about these compressors is: they have transparent bypass, a dedicated power button, robust construction, mature design, and are cheap.

[duped]

A limiter is a compressor with an infinite ratio. It does not clip.

[walthamstow]

I just gave up and started using headphones at night

[robinsonb5]

I gave up and started using subtitles.

[notatoad]

my Sonos Beam soundbar has "night sounds" and "voice booster" modes that do an excellent job of solving this problem.

[piter22]

Hi, Major progress on loudness has been done in the broadcast area (see specs and publications around ebu r128 and itu-r bs.1770). See example products at: https://www.tcelectronic.com/loudness-products.html Cheers

[guy234]

do you have a sound bar at least?

[PaulHoule]

It's been a problem w/ Hollywood movies since "home theater" came out. That is, a really boomy soundtrack adds to the emotional impact when you are in a closed room but in an open space where people come in and out (where there average TV is) it's totally inappropriate.

Systems like Atmos that decompose the sound track into components might help but they're likely to get used for the wrong reason -- in the last 10 years Hollywood gave up on making the vocals in movies legible, which has the positive effect that a lot of people are used to reading subtitles, which is why you can find subtitled anime [1], Italian crime dramas [2] and such in downmarket places like Tubi these days.

(Maybe it's why my acting coach who yelled at me to enunciate the same way my wife yells at horse riders to keep their heels down is here and not in LA)

[1] https://tubitv.com/series/2082/accel-world [2] https://tubitv.com/movies/571052/mafia-millionaires-subbed

[riobard]

Not just sound. Ever since HDR is a viable home theater option, new movies tend to get very dark featuring long runs of dark scenes with occasional blindingly bright scenes in between. If your TV screen is slightly subpar or the watching environment is even dimly lit, the movie quickly becomes very difficult to watch.

[memco]

I know there have been multiple complaints that a theater in my area has the volume too loud. The staff reply is that it’s supposed to be loud. Gives the “you’re listening wrong !”vibes.

[mitnichiter]

Dolby Digital