Bass Problem In Final Mix

[Paul Whittington]

Hello,
I have been trying to learn more about audio for my latest film in order to create the best sound possible and so far things are going well. But I am at the final mix stage and have run into a problem that I'm not sure how to fix regarding bass:

To edit, I use a pair of entry level monitor speakers and a pair of Sony headphones (MDR-7506). With the speakers the audio sounds perfect, in the headphones there is a little more bass, and on the TV soundbar (set to normal 'pass' mode) there is a huge amount of bass that makes it sound like there is a thunder storm going on outside! In an attempt to decrease the bass I applied a low-cut filter in Soundtrack Pro set at 100Hz. This helped lessen the bass on the TV but there is still too much bass and if I increase the low-cut filter higher than 100Hz the audio starts to sound bad on the monitor speakers. Can anyone tell me what is happening to cause this bass and also the proper way to deal with this problem? Was it a mistake to use a low-cut filter in this situation or is there a better tool in STP I can use?

In the final mix, should the dynamic range of the frequencies be compressed to avoid unwanted highs and lows? A brief list of all the things needed to be done in the final mix would be greatly appreciated. Thanks so much for you time. I have learned a lot about audio while making this film but I still have a long way to go.

Cheers :)

[Greg Miller]

There's no simple answer to your question.

First of all, before making specific recommendations, we need a bit more information and we need to hear some audio samples of your track. You've given us no idea whatsoever of the content of the track. It is a female voice recorded in front of a waterfall? Dialog in the space shuttle? Recording of a local rock band? What's this excess bass you're talking about? Is it wanted effects, unwanted effects, is it music, is it low frequencies in the voice?

You say you edit using "entry level loudspeakers" and MDR-7506 phones. Given the usual use of the terminology, "editing" is one procedure, and performing your final mix is a different procedure. I think we're really talking here about your final mix. (But maybe not. Maybe you're hearing LF noise that's part of the dialog track, and should have been cleaned up before the dialog track was added to the final mix. We will start to understand this after we hear some samples.)

Headphones are good for editing because they shut out room sounds, helping you hear details within your track (for example, unwanted noises in a dialog track), but they give you an unrealistic perspective in terms of the final mix. Additionally, the MDR-7506 (I have a pair) is somewhat unrealistically bright in the midrange, and a bit thin in the bass range. This may be useful for on-set dialog monitoring, but will really confuse you if you use them for the final mix. (HD-280s, for example, are much flatter.) You really need to do your final mix on good quality monitor speakers, not phones. If you want professional quality results, you need to have some professional quality speakers to monitor your mix.

I'm not familiar with Soundtrack Pro, so the term "Lowcut filter" doesn't tell me exactly what you did (in terms of how it actually changed the frequency response). However, "cut" usually implies a fairly steep filter. It might be useful for removing LF noise from a dialog track, if that's where the noise originated; but it's probably too steep for your final mix. A gentler LF rolloff might be useful, depending on where the "bass" problem originated in the first place. Ideally, each separate element will be clean and with the proper frequency spectrum, before you get to the final mix; then in the final mix you can adjust relative levels of the different elements.

Take the time to post a description of your track, specifically what you hear that sounds like "too much bass." Post some samples of your track... high bitrate (256kbps) MP3 files should be adequate, you probably don't need to post WAV format. After we know what you're actually doing, and hear the track, someone should be able to give you some helpful advice.

[Paul Whittington]

Thanks Greg for the reply...

Luckily I found the source of the extreme bass. It was coming from two of the background music tracks - on their own they were ok but when combined together they created too much bass so I managed to decrease it to an acceptable level :)

That's good to know about the mid-range of the Sony headphones, I'll keep that in mind for future films. Also, what you said about having a more gentle rolloff instead of a sharp cut makes a lot of sense. Thanks for taking the time to write. Much appreciated :)

[Greg Miller]

Paul,

Glad you're back on the right track.

A few years ago, the Sony headphones were all the rage for location dialog monitoring. They have fair isolation (but not really great), and they have a "hot" midrange. The combination of those two features meant that the dialog would "cut through" a lot of ambient noise on location, and make it easy for the boom op or mixer to hear the dialog clearly (as well as problems with the dialog recording).

They are definitely not good for mixing, or, IMHO, for music. Shortly after I got mine, I tried listening to a commercial music CD. I forget what it was, but as I recall it had a rather prominent female solo vocalist. I don't think I even got through one track before I pulled them off. They boosted the vocal to the extent that it was almost painful.

If you're going to do very much mixing, for anything other that EweToob, a decent pair of monitor speakers will be worth their weight in gold.

Carry on!

[Paul Whittington]

Yeah, I know what you mean about the vocals with the Sony headphones... they definitely sound much different in the headphones than they do on the monitor speakers and TV. I mainly use them for recording. Now I think I'll keep them for just that (recording) and, as you say, get myself a pair of decent monitor speakers. The monitor's I use now (Behringer MS40) are ok for the short films I have been making but I plan to shoot a feature film next year and I will want the sound to be as good as possible. If you have any recommendations on good monitors please let me know - I can afford to go as high as $1000... will that be enough?

BTW, in case you were curious to see (or I guess I should say 'hear', haha) the short film I had the base trouble with, I posted a link to it in the 'Show You Work' forum. The sound isn't fantastic but definitely a big improvement from the previous work:
http://www.dvinfo.net/forum/show-you...ust-movie.html

Thanks again, Greg.

[Greg Miller]

There are many amplified or "powered" speakers on the market today. I'm definitely an "old school" kind of guy and I think differently.

The manufacturer's temptation with amplified speakers is that, if the frequency response of the drivers isn't flat, they can tweak the internal amplifier a bit to try to manipulate the overall response curve. That scares me because it would tempt the manufacturer to settle for "not quite good enough" drivers, trying to make them sound just a little better than they are by tweaking the amplifier.

I would rather find a speaker that sounds as good as I can afford, then use an amp which is clean and flat. (It's much easier to make a clean flat amp than a clean flat speaker.)

So my monitors are JBL 4412 studio monitors. If you're lucky you may find a used pair on eBay. I had to look for a while, before I found a seller within reasonable driving distance, who would let me listen first and then accept or reject them. I was really lucky, mine came from a smoke-free home environment, had been babied and never over-powered. Sweet. Well worth a drive from PA to Delaware. (I just checked eBay and I see a pair was recently sold for $280, a lot less than I paid for mine many years ago. If I had seen those while they were still listed, I might have been tempted to bid on them for a second pair.)

The 4410 was a similar model with a smaller woofer and slightly less LF response.

Of course if you eventually plan to mix 5.1, then things become worse because you need more speakers.

Having said that, I'm sure a lot of the newer folks will recommend some popular newer monitors, many of which are probably self-amplified. In the final analysis, of course, it's best to try to listen before buying. And there are huge differences between speakers, so it's a somewhat personal and subjective decision. The listening environment -- room dimensions and surface treatment -- can make a big difference too.

You definitely want to find out where the crossover frequencies are. The low - mid thousands of Hz (let's say roughly 1500 - 3000 Hz) are very important for voice intelligibility and character. Many 2-way speakers, especially "music" or "hi-fi" speakers, cross over in that range. That can give you a misleading impression of what your voices sound like, and perhaps cause you to EQ or mix badly. It's especially hard to make a 2-way speaker that doesn't cross over somewhere in this range, so be especially careful if you're buying "on the cheap" and looking at 2-way systems.

It's a tough and important choice. Good luck!

[Steve House]

Originally Posted by Paul Whittington

...Now I think I'll keep them for just that (recording) and, as you say, get myself a pair of decent monitor speakers. The monitor's I use now (Behringer MS40) are ok for the short films I have been making but I plan to shoot a feature film next year and I will want the sound to be as good as possible. If you have any recommendations on good monitors please let me know - I can afford to go as high as $1000... will that be enough?

....

I have a pair of JBL Pro LSR4328P that are excellent monitors IMHO. Runs $1500 for the pair from B&H. If you budget won't stretch that far, their 6" bass driver little brothers, the LSR4326P, runs $1100 the pair from B&H. Highly recommended.