[pinnahertz]

One of the challenges in mixing multichannel music is that we don't know if the user will be doing any bass management or not, and yet the client often will want at least some activity in the LFE. If you mix a bit of bass from the mains into the LFE and the user has bass management on, you'll end up with more bass than you planned. If you leave the LFE dark, and the user doesn't have bass management on, you won't light up his subs at all. Most opt for something in the LFE, but in some music there isn't a lot of real sub-tickling bass anyway, so it's a tough call. Then there's the issue that the LFE channel is up to 120Hz, but they typical bass management crossover is 80Hz. Best option is not to do much built-in bass management, and let the user figure it out with his own bass management. And LFE is always there if you want an actual Low Frequency Effect.

What a mess.

 

[bigshot]

This recording has nothing at all below around 80Hz. It's probably just some sort of mastering mistake. The bass above 80 is low too, so maybe they grabbed a master with RIAA pre-emphasis and didn't realize it.

 

[pinnahertz]

This recording has nothing at all below around 80Hz. It's probably just some sort of mastering mistake. The bass above 80 is low too, so maybe they grabbed a master with RIAA pre-emphasis and didn't realize it.

Masters didn't have RIAA EQ on them, that's not what an "equalized master" is. The RIAA network was/is in the signal path from between the master playback deck and the cutter head, usually in the lathe electronics.

An 'equalized master" would have been dub of the master that had mastering EQ and level adjustments applied, basically a kind of "safety" dub.

What's the recording?

 

[bigshot]

Sub masters were offten made for LP mastering that had the RIAA curve in them. It was done for convenience. Early on there were examples of CDs that had the RIAA pre emphasis applied because they grabbed the wrong master. For a quad recording, it is probably even more likely because LP was the eventual destination and they didn't need any other master.

It was Mancini and Doc Severinson by Dutton.

 

[gregorio]

I can assure you that even though you don't understand the theory behind what I'm doing, these ideas work spectacularly in practice.

I'm not talking about whether your ideas work "spectacularly in practise", almost certainly they don't and you just like it that way or, just maybe they do work but the issue I'm talking about is fidelity, not how good your system sounds to you and your friends! I'm using the true meaning of the word "fidelity" here - trust in a system reproducing what was intended, as opposed to reproducing something which sounds good. This is an important distinction because the two can be quite different, massively so in some/many cases. As I mentioned previously, commercial films and music are mixed on systems with matching 3 front speakers. Having a far more directional centre speaker with different crossovers and a different sound presentation might sound good to you, it might even sound good to others but it almost certainly cannot score highly as far as fidelity is concerned. Likewise with your two "fill" front speakers, if you have a gap in your image then there's something quite seriously wrong with your system setup, maybe your L/R speakers are far too widely spaced, maybe they're under powered or under driven or possibly you're looking for the same presentation from your L/R speakers in a surround setup as you would get in a stereo setup.

Going back to what pinnahertz was talking about previously. In a surround system, bass accuracy is always a serious problem in a small room, there isn't any cure for this problem. In virtually every situation though, spreading the bass between two or more physical subs produces a very significant improvement, not a cure but far better than anything you can realistically achieve with just one sub. Two small subs as opposed to one big one is, in pretty much every conceivable practical consumer environment, going to give significantly higher fidelity.

I'm going to continue to share my experiences. I think they're valuable to people who want to efficiently put together great sounding speaker systems in their homes.

I'm not so sure your experiences would be valuable to others. Even if we hypothetically assume your system does produce high fidelity, it would do so only because of a number of unusual simultaneous quirks of your particular listen environment. I personally would therefore not recommend your setup to others and IMHO is likely to confuse them and result in lower fidelity.

There's a bit of variability to how multichannel music is mixed, so there really isn't a "one size fits all" solution.
There's a multichannel Mancini SACD that has an LFE channel that is so low, my AVR can't boost it enough to make it audible.

1. There is massive variability in multichannel music mixing. Unlike with films and even TV, there are no standards or hardly even any conventions. It's impossible to get a setting that provides simultaneous fidelity of music mixes and films!
2. SACDs, unlike most other 5.1 mixes, are not supposed to have +10dB on the LFE channel. Additionally, if your AVR/sub cannot achieve a +10dB boost, then it cannot be a properly balanced system in the first place.

G

 

[bigshot]

Do you think I care if you think my advice is valuable? By the way, your whole post turned up as one big quote that didn't all display on the page. That reduces readability. I know I didn't read it all myself. Maybe other people will feel the same way.

 

[gregorio]

Do you think I care if you think my advice is valuable?

How can your advice be valuable? If it goes against standard practice, logic and the facts, is inapplicable to anyone else and is more complex and confusing?

You started this thread asking for the science behind the acoustics and with the information you've provided, the most likely outcome is a complete dog's dinner of a system. Now maybe you've somehow managed to tune your system so it's not a complete dog's dinner but it's impossible to imagine that you've managed to get it better than mediocre. You obviously don't like what you've been told and now you're turning it into a "my advice is valuable, regardless of what you say" thread, and this isn't a great choice of forum for that kind of tangent, as you well know!

G

 

[pinnahertz]

Sub masters were offten made for LP mastering that had the RIAA curve in them. It was done for convenience. Early on there were examples of CDs that had the RIAA pre emphasis applied because they grabbed the wrong master. For a quad recording, it is probably even more likely because LP was the eventual destination and they didn't need any other master.

It was Mancini and Doc Severinson by Dutton.

There is no way a CD was made with RIAA EQ on it! It would be totally unlistenable, and every single person buying it would return it. The RIAA curve has a 40dB variance! It would have been instantly detected in the transfer to CD master in the first place.

 

[pinnahertz]

Sub masters were offten made for LP mastering that had the RIAA curve in them. It was done for convenience. Early on there were examples of CDs that had the RIAA pre emphasis applied because they grabbed the wrong master. For a quad recording, it is probably even more likely because LP was the eventual destination and they didn't need any other master.

I thought RIAA on sub masters was nonsense, but as a sanity check I ran it by a friend of mine who actually did a lot of mastering work out in LA (he was part of the team that mastered Sgt. Pepper for US release). Nope, not done. The RIAA curve was applied in the cutter electronics, and there were several settings with minor adjustments for different purposes, like hot 45s vs LP. It was never pre-recorded on tape because that tape could then possibly be recorded to a master with RIAA for a double whammy of RIAA.

 

[bfreedma]

I can't tell you how many systems an owner has told me is already great and that they only want me to assist them in making some minor tweaks.

Then we take measurements - and find out major tweaks, EQ, and acoustic room treatments are necessary to get anywhere close to a reasonable in room response at the MLP, let alone a significant section of the room. Preference is rarely close to Reference, though every one of them regales me with stories about how much other people liked their system tuning with an FR that looks like an EKG.

 

[pinnahertz]

It was Mancini and Doc Severinson by Dutton.

Which track? Looking at frequency analysis I see plenty below 80Hz on this sample ("Sometimes"). Perhaps we're looking at different tracks?

 

[bigshot]

I can't tell you how many systems an owner has told me is already great and that they only want me to assist them in making some minor tweaks. Then we take measurements - and find out major tweaks, EQ, and acoustic room treatments are necessary to get anywhere close to a reasonable in room response at the MLP, let alone a significant section of the room. Preference is rarely close to Reference, though every one of them regales me with stories about how much other people liked their system tuning with an FR that looks like an EKG.

That might be true for a lot of people, but I've worked in the sound business and have done a lot of EQing. I started with room correction software, then made small adjustments to the channel levels and EQ by listening to a wide variety of well recorded music and movies. When I was done, I brought in a sound engineer friend who ran sweeps and told me that I was as close to flat as I could get with my 5 band parametric equalizer. That's good enough for me. I'm not using my living room to do mixing and mastering in, so it doesn't have to be absolutely calibrated.

My system has to do multiple things- both music and movies, and it has to serve as a comfortable living room to entertain in too. When I balance it I sit in all of the listening positions and come up with a happy medium that gives me what I want from the main listening position as well as the off axis ones. I've also found a speaker placement that works with the room and creates a large enough soundstage to fill the area of my ten foot projection screen. Room correction is out of the question for me, because my listening room is paneled floor to ceiling in antique knotty pine. Luckily reflections in the room are minimal, and I've placed furniture to cut down on primary reflections. Any real world listening room in a home is going to involve compromises to accommodate livability. The thing that determines whether a system will sound good or not depends more sometimes on being able to problem solve by thinking outside the box to make those accommodations well, rather than it does lining up a meter on the line. Building a room to listen to music in the home is different than designing a recording studio.

My deviation from calibrated flat is only a couple of dB at most, and it's mostly in the upper mids and treble where ears are most sensitive to imbalances. I don't think that anyone should be afraid to touch their EQ settings or channel levels. They should be encouraged to learn how to adjust them well.

One interesting thing about the shape of my room is that the bar and bathroom in the back form an almost perfect exponential shape that culminates in the shower. When I have music playing and I stand in the shower, the bass is very strong and sounds like it's emanating from the shower.

 

[bigshot]

My original question had to do with the difference in sound between a horn loaded speaker and a wide dispersion pattern (an extreme example would be a bipole). There is definitely an aspect to directionality of sound that allows you to easily pick a directional sound out from among widely dispersed sound. Directional sound has some sort of presence... perhaps it's easier to place by moving your head. My mains have exponential tweeters and my center channel is a horn loaded Klipsch, and I really like the way they cut through and have pinpoint directionality to the extreme left and right, and the center. It gives the soundstage a feeling of greater width and depth. Having my fronts arranged in an open V shape and raising the center and rears a little higher than the mains adds to that as well, and it increases the height of the soundstage. When all the channels are level balanced at the listening positions, it creates a sound stage that covers the whole end of the room, 20 feet wide and 10 feet tall.

 

[bigshot]

Which track? Looking at frequency analysis I see plenty below 80Hz on this sample ("Sometimes"). Perhaps we're looking at different tracks?

If you have this SACD, can you show me a graph of just the LFE channel? When I play it with bass management turned on, the subwoofer just puts out a tiny low level signal and the overall sound of the recording is thin. I have a CD of the same album and it sounds fine. I have the other Mancini Dutton/Vocalion SACD and it sounds fine to me.

 

[bfreedma]

That might be true for a lot of people, but I've worked in the sound business and have done a lot of EQing. I started with room correction software, then made small adjustments to the channel levels and EQ by listening to a wide variety of well recorded music and movies. When I was done, I brought in a sound engineer friend who ran sweeps and told me that I was as close to flat as I could get with my 5 band parametric equalizer. That's good enough for me. I'm not using my living room to do mixing and mastering in, so it doesn't have to be absolutely calibrated.

My system has to do multiple things- both music and movies, and it has to serve as a comfortable living room to entertain in too. When I balance it I sit in all of the listening positions and come up with a happy medium that gives me what I want from the main listening position as well as the off axis ones. I've also found a speaker placement that works with the room and creates a large enough soundstage to fill the area of my ten foot projection screen. Room correction is out of the question for me, because my listening room is paneled floor to ceiling in antique knotty pine. Luckily reflections in the room are minimal, and I've placed furniture to cut down on primary reflections. Any real world listening room in a home is going to involve compromises to accommodate livability. The thing that determines whether a system will sound good or not depends more sometimes on being able to problem solve by thinking outside the box to make those accommodations well, rather than it does lining up a meter on the line. Building a room to listen to music in the home is different than designing a recording studio.

My deviation from calibrated flat is only a couple of dB at most, and it's mostly in the upper mids and treble where ears are most sensitive to imbalances. I don't think that anyone should be afraid to touch their EQ settings or channel levels. They should be encouraged to learn how to adjust them well.

One interesting thing about the shape of my room is that the bar and bathroom in the back form an almost perfect exponential shape that culminates in the shower. When I have music playing and I stand in the shower, the bass is very strong and sounds like it's emanating from the shower.

Sounds good but I don't see any "secret sauce" there, just standard auto EQ and then personal preference adjustments of EQ and channel levels - maybe I'm missing something.

Most systems, both mine and others I've calibrated need to support both movies and music. There shouldn't be any difference in calibration technique or end state between the two. That's an old misnomer as the requirements for addressing room issues are the same for both movies and music. If you introduced a second subwoofer and calibrated them correctly, you should be able to smooth out the bass response so that it's more balanced through the room. As mentioned before, a second sub would reduce the number and perhaps depth of the nulls in your listening room.

Don't suppose you have any of the measurements either you or your sound engineer friend took that you could post?

BTW, I think you mean you can't put any physical room acoustic treatments in your space. Room correction is a term typically applied to EQ and most often, the built in room EQ systems like Audyssey, Trinnov, Dirac, etc.. seen in most current AVRs