Why the fascination with subwoofers?

@noble100

     Nice thread everyone. Sorry my work is crazy so I don’t check the site as often as I would like. Just had my daughter graduate college yesterday and she did it in three years with a foreign exchange in Japan. Pretty excited about that and the fact she has an second interview with a Fortune 500 company Tues in New York, fingers crossed!!

Here are responses to your questions below Tim and a few notes about setting up my system with Magnepan 20.1 mains. 

hifidream,  

I forgot to ask a few questions about your custom dba system in my previous post. I hope you don't mind, I'm just curious about a few things:

1. What brand and model were the initial subs:
 - Kinergetics SW-800 subs (next to my 20.1’s - five 10” Seas subwoofers in their own non-ported enclosures) driven by a Pass X-250. I researched a ton and wish there were some threads like this when I was planning my system. I looked for five years before finding the Kinergetics online used. I bought them and owned them for another four years before I could play them. 

2. What brand and model were the last 2 subs you added to your system?
- SVS SB-16 Ultra subs (2 enclosed mosfet powered subs). Funny story, I turned them on low without optimizing them and played the music from the Gladiator and the water on my table rippled, house creaked, I jumped out of my couch because my gut wrenched, and my wife leapt out of the shower telling me to unplug the system as thunder just shook the house! Ergo too much base :)

3. Do you operate your 20.1s full-range or limit their bass output?
- I operate them full range. I don’t want to loose all that beautiful sound. 

4. What upper cutoff frequency are your subs set at?
Simple answer around 80Hz at the highest. Each of my 8 channels has 12 biquad active filters created by Multi Sub Optimizer (MSO) inputted into my Mini DSP working at 24/96, details below. 
- In order to maximize the accuracy by eliminating room nodes, and best integrate with the 20.1s I measured the speakers individually with Room EQ Wizard (REW) and the room from my listening position with my Earthworks microphone. I used all the data and followed the instruction manual in MSO plugging in my data and adding more filters as I started to understand how it works and listening to the results. MSO suggests running the subs full range and I was surprised how high they actually ended up crossing over to counter room nodes outside of the subwoofer region. 

So I’ve listened to my 20.1s without subs and while big and dynamic they didn’t give me what I heard when I played in an orchestra. Added the Kinergetics and the sound was close but standing waves were messing with the room (it was a small place). We moved into a nice big apartment  and I got the SVS hooked up and did my room correction and all I can say is OMG. It’s the closest thing to my live playing experience I’ve ever heard. 

Yes there is sound in those very low octaves, organ notes, tympani, and the low rumble of the orchestra in full swing. You can feel it in your body. . . (I could hear most of the music in my 20.1s but not feel it). No one listening to my system can articulate there is one subwoofer much less 4 of them or 6 if you count the Maggie’s. They integrate perfectly and seamlessly. It’s not about loudness but accuracy and I agree with many who have spoken to poor base integration ruining their set up. The one comment I get when people come hear my set up is how “clear” it is. This is the sign that everything has been set up correctly. It’s not an easy thing but the reward is awesome. 

I do bump up the subs 5db for movies and the last time I had my dad and daughter’s boyfriend over for an action movie they jumped out of their seats on an explosion and move their heads out of the way when there are gun shots (they didn’t even know they were doing it because they were so into the movie.) . . . The anamorphic 11x5ft 4K image helps too. It’s a lot of fun.

Thanks,
Steve

Dear @noble100 : As you I continue in the quest and each " day " nearer to.

Now and for the low bass stereo or mono. How was recorded stereo or mono?:

after some days of hard work and a lot learning sessions listening to CDs containing true low bass, at least to 16hz and even lower that that, as these CDs recorded in different times from early 80’s to today days. I listen it mainly Motion Picture Original Soundtracks ( lovely !. ):

Telarc 1812, Casper, Black Hawk Down, Vangelis 1492, M:1-2 ( Mission Imposible. ), Gladiator ( second recording where the titles does not appeared in the Picture, was part of the Zimmer overall takes before decided which use it for. ), Glory, The Thin Red Line, Blade Runner ( first picture. Vangelis. ), The day After Tomorrow, Interstellar and Alita.

The low bass comes recorded in MONO as you posted in the other thread but now I’m totally sure about.

Even that still is one point that I would like to have clear and is if the low bass information is recorded mono from 50hz or 40hz or 30 hz down these frequencies. I ask my self which is the bass frequency range recorded in MONO and from where starts to recorded Stereo ?. I don’t know, yet.

I listening to those CDs first whith all my system playing in stereo and mono fashion, then single channel in stereo and mono fashion, after those I started to listen only to the information coming from the subs and when I try to find out that bass frequency range recorded ( from-to. ) is impossible to find out by listening it because the very low bass dominates the subs response and ( at least me. ) can’t distingish any thing about.

Anyway, my test experiences were to confirm or not what you posted and you are rigth: MONO is the way is recorded and those CDs producers/engineers are loosing out on the opportunity to make the CD recording with the bass information that the microphones pick up at the recording sessions.

Seems to me that because the recording of LP’s during the cutting proccess the bass information must goes in MONO due to the analog/LP limitations the producers/engeneers accustom to never think to make CD recordings taking advantage of the digital alternative that has no limitations about ! ! ? ? ? ? Maybe exist something in those very low bass information that the microphones pick-up that could or can makes useles doing it in Stereo fashion, who knows?

Well I hope that some one there can do it in the near future or at least try it/test it and decide about.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

Seems to me that because the recording of LP’s during the cutting proccess the bass information must goes in MONO due to the analog/LP limitations the producers/engeneers accustom to never think to make CD recordings taking advantage of the digital alternative that has no limitations about ! ! ? ? ? ? Maybe exist something in those very low bass information that the microphones pick-up that could or can makes useles doing it in Stereo fashion, who knows?

Its not so much the limitations of the format as it costs a lot of money to pay an engineer to work a way around  "out of phase bass". If you spend the time with the recording, you can usually find a way to master it without having to process it. But that takes time and at $500/hour most often bass processing is used. This is a simple circuit that senses when bass is out of phase and makes it mono below about 80Hz for a few milliseconds until the event has passed. This makes mastering LPs less expensive!

But CDs do exist where out of phase bass exists. This can happen because a microphone is out of phase with the rest of the recording when a bass guitar or bass drum is recorded. For this reason, the recording engineer has a phase inversion switch on every channel of his mixer but he may not have thought to use them.


If the recording is done in its entirety with only two mics, out of phase bass will not exist.

Dear @atmasphere  : What I really mean was not a LP limitation perse but an analog rig limitation because cartridges just can't track with applomb very low bass grooves.

Telarc 1812 is a good example where I own over 120+ cartridges and only a few can track those cannon shots with clean and pristine true applomb.
Between other things cartridge self abilities is always a limitation and not only at very low bass.

"""  For this reason, the recording engineer has a phase inversion switch on every channel of his mixer but he may not have thought to use them. """

So, recording engineers do not really care about and even to check the microphones phase in between.

Thank's for your explanation, makes sense.

R.

What I really mean was not a LP limitation perse but an analog rig limitation because cartridges just can't track with applomb very low bass grooves.

Telarc 1812 is a good example where I own over 120+ cartridges and only a few can track those cannon shots with clean and pristine true applomb.
Between other things cartridge self abilities is always a limitation and not only at very low bass.

@rauliruegas More depends on the tone arm's ability to track the cartridge than it does on the cartridge itself. Its a good bet that when they cut that track they played it on a very ordinary turntable to make sure it was playable.