How low is low?
Originally Posted by BeeMan458
I'm stuck on the question, how low is low? What is realistic and what are bragging rights? There's nothing wrong with bragging rights but I'm totally in the dark regarding the benefit of a 10Hz system vs a 12.5Hz or 16Hz, reference capable system.
At reference, how low do we need to go so we're not missing "important" content? Where does the sonic line start to get fuzzy?
WOTW; Plane Crash Scene:
How low is low is simply as low as is practical with current technology. Thigpen's Rotary Woofer is clean and flat to below 2 Hz at astounding playback levels. Many here would never consider the outlay in dollars for such a system, but I contend that many of them will have that invested in total before they reach the end of their quests, if they ever indeed do.
For conventional systems, as I'll repeat for other questions below, 3-5 Hz is low. It's very doable if more attention be paid to the system as a whole vs how many of what drivers are used with what amplifier to drive them.What is realistic and what is bragging right?
Correct phrasing of the question in these matters is crucial. With this question it depends on the desired playback levels.
All things considered (which they rarely are), room gain, flat response, signal chain, performance capability of the EQ, the amplifier and drivers, what's realistic in-room is reference playback to 3-5 Hz.
This is a version of the above posted scene mic'd at the LP. There are no calibration files used or graph fudging. The spectrograph shows what the microphone picks up at the listening position with the system calibrated and bumped to reference level.
Bragging rights is a system consisting of dozens of 18" drivers. Many of them do not yield reference playback to 3 Hz because the focus in on driver displacement and little else. I've tested the difference between a system with 8x15" high displacement drivers (more displacement than many of the current popular 18" drivers have) and increasing that system to 16x15". It's this simple; if the system gives reference playback with headroom using 8x15", then upping the displacement to 16x15" adds nothing at reference level, except… bragging rights.
Now, lots of folks prefer bumping the sub extremely hot. MKT has said many times he prefers reference level with the subs at +10dB hot. notnyt has said he runs his sub system at +15dB hot. That's a crap pile of added system over flat response. 32 times to be exact.
So, in those cases, it's necessary, not bragging rights.At reference, how low do we need to go so we're not missing "important" content?
This is a very good question and one that this thread can't address. For Dom's (most excellent) efforts here, he uses Josh's (most excellent) GP test results. The problem is that GP measurements are only practical to 10 Hz and they do not address 3 very important metrics; 1) how a GP-tested DUT responds to complex program input that has content to DC, 2) how the result relates to various signal chains (different AVRs, PEQs and amplifiers and 3) how that result will translate in a typical room at the LP.
For example, using the spreadsheet for this thread, my current system would not be a 5 star system, but, as anyone can see by hundreds of posted measurements taken with extremely accurate measurement hardware, I have reference playback to 4 Hz with headroom, in-room. OTOH, many of the 5 star systems do not have that capability and it isn't because they lack the main ingredient of the spreadsheet calculations (driver displacement), because they have more than my current system does in that single aspect.
I've conducted many tests to answer that question over the years. Instead of asking listeners what the importance is of going lower and lower in playback capability, I ask them if they notice a difference at all and, if so, how they might describe that difference.
Here's an animation of the scene capped and posted above with a response at the seats equivalent to an 18 Hz tuned ported sub vs a flat-to-3 Hz system:
So, it's easy to "see" the difference, but what's the difference in experiencing the scene between the 2 presentations? I have yet to have a single person say that there was little or no difference. The subjective descriptions, as you might expect, are all over the map. "Like being under water", "scary", "like you're in the starship instead of watching it from the outside", etc. But, the point is that every person said "yes, a HUGE difference".
How low before it makes very little difference, of course, depends on the content in the recording. Obviously, if the content is down to 10 Hz, 5 Hz playback is irrelevant. But, when the content is to 5 Hz, is the difference between flat-to-10 Hz and flat-to-5 Hz noticeable?
I ran the test with flat-to-5 Hz, flat-to-10 Hz and flat-to-18 Hz systems using the Hulk fight scene where the content is strong to 5 Hz:
Going from 10 Hz to 5 Hz was noted by some listeners as being less noticeable, I believe, because the strongest part of the final effect is centered at 5-7 Hz and the 10 Hz tuned system still picks some of it up. That result may have been different if, say, the mostly-4 Hz-WOTW lightning strikes scene is used.
The bottom line for me (and for the reality of the art) is that; if you have reference level playback to 10 Hz, you can easily have it to 5 Hz. The only requirement is to look at the SW as a system and not the latest bang-for-buck driver darling in multiples powered by the latest bang-for-buck amplifier darling.
In the case of the latest bang-for-buck ID commercial sub darling, it was never possible and likely never will be. A few of them claim output to 10 Hz and multiples of those may make a majority of interested folks happy, but there's the catch:
12 years ago, a 25 Hz tuned 1x12" sub made the majority of interested folks happy. Over the past 12 years, ID subs have gone from 25 Hz tune to 20 Hz, then 16 Hz, then 10-12 Hz using 12", then 13", then 15", then 18" drivers with 500W, then 600W, then 750W, then 1000W amps in ported subs. Then in 1X15", then Quad-singles, then dual opposed 15", then 6x10", then 3x15", then 1x18", then 2x18" with 1000W, then 1500W, then 2400W, then 4KW, then 7KW in sealed systems.
So, having been here for a loooooong time, some might now see why I bristle at reading "…the majority of people are happy with…". People are rarely EVER happy beyond the release of the next new thing. I've witnessed first hand thousands of people riding the upgrade path along all of those subs mentioned above. I saw it coming in my own case and just skipped ahead to the system that would get me where one needs to be to play WOTW at reference level and not miss anything. And, I have to add this here; I saved many of the posts in which experts and company principles responded as though I was some kid off the short bus with absolutely no clue. Sealed subs to reference? BAH! Single digit playback with no harmonic distortion? IMPOSSIBLE! There is no single digit content! Your measurements are all wrong! Must have been a truck passing by when you measured! You're insulting members with your PHAKED GRAPHS! And, many, many more like that.
IMHO, According to my data over 12 years, YMMV, Smoke 'em if ya got 'em.