Purpose of flat response below 20Hz - Why does it matter? - Page 7

I have never posted any opinion that is extreme.

I have posted.

1. There is content below 20Hz.

2. There are designs and amps that handle that content very well.

3. Its 100% choice but to make an educated choice a person should be exposed to the best solutions.

4. There are many, many solutions posted on this forum that do 10Hz to 100Hz or 200Hz prefectly. There is really no sacrifice 30Hz to 80Hz for those who understand what it takes to have 10Hz to 200Hz performance.

Again, there is no extreme position, I do not care what anyone elses builds, buys or owns. I will not post dictating < 20Hz does not matter. I will say that content simply exists and every single person has 100% free will to choose if it matters and the can figure out a way to get it in their room. Several of us can explain ALL compromises, ALL budget choices in figuring it out.

One of my favorite movies. When I read your rants I think fondly of this movie. My current evaluation of your "thought process' rates you a class 1 Commander Krill.

Refer to spectrogram of the time period starting at 24 min 30 sec thru 25 min 05 sec for the overview of this evaluation.

The OP quoted the power amplifier specification (AKA channel driven). There is no "channel driven" spec for preamp level outputs.







They cut out 10 minutes of content, but dialog is not what I was talking about.

Then again, I run stereo bass so what do I know!

This discussion is not really about music. Its about HT and movie content.



subwoofer design compromise?? Not true at all, Its not hard to have 10Hz to 200Hz. It just takes education and $$$. Im not sure where the +6 dB max SPL loss is coming from.

Lets just the LMS5400 18" woofer. Its the subwoofer driver that has no equal, show me the models and the sacrifices it has above 20Hz. It can work in a 4cuft box too so no need for LARGE boxes, just EQing and tons of power. FWIW, I never consider one subwoofer a complete system. A high end room requires many subwoofers acting as one ultimate subwoofer system.

What amazes me is that the discussion about "sarcifice" is silly when > 90% of all mains seen on this site are purely a HT compromise to start with and very few even match the output of the corresponding subs people owned. Ie....they have a great sub then have a main speaker with a <= 6" woofer

What does that all mean....Know and Choose your compromise



I want a system to cover most octaves that is all, I deem all other choices as simply a compromise for me and my room. As Bosso posted > 20Hz is freaking easy. There isn't anything special with getting great bass above 20Hz. We can do it in DIY for $150 and have 110dBs @ 20Hz and 5% distortion.....thats easy if someone is creative with their room design/space.

Yes going down below 20Hz one or more octaves is an exponential increase in $$$. There is no free lunch when it comes to audio science.

"Do I look like I need a pyschological evaluation?"



http://www.youtube.com/watch?v=UCId3kjWPs8

Aww, hey! I don't think of anyone around here like that, even. Don't say that about Bosso. He's badass. You just don't get it, I guess. When you think of Bosso, you think this:



THE embodiment of badassery. Get it right. Learn it, love it, live it.

Damnit, JPC. Now you're my friend. And youz hate my subbies. Why?!?!

I know. I was just being silly.

Oh and the Onkyo, I was responding to Bosso who said,
...and I was referring to my LFE output not the amp channels. Are you just trying to ruffle some feathers or what?



Oh... you might have missed something about that in one of my more recent posts.

Anything above 20hz is pointless!


My statement was not directed specifically at you so I am not going to nitpick the fact that you said 16hz in some of your posts.


Because there are people that buy them. But that is like saying a $200 sub will do the job of a $2500 sub. They both play bass.


It is being disputed that there is nothing down that low that is worth playback, when there are actual figures that prove that there is, and people saying that it is worth playback. That right there makes the whole argument invalid, regardless of your opinions. It may not be for everyone, obviously you, but a lot of people want and like the ULF. Also what you call 'special effects plotless wonders' is your own subjective opinion/attack on others views and opinions. That does not rule out the validity that there is content down into the single digits and if there is content then it was meant to be there. If you don't want response down low so be it, but I'm not going to go attack you because your opinion is different that others.

I fixed it for you. I now realize that it is your sheer genius that makes you appear impractical and immune to inference. Did I mention that folks like you is the reason I now enjoy sweet bass?

No kidding, of course it takes more money, EQ, better equipment, etc.... to get a much better movie experience. How much do you think the cinemas equipment cost? In our smaller rooms it is much easier.

You do realize that I tend to travel (100 hotel nights a year, > 25,000 air miles)?

To assume that I do not live without < 20Hz shows how little you know about me. I watch most of my movies on a 15" notebook with sennheiser ear plugs or a crappy hotel room TV. I can enjoy a movie even at a friends house that has BOSE (when I travel to see some of them). When Im home, Im putting little girls to bed and guess what TV/sound system content is playing then

I think you assumed a little too much, I do want a HT room that is a no compromising solution room though. Including JBL K2 DIY type deisgns and a DIY rotary sub to round it all out but that will take more time

FWIW, you post 1% like its meaningless for you. Thats cool...1% costs some of us a great deal of money again its just a choice


btw, Im confused about your Polk sub point?

Ok I am done with this thread. I couldn't resist......ABOVE 20 HATER Just remember that you exist on the fringe.

You're the insecure guy with the Epic Empire, right?

Craig

Do you guys backup your movies using digital copies? I know it was mentioned before in this thread.

Lmao, you post that like its a bad thing.

A very wise old man 25 years ago told me if Im not making my own path and going against the grain of the general public I have not done anything meaningful....Loved everything he taught me, RIP John!!

LOLZ! I need to be done with this thread too!

Peace out!

(This is craig john, the unrepentent "mean girl". Craigsub is the cool one) Ok! Yep that is me. I envy you. Spout your genius. I promise to be impressed and yet find favor in your sight. You are so it!. The Empire is the best sub I ever owned, thanks to you folks. I sold it because I now have some workout equipment where it sat. I now have a ULS-15 tucked under a table. I have 2 ACI Titans to fill in the midbass that I had with the Empire. I want to have the Titans handle the LFE frequencies from 30-80hz. How do I accomplish that? I can't believe that subwoofer amps don't have a LFE output for daisy chaining subs. Make yourself useful and suggest something.

I guess you've never done the math, ran any subwoofer simulations, and/or designed any above average performing subwoofers because if you had of, you wouldn't question what I wrote.

I don't have the parameters for the LMS5400 18" woofer but regardless, if it has been designed to prioritize 10-20Hz, sensitivity above those frequencies has been sacrificed. BTW " EQing and tons of power" = sacrifice.



There isn't anything special with great bass at 10Hz either. A DIY guy can stick a few 18" woofers in a 20ft cargo container with a $300 Behringer amp and have 110dB @ 10Hz and 5% THD. It's just physics. What's your point?

20Hz is easy? How about 20Hz ,110dB, 5% THD, anechoic but you only have 1cu ft cabinet volume, 200W, and an 8" driver. Is it still easy? Anything is easy without limitations such as driver size, cabinet volume and power

Well, some do have daisy-chainable outputs. But you don't want one. The best way to do a multisub system is with a separate box to handle relative levels, delay/"phase" and EQ. Fortunately, that's cheap today. The miniDSP-in-a-Box costs $160 shipped to the US, with the appropriate plugin. There are also pro pieces from Behringer and others. See here for some pointers about how to set such a system up.

Also, consider using your subs higher than 80Hz. You'll get more benefit from the multisubs that way.

Yep, never model or built a sub


Please ask Dr. HSU, ask Mark Seaton, ask John Janowitz about that false opinion about "EQing and tons of power = sacrifice" Heck email Linkwitz himself, you know the guy who created the LT circuit. Eqing is part of having a proper subwoofer setup. Sensitivity/efficiency changes are not a sacrifice, more importantly its not a compromise. Remember displacement and headroom requirements just need planning.





Again, its 100% choice. Its okay that you think there is nothing special, I do wonder what your reference point is though or if you even care about HT. Remember this discussion is about HT and not really about music. If its okay with you some of us think that < 20Hz cotent is special and if its okay with you we would like designs that handle it cleanly.

Great point about removing limitations but do you know of a 18" driver these days that is cheap??? None exist!! There was a $70 15" driver that produce numbers no other subwoofer can match but that is a different discussion and the driver does not exist now). Im not sure the point of a 8" driver since that isnt a subwoofer choice whatsoever. You want to compromise bass go ahead and use an 8" driver It definitely seems like our reference points and our application requirements are completely different. With that in mind it would be nice to konw what your application requirements are. I require 115dB clean peaks from my subwoofers and I only care about HT applications.



Btw, I own 4 velodyne SC-8s so I know about 8" drivers used as bass woofers......they definitely are not subwoofers.

Use 30hz f-mods to high-pass the Titans.

The Titan is a closed box sub (unless I'm mistaken) so why highpass it? Just let it sum down with the other subs.

Free output = good.

What, you think that just because one of my ex's relatives (Otto von Habsburg) died you can become dictator? Even he was only a titular K.-u.-K. (Emperor-and-King).

"This discussion" is most certainly about music.

The Peavey Low Rider 18 is one surprisingly good cheap one.

How come you never showed us the measured results of your attempts to effect a Geddes-style multisub system with those little boxes?

We know it is for you.Of course Bosso, MK, Scott, myself and many other members are only referencing HT so I guess its important for us to clarify that to you. Considering that most talking about < 20Hz content have referenced movies, Im not sure how you still concluded its about music

They never sounded good enough to bother with posting measurements. The are fun little office subs but that is it.

Of course would a flat single point line from 10Hz to 200Hz with a 1/6th resolution on a blue screen make you happy though?? I can produce one when Im back home. FWIW, I never cared for the Geddes appoarch. Multiple subs is a Toole/Welte thing period for me.

Smaller sealed subs with limited power distort like hell when driven hard. Why ask them to waste power by trying to deliver deeper bass than they are capable of? With a 20hz signal, you're just going to wind up with a bunch of harmonic distortion. I highpass my SB12 pair at 40hz. >40hz, they are very capable and they deliver in spades.

At lower volume, it wouldn't really matter all that much.

That is a matter for another thread, don't you think? But since you brought it up, properly placed mains with 6" woofers and dome tweeters can do just fine in a HT system.

Conversely, even the best HT specific speaker can be compromised with poor room integration, don't you think?

It is bad audio science to get subwoofer tunnel vision and ignore the rest of the audible range.

That really gets down to how much you are going to ask that 6" woofer to do. What output are you seeking? From what distance? What's the crossover frequency?

Exactly. And if you observe these needs, along with proper placement, the 6" driver will fit the job.

Then we can get onto the matter of bass.

Oh, so Bosso didn't mention a song by Sting to bolster his argument?

My bad.

Have you bought a JBL BassQ? After all, how many times have you bragged about how many electronics boxes you've bought in some quixotic attempt to tell a difference between them. (On those mains bathed in diffraction products?)

If you haven't bought a BassQ or a full-on JBL Synthesis electronics setup, you're actually not that committed to the "Toole/Welte [sic]" approach.

Besides, you do realize that the all of the examples of the more advanced Harman multisub procedure (SFM) produce basically the same end result as Geddes' procedure would, except that SFM is automated (and presumably much quicker) rather than manual?

Basically, what we're seeing is a convergence to best practices.

I've done enough setups using Dr. Geddes' methods to conclude that anyone who can't get superior results in the modal region from them when using appropriate gear (i.e. subs that extend high enough and have enough volume displacement to reach the desired low-end cutoff at a given SPL) is basically just incompetent and should hire someone to set up her/his system for her/him rather than trying to muddle through. It does take some patience the first time out, admittedly.

Yes, actually. That would remove some doubts about your competence. Assuming, at least, it was a spatially-averaged measurement (if you're using an SMS-1, that means also using the MIC-5 mixer and mikes) and was not the result of heavy EQ, but proper setup with perhaps a minimal gloss of EQ.

Depends on how one configures the multisubs. If one uses an archaic method*, then yes, one could have an issue.

However, if one uses a modern method, such as Geddes' multisub setup method or Harman's SFM, the subs won't all be at the same level. In fact, all but one will usually be attenuated, often significantly. So they can contribute to ULF without overloading.

For instance, Dr. Toole reports in Sound Reproduction that his own 4-sub system has one sub on level, two subs 6dB down, and one sub 12dB down after SFM optimization.

Now, take those two ACI Titans, which each a closed-box subs with a ~13mm xmax 12" woofer in a fairly large cabinet, and attenuate them relative to the ULS-15 by let's say somewhere between 3 and 15 dB, depending on what measurements say give the smoothest in-room response. What are the chances they will overload at any frequency before the main sub?

*or a "double bass array." DBA is not archaic, just rigid in placement demands and room geometry requirements, and expensive for a given output. Not to mention impossible with three subs, identical or otherwise.

Why would I ask them when I can chat with Wolfgang and Floyd?

Who doesn't consider having to quadruple amplifier power a sacrifice? Siegfried would be ashamed at your reply and referencing his name. I'll mention it to him at the next AES so we can both have a laugh.

It's a fact, not an opinion. I guess physics on your planet are different Maybe you can teach us how to achieve perpetual motion too.

cheers

There are many ways to skin a cat, so to speak. Not just the "DS" way. Apparently morris is looking to use the Titans for mid-bass enhancement. The Titans were not specifically designed as mid-bass radiators, but one way to maximize their performance in that capacity would be to filter out the frequencies that are likely to drive them into distress at high levels. Sure, they could be blended with the ULS to keep them from overloading, but by instead running specifically for mid-bass enhancement, it gives you total control over the level of the mid-bass you wish to dial in. I'm not suggesting your way won't work, but I'm definitely suggesting that there are good alternatives as well.