Paradise_Ice said:
It's their own fault, they just like it loud! On an install I once did we actually made up a "trick" DJ mixer, that had the master volume only connected to the monitor speakers, the house sound engineer actually controlled the levels on the floor. I think every single DJ that played there cranked the volume up to full...
No significant bass below 30Hz? Makes me wonder what music he listens to. Ever heard of pipe organs? The thought springs unbidden to mind: Just how good are the subs if the builder doesn't understand the underpinnings of an orchestra.
It's an unfortunate fact that the vast majority of people have absolutely no clue what deep bass sounds like. Oh, they'll tell you they do; go on at length about how good their hearing is, and so forth. The cat leaps from the bag however, when they talk about how good the bass is at live rock concerts or at clubs. That pretty much tells the tale, right there. It ain't flat, and it ain't deep. It's just loud. "But I can feel it in my chest!" isn't exactly what you'd call evidence of deep bass--it's about 60-80Hz and loud.
The question of rolling off the bass to make it sound "tighter" is easy to demonstrate. It's really the flipside of the PA system bass syndrome--if people don't know the difference, and if it allows you to cut the cost of a system (in terms of amplification and speakers) in half, it's a no-brainer. Bump the 80Hz and roll it off as fast as possible below 50-60Hz.
Grey
It's an unfortunate fact that the vast majority of people have absolutely no clue what deep bass sounds like. Oh, they'll tell you they do; go on at length about how good their hearing is, and so forth. The cat leaps from the bag however, when they talk about how good the bass is at live rock concerts or at clubs. That pretty much tells the tale, right there. It ain't flat, and it ain't deep. It's just loud. "But I can feel it in my chest!" isn't exactly what you'd call evidence of deep bass--it's about 60-80Hz and loud.
The question of rolling off the bass to make it sound "tighter" is easy to demonstrate. It's really the flipside of the PA system bass syndrome--if people don't know the difference, and if it allows you to cut the cost of a system (in terms of amplification and speakers) in half, it's a no-brainer. Bump the 80Hz and roll it off as fast as possible below 50-60Hz.
Grey
Bill Fitzpatrick said:
Isn't it a trifle embarrassing making a comment like that about his spelling and then talking about "the buying pubic"? 🙄
I also appreciate Grey's remark about pipe organs, which in my book certainly belong in the category "musical instruments", at least for the last several centuries. Ever heard (or felt, as the case may be) an organ hitting notes down to 16 hz?
There are also a fair number of movie soundtracks that go that deep. Whether it's considered "music" or not is semantics, what matters is that we want to hear those sounds reproduced in our homes. At least I do, to the consternation of my neighbors. . .
Dayne
dayneger said:
I see your point. I try for good grammar to avoid any negatives in the mind of those readers who know the difference.
I do listen to the organs (most of the time with other instruments). However, even with organs, what most of us hear is harmonics of the notes, not fundamentals. The fundamental frequency below 20hz is mostly felt in the chest, not heard in the ears. In addition, when the lowest notes are played, all other instruments are often stopped to prevent masking effects. Granted, the comment about no significant bass below 30hz is a gross generalization. It was made in the context of bass quality perception. While the ability to play bass sound below 30hz cleanly and powerfully is one metric of merits, it is not the only one. Very often the bass quality can be and should be appreciated even on ordinary pieces of music. There is no point of building a subwoofer that one only wants to turn on when playing organs, synthesized music, or movies.GRollins said:
This is the main point in the discussion -- whether or not simply rolling off the bass will make the bass sound tighter. IMHO, it does not. It is something else (such as lighter cone mass that leads to lower mid bass distortion and thermal memory effect) that makes the bass sound tighter. Take the Wilson Puppy for example, some will credit the better bass quality to its low Q and somewhat higher bass extension. But is that the direct cause? Or is it because the lighter cone mass that makes the bass sound more dynamic? If the frequency response is the only concern, one can simply take a driver with heavy cone mass and equalize the frequency response to be exactly as Puppy and we get a Puppy clone. My experience with LT and other EQ tell me it does not work like that. Simply put, with a few exceptions, one cannot hide the true color of a bass driver.
Brian
What about a dipole bass up to 200-400 Hz? Then you’ve eliminated most of your room modes.
Maybe not faster, but certainly cleaner & less boomy.😉
You'll need big Xmax & EQ. per SL.
Maybe not faster, but certainly cleaner & less boomy.😉
You'll need big Xmax & EQ. per SL.
rick57 said:
Dipoles do look promising. Again, driver selection is the key. As it is often seen, "it is not the theory that is flawed, it is the execution." In another words, the true benefits and potential of dipole subs may not be realized until the "correct" drivers are used.
Almost all of the so-called "high excursion" drivers have high inductances which lead to roll-off above 80hz. While this may look like a frequency response issue which can be corrected with EQ, it actually also causes higher distortion in the midbass and upper bass regions that cannot be EQ'ed.
Brian
Rythmik Audio
Nanook
What frequency do want to XO?
EG If crossed 4th order, the Peerless XLS is quite flat up to 280 Hz.
Some have used a (less $) Pyle 15 inch in a dipole.
What frequency do want to XO?
EG If crossed 4th order, the Peerless XLS is quite flat up to 280 Hz.
Some have used a (less $) Pyle 15 inch in a dipole.
cone mass has next to nothing to do with the "speed" or "tightness" of bass-it SEEMS like it would-but by the time mass starts to matter you're probably well into the midrange
if you want fast,tight bass try an IB subwoofer-or a dipole
if you want fast,tight bass try an IB subwoofer-or a dipole
robertwb70 said:
I would agree with the first part of your statement if and only if the xover point is relatively low, something like 40hz. I do respectfully disagree with the second part. If you look at the impedance curve of a bass driver, the valley point around 100hz in the impedance curve indicates where the EMF from the driver begins to yield to the inductance (and hence at the mercy of nonlinearity in the voice coil inductance). Lighter cones raise that transition point to a higher frequency. And 100hz is not midrange. This is not to mention these days it is common to see that the transition to start as low as 80hz. And it looks like the trend is going down, not up. As I have mentioned over and over, the cone mass is not a causation for a particular bass sound characteristic, it is just a correlation. Correlation is not universally 100%. You can definitely find a big cone bass driver that is just as dynamic as smaller drivers because it is properly designed (such as using techniques to increase BL value and at the same time reduce voice coil inductance to reduce the contribution of mass to the level of smaller drivers).
BTW, I find sealed box subs, when designed properly, can deliver a true life-like bass definition. There is no technical limitations to prevent sealed box subs from doing that. I am not saying IB or dipole are no good. However, I would not like to see sealed box subs to be written off like this just as people write off subwoofers in general by saying the best bass is no bass.
Brian
Rythmik Audio
I was remembering a little experiment Dan Wiggins did where he something like quadrupled the weight of the cone and it changed the response so little that it was hard to even see-IIRC his point was that inductance was the real culprit-and of course he was using an XBL driver
Yes, and is pipe organ bass "fast"?
This seems to produce the most positive reactions from listeners during demos. However, a few A/B "tune tests" (courtesy Linn Audio) and that can reaction can change. 😀
robertwb70 said:
You have to enlighten me a bit. I am not aware of any subwoofer configuration (sealed, vented, IB, .... you name it) that after quadrupling the cone mass can still maintain almost the same frequency (unless it is servo 😀). Unless you meant the cone mass by literally the mass of cone itself. If that is the case, it is a confusion of terminology. The true mass of cone is not even in the T/S parameters. What I meant was Mm in T/S parameters. It is easy to defeat the benefits of having a lighter cone by using 6-layer or even 8-layer voice coil. If you check the PA bass drivers from JBL. A 15" cone with a bit less than 100g moving mass is just amaizing. People still like them because of very dynamic bass sound. Of course it does not play very loud because of Xmax. Still for a lot of people, it is quality, not quantity that counts.
Brian
Rythmik Audio
Timn8ter said:
One day John Koval came to my house and I gave him a demo for without and with subwoofer with just ordinary pieces of music (not even the bass heavy demo that most stores will use). His immediate reaction was "you change the frequency response" (sort of implying I cheated). I told him yes I changed the frequency response by taking out the bump at 80hz. That is the first benefit of having a subwoofer. You can undo the cheat that most speakers manufacturers have put in since the days of BBC LS3/5A.
Brian
Rythmik Audio
robertwb70 said:
This is in reference to a tech article on Adire's website.
http://www.adireaudio.com/Files/TechPapers/WooferSpeed.pdf
He did increase Mms by placing weight on the dust cap and increased inductance by adding an inductor to show transient response is a result of voice coil inductance assuming that BL is constant. Adding mass did make a change due to inertia but not to acceleration. Increased inductance did change acceleration.
Timn8ter said:
Tim,
Thanks for the reference. Now I understand what Robert meant. The first thing I notice is the entire paper was based on impulse response. But impluse is more accurate for the higher end frequency in the analysis window. The reason is very simple. If you look at the energy density, then you know the density is skewed towards the upper end (if you have a 10khz window, half the energy is above 5khz, and 90% is above 1khz, 99% is above 100hz). In most review magazines, step reponse is used when discussing bass performance. A step response, which is an integral of impulse, de-emphasize higher frequencies. The conclusion in the paper further confirms that (by observing a dip of 5db at 4khz!). If he had used a step response, he would have a lot of explanation to do 😉.
In Speaker Builder 1988, issue 6, the article "A conversation with Keith Johnson" discussed how he thought about the cone mass, among other things. And he agreed that some of these sonic differences we discussed cannot be measured with conventional methods. I haven't given up yet 😀
Brian
Rythmik Audio
I wonder... in what way would it be possible at all for dynamic drivers to ever reproduce faithfully a sqare wave at low frequency? The subwoofer would probably need pretty good impulse response... or would a crossover smooth out the sqareness?
BassAwdyO said:
First, a step response is not equivalent to a square wave. A square wave does not have spectral components below its fundamental frequency and a step response has spectral components all the way down to 0hz. Do not expect any dynamic driver to produce a perfect step response (similarly, do not expect a dynamic driver to produce an infinite slope impulse response). That is not the purpose of a step response analysis. The purpose of the step analysis is merely to check the tail of the transient response against a known response (similar to checking the impulse response against a known bandwidth limited impulse response). The intial transient response is the high frequency component. The tail is the low frequency components. When one uses the impulse response to check for low frequency components, there is simply very little in there to check. The noise and other artifacts can easily mask them out.
My question is really about why focusing on how fast it starts (the begining, or the high frequency components), instead of how fast it stops (the tail, or the low frequency components). Does how fast it starts also implies how fast it stops? Absolutely not. A driver can start fast and ring all the way till it finally stops.
Brian
Rythmik Audio
BassAwdyO said:
IMHO Square wave reproduction is only useful if you know what it means.
The subwoofer if filtered[as most subwoofers are] will have less HF information present-so it cant reproduce a square wave.
What is interesting,is the damping[control] and how this integrates with the tweeter or midrange woofer and the final step response[delays between drivers due to physical offset is easy to see]
Cheers
Certainly,I own a 2226 on EBS BR enclosure,its great for music! I have no desire to change! Its MMS is ~88gdirectservo said:
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