Re: Re: Rockport
Ahhh...OOhm... I'm going to my special place...
Actually, I've sort of been inspired by the finish on the VMPS RM-V60's... and the wife's interested...but who knows???
BTW: Your renderings are super... you must have:
>Well, Im a jet fuel genius - I can solve the worlds problems
>Without even trying
>I have dozens of friends and the fun never ends
>That is, as long as Im buying
>Is it any wonder Im not the president
>(hes not the president)
>Is it any wonder Im null and void?
>Is it any wonder Ive got
>Too much time on my hands, its ticking away at my sanity
>Ive got too much time on my hands, its hard to believe such a calamity
>Ive got too much time on my hands and its ticking away from me
>Too much time on my hands, too much time on my hands
>Too much time on my hands
C/O Styx
sorry for the OT... just havin' some fun...
L8tr
John L.
ShinOBIWAN said:
Ahhh...OOhm... I'm going to my special place...
Actually, I've sort of been inspired by the finish on the VMPS RM-V60's... and the wife's interested...but who knows???
BTW: Your renderings are super... you must have:
>Well, Im a jet fuel genius - I can solve the worlds problems
>Without even trying
>I have dozens of friends and the fun never ends
>That is, as long as Im buying
>Is it any wonder Im not the president
>(hes not the president)
>Is it any wonder Im null and void?
>Is it any wonder Ive got
>Too much time on my hands, its ticking away at my sanity
>Ive got too much time on my hands, its hard to believe such a calamity
>Ive got too much time on my hands and its ticking away from me
>Too much time on my hands, too much time on my hands
>Too much time on my hands
C/O Styx
sorry for the OT... just havin' some fun...
L8tr
John L.
Re: Re: Re: Re: Re: Re: Re: Re: Re: Re: No More Re's!!
He is when he says force stays the same (ignoring the dipole), but it takes energy to do the work of exciting a resonance... so the only columns that are relevant to the discussion are the energy columns, and they decrease with frequency.
dave
dlr said:
He is when he says force stays the same (ignoring the dipole), but it takes energy to do the work of exciting a resonance... so the only columns that are relevant to the discussion are the energy columns, and they decrease with frequency.
dave
Re: Re: Re: Re: Re: Re: Re: Re: Re: Re: Re: No More Re's!!
No, that has nothing to do with the context of the discussion at that point, the energy column is meaningless with regard to the original context. The original context was that of the force applied as a function of frequency, there was nothing about resonance. An unequalized driver, regardless of its use in a monopole or a dipole, will be under constant force when unequalized. The energy column is useless in that regard.
If you want to diverge to some other aspect, fine, just address the topic in context.
Dave
planet10 said:
No, that has nothing to do with the context of the discussion at that point, the energy column is meaningless with regard to the original context. The original context was that of the force applied as a function of frequency, there was nothing about resonance. An unequalized driver, regardless of its use in a monopole or a dipole, will be under constant force when unequalized. The energy column is useless in that regard.
If you want to diverge to some other aspect, fine, just address the topic in context.
Dave
planet10 said:
Not the context of John's post to which Gedlee replied, the statement of interest by John being this one:
"The further the cone travels, the more opposing force, therefore more kinetic energy to deal with.".
The opposing force will be constant with frequency if the original applied force is constant with frequency. Beyond that it's trivial.
There will be no transfer of energy without force, that is trivial as well and ought to be obvious. It takes force to move an object, it's the force that matters. Energy is accumulated over time with the continued application of force. A resonance is the result of energy transferred over time, but not transferred out as an acoustic wave or dissipated, in this case as heat.
What really counts is what resonances may exist in the object to begin with and how much damping exists at those frequencies. It takes far less movement (linear displacement) of a panel at higher frequencies to achieve the same SPL output, so higher resonance frequencies could easily result in higher SPL from a resonating panel than at lower frequencies, especially when one considers that panels are strict implementations of bending wave transducers, having very strong end terminations (corners). Raising the resonant frequencies can be counter-productive. The fact that total transferred energy drops with increasing frequency is not relevant, what is relevant is the amount of force applied, be it the driver attached to the baffle or the air motion inside a box.
Dave
Re: Re: Re: Re: Re: Re: Re: Re: Re: Re: Re: No More Re's!!
You all seem to be misinterpreting what I'm talking about. I even gave a very graphic example (the bass driver that will make a box "walk"), in the original post. How can you suggest that there is the same amount of mechanical energy at all frequencies?
That is the point after all, the amount of mechanical energy from the driver, right?
Thanks Dave.
dlr said:
You all seem to be misinterpreting what I'm talking about. I even gave a very graphic example (the bass driver that will make a box "walk"), in the original post. How can you suggest that there is the same amount of mechanical energy at all frequencies?
That is the point after all, the amount of mechanical energy from the driver, right?
planet10 said:
Thanks Dave.
Re: Re: Re: Re: Re: Re: Re: Re: Re: Re: No More Re's!!
Not that it matters, but Earl hasn't responded since then. His approach is to abandon the discussion when someone is not agreeing with him.
To reiterate, the point was "how much energy comes from the drivers mechanical as opposed to the acoustic." Simple, straightforward.
If I used "force" where I should have used "energy", I'm sorry for the confusion. I thought I was engaged in a discussion with fellows who understand the basic concept, and weren't here to nit-pick about terminology.
Bratislav said:
Not that it matters, but Earl hasn't responded since then. His approach is to abandon the discussion when someone is not agreeing with him.
To reiterate, the point was "how much energy comes from the drivers mechanical as opposed to the acoustic." Simple, straightforward.
If I used "force" where I should have used "energy", I'm sorry for the confusion. I thought I was engaged in a discussion with fellows who understand the basic concept, and weren't here to nit-pick about terminology.
MJL21193 said:
I didn't say there would be the same amount of energy at all frequencies, neither did Gedlee. His comment was narrowly focused on your comment about force that was, as he said, a statement that is untrue, the one about unequal force. The data in the supplied link supports that.
The point you intended to make was not what you your words said. Gedlee's response addressed that error.
But yes, the energy transferred from the driver to the box by the force applied could move the box.
Dave
dlr said:
To argue this point, go to the real context, back in post #331. Read that over and tell me if what you say above still applies.
I'm not a famous speaker designer nor do I have any formal training in acoustics, but I still have the power of reason, some common sense and a brain in my head.
Several times here, I've found myself trying to explain things that are so obvious to me, it's nearly embarrassing to argue about.
Soon I'll do like Earl and just leave and let you guys squabble about who said "force" when he should have said "energy".
Re: Re: Re: Re: Re: Re: Re: Re: Re: Re: Re: No More Re's!!
The same amount of force is supplied by the driver to the box for any given signal applied to the driver. The difference is related to the box. If it's solid and secure on the floor, there will be the maximum of acoustic output from the driver because the "mass" against which it pushes is essentially that of the box and whatever it is coupled to. If it's on a concrete slab floor solidly planted, then the mass is that of the slab and the earth underneath it. If the box is not secure and can slide or it flexes, then the driver output will be affected somewhat and the acoustic output will drop a bit depending on the movement of the box. In that case some energy is transferred into the box movement.
Give a box enough energy (from applied force) at any frequency and it can be moved. Have you ever seen something "dance" on a flat surface from vibrations beyond your hearing? I worked for Michelin in a tire production facility for many years. They converted a number of rubber cutting machines from hot press cutters to ultra-sonic cutters. They varied in frequency depending on the material to be cut. They moved imperceptibly, but they would cut through the bone if you stuck your finger in front of one.
Dave
MJL21193 said:
The same amount of force is supplied by the driver to the box for any given signal applied to the driver. The difference is related to the box. If it's solid and secure on the floor, there will be the maximum of acoustic output from the driver because the "mass" against which it pushes is essentially that of the box and whatever it is coupled to. If it's on a concrete slab floor solidly planted, then the mass is that of the slab and the earth underneath it. If the box is not secure and can slide or it flexes, then the driver output will be affected somewhat and the acoustic output will drop a bit depending on the movement of the box. In that case some energy is transferred into the box movement.
Give a box enough energy (from applied force) at any frequency and it can be moved. Have you ever seen something "dance" on a flat surface from vibrations beyond your hearing? I worked for Michelin in a tire production facility for many years. They converted a number of rubber cutting machines from hot press cutters to ultra-sonic cutters. They varied in frequency depending on the material to be cut. They moved imperceptibly, but they would cut through the bone if you stuck your finger in front of one.
Dave
Nice link about the Rockport, very interesting, for once engineering is applied to speakers.
I wonder however, if I had a $50K budget to dedicate to speakers, would it not be more rational to flush them in the walls ? I mean, the Rockport is probably as good as a cabinet can get, but would it beat a few tons of bricks ?
I wonder however, if I had a $50K budget to dedicate to speakers, would it not be more rational to flush them in the walls ? I mean, the Rockport is probably as good as a cabinet can get, but would it beat a few tons of bricks ?
MJL21193 said:
It does still apply.
Well, he had said "Good point" at that point, it seemed done then. He pointed out the motor force is constant with frequency, again demonstrated in Linkwitz's page. Energy is another matter.
When a term with specific meaning is used in error I think it's over-reacting a bit when that is addressed. It's not easy to have a discussion in that case, so corrections ought not be taken as personal. I don't think Gedlee intended that nor do I. Clarity is important.
Dave
dlr said:
I probably wouldn't be far off in saying that most here will not have a problem understanding what I'm saying, especially when I use an example such as the woofer that can move the box with it's mechanical vibration, whereas the tweeter can't even make itself move, hanging in free air.
It's patently obvious.
ShinOBIWAN said:
It was not I who started it. Gedlee pointed out the error in his post #361 in regard to force and whether it is constant or not. John used the right descriptive word at the right place in that post in making his point, but the detail was wrong. Gedlee pointed out the error. John "found it interesting" that he would disagree with Linkwitz, though he did not, I'm sure. He had even agree with John on his main point by saying "The kinetic energy of the cone decreases with frequency above resonance.".
It didn't need to go any further.
Dave
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