Dear Manoj,
1) You argued scientists and audio engineers said that 3dB increase is twice the loudness. I provided explanation about the common mistake to think that 3dB increase means twice the loudness. Did you admit your mistake? Nope. And you have not named the scientists and audio engineers who said so. But I can guess who that could be. You could easily name the scientists and end the discussion here.
I have to hand you here. I should have been careful with using the terminology and instead of saying loudness, should have used the correct term "twice the output". Loudness is perceived so, I shouldn't have used the term. However, that still does not negate the fact I was trying to get. If you add two 82 db sources together, you will get 85 db. That's twice the output. Same analogy can be used for comparing 58 db vs 82 db. The whole loudness discussion came about because of this. So, I accept, should have used the correct term instead of "loudness".
Now, can we say the same thing about the whole "vacuum" sideshow that you created. Or you are still insisting that a driver mounted in vacuum chamber can be made to move and create audio?
2) You also kept on saying drivers would not go below Fs. To reiterate: A driver by itself will not be able to produce lower frequencies than Fs..
You are wrong. Fs is just a frequency where the cone moves freely with least restraint due to its natural resonance. Below Fs the drivers will continue to produce sound but less efficiently.
Show me a driver measured this way and generates output below Fs. Should be easy enough, right?
3) Your position kept on changing from your first post.
a. Post 19 - "Fs is the free air resonant frequency of a driver. Meaning, if the driver has no air resistance, this is the lowest frequency it can produce. The air in speaker cabinet acts like a spring and does not allow the driver to move freely, so it can't achieve Fs Bottom line is - No driver will be able to produce lower frequencies than Fs in an an-echoic chamber.".
b. Post 23, again you said, To reiterate: A driver by itself will not be able to produce lower frequencies than Fs..
c. Post 25, and again you said As I said earlier, the driver itself (no box), in an-echoic chamber will not be able to go below Fs..
Read all the posts in context. Those mean the same thing. I never shifted my position from a free air driver output. You took "no air resistance" and created "vacuum" sideshow. So, I had to mention, "by itself" meaning "not in a box". To take out room gain out of question, I had to use anechoic chamber because we want to see measurements of a driver without an external influence. But you just want to quote things out of context and try to be one-up. Rather than focusing on my words, I think posting some concrete things would actually help.
4) Referring to 3 above, you then changed your position from no frequencies below Fs to damaging the driver and etc:-
5)
a. In post 45 maximum excursion. Its impedance drops drastically below the f/s as at it becomes inductive. An improperly designed crossover, set to cover these lower frequencies can hence damage the driver. I agree to the first two part of the definition but have nowhere said all of those opinion entirely correct without qualification.
That post was not mine. It was Kannan's. And I think it was in response to the datasheet that you linked containing impedance graph. Then without understanding it, you started patting yourself on the back, and said that proved the Fs is not a lowest frequency point of a driver. All I did was to tell you to read the post again. Here was your post.
Thank you! I hope now Fs becomes clearer. Fs is not the lowest frequency point of a driver. Thanks again Kannan.
here is my response to it.
Before congratulating yourself, may be you should try reading the Kannan's post again and understand what he is saying.
Now, where does it look like I have changed the tune? It was you who was using that post to pat yourself on the back. But when I pointed out it was rather opposite, here you are calling it "not entirely correct without qualification". Who is changing position now?
b. In post 46, you have now changed tune and beginning to qualify your position . You pointed to speakersplan website and nowhere in there they stated that drivers couldnt produce frequencies below Fs. They said So a driver with an fs of 60 Hz will not produce 35 Hz very well. See the word very well. From your own reference it is clearly without doubt that Fs is not the final point of lowest frequency that a driver is capable of.
What new position did I change to? Care to explain? Again - you are taking things out of context and quoting it. I guess its an habit to you. Here is the complete para from that site.
"The point at which all the moving parts of the driver sympathize or resonate. Resonance is a hard thing to explain simply, but a rule of thump is that you will find it hard to produce lower frequencies than the drivers fs. So a driver with an fs of 60 Hz will not produce 35 Hz very well. A driver with an fs of 32 Hz will produce 35 Hz, if the box is tuned low enough. These two examples relate to closed, ported and bandpass cabinets, horns are less affected by fs as they use the driver as a piston. "
Read the very next line after your green "very well". Clear enough? Or trying to omit that as well. Btw, the whole site is dedicated to speaker plans and designing speakers (not drivers), so their context is invariably a "box"
So again - where did I change my tune?
I could explain further but since your are insisting of non existing scientists and audio engineers who allegedly have said 3dB increase is twice the loudness, I doubt you would really understand the complexity of Fs. And the final nail in the coffin was when you said in post 46 However the impedance is shown down to 4 Hz. That's the only reference I see to 4 Hz. I dont thing you know how to read graphs or the actual unit for impedance.
Well, you mentioned that there is a speaker with Fs in 40s having output upto 4 Hz. Your exact post was.
Furthermore, I think drivers are way capable to go beyond Fs. The Manufacturer datasheet clearly shows that as the Morel was shown to go as low as 4Hz! even though the Fs was 39Hz.
When I asked you show me the links, you said its posted. I have been asking to show a graph but you evaded. On your posted links, I could not find any reference of 4 hz except the impedance one. You confirmed my suspicion by posting this.
It is there. Understand what Fs is and you will see it in the link. See Kannan's post.
Clearly you were referring to the impedance chart because Kannan's post was about impedance. So, how about supporting your claim of Morel driver going upto 4 Hz? . I have been asking for that driver which can do 4 Hz for last 5 days.
I dont think this discussion is about understanding the question of Fs or twice as loud. It about who is having the last say.
Yes. Quite evident from the way you have been going about this. But if that's your goal, you won't win it.
