Hi! Nunayafb
you explain very good.
I ask you that the impedance of the woofer section V^2/Rp or 2.83^2/4 ~= 2W,2w=efficiency,because the impedance
is lower than 8 ohms. I think that is not sensitivity. Is it correct?
("loud" My country call this.) Nunayafb, About bsc i think that is old
story.Because in the past,Some manufactures began to used The spectrum analyzer to measure it. They knew some speaker of them. The respond frequency are not flat respond.They knew that the point of frequency respond are upper.I often listen some old speaker and measure it. It is near that's a flat respond.
I want to ask you.Is it old story?
Thanks
Thawach
you explain very good.
I ask you that the impedance of the woofer section V^2/Rp or 2.83^2/4 ~= 2W,2w=efficiency,because the impedance
is lower than 8 ohms. I think that is not sensitivity. Is it correct?
("loud" My country call this.) Nunayafb, About bsc i think that is old
story.Because in the past,Some manufactures began to used The spectrum analyzer to measure it. They knew some speaker of them. The respond frequency are not flat respond.They knew that the point of frequency respond are upper.I often listen some old speaker and measure it. It is near that's a flat respond.
I want to ask you.Is it old story?
Thanks
Thawach
you are redefining efficiency, the word efficiency is used to explain a a drivers ability to convert electrical power into acoustic power. Or...
((Acoustic power)/(Electrical input power))*100 = Efficiency
Most drivers are about 0.1-0.5% efficient
Typically a speaker with a higher efficiency will have a higher sensitivity, hence the reason people interchange the two.
BSC is not old, I am assuming you mean not necessary anymore. BSC is always an issue, it is based upon the radiation resistance properties of sound in air and the geometric properties of the baffle.
-Some xover designers tweak the low pass cap/inductor values to compensate for baffle step, ie they build bsc into the main filter topology to reduce the component count.
-Some designers tweak the baffle to alter the baffle step
-Some designers use 3-way and xover at the baffle step frequency and then just use L-pads.
-Some designers ignore it and produce cheap speakers
-Some designers factor in the probable placement of the speakers and determine it unnecessary, think a book shelf speaker placed near a wall, or on a large book shelf which acts like a baffle, kind of.
-Some use BSC in the traditional way
I would imagine most do a combination of several of the above to achieve the cheapest system with the flattest fr.
-J
Hi Nunayafb
About bsc I agree with you. It is the good answer that someone can not answer this question. He call the "......" for me. I belive that everyone wants to know about this. I must ask you again.
About the efficiency and sensitivity I'm not agree.I think that the sensitivity be the same. The loud is higher that's not
the sensitivity.The sensitivity of driver is only measure it at
the 2.83 v/1w/8ohm. When the woofers in parallel(4ohm) are not the sensitivity.+6 db=the efficiency.
Thawach
About bsc I agree with you. It is the good answer that someone can not answer this question. He call the "......" for me. I belive that everyone wants to know about this. I must ask you again.
About the efficiency and sensitivity I'm not agree.I think that the sensitivity be the same. The loud is higher that's not
the sensitivity.The sensitivity of driver is only measure it at
the 2.83 v/1w/8ohm. When the woofers in parallel(4ohm) are not the sensitivity.+6 db=the efficiency.
Thawach
Attachments
nunayafb said:
Hi,Thawach said:
efficiency is usually quoted as a percentage being shorthand for a proportion less than 1.
Sensitivity is usually quoted as the SPL in db/m/W or db/m/2.8V
Thawach's quoted text (post83) has substituted the word efficiency where clearly most readers would expect to see the word sensitivity.
In my opinion this http://www.diyaudio.com/forums/attachment.php?s=&postid=1389157&stamp=1199267194
is, by convention, wrong.
Hi!AndrewT
The efficiency that I had already known.It is express in percentage .But I want to know when i measure each one speaker in hometheater.I use decibel meter.It display in db.I think that db is not the Sensitivity because it is not 2.83 v/1w/1m. And sometime the speaker is 2 or3way.I want to know that i call that is "loud". Is it corect?
Thawach
The efficiency that I had already known.It is express in percentage .But I want to know when i measure each one speaker in hometheater.I use decibel meter.It display in db.I think that db is not the Sensitivity because it is not 2.83 v/1w/1m. And sometime the speaker is 2 or3way.I want to know that i call that is "loud". Is it corect?
Thawach
Thawach said:Hear is new epos speaker.
Someone tell me please. i don't understand why the epos sound
engineers don't interest to design baffle step circuit in those speakers.
Thawach
Hi,
The response of this speaker is controlled by the mechanical design
of the mid/bass driver much as AR did years ago. Varying the actual
mechanical properties and geometry of the cone is not a viable
option for the amateur.
BSC is considered as much as is possible in the above design.
The "Epos" approach started with designer Robin Marshall
http://www.stereophile.com/interviews/567/ and the ES14 :
http://www.stereophile.com//loudspeakerreviews/566/
I'd say figure 4 indicates BSC is not dealt with that successfully.
/sreten.
hi sreten
In the past,Nobody told about the bsc. About 20 years old I did not knew about the bsc. At the time I knew about SL6 celestion speaker. it's the best speaker. Design by Mr. Graham bank. i ever saw the respond frequency graph of it. it's near the flat respond graph. I ask you, At the time Nobody knew about the bsc. Why did it has the flat respond graph.(no upper)?
Thawach
In the past,Nobody told about the bsc. About 20 years old I did not knew about the bsc. At the time I knew about SL6 celestion speaker. it's the best speaker. Design by Mr. Graham bank. i ever saw the respond frequency graph of it. it's near the flat respond graph. I ask you, At the time Nobody knew about the bsc. Why did it has the flat respond graph.(no upper)?
Thawach
Hi,
Anyone with measuring equipment, a large flat baffle and a box will
rapidly find out about bafflestep whether they like it or they do not.
Then, as now the amount of BSC is nominally the difference between
the bass/mids sensitivity and the quoted loudspeakers sensitivity,
e.g. see LS3/5A and B110 specifications.
Then, as now, show me any major manafacturers site or documentation
that discusses BSC. There are lots of amateur designs with no BSC.
The SL6 i wouldn't call flat, I'd call it decidedly dull ......
Anyway the old UK principle was stick your drivers in a box, measure
them and then EQ them near flat, simulation has little to do with it.
/sreten.
Anyone with measuring equipment, a large flat baffle and a box will
rapidly find out about bafflestep whether they like it or they do not.
Then, as now the amount of BSC is nominally the difference between
the bass/mids sensitivity and the quoted loudspeakers sensitivity,
e.g. see LS3/5A and B110 specifications.
Then, as now, show me any major manafacturers site or documentation
that discusses BSC. There are lots of amateur designs with no BSC.
The SL6 i wouldn't call flat, I'd call it decidedly dull ......
Anyway the old UK principle was stick your drivers in a box, measure
them and then EQ them near flat, simulation has little to do with it.
/sreten.
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