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-   -   speaker impedance and sensitivity (http://www.diyaudio.com/forums/car-audio/225573-speaker-impedance-sensitivity.html)

Amit_112dB 13th December 2012 01:52 AM

speaker impedance and sensitivity
 
Recently i bought a Pioneer TS-W310S4 which has 95db 1w/m. I think pioneer did not cheat.

I was considering buying infinity Reference 5032cf or 5002ix or 6032.
They claim 92db sensitivity 2.83v/m. 2.83volts at 2 ohms means 4watts and not 1 watt/m (as power=voltage*voltage/impedence)
92db @ 4watts/m
89db @ 2 watts/m
86db @ 1 watts/m <--- True sensitivity

Did Infinity car audio lie about their sensitivity by 6 dbs ?

Perry Babin 13th December 2012 05:47 AM

If they give the input voltage, they aren't trying to mislead except those who are too lazy to read all of the information provided.

These numbers shouldn't be your only reason to buy them. You can make speakers that are more efficient but there are tradeoffs. Many times, a speaker will appear (from the specs) to be more efficient but the frequency response isn't as good and the lower frequency output suffers. It's also possible to make speakers more efficient but with less power handling. To get greater power handling and more efficiency often requires that the speaker is made of better materials which makes them more expensive.

The 95dB spec on the pioneer is also suspicious. It's almost certainly not 95dB efficient from 20-250Hz. If so, in what enclosure? In what environment?

Speakers and audio are very complex. You have to know MUCH more than what a few specs will tell you to know how they will perform. Even if you punch in all of the T/S parameters, they will not tell you how the speaker will sound. To know how a speaker will perform, you have to listen to it in it's intended environment with the other equipment that it will be used with. Even then, you'll get as many opinions on how it performs as the number of people that listen to it.

Amit_112dB 13th December 2012 02:59 PM

Comparing Pioneer with JBL p1222
 
Thank you Perry,
I am comparing this Pioneer to this JBL P1222
It seems the 5db range for JBL is 35hz-100hz only
It seems the 5db range for Pioneer is 40-220hz
I think the wide range is another reason I would prefer pioneer

Pioneer's chart is max at 0db, i think 0db could be 95 sensitivity they claim.
This woofer seems to have very very good sensitivity rating. Will talk more of pioneer when i hear it.

JBL on the other hand :confused:
i see 90db @ 2.83v 2ohm * 2 in parallel= 1 ohm
2.83v in 1 ohm = 8watts
so actual 1watt/meter sensitivity is 90-9=81db
yet they claim 97 (2.83v /meter)in specs
Why dont they number just dont add up for JBL
Where did the missing 16 db go:eek:

JBL
http://s9.postimage.org/3pkalcr17/JBL_P1222.jpg
JBL datasheet- http://www.jbl.com/resources/Brands/...rev3_27_06.pdf

Pioneer
http://s16.postimage.org/qmzfy3bhd/pioneer_tsw310.jpg

JMFahey 20th January 2013 04:19 PM

Check them side by side.
In the world of car audio, ***everybody*** lies.
Ok, correct that to "writes specs creatively".:p

4real 20th January 2013 04:28 PM

Well, if you want to know which of the two can move more air, that Is the jbl. It's got 3.2 mm more excursion than the Pioneer. If you really want to compare them, put them side by side in WinISD or similar tool. Those tools don't lie..

Amit_112dB 21st January 2013 01:17 PM

Quote:

Originally Posted by Perry Babin (Post 3282708)
If they give the input voltage, they aren't trying to mislead except those who are too lazy to read all of the information provided. The 95dB spec on the pioneer is also suspicious. It's almost certainly not 95dB efficient from 20-250Hz. If so, in what enclosure? In what environment?
.

They are EVIL, Pioneer TS-W310S4
Has a sensitivity of 95db/watt ........... ..Inside car :worship:
http://www.diyaudio.com/forums/car-a...ml#post3286192

Talk about specs creatively..lol
I returned it without even trying it and even thought about filing a complain against FTC but i realized it would be useless. wasted $40 on return.

I returned it and got JL audio W3v3-4, i get getting 290rms and now wishing i had got the 2 ohm version so i could have 500rms.

1st sub so i dont have a reference but it sounds really nice.

JMFahey 21st January 2013 01:41 PM

Quote:

I returned it and got JL audio W3v3-4, i get getting 290rms and now wishing i had got the 2 ohm version so i could have 500rms.
Or get a *real* woofer instead and blow the car roof with 100W ;)
"Real" meaning a PA woofer: Eminence Gamma or Delta/PA type JBL/RCF/Beyma/EV/Peavey Black Widow .

Amit_112dB 22nd January 2013 06:27 PM

Quote:

Originally Posted by JMFahey (Post 3335838)
Or get a *real* woofer instead and blow the car roof with 100W ;)
"Real" meaning a PA woofer: Eminence Gamma or Delta/PA type JBL/RCF/Beyma/EV/Peavey Black Widow .

Eminence Gamma or Delta look like paper cones :scratch:

Black Widow Speaker is 8ohm which may work fine if they are efficient. they claim 97.5 dB / 1 W 1 m , at this spec i can even run them on 50watt n be fine :)
Are Kevlar impregnated cellulose cones good? can they survive -10 to 110 degrees ?

Will look into JBL/RCF/Beyma/EV. You gave me lots of new options.

Doono if home audio PA subs are a good idea in cars or not ? But i hear people use dayton ho sub is car all the time.


Update: Most of the these 12inches dont seem to have a good low freq response and higher F air resonance.

sreten 22nd January 2013 06:40 PM

Quote:

Originally Posted by Amit_112dB (Post 3282556)
Recently i bought a Pioneer TS-W310S4 which has 95db 1w/m. I think pioneer did not cheat.

I was considering buying infinity Reference 5032cf or 5002ix or 6032.
They claim 92db sensitivity 2.83v/m. 2.83volts at 2 ohms means 4watts and not 1 watt/m (as power=voltage*voltage/impedence)
92db @ 4watts/m
89db @ 2 watts/m
86db @ 1 watts/m <--- True sensitivity !!!wrong!!!(sreten)

Did Infinity car audio lie about their sensitivity by 6 dbs ?

Hi,

No the senstivity is correct as that is the level for a voltage.
Sensitivity is what you use to match the level of drivers.
Your confusing it with nominal efficiency which is per watt,
and for a 2 ohm driver they will differ by as you say 6dB.

rgds, sreten.

4real 22nd January 2013 06:54 PM

Do you want loud or efficient? PA woofers generally do not have a lot of Xmax, meaning that while they are efficient, their maxspl will be lower than the real low efficiency subwoofer drivers in the lowest octaves.

What about Dayton Audio RSS315HF-4 12". Not efficent, but low distorion and can go very loud. Or, if you want a PA woofer, look at Eminence's LAB 12C. It's a bit more efficent than the Dayton, and looks vey well made.

Ow,and powerhandling is not that important in the lower octaves, excursion is the limiting factor in most cases.


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