# Sensitivity and SQ.



## RaptorHunter (Feb 5, 2013)

I have noticed one thing, some budget brands sell speakers with higher sensitivity ratings than SQ brands,
1. Are the budget brands overrating?
2. Are the SQ brands underrating?
3. Is there a trade-off between SQ and Sensitivity?
4. How much is too much and too little Sensitivity?


----------



## Wy2quiet (Jun 29, 2010)

I wouldn't equate a relation between a speakers "quality" and it's sensitivity ratings. However, usually the compromise is that higher sensitivity speakers for their size do not always have flat response, since they inherently do not go as low (frequency wise) as efficiently. This is seen in many pro woofers than can reproduce 100db+ @ 1 w in the speaking range, but fall to mid 80's at bass frequencies.

Furthermore, the cone and motor are usually light which help keep sensitivity high. This usually leads to a lower excursion limit than similar drivers.

This is why horns are so popular. They increase efficiency by remarkable margins and the larger the horn, the lower the extension is therefore being virtually unrivaled in high volume performance.


----------



## cajunner (Apr 13, 2007)

a budget brand's marketing department is more likely to use misleading specs, or just outright wrong specs in order to sell their products.

the sensitivity specification itself is riddled with misunderstandings and there is no real definition for it, other than what manufacturers state in their use.

1 watt, at one meter, is the de facto standard.

1 watt, is 2.83V at 8 ohms.

however, for 4 ohm speakers, that is not the case.

so, you can say "sensitivity of 90 db" but it can be based on the 4 ohm spec, which would mean 87 db, roughly, at the 8 ohm spec.

the frequency where you take the ohm reading has a lot to do with the spec having a realistic value.

pro woofers were spec'ed at 400 hz, as a standard for comparison, but with the advent of car audio and long excursion woofers the ability of some subs to reach 400 hz is compromised and the spec is no longer as valid.


----------



## RaptorHunter (Feb 5, 2013)

cajunner said:


> a budget brand's marketing department is more likely to use misleading specs, or just outright wrong specs in order to sell their products.
> 
> the sensitivity specification itself is riddled with misunderstandings and there is no real definition for it, other than what manufacturers state in their use.
> 
> ...


Can I trust Polk db Values their sensitivity ratings only give a value in db not db/m.


----------



## cajunner (Apr 13, 2007)

RaptorHunter said:


> Can I trust Polk db Values their sensitivity ratings only give a value in db not db/m.


no.

you cannot trust a spec that has no qualifiers, when the spec is supposed to mean something.

MB Quart did this, but in their defense their use of the .5 meter spec, was stated in their sensitivity rating.

A sensitivity spec is only as good as the standard, and unless they state the standard, or have a statement about the standard in their "glossary of terms" that they use, then it's a meaningless spec.

let's say they rate a 12" sub at 88 db. 

what does that mean?

it means that under a specific set of conditions, they can get a 12" sub of that model to hit 88 db with 2.83V, at the very least, in the space of one meter.

it doesn't mean the 88 db is valid for 1 watt, or one meter, or even 4 or 8 ohms, depending on the coil for the 12" sub. Or if it's at 1000 hz, or 200 hz or whatever.


----------



## RaptorHunter (Feb 5, 2013)

Just did a little research on my own now, looked for CEA-2031 Compliant speakers (on SonicElectronix), and I couldn't find any speaker or sub with values higher than 88db.
So in the best case scenario when you are buying speakers with that aren't CEA-2031 Compliant you are getting 88db maximum.


----------



## cajunner (Apr 13, 2007)

compliant is not complaint.

spell check only goes so far.


----------



## RaptorHunter (Feb 5, 2013)

cajunner said:


> compliant is not complaint.
> 
> spell check only goes so far.


English is not my strong point, my first language is Portuguese. But thanks anyway.


----------



## cajunner (Apr 13, 2007)

RaptorHunter said:


> English is not my strong point, my first language is Portuguese. But thanks anyway.


you never would have knowed it!

compliant is a working word and so is complaint.

most people would use spell check but then not realize they had typed the word compliant wrong.


----------



## Wy2quiet (Jun 29, 2010)

cajunner said:


> you never would have* knowed* it!
> 
> compliant is a working word and so is complaint.
> 
> most people would use spell check but then not realize they had typed the word compliant wrong.


:laugh:
_known_


----------



## tnbubba (Mar 1, 2008)

they all suck!!!!
get a calculator and calculate the sensitivity the off the TS parameters if a manufacture cant give u TS parameter dont buy it! at a min they should have that in todays world if not then they are just blowing smoke


----------



## Oscar (Jun 20, 2010)

tnbubba said:


> they all suck!!!!
> get a calculator and calculate the sensitivity the off the TS parameters if a manufacture cant give u TS parameter dont buy it! at a min they should have that in todays world if not then they are just blowing smoke


that is just as useless as a random sensitivity spec on a subwoofer because the calculated value _only_ applies to the mid-band. You are not guaranteed that sensitivity level anywhere else on the audio spectrum of frequencies. The sensitivity of a subwoofer in the sub-bass range is ultimately determined by how well the enclosure/tuning manipulates the inherent electro-mechanical efficiency of the speaker.



RaptorHunter said:


> I have noticed one thing, some budget brands sell speakers with higher sensitivity ratings than SQ brands,
> 1. Are the budget brands overrating? *Yes and No.*
> 2. Are the SQ brands underrating? *Yes and No.*
> 3. Is there a trade-off between SQ and Sensitivity? *Yes and No.*
> 4. How much is too much and too little Sensitivity? *"that" is too much and "this" is too little*


As if it wasn't confusing enough, there are no straight answers to your questions. There are just too many difference scenarios that exist (or can exist) that one conclusion will fail to hold elsewhere. You can attempt to evaluate specific cases if you like, but over-generalized assumptions will lead no-where without going the route of learning the actual science/art of speaker driver manufacturing.


----------



## amalmer71 (Feb 29, 2012)

A lot of it has to do with the wire used in the voice coil.

The amount of power a speaker can handle depends on the voice coil. The cheap no-name brands (or bargain basement, if you'd rather) can't handle much power. They're rated for 20-30 watts at the most, and if they say they can handle more, they're lying. LOL

Anyway, the more power, the thicker the wire. The thicker the wire the more movement they get but the speaker becomes less efficient.

Click here and go down to "BL". Once again, Mr. Perry Babin explains it very well.
Speaker

I.E., it's easier to make a efficient speaker if you don't need it to handle a lot of power.


----------



## tnbubba (Mar 1, 2008)

oscar you are soooo wrong... it establishes s reference point in which to compare all speakers from, a electrical efficiency standpoint .usually at 1K or what ever inductance the vc is measures at.. any deviation in response from that point is is due to electromechanical vibrations of the moving assembly.


----------



## minbari (Mar 3, 2011)

without getting into weather the specs are right, wrong, or even usefull. you also have to consider Hoffmans Iron law. if you have a sub that is rated for 99db 1watt / 1 meter at 400hz, but that will most likely mean that it will not play very low.

best bet for any speaker is looking at the freq resp plot. then you know how it reacts, at least in free air.


----------



## todj (Dec 11, 2008)

If you only have a low powered amplifier (200-700 rms) get an IDMAX 

(93.1 db 1w/1m). If you have 1000 rms and want a great sub purchase a TC Sounds PRO 5100 (94.5 db 1w/1m). You won't be sorry with either one. Aside from those two I can't really think of any subs with great efficiency and sq. I am sure someone else can. In a world with cheap power


----------



## todj (Dec 11, 2008)

..............people seem to have forgotten about the sensitivity spec.


----------



## RaptorHunter (Feb 5, 2013)

todj said:


> If you only have a low powered amplifier (200-700 rms) get an IDMAX
> 
> (93.1 db 1w/1m). If you have 1000 rms and want a great sub purchase a TC Sounds PRO 5100 (94.5 db 1w/1m). You won't be sorry with either one. Aside from those two I can't really think of any subs with great efficiency and sq. I am sure someone else can. In a world with cheap power


I already have 2 Subs (Pioneer TS-W3002D4) I know they are far away from good subs, but Subs are heavy and importing subs would be a shoot in the foot budget wise. With exception of the subs all my audio gear was imported I ended up paying twice the price because of shipping and taxes.


----------

