sensitivity of subs

[86civicSI 10+ year member]

i hate them but i've seen impp's do some pretty high numbers(i don't know there specs) you gotta figure a 3db increase is twice the volume so say you have a 1000 watt sub that 86 db 1watt 1 meter and a 500 watt sub that's 96db 1 watt 1 meter that 500 watt sub is gonna be WAY LOUDER if a 3db increase is twice as loud 89 is twice as loud as 86 and 92 is twice as loud as 89 and 95 is twice as loud as 92 that's why pioneers are so loud they are efficient it don't seem like any one pays attention to efficiency of the sub all they care about is how many watts they claim they can take high wattage subs can take alot of wattage because most the time they aren't very efficient but look at the specs of this soundstream splx15 the sensitivity is 99.9 WHAT!!! http://cgi.ebay.com/NEW-SoundStream-...d=p3286.c0.m14 pretty sweet now that motherfooker will get REAL LOUD

NEW IN BOX.

SoundStream SPLX154 15" 2500W 4-Ohm Car Subwoofer

Sensitivity: 99.9 dB

RMS Power Range : 1200 Watts

Peak Power Handling: 2500 Watts

Impedance: 4 Ohm

Low Frequency response: 22 Hz

High Frequency Response: 1000 Hz

Diameter: 15 Inch

Max: 2500W Burst

Max power handeling: 1200W

Magnet Wgt. (oz): 192

Frequency response: 22-1kHz

Mounting hole size: 14.25"

Woofer depth: 8.125

Recommended enclosure: 3.5

Recommended enclosure type: vented

Cast aluminium basket

Large -roll foam surround

Dual stacked magnet structure

Aluminum voice coil former

Extended back-plate with Aero-Vent

Stitched tinsel leads

Spring loaded push terminals

Rubber gasket

Rubber magnet cover

Click to read more...

 

[bass_lover1 10+ year member]

My brain hurts...

 

[slim2fattycake 10+ year member]

Seriously, use a period somewhere.

 

[tc3k101 5,000+ posts]

my question is wtf are you babbling on about?

 

[audioholic 5,000+ posts]

Uhm we talk about subwoofer sensitivity alot here. By talking about it alot, I of course mean we let people know the spec means very little, considering its measured at 1khz, does not account for the enclosure which affects over all efficiency alot, and many manufacturers rate sensitivity differently to make their sub seem artificially better. And no subwoofer I can recall, with a true 1 watt @ 1 meter measurement, comes anywhere near 99.9db.

 

[snb778 5,000+ posts]

Uhm we talk about subwoofer sensitivity alot here. By talking about it alot, I of course mean we let people know the spec means very little, considering its measured at 1khz, does not account for the enclosure which affects over all efficiency alot, and many manufacturers rate sensitivity differently to make their sub seem artificially better. And no subwoofer I can recall, with a true 1 watt @ 1 meter measurement, comes anywhere near 99.9db.

but if it did... thats pretty dam impressive... ya gotta admit! hahah

 

[ciaonzo 5,000+ posts]

Not to mention, that if two drivers with the same Sd are both moving one inch while playing the same frequency but one is more sensitive than the other, they're playing at the same volume level. The only difference is that one needed more power to get there.

That comparison is, of course, made with a sealed enclosure.

 

[audioholic 5,000+ posts]

but if it did... thats pretty dam impressive... ya gotta admit! hahah

And if a pig flew, that would be impressive as well. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[snb778 5,000+ posts]

pffffffffffff... see it every day

 

[audioholic 5,000+ posts]

Oh and I almost forgot, Hoffman's Iron Law also tells us many times we WANT a sub with low sensitivity. Unless you like huge enclosures or poor low frequency response. Advertising a 99.9db sensitivity is simply for people who dont know any better to assume that's even possible, let alone desirable. Make a mental note fellas, apparently SoundStream is not above falsifying specs to sell speakers to noobs. Dont let them fool you.

 

[Electrodynamic 10+ year member]

As audioholic pointed out, subwoofers are about give and take. Read this paper on the subject (click on this sentence). It'll explain a lot.

In small sealed boxes, you don't want high efficiency subwoofers. If you don't care about enclosure size (a huge box), you can really gain from high efficiency drivers. And also as he pointed out, you have to be careful and weed through the marketing BS and flat-out false information thrown out there by many car audio companies about their drivers sensitivity ratings. Remember that sub about a year ago that was rated at 99 db, but come to find out that the figure was taken with its quad 1 Ohm coils wired in parallel. If it were wired up to 4 Ohm (like it should have been), it would be rated at 87 dB.

High efficiency, high Xmax subs are out there (not very many of them though) like this one (click this text), but again, it all depends on what you want out of your system and what your limitations are...especially box size, box type, and amount of power available.

 

[86civicSI 10+ year member]

here's those periods ...........................................................................put them where you think they should go haha i don't have time for proper punctuation. i agree with soundstream's insane claim being inflated.however i had a old school soundstream spl dvc 15 it was very efficient. it got REAL LOUD with a MTX 500d (the first series)i replaced that set up with a old school RF POWER DVC 15 and a os bd1000.that fosgate set up never achieved the same volume due to the low efficiency of the fosgate. keep in mind this was back in like 1999 when this equipment was currant.we had a click called the one sub club,and believe it or not quite a few of us were doing in the mid 140's metered at the dash in local competitions with 1 15. in a hatchback of-course.a 1000 watt amp was not common at the time but then again neither were Korean made amps.thats back when it was a dollar a watt

 

[86civicSI 10+ year member]

ps. back in 97 i had 2 regular punch 12's(8ohm) in a 6th order 6 cube box in a 86 crx si with a PPI 2150 doing like 147 those were HUGE numbers back then.i'm too old for that shit now.

 

[audioholic 5,000+ posts]

Yep, older subs tended to be more efficient than the ones we use today. Not because they were better, but because the car audio industry hadn't realized the advantages of lower efficiency subs in car applications (ie: smaller enclosures to fit the ever increasingly smaller cars). Again, low efficiency is many times desired to keep the enclosure size small while still maintaining good low-end performance. This, of course, also coincides with the ever cheaper amplifiers coming from China these days. Use to be you figured a dollar a watt back in the mid 90's.

Smaller cars and cheaper amplifiers have ushered in the era of low efficiency subs.