Help getting to understand subwoofer db sensitivity and loudness

[guimond47]

Alright everyone im kind of caught up under this term. I use to have 1 18 fi btl that had a sensitivity of 94 db I think ... around there. it was loud. apparently they scale it at 1watt to 1 meter distance. now that being said I sold my fi btl year ago and replaced it with two 10"s alpine type x's (room purpose). I really miss my 18..... but now I heard that these type x's are power hungry and their db sensitivity is at 82 db each.... which makes me understand why now.

im powering it with an orion 2500.1d, best amp ive owned yet. they handle the power really well. at high volume I think they are clipping because I can smell some burn...... they don't get really hot tho.... ( if you touch the center after a while of music) now im wondering if I need two orions for each of these subs... so the gains can be turned down and then receive less clipping. they would see 1700watts rms each at 2 ohm instead of 1ohm. but my main question here is about db sensitivity ... compared to the fi btl at 94 db and my 1 type x at 82 db... does that mean the type x needs more power to reach up to the btl db levels.(more then 1200rms).... I know they are sq subs but even the btl 10" online is 83db..... im confused with these measurements. and xmas.... more xmas does that mean more spl (more moving air for that same amount of power)

I built a sub box but it isn't tunned the way I want it to be.... can some one on here help me out with that too ? thanks.

also shouldn't my two x's be the same loudness as my btl... ive got the same amount of air movement as the btl....20" vs 18" if that's how it works ... maybe my box isn't tunned like I think it isn't

[Triticum Agricolam]

You don't really want to try to compare two subs based on what the manufacturer lists for sensitivity. The way they measure that number isn't consistent between manufacturers and it doesn't take into account what the box is going to do. For example, if you have a sub with 91 dB sensitivity and stick it in a sealed box vs a ported box its is going to have a lot different performance.

For setting your gains, you really should find someone with a DD-1 or o-scope and do it properly.

Its pretty common for people's boxes to not be tuned to what they think they are.

[Jessica]

cone area is pi*r^2 not the diameter of the sub. 1 18 has a lot more area then two 10's

I wouldnt worry too much about sensitivity when it come to subwoofers. maybe with tweeters or mids.

[kirill007]

Alright everyone im kind of caught up under this term. I use to have 1 18 fi btl that had a sensitivity of 94 db I think ... around there. it was loud. apparently they scale it at 1watt to 1 meter distance. now that being said I sold my fi btl year ago and replaced it with two 10"s alpine type x's (room purpose). I really miss my 18..... but now I heard that these type x's are power hungry and their db sensitivity is at 82 db each.... which makes me understand why now.

im powering it with an orion 2500.1d, best amp ive owned yet. they handle the power really well. at high volume I think they are clipping because I can smell some burn...... they don't get really hot tho.... ( if you touch the center after a while of music) now im wondering if I need two orions for each of these subs... so the gains can be turned down and then receive less clipping. they would see 1700watts rms each at 2 ohm instead of 1ohm. but my main question here is about db sensitivity ... compared to the fi btl at 94 db and my 1 type x at 82 db... does that mean the type x needs more power to reach up to the btl db levels.(more then 1200rms).... I know they are sq subs but even the btl 10" online is 83db..... im confused with these measurements. and xmas.... more xmas does that mean more spl (more moving air for that same amount of power)

I built a sub box but it isn't tunned the way I want it to be.... can some one on here help me out with that too ? thanks.

also shouldn't my two x's be the same loudness as my btl... ive got the same amount of air movement as the btl....20" vs 18" if that's how it works ... maybe my box isn't tunned like I think it isn't

Xmax is not so important for ported enclosures.

Use WinIsd to design a enclosure.

20 vs 18 inch doesn't work that way, read strangeduck's comment.

Alpine type X's aren't power hungry subwoofers at all, something is wrong in your install.

And yes there is a big chance that both Type X's in their optimal enclosure are less loud then a 18 inch BTL.

Lower cone area and subwoofers with different goals.

Sensitivity is usually measured at 1Khz, that makes it pretty much useless for use with subwoofers.

[guimond47]

Alrighty.. Is there someone on here that has the chance to check my porting with a calculator if i give them my demensions... I feel i need bigger ports... Im currently running two 4" in diameter ports with a 90* bend roughly 5-6 long ... For the two 10"s also with one sub inverted (reverse polarity) and one normal firing(regular polarity) in. A 2.75-3cu ft box..

I also found a burnt power wire spot in my 0 guage(copper was black) so im going bigger then 0 guage...

[Joe X]

One has to learn to see a system as a whole and NEVER draw conclusions from little pieces of information, UNTRUE that low Fs is always going to deliver low end regardless of the box, UNTRUE that sensitivity always means that you are going to get louder, if anything can help at all is MODELING your situation with software as best as you can, beware of most companies that don't disclose full parameter sets for their products (or phoney specs like peak to peak Xmax) as they surely are hiding information from the potential buyer.