Spl Difference With Same Power To Different Subs?

[imfrom210texas]

I was just wondering what would be the difference in SPL, in 2 subs having the same excursion, but one is 400 Rms and the other is 750? This question is assuming both subs have the same optimal tuning frequency, and are powered by the same amp. Thanks

[Guest Caps]

look at the sensitivity

[imfrom210texas]

look at the sensitivity

But if they were at the same point of excursion, it wouldn't matter would it (I'm not sure that's why I'm asking)?

[reinke]

i gained .1 possibly more with more time on the mic. from switching from power acoustic's to memphis power reference. the PA's to me sounded way better to the ear but the PR's are handling the truck better.

[imfrom210texas]

i gained .1 possibly more with more time on the mic. from switching from power acoustic's to memphis power reference. the PA's to me sounded way better to the ear but the PR's are handling the truck better.

Not quite what I meant, because you're talking about 2 diff. subs that are not going to have the same optimal tuning, and probably have diff. sens(db) levels.

[alvitae]

I would guess it depends on a lot of factors.

But this is what I found out using an audiocontrol meter at a local shop. numbers may be inflated a tad because it's not a T.L. But it is a nice A.C.

Older kenwood amp 850 watts @2ohms($100 Craigslist) 2 entry level powerbass ps-12's 250 rms ea. Sensitivity 91 db's. Single 4 ohm coils ($45 ea. new) pre-fab slot ported box in the trunk 147.0 db's.

Then I wasted money on new power bass xl-12's 350 rms, Sensitivity 92 dbs. Dual 4 ohm coils and an P.B. asa 1000.1d amp 1000 watts @ 1 ohm. Same box.

146.6 db's.

The cheap subs call for 2.5 cube ft. ported and the xl's for 2 cube feet. both about the same herz, Maybe one Hz diff. Not positive on the sq. ft. of the box used because it is a prefab but I think 3.5ish total? not counting port.

I'm sure I'm missing alot of reasons why But I think the lighter and easier to move sub is easier to get spl out of with low watts.

[imfrom210texas]

?

[01xtreme]

There is no way to tell from your hypothetical situation. Technically the more efficient speaker would be louder (all things held constant), so you would have to look at the sensitivity, but even then there are too many changes going from one sub in it's optimal enclosure to another sub in it's optimal enclosure to tell definitively.

[MickyMcD]

But if they were at the same point of excursion, it wouldn't matter would it (I'm not sure that's why I'm asking)?

Yes, it does. Overall movement of the cone isn't what dictates 'loud' and 'quiet.' In fact, you will notice that for extreme SPL bursts at the enclosure and vehicle resonant frequency, the driver really isn't moving too much at all.

So let's look at it this way. You have a woofer that is 2.4% effecient with respect to both electrical and mechanical factors. You put in 1000w, you get 24 acoustic watts of sound out of it (hypothetically.) You have a woofer that is 5% effecient with the same 1kw of power, you have 50 acoustic watts of sound. BIG difference in overall sound pressure level.

Your situation may not be that extreme, but the point I am trying to get across is that a more sensitive loudspeaker system, that is the enclosure, damping, driver, tuning etc will most likely (ie 95% chance) be louder. Whether that be .1 decibel or 1 decibel difference, I don't know.

Cheers,

Mick

[Bryan]

Yes, it does. Overall movement of the cone isn't what dictates 'loud' and 'quiet.' In fact, you will notice that for extreme SPL bursts at the enclosure and vehicle resonant frequency, the driver really isn't moving too much at all.

So let's look at it this way. You have a woofer that is 2.4% effecient with respect to both electrical and mechanical factors. You put in 1000w, you get 24 acoustic watts of sound out of it (hypothetically.) You have a woofer that is 5% effecient with the same 1kw of power, you have 50 acoustic watts of sound. BIG difference in overall sound pressure level.

Your situation may not be that extreme, but the point I am trying to get across is that a more sensitive loudspeaker system, that is the enclosure, damping, driver, tuning etc will most likely (ie 95% chance) be louder. Whether that be .1 decibel or 1 decibel difference, I don't know.

Cheers,

Mick

very technical answer there