Sub Theory?

[Mosin]

Now I'm sitting here thinking about woofers and there excursion/power limits.

My 'theory' i think it is, is:

Brand A - 15" sub, 4" peak to peak excursion, 3" coil, wired at 1-ohm. Reaches peak excursion at 5K RMS

Brand B - 15" sub, 4" peak to peak excursion, 3" coil, wired at 1-ohm. Reaches peak excursion at only 500RMS

Now if brand A reaches its peak at 5kRMS and brand B at 500RMS. With basically the same specs, would they be just as loud as each other?? Or would more watts be dominate?? I would think that they would perform the same seeing as same specs/stats.

Can someone school me on this??

I'm not to experienced with the technical shit of woofers.

[Forevrbumpn]

There are a lot of mechanical, and electrical issues in this.

1) the sub with the 5kw at 4" is more than likely having a lot more spiders, super stiff suspension, and the motor design is probably optimized for peak xmax at a higher Fs than the second woofer

2) second woofer more than likely has a lot softer suspension maybe just 1 spider, and a lower Fs, allowing the sub to reach its max excursion at lower power

its really simple suspension and motor design that creates the woofer, and where the peak xmax will be, and what freq

[Mosin]

There are a lot of mechanical, and electrical issues in this.

1) the sub with the 5kw at 4" is more than likely having a lot more spiders, super stiff suspension, and the motor design is probably optimized for peak xmax at a higher Fs than the second woofer

2) second woofer more than likely has a lot softer suspension maybe just 1 spider, and a lower Fs, allowing the sub to reach its max excursion at lower power

its really simple suspension and motor design that creates the woofer, and where the peak xmax will be, and what freq

Well let's say in an un-realistic environment that they both have Fs of say 30Hz. with both tuned 2.8 cube boxes at 28Hz. Now I'm not sure if that high powered of a woofer would work physically with that low of Fs.

I just wonder which would be louder. I've been pondering this all day and need closure.

[HHR Ed]

you gotta think about the energy it takes to drive a cone of a certain mass 4" in each direction.

500w is not enough energy to push any modern cone 4" each way but 5K is. But lets say 500w can with a new type of cone that has a fraction of the mass that the 5K sub has.

Now think about the resistance of the air in the enclosure and in the vehicle.

It takes alot of energy to compress all that air, so even if 500w can push the cone 4", it wont move 4" cause the force of the air pushing back on the cone will limit travel to the peak of what 500w can do, while the 5K sub can push alot more air mass.

Basically, the 5K sub will be louder

[audiofanaticz]

Well if your theory is true, there would be no need for subs that handle these high wattages.

we will use Meade for an example since we all know his setup, if he swapped out his btls for some 18s that where 1000watts rms or even peak, and used just one rf t40001bd. He would be lucky to break 150s let alone 145-148 deebeez.

Also to go along with Forevrbumpn spider comment, some companies use many spiders like DD for example that have 8+ spiders with a mixture of medium to stiff spiders, while other companies only run 4 super stiff spiders like sundown and fi I wanna say.

A sub with a weaker spider will reach its mechanical limits before a sub with a super stiff spider.

My boss has some custom built Image dynamics idqmax subs that he use to run in his extreme vehicle that have only 1 weaker spider. He burped something like 174's on a termlab (sealed in the kick) on 3 15s with about 12krms. The subs took the power fine, but he said on music you would tear the spiders and launch the cones, but it gave him a edge back in the day having speakers that would hand the power with the weak suspensions.

Most the time when your looking at 500 watt subs however, your gonna be lucky to find them with a 2.5 inch voice coil, let alone a 3 inch.

[Mosin]

Ahh...

So basically the 500W woofer wouldn't be able to compress the air in the vehicle enough causing the 5k woofer to be louder?

If so, gotcha.

[HHR Ed]

Ahh...

So basically the 500W woofer wouldn't be able to compress the air in the vehicle enough causing the 5k woofer to be louder?

If so, gotcha.

yes exactly, thing of one of those huge air compressors with a 5hp motor, then look at the little tanks with a 1 hp motor. Same concept.

[Forevrbumpn]

The suspension also helps with the back stroke of the coil/cone assembly to cause a lot more 'Spring" in the opposite direction, its a catch 22 to use a very stiff suspension

A stiff suspension is harder to move in the up stroke, but the back stroke, it releases all that spring pressure back to help with the voice coil, that is why a lot of companies use these godly huge motors, and then a super stiff suspension, to move that coil up and down with a suspension that tight, you need some serious power, but that is where motor design, and BL force comes in to play, and high DB #s

[Boon]

All you're trying to do is convert electrical energy into kinetic energy and then convert that energy into sound energy (still a form of Kinetic energy in itself)

500w of electrical energy can only turn into 500w of sound energy (unrealistic anyway) regardless of how much excursion or whatever it's reaching.

[Kapetol T]

Now I'm sitting here thinking about woofers and there excursion/power limits.

My 'theory' i think it is, is:

Brand A - 15" sub, 4" peak to peak excursion, 3" coil, wired at 1-ohm. Reaches peak excursion at 5K RMS

Brand B - 15" sub, 4" peak to peak excursion, 3" coil, wired at 1-ohm. Reaches peak excursion at only 500RMS

Now if brand A reaches its peak at 5kRMS and brand B at 500RMS. With basically the same specs, would they be just as loud as each other?? Or would more watts be dominate?? I would think that they would perform the same seeing as same specs/stats.

Can someone school me on this??

I'm not to experienced with the technical shit of woofers.

Well there is a lot more to consider, as others have said, about the speaker than just those facts. Both speakers will move the same air mass each at their respective power levels. The second one would have a much higher sensitivity rating.

But the other factors to consider are all the other Thiele-Small parameters of each speaker. These parameters will determine what box the speaker will perform best in. So each sub given its optimal box should, in theory, perform the same.