Objective calculations for increasing sub stage output (not a question)

[Jakerrr 10+ year member]

for my personal use

(weighing options and considering a loud future system with the limited space I have)

but I figured I might as well share it

doubt anyone will get any use out of this but a few may find it interesting

SA

6 8's fed >4800w : ~2.45 X SPL of 1 SA-15 on 1200w

3 10's >3600w 1.89

2 12's >2400w 1.50

sq root of (product of cone-area and power ratios) = SPL ratio

SPL ratio of 2 (X2 SPL of original system) = 2*(sq rt of 10) dB = ~6.32 dB gain

obvious "in a perfect world" and "all else equal" assumptions made

but measures were taken to decrease likelihood of "overshooting" the ratios

the classic definition of SPL is the one referred to in this model

that is, sound pressure in Pascals/PSI/etc

a ~6.32 dB gain corresponds to pressure (or voltage, albeit with a mythical zero resistance rise) increasing by factor of 2

Click to read more...

 

[adulbrich 5,000+ posts]

Wat?

Too much math.

Step one: Get beast subs

Step two: Throw 37 jiggawatts of power at them

Step three: Enjoy your SPL's //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Jakerrr 10+ year member]

Wat?
Too much math.

Step one: Get beast subs

Step two: Throw 37 jiggawatts of power at them

Step three: Enjoy your SPL's //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Like I said, this was just for my personal use. I'm a physics major and this stuff is pretty interesting to me and this in particular was pretty simple to figure out. I had it all on notepad and just copy pasted and added annotations. Thought it was kinda cool that 6 sa-8's on double rated power would generate 2 1/2 times the pressure of my current setup (1 sa-15 on double rated power before rise) theoretically. Also not many people seem to know that the theoretical 3 dB gain one gets from doubling power is actually sq.root(10) dB (~3.16).

 

[adulbrich 5,000+ posts]

Yeah, you're not accounting for power compression though. The more power you try to feed a sub, the less you'll gain. Also, that's not talking about phase at all.

Less subs are better to reduce phase issues with large enclosures.

 

[Jeffdachef 5,000+ posts]

Like I said, this was just for my personal use. I'm a physics major and this stuff is pretty interesting to me and this in particular was pretty simple to figure out. I had it all on notepad and just copy pasted and added annotations. Thought it was kinda cool that 6 sa-8's on double rated power would generate 2 1/2 times the pressure of my current setup (1 sa-15 on double rated power before rise) theoretically. Also not many people seem to know that the theoretical 3 dB gain one gets from doubling power is actually sq.root(10) dB (~3.16).

Estimated cone area of 6 8s is 301 in^2

Estimated cone area of 1 15 is 176 in^2

You have more cone area and cooling with the 8s Its not hard to win when you have one side completely stacked.

 

[los33]

Like I said, this was just for my personal use. I'm a physics major and this stuff is pretty interesting to me and this in particular was pretty simple to figure out. I had it all on notepad and just copy pasted and added annotations. Thought it was kinda cool that 6 sa-8's on double rated power would generate 2 1/2 times the pressure of my current setup (1 sa-15 on double rated power before rise) theoretically. Also not many people seem to know that the theoretical 3 dB gain one gets from doubling power is actually sq.root(10) dB (~3.16).

Is that so?

You just did an obvious post trying to prove how smart you think you are.

Just so you know you calculated a real world equation for cone area which depending on actual sub specs you can be louder on 500 more watts then the single 15.

Add in amp efficiency, amp power, box volume, port specs, size of cabin or car interior, frequency of box.

Maybe you would then be more considered a physics major...

//content.invisioncic.com/y282845/emoticons/applause.gif.bb805d8088f72dbc2fe808c29e85fb4c.gif

Sent from my draconis using Tapatalk

 

[Jes 42 10+ year member]

//content.invisioncic.com/y282845/emoticons/lightning.gif.3313d59263b518d6d89ddcbfead237d0.gif

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[adulbrich 5,000+ posts]

Geeeeeeeeeez //content.invisioncic.com/y282845/emoticons/uhoh.gif.c07307dd22ee7e63e22fc8e9c614d1fd.gif

 

[speedyjuarez Premium Member]

Nerd fight!!!!!!!!!!!!!!

 

[adulbrich 5,000+ posts]

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[LongThrow]

he more power you try to feed a sub, the less you'll gain.
Less subs are better to reduce phase issues with large enclosures.

Elaborate on these, please?

 

[Jakerrr 10+ year member]

Is that so?
You just did an obvious post trying to prove how smart you think you are.

Just so you know you calculated a real world equation for cone area which depending on actual sub specs you can be louder on 500 more watts then the single 15.

Add in amp efficiency, amp power, box volume, port specs, size of cabin or car interior, frequency of box.

Maybe you would then be more considered a physics major...

//content.invisioncic.com/y282845/emoticons/applause.gif.bb805d8088f72dbc2fe808c29e85fb4c.gif

Sent from my draconis using Tapatalk

See: 'obvious "in a perfect world" and "all else equal" assumptions made' Surely you didn't think I was making a real world calculation. Especially with multiple disclaimers that blatantly indicate that it was approximate AND theoretical

And in regard to the proving I'm smart thing. I kind of figured there would be that one immature person that "does an obvious post to prove how socially superior they think they are"

I'm going to give you the benefit of the doubt and assume you just didn't read the post in its entirety and do you the kindness of not using a clapping emoji

 

[adulbrich 5,000+ posts]

Elaborate on these, please?

If you were serious:

As you try to feed a coil more power, it heats up. This causes the impedance to rise and is *one of* the factors that causes impedance rise. Higher impedance creates more heat, which creates higher impedance... and just keeps going up as you add power. I'm sure I'm forgetting something important with this explanation, but I'm sure someone else on the internet will jump in and correct me.

With phase issues, it gets complicated. There is more cancellation when you have more drivers. Have you heard of active noise cancelling headphones? the drivers produce a sound wave exactly inverse the one that the microphone picks up. This pretty much negates it and the noise you hear is far less audible. It's late and I just got home from a 9 hour shift, so pardon me if I didn't do a fantastic job explaining things

 

[Jakerrr 10+ year member]

Elaborate on these, please?

Drivers should be spaced close to each other if you want as much efficiency gain from increased cone area as possible. Only a single driver is perfectly coupled. And he was also referring to power compression or non linearity. It was adulbrich's post so if he wants to elaborate he can do so

nvm he did

 

[speedyjuarez Premium Member]