in home 8 inch woofers

[daproducer]

ok i have 2 technics sb-l51 subwoofers with bulit in mids and highs. i have slots for 2 more i bought the other two and was just wondering if it would have as much bass as it did with only 2?

btw new build coming 3 12" pioneers 2400 watts in the passenger seat of my s10

[Sanitarium]

ok i have 2 technics sb-l51 subwoofers with bulit in mids and highs. i have slots for 2 more i bought the other two and was just wondering if it would have as much bass as it did with only 2?

Given nothing else changes, double the cone area should net you 3 db increase with the same wattage feeding the 4 that once fed the 2.

.. in a perfect world anyways.

[daproducer]

Given nothing else changes, double the cone area should net you 3 db increase with the same wattage feeding the 4 that once fed the 2.

.. in a perfect world anyways.

thanks but

that system is history except for the radio anyway

i now have 2 12' sb-l75 and 2 bose 8" woofers

u have a system in ur household

jw?

[audiofanaticz]

Given nothing else changes, double the cone area should net you 3 db increase with the same wattage feeding the 4 that once fed the 2.

.. in a perfect world anyways.

Never the case. Even in a perfect world

You dont have to agree to it tho.

One of the biggest problems on car audio forums is that people try to apply the dynamics from one environment within another. Classical horn theory, transfer theory, quarter-wave theory, standing wave theory, etc... I can see how this could happen, as just about every book and web site out there that tackles the dynamics of sound is written from a home audio / infinite environment perspective. Exporting these principles into contained environments (i.e. vehicle cabins) is kind of like attempting to build a flying machine on Mars by reading about the design principles behind the flying machines on Earth.

What I'd like to attempt here is to illustrate the problem with the theory that doubling your power results in a 3dB gain. This theory was never intended for low efficiency drivers, high gain environments, and high current applications. As most other theories mentioned above, this one has it's roots elsewhere. Think of infinite environment low current sound reproduction systems and 1 meter on-axis benchmarks where the first watt is always the most important watt... you may begin to see why this theory falls apart when applied to car audio.

Let's take a relatively inefficient woofer with a 1W sensitivity of 80dB and start doubling the power, each time resulting in a 3dB increase:

You see what's happening? By this principle, over a million watts would be required just to achieve 140dB. More importantly, take a look at the distinct curvature of the plot. Since the (W*2)=(dB+3) formula is fixed, so is the nature of the plot, no matter where we start in regard to power or efficiency.

But let's improve our odds by starting out with a subwoofer system that's a whopping 100dB efficient at 1W:

We still need about sixteen thousand watts just to break 140dB (and well over a hundred thousand watts for an additional 10dB.) See the problem? Visually, we can isolate it to the vicinity of where the curve begins to bend into a near-flat line. Suffice it to say, this is an extremely misleading and erroneous way to look at the effects of power on the SPL product, especially once we've gone several orders beyond the magnitude of ~8, and even more so at the point where, mathematically, the gain to raw power ratio is virtually unchanging.

I hope this sets off a light bulb over some heads