Shattering Rediculous Bass

We’re talking today about big bass that can hold a presence at a Sound Pressure Level (SPL) competition.

The trick to SPL is a combination of three things:

1- Choice of subwoofer (Driver)
2- Choice of enclosure (Box)
3- Amount of power (Wattage).

If we take the first item and scrutinize it, then a good SPL subwoofer will be designed in a way that allows it to reach peak pressure levels at a single dedicated frequency, in a signle dedicated enclosure, playing the perfect track, and measured at exactly the right place.

One of the things to consider here are the mechanics and electrics of the speaker …

A speaker with a larger area (such as a 15 inch subwoofer compared to a 12 inch subwoofer) will be able to move more air per stroke. The more air we can move, the more air (sound) pressure we can create, and the higher the SPL.

At the same time different speakers have different stroke lengths (how far the speaker moves forwards and backwards in a bass hit) known as xMax (maximum excursion). A speaker with double the xMax will move double the air volume per stroke compared to a similar diameter speaker.

Thirdly, speakers have a resonant frequency FS where the speaker is most happy to move at its maximum stroke and can make the most out of it size performance. For example a speaker with a resonant frequency of 50hz when coupled with a box enclosure that allows it to play at 50hz will be able to produce 25% more air volume in a second than a similar driver with a resonant frequency of 40hz playing at 40hz.

Obviously if we’re looking high quality bass (at all frequencies) we would not want to amplify the resonance characteristic of the driver… but if you’re looking for that single high pressure competition winning bass hit, then milking every advantage that you can out of your speaker becomes necessary.

Because it’s complex to measure these things and simulate them, engineers have come up with a standardized measure of SPL performance for a speaker called sensitivity. Sensitivity is typically between 80 and 100 dB @ 50hz @ 1 Watt @ 1 meter.

What this means is that a speaker with a sensitivity of 85dB will create 85 decibels of sound pressure when playing a 50 hertz sign wave and powered with 1 watt of power measured at a standardized distance of 1 meter away.

Based on this information, I have chosen to showcase two drivers here that I would gladly take into competition…

Pyle PLD15WD

Custom Titanium Moulded Poly Cone
Custom Grooved Specially Treated Rubber Surround
Diamond Cut Aluminum Die-Cast Basket
Dual Stacked Magnet Structure
Chrome Mesh Magnet Vent
2.5” 4 Layer Dual Voice Coil
Moulded Plastic Gasket
Spring Loaded Wire Connectors
4000 Watts Peak Power
Magnet Weight: 2 x 100 oz.
Nominal Impedance: Dual 4 Ohms
Fs:20,
Qms:5.03,
Qes:0.89,
Qts:0.66,
Vas (Cu ft)8.689
SPL: 92 dB
Overall Diameter: 16”
Mounting Depth: 6.40”

What’s great about this driver is that it combines higher power handling (4000 Watts at peak) WITH high sensitivity over 90dB (92 dB to be exact).

Let’s take this subwoofer, and mount it in a 9 cubic foot enclosure, powered by a 4000 watt amplifier, and ‘wall loaded’ playing upwards and reflecting into the passenger compartment reflected off of the glass hatchback…

Measuring the resulting sound pressure level about 6 feet away in the driver seat will result in an impressive 126 dB SPL!

This is 4 times louder than the maximum recommended safe listening level of 110dB and if you listen to it straight for more than 6 minutes it WILL cause hearing loss… (not that you will be listening to it at full blast from your driver seat… ) but when competition comes around, or you and your friends are having a sound off… this thing will shake the earth.

Note: Click here to get your Pyle PLD15WD 15 inch SPL competition subwoofers, get pavement-cracking BASS, and save 115 dollars off retail!

Technorati Tags: 4ohm, dB, DVC

Related posts:

1. 12 inch subwoofers for big bass
2. Feel the power of 15 inch subwoofers

Here’s one great example of a rear seat delete. This is a fiberglass enclosure where the rear seats used to be and the whole arrangement with a single center mounted subwoofer is pretty ominous. The center subwoofer is a single Rockford Fosgate T2 15 inch subwoofer.

The central placement of the subwoofer and the implicit lettering on the aluminum cone “POWER” amplifies it’s presence. On each side of the woofer is a large 5″ bass port aimed directly towards the back of the driver and passenger seats for a maximized effect.

Below the subwoofer, the owner has mounted a digital volt meter to monitor the car’s voltage with every single hit of the RF-1000 , 1000 Watt amplifier. I personally would rather use a purely analog gauge or a needle based gauge to reduce the amount of ‘averaging’ in the voltage reading… By doing so, you’ll be better able to see how low the voltage dips (if it does) during a bass hit and you can fix that problem, if it exists, with a capacitor for power storage and larger gauge wiring for faster current delivery.

What’s really cool about this subwoofer is that Rockford Fosgate has engineered it as a low hitting subwoofer optimal for a vented enclosure. RF does not recommend using this subwoofer in a free air installation or in a sealed box. But rather, placing this subwoofer correctly in a properly designed (fairly small sized box) can hit frequencies as low as 36 hz with authority from a tiny 2.25 Cuft box. This is exactly the power and uniqueness of 15 inch subwoofers as smaller subwoofers will not be able to generate that much sound (and thus, that much feel) at such a low frequency. To hit this tuned frequency (Fb) of 36hz, RF recommends a long (17″) and wide (6″) bass port to help the box breathe and resonate.

This dual voice coil sub is no lightweight, with a total weight 50lbs and a driver weighing in at 304 oz with a dual voice coil triple stacked driver, the sub is rated for 1000 watts RMS and 2000 watts at peak.

Note: Find out more about how you can feel the power of 15 inch subwoofers, and save over $500 off retail.
Note: Click here to get your own 7 color voltage display gauge and save $46 dollars off retail.

Technorati Tags: 4 ohm, Aluminum, DVC, Vented

Related posts:

1. 12 inch subwoofers for big bass
2. 15 inch SPL competition subwoofers