Are Infinite Baffle Subwoofers Good? (Explained)
Finding a subwoofer that delivers the desired punch is critical in pursuing the ultimate bass. And often, the only way to achieve this is to set it in IB. But are infinite baffle subwoofers any good?
Infinite baffle (IB) subs top the list for bass. They are designed to produce extremely low, clean, uncolored bass. IB subs offer significant advantages because this audio technique performs very well in multiple settings.
But compared to other types of audio technology, are IB subs better? Stick around as we explore why numerous sound experts acknowledge that this speaker design could give good results.
Are Infinite Baffle Subwoofers Good?
The performance of IB subwoofer systems doesn’t come anywhere close to being a fair comparison with other types of audio technologies. It is superior to most decade-old sonotube subwoofers, which are no pushovers!
A subwoofer with an infinitely large baffle can accomplish the necessary separation minus the cancellation compared to an open baffle system.
Typically, infinite baffle systems are used only for lower bass frequencies because they affect sound staging. It is widely believed that when the enclosure volume in which a subwoofer speaker is mounted exceeds its Vas, the driver is considered to be in an infinite baffle.
That is why drivers that work well in IB setups can be tricky to find, but the results are rewarding. Stick around; we’ll talk about this a bit later.
How Does Infinite Baffle System Work?
The infinite baffle system could be a closed speaker box. The loudspeaker box is typically made of reasonably thick and rigid boards. Internal sound-absorbing material and panel damping is also used in the box.
The sealing aims to minimize the panels’ vibrations and ensure as little sound as possible emanates from the cabinet. The sound deadening wadding also plays these roles.
You can find some high-end loudspeaker infinite baffle cabinets crafted from cavity panels filled with sand, metal, or concrete. But most domestic-use speakers are made from high-density wood products. The important thing is that it’s made of high-quality material.
Since there’s an infinitely large boundary between the front wave and the rear wave coming off the driver/drivers, an area of isolation is created. The function is to absorb the rearward sound wave.
The sealed air inside the back of the cabinet acts as a “spring” that helps return the speaker to its resting position, which enables the use of heavier, longer-throw drivers. It also influences an excellent transient response. It may, however, result in lower efficiency, requiring more amplifier power for a given output volume level.
Infinite baffle subs deliver the perfect low frequencies – the answer for anyone who’s after chair-shaking, chest-pumping vibrating sounds. It’sIt’s the best bass you will ever experience.
How Many Drivers Do I Need?
As a general rule, use multiple drivers if you want it to play loud and low. An IB subwoofer is critically dependent on the drivers: So choose wisely. Ensure the specs are compatible with the setup.
Generally speaking, you only need to know the displacement of one driver to determine the number of drivers you require, regardless of type or size.
In a standard-sized listening room, an average of four drivers for an IB system will perform admirably. The output is often limited by the thermal capacity of the driver’s motor system.
According to “The Cult of the Infinitely Baffled,” there is a formula we can use to calculate the volume of displacement:
Volume of displacement (Vd) = (2 x Xmax) x Sd.
For instance, if you are after the recommended 12 liters of displacement with an Xmax of 12.5mm and Sd = 466 sq. cm:
Vd = (2 x 12.5)mm x 466 sq.cm
2.5cm x 466 sq.cm = 1165cc (The Xmax figure is converted into cm for uniformity)
Then convert into liters: 1165/1000 = 1.65 liters per driver.
Therefore, to achieve your desired 12 liters of displacement volume, 12/1.65 = 7 drivers.
But unless you have money to spend on 7 amplifier channels, your best bet is to use 8 drivers wired on a mono, bridged amp. or connected series-parallel to run 4 per channel.
The Vd increases (8 drivers x 1.65 liters = 13.2), but the discrepancy doesn’t significantly impact the sound.
However, due to differences in pricing and performance, most people will consider other factors, such as:
- Size of the room.
- Type/ brand of the driver.
- Size of the driver.
Most people opt for four 18″ in rooms above 5,000 cu ft and two if it’s a smaller room. You can also use four 15″ drivers for IB in a small space.
Whoever is after a better bass response should aim to reduce the resonant frequency of the IB sub. An excellent way to achieve this is using a larger loudspeaker cabinet. Increasing the volume of the box means less air is compressed.
However, you’ll require more building material making the loudspeaker box heavy and visually bigger. But if you don’t mind the weight and aesthetic effect of a large cabinet, go right ahead. You must also consider where to mount the subwoofer as big loudspeaker boxes aren’t suitable just anywhere.
Mounting Options
In a room scenario, the drivers are mounted in such a way that they share a common boundary between the listening room and adjacent space. This is why you’ll find most people prefer to set up the infinite baffle subwoofer in a place with ample space.
In closed spaces like automobiles, speakers are typically installed in the headliner, doors, rear package trays, and dash, making them IB. However, if the speaker is housed in a specific ported or sealed enclosure within the rear package tray or door, this is not considered an infinite baffle.
The most prevalent mounting option, however, is a cube. The cone’s rear is trapped within the sealed rear portion of a cabinet while the front of the cone faces the exterior.
In a home setting, some suitable spots to place IB subwoofers include:
- In the room wall, with speakers coming through the wall into an adjacent, seldom-occupied space such as the attic or garage.
- Next to a room that shares a common wall with the listening area.
- Through the floor, using an unfinished basement or crawl space below as the enclosure.
- In the ceiling, with the back of speakers coming up into the space above.
Are Attic Mounted IBs a Fire Hazard?
Well, not really. Instead of a fire, the driver’s voice coil will melt due to DC received from the defunct amplifier. It creates an open circuit that shuts down the speaker. The ”plastic burning” smell does not signify a fire.
If you still stand unconvinced, there’s no harm in taking precautions. I think a smoke detector installed beside an attic-mounted sub would be an excellent solution.
The Bottom Line
If you’re considering building your own IB sub, ensure you familiarize yourself with the basics to get it right. Now that you know the advantage and performance of IB subwoofers, you know what to do with the sub driver tucked away in the garage, gathering dust.