What Are Horn Subwoofers?

If you are a true bass fan and want something that can play on a larger scale at concerts. This can only be achieved by a lab horn subwoofer. Tom Danley provided the conceptual idea for these subwoofers as the first DIY lab horn subwoofer.

And if you want to make one by yourself, or looking for expert advice regarding lab horns, then this is the article for you.

What Are Horn Subwoofers?

folded horn subwoofers

Tom Danley built these subwoofers, but he didn’t actually build them. He just created the concept design, which was freely given to the public and was influential as the first DIY laboratory horn subwoofer.

The horn subwoofer improves the coupling between the speaker driver and air. Although it may appear to amplify the sound, properly designed horns have the effect of making speaker cones transfer more electrical energy from the voice coil into the air. This makes them appear more efficient.

This subwoofer is heavy and can be used as four enclosures that are connected in a “cube” shape. It has a frequency of 32 Hz, which increases the effective mouth size.

The Lab Sub can play between 80 Hz and 28 Hz in groups of up to four. The Lab Sub is not intended to play beyond 80 Hz, so it has a very low output of 85 Hz.

The design by Danley was a 45″ x 45″ x 22.5″ (114 cm x 114cm x 57.1cm) snail-shell folded horn subwoofers with two 12-inch drivers at its horn throat.

Eminence, an American speaker firm, designed a 12-inch driver to meet these requirements: the LAB12.

There are many subwoofer types, but the most common ones are:

The majority of horn subwoofers from the past used a folded design. This allows for a longer horn path while also reducing the size. Modern designs tend to be tapped. High-efficiency horns produce more power with less output. When multiple of horns are connected, they have a 3dB gain for every doubling power. However, they must be run at a lower frequency and with increased directivity. This design reduces resonance and nonlinear distortion.

Horns are not tubes. They taper. The cross-section of the duct or tube increases in size. The horns, also known as couplers, act as an impedance transformer or coupler because of their flare or taper. They smoothen the transition between the cone’s high impedance and the air’s low impedance.

We’ll be looking at both types and discussing how they work.

What Are Lab Horn Subwoofers?

Tom Danley created these subwoofers; he didn’t actually build them, but he designed the concept design that was distributed free to the public. It proved to be as influential as the first DIY laboratory horn subwoofer.

It is a subwoofer that weighs in at a heavy 3.5 lbs.

Lab Sub is intended to be played in fours, ranging from 80 Hz up to 28 Hz. It is not designed to play at 80 Hz and has a very low output above 85 Hz.

Danley created a 45″*45″*22.5″ (114 cm 114cm 57.1 cm) bivalves folded-horn subwoofer, with two 12-inch drivers at the horn throat.

Eminence, an American speaker company, designed the unique 12-inch driver, the LAB12, to meet the needs.

Is there anyone who has actually constructed a subwoofer for a lab horn?

The LABhorn is a DIY project, so it’s not surprising there are at most five versions of Tom Danley’s baby. Each one will be examined individually.

Version 1:

Tom drew the first version on February 17, 2002. However, he didn’t actually create it. Instead, he provided the concept design and sketches to someone else to construct.

Version 2:

There’s also the second version, which Brian Fehrman created and Tom accepted. This is where the sub-is built. It is more detailed and professional. It was used to build the first LAB horns recorded.

Although there are many modifications to Tom’s original design that can be made, they do not make a significant impact on the horn flare.

At the time, we were all still in “horn learning”, and many people noticed differences between the two versions of the “ideal” Horn.

Many believed that 3/4 inch plywood was different from 18mm plywood.

During this phase, Peter Sylvester created a third LABhorn version using dados, biscuits, and that “fixed” both Brian and Tom’s versions.

Version 3:

Peter made one LABhorn and then made “corrections” before building another. Peter said that there wasn’t any difference in his cabinets from the results reported by Al Limberg (Too Tall) and others.

Although he didn’t “improve” any important acoustic features, Peter’s box is one of the strongest. His website is a source of inspiration for many, thanks to his drawings, images, and explanations.

Version 4:

Jeremy Bridges’ version of the scene was a failure because his drawing has too many flaws that someone without enough experience can spot.

Although it claims to be a “metric” edition, the key dimensions are still in English. Sometimes they are rounded to the nearest inch.

Most of the drawing was done in the third-angle projection, but Jeremy illustrated one part of the nose flare using the “Dutch projection” (first-angle). Horizontal flare #1 is missing a few lines that should have been dotted.

Version 5:

Brad Litz’s version 3 represents a major revision. This version is for home theatre use.

His sacrifices may have made his version less useful for professional sound and more like fine furniture than a ” roadie-proof ” speaker.

He increased the compression ratio from 2 to 3 and put a strain on the speaker cone. We will not know if the LAB-12 can withstand stress until the version is built.

His website contains 3-D cad files and detailed part drawings. You will need a 3-D cad in order to view the information. Horn resp was used to model the adjustments, and he seemed pleased with the results.

Tom’s design was a huge success. The Horn was not affected by any of the “improvements” made by builders. All horns work perfectly with a one or two-piece baffle, 3/4″ to 18mm plywood, a 5 1/2″ corner brace or an 8″ corner brace, and various access covers.

Many others attempted to make lab horns using Danley’s designs. This can be very simple if you are familiar with cutting and combining wood.


Horn Subwoofers can increase sound volume by matching the acoustic resistance of outgoing sounds to the air. Hearing horns amplify sounds when waves are reflected into narrower areas, increasing the sound pressure reaching the ears. 

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