Should You Put A Down-Firing Subwoofer On Carpet or Concrete Floor

Norvan Martin

You can place a down-firing subwoofer on the carpet without any issue. The fact is that even thick carpet has little effect on bass waves, they simply pass straight through, only higher frequencies are dampened, and therefore sound ‘muffled’. 

Although carpets will absorb some of the bass and reduce its intensity, it is still better to place the down-firing subwoofer on the carpet than on hard, smooth surfaces like concrete. Concrete will reflect sound directly and may cause a boomy and unpleasant listening experience.

Another issue is that the concrete will kill the sub’s vibrations. Moreover, subwoofer frequencies are omnidirectional so there’s no need to point them down on hard surfaces like concrete. 

What Is a Down-Firing Speaker

Down-firing subwoofers are designed with speaker drivers angled downwards that push the soundwaves they produce toward the floor.

Down-Firing Subwoofer

The sound waves are then reflected from the floor to give a stronger sound and a better rumble effect for games and movies.  

Should I Place My Down Firing Subwoofer On the Carpet?

We already discussed that placing your down-firing subwoofer on your carpet shouldn’t be a major problem because the carpet will simply allow the waves to pass through. 
Down-Firing Subwoofer On Carpet or Concrete Floor
This means that placing your down-finding subwoofer on a caplet will not improve its performance. However, it is a good way to decouple the sub from the hard floor underneath. 

Should I Place My Down-firing Subwoofer On Concrete?

As we have mentioned before, placing your down-finding subwoofer on concrete will probably cause an unpleasant experience.

This is because the concrete floor will reflect the sound directly and then all these reflected soundwaves will cause an unpleasant listening experience. 

An easy, simple, and cheap fix for this is to place some sort of soft material under the subwoofer to reduce some of that unpleasant reflection. You don’t even need to do anything fancy. You could even use a terrycloth dish towel under the sub to tighten up the sound!

Should I Place My Down-firing Subwoofer On Concrete

Another major issue with placing your down-finding subwoofer on hard concrete is the lack of vibrations. If you are someone who enjoys the vibrational experience, then placing the sub on hard concrete will kill that completely. 

If this is very important to you and you definitely want to keep the subwoofer on the concrete floor, your only solution to getting that tactile experience in the floor back is to build a floating floor often called a wooden subfloor over your concrete floor.

That might sound very expensive, but it can be done relatively cheaply. You can even do it yourself as it will only involve wood, screws, some carpet, and some other minor items.

Another simpler and cheaper fix for this is to use bass shakers like the AuraSound AST-2B-4 Pro Bass Shaker.

Don’t however be tricked by anyone telling you more subs will do the trick. Remember that if you’re trying to move thousands of lbs of heavy concrete, it won’t work!

Advantages Of Down-Firing Subwoofers

Among audiophiles, the controversy over front-firing vs. down-firing subwoofers is heated.

  1. Weight Advantage: An advantage of gravity is that the driver is on the bottom. When the driver is at the bottom, it also drags along its magnet.
    Because the driver is on the bottom, it functions as an anchor for the subwoofer and reduces the likelihood of it shaking.
  2. Protection for subwoofers: Subwoofer protection does not refer to a physical cover, design, or piece of equipment. Subwoofer protection refers to the notion that by facing your subwoofers downward, you are indirectly protecting them from environmental influences.

Disadvantages Of Down Firing Subwoofers

  1. Music Instrument Replication: The sound of musical instruments is messed up by a downward-facing subwoofer.
  2. When sound waves are directed downward, the energy is absorbed by the floor rather than your ears. When musical instruments are present in the recording but are delivered through the subwoofers, the sound quality degrades by a factor of two.
  3. Shakiness: When a down-firing subwoofer box is installed within a room, it creates a domino effect.
    The shaking of the subwoofer box sets off the domino reaction. And because the floor is directly affected by the shaking, the floor begins to shake as well.


Do You Need a Down Firing Subwoofer?

If you already have a subwoofer and you’re thinking about purchasing a down-firing subwoofer, it is important to assess the effectiveness of the subwoofer that already exists prior to getting the down-firing sub.

Should You Put A Down-Firing Subwoofer On Carpet or Concrete Floor

The best question to ask yourself is if you require better bass performance and overall vibrations in your home theater. If you want better bass performance and more vibration from your sub throughout the room, getting a down-firing sub is probably a great idea. 

The next step is to ensure that the down-firing sub that you are purchasing matches the specs of your amplifier. Otherwise, you will risk under-powering or over-powering your sub. 

Should I Place My Down-firing Subwoofer On Isolation Pads?

If you decide to place your subwoofer on hard concrete or hardwood without any carpet and you want to reduce vibrations, then you should use isolation pads to isolate your subwoofer from the floor.

Should I Place My Downfiring Subwoofer On Isolation Pads

It will make an audible difference as well but is mainly to decouple the sub from the floor.

A quick recommendation for a good subwoofer isolation pad is Auralex Acoustics SubDude. This is a very popular and very good isolation pad, but it is costly.

You should use an isolation pad regardless of what surface the sub was on. They will almost always improve bass performance if the floor type is carpet, wood, concrete, or carpet. 

How To Position Down Firing Subwoofers?

Most down-firing subwoofers are placed on soft surfaces such as carpets. Although carpets will absorb some of the sound, it is better to place the sub on a carpet than it is on hard, smooth surfaces, as these will reflect sound directly and cause an unpleasant listening experience.

Positioning Down Firing Subwoofers

Additionally, since the low frequencies that subwoofers emit exclusively are omnidirectional, it is unnecessary to point them directly at a hard, reflective surface.

You could also place a small piece of carpet or another soft surface directly underneath it to absorb some of the sounds. This will ensure you don’t bother your neighbors with the rumble of movie noises from your home theater.

Why Are Subwoofers Unaffected By Carpets?

Simply put, subsonic wavelengths are so long that they are not interfered with by things as negligible as carpet and simply pass right through. A carpet would need to be 4-6 inches thick to even begin to have any effect.

If the depth of your carpet is less than say 16 inches (which would create absorption at frequencies above 200 Hz), then you should be just fine.

Only very thick, absorbent structures can affect subfrequencies. This is why people have 1.5m deep rear wall absorbers. 

Subwoofers With Plinth Placement on Carpets

What about placing your subwoofer on the carpet if it doesn’t have plinths? The fact is, if it’s a powerful enough subwoofer, you could in theory end up with a pressure build-up. 

While you may this won’t be a major problem, the fact is, if the air backs up and moves too quickly, it becomes turbulent and the movement of the air will be audible.

How To Improve Subwoofer Sound Output On Carpet?

If you decide to place your sub on the carpet, there are a few things you can do to improve its performance.

  1. Firstly, just make sure it sits on spikes or cones that go all the way through the carpet and bite into the hard floor underneath.

2. Another option is to put a hard platform on the carpet. If you decide to do this, you need to be careful and consider the following:

  • Make sure the surface is at least 16″ larger than the sub all the way around. This way, you ensure that the waves are launched properly.
  • It should be heavy enough with the sub on top of it such that it compresses the carpet so that if someone steps on the edge, it won’t tilt.

Should I Place A Tile Below The Sub On The Carpet?

Many people will suggest that you place a tile under the subwoofer when placing the sub on the carpet. There may be some benefits to doing this, but there are disadvantages as well. 

For one, you won’t have to worry about spikes damaging your hard floor under the rug. On the other hand, however, you may not have the best bass response that you would expect because the surface may be too reflective, just like a concrete floor. 

A better option may be to use another hard surface that is not as reflective such as an MDF board as a base plate.

You could also use granite. In this case, you could even use a 3cm thick slab of granite and then use silicone to attach feet to the bottom of the sub. 

Will My Down Firing Subwoofer Affect The Neighbours?

For one thing, placing a sub on the carpet will certainly not change the effect it will have on your neighbors because the bass waves will pass all the way through the carpet. 

Is Driver Space Important For My Subwoofer?

Apart from the type of floor you place the sub on, people often also wonder about the driver space, meaning the space between the subwoofer driver and the floor.

down firing subwoofer driver space

However, the fact is unless your carpet actually touches the driver and physically restricts its movement it won’t make any difference to the sub’s performance.

This is because subwoofers are point source radiators, radiating bass in all directions. This is different from tweeters that fire along a narrow axis and so can be affected by proximity to surfaces. 

What Are The Best Subwoofer Placement Options?

Now that you have made your decision about what type of floor to place your carpet on, the next decision is where in the room to place the sub.

Most people place the sub in the middle of the room, some in the corners, and others place their sub behind the couch.

While placing the sub behind the couch is a great idea for a front-firing sub, it’s not so much of a good idea for a down-firing subwoofer because you won’t enjoy the benefits of the vibrations.

On the other hand, down-firing subwoofers are designed to be close to the listening area. As such, you can place it behind your couch or seat or next to the sitting area, but this won’t improve vibrations, just the overall bass response that you will experience.

Should A Subwoofer Be Placed On The Floor?

The output of a subwoofer can be increased by placing it in the corner of a room, making it sound louder. A subwoofer (particularly a wireless subwoofer) has the advantage of being able to be placed practically anywhere on your floor.


Many people worry about down-firing sub on the carpet and on concrete floors. While the sub won’t be affected by the carpet, it will certainly be affected by a hard concrete floor.

However, there are some measures you can take to avoid an unpleasant listening experience. In any case, if you want to know for sure, just experiment and find out!

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Norvan Martin is the founder of He is a professional Electronics Engineer and is passionate about home theater systems and AV electronics. BoomSpeaker was created as an online hub to share his knowledge and experiences as it relates to home theaters and home audio electronics. My email: [email protected]  Connect on Pinterest and Linkedin