Exploring Real-World Subwoofer & Sub Amp Needs — Beyond the Specs

[maxliii]

I’ve been doing some reading here and on other forums about subwoofers and subwoofer amplifiers.
It’s clear that measured performance — things like frequency response, THD, output levels — tells part of the story.
But I’m curious about how people actually use them in their daily setups, and whether that lines up with what we measure.

Some examples I’ve seen in other discussions:
1）Home theater users who prioritize tactile impact over absolute low-frequency extension.
2）Music listeners who value tightness and speed in bass reproduction more than sheer SPL.
3）Gamers who want bass effects localized without overwhelming dialogue or other sounds.

I’m wondering why people primary use subwoofer for (movies, music, gaming, mixed) relax, shaking?
What measurable performance traits matter most? Extension, distortion, group delay, headroom, etc.)?

 

[Somafunk]

I just want that physical thump through my body when listening to music (electronic/techno), it’s also very useful for seeing what can be made to rattle in my house…….I removed two pictures from my hallway as they rattled of the plasterboard wall, removed bathroom/kitchen/living room door as they are of the cheap hollow type that vibrated, removed plates from my kitchen cupboard, as I live alone I mostly eat from a plastic plate or bowl anyway, only have a couple of mugs on a cut up towel in cupboard, other similar tweaks were carried out around my tiny hovel/house.

I live alone with no neighbours, prob just as well given I listen 10hrs+day

 

[DVDdoug]

Both movies and music. Music is more important to me and if it's good for music it's good for both.

Ideally, a sub will go both low (with a fairly smooth response) and loud and then it's good for music, movies, and games.

My pair of DIY 15-inch subs in rather large boxes are ported and designed to go down to around 30Hz. They will "rattle my walls" but I have nearby neighbors that I don't want to annoy too much.

I took an approach similar to most pro woofers used live and in dance clubs. With a big woofer in a big ported box you can get an efficient design that can put out strong bass you can feel in your body. Most of these "pro" woofers go down to around 40Hz which is about lowest note on a standard electric guitar and if it's strong enough you can feel it in your body.

As you "tune" a woofer to go lower they tend to become less efficient so you need more power and usually more speakers to fill a large venue with strong bass. Full size studio monitors go lower, so the normally need more power. And the space is usually smaller than a club or performance hall.

Size isn't everything and a bigger woofer doesn't always go lower or louder but physics does have limitations. A kitten can't roar like a lion.

Most people don't want big boxes and a smaller sealed box with EQ/DSP and lots of extra amplifier power can go lower and put-out enough bass to fill a living room.

1）Home theater users who prioritize tactile impact over absolute low-frequency extension.

You can probably compromise most if you are reproducing explosions and other effects. We don't really know what it's supposed to sound like and we are less likely to detect distortion.

2）Music listeners who value tightness and speed in bass reproduction more than sheer SPL.

You want smooth, fairly deep response and you might want "realistic" SPL levels that you can feel. Most music doesn't have much energy below 40Hz but some does. "

"Tight" and "fast" don't really mean anything. Floyd Toole was talking about a particular speaker known for "tight bass" and in that case he says it simply has weak, rolled-off bass. The higher the frequency and the louder the sound, the faster the driver is moving. It HAS to move at the correct speed. Woofers don't need to move fast like tweeters.

3）Gamers who want bass effects localized without overwhelming dialogue or other sounds.

Bass isn't generally directional or localizable (because of the long wavelengths). If a subwoofer is distorting, the distortion harmonics make it easier to locate. And dialog/voice frequencies don't come out of the sub.

...If a woofer goes strong and low the real world response is rarely "flat" and usually not that "smooth" because of room resonances.

 

[maxliii]

I just want that physical thump through my body when listening to music (electronic/techno), it’s also very useful for seeing what can be made to rattle in my house…….I removed two pictures from my hallway as they rattled of the plasterboard wall, removed bathroom/kitchen/living room door as they are of the cheap hollow type that vibrated, removed plates from my kitchen cupboard, as I live alone I mostly eat from a plastic plate or bowl anyway, only have a couple of mugs on a cut up towel in cupboard, other similar tweaks were carried out around my tiny hovel/house.

I live alone with no neighbours, prob just as well given I listen 10hrs+day

This is an absolutely epic post. Your dedication to the "physical thump" is on another level—you're not just listening to music, you're acoustically engineering your entire living space for it. That's true bass purism right there. Most people try to fix the room with their gear; you removed the room to let the gear sing. I have so much respect for that.
It sounds like you've achieved a level of low-end nirvana most of us only dream of. I'm incredibly curious about the gear that enables this kind of experience.
I'd love to learn more about the engine behind this operation. What kind of subwoofer and subwoofer amp are you using to achieve that "physical thump" that literally removes doors from their hinges? Was it a combination of sheer power, or did you use some specific DSP or acoustic tuning to get it just right?

 

[Chrispy]

You're thinking of a passive sub and separate amp? Most subs don't come with amp options....

Get a few of the most capable subs you can, you should be ready for anything you want to do with whatever content you want.

 

[maxliii]

Both movies and music. Music is more important to me and if it's good for music it's good for both.

Ideally, a sub will go both low (with a fairly smooth response) and loud and then it's good for music, movies, and games.

My pair of DIY 15-inch subs in rather large boxes are ported and designed to go down to around 30Hz. They will "rattle my walls" but I have nearby neighbors that I don't want to annoy too much.

I took an approach similar to most pro woofers used live and in dance clubs. With a big woofer in a big ported box you can get an efficient design that can put out strong bass you can feel in your body. Most of these "pro" woofers go down to around 40Hz which is about lowest note on a standard electric guitar and if it's strong enough you can feel it in your body.

As you "tune" a woofer to go lower they tend to become less efficient so you need more power and usually more speakers to fill a large venue with strong bass. Full size studio monitors go lower, so the normally need more power. And the space is usually smaller than a club or performance hall.

Size isn't everything and a bigger woofer doesn't always go lower or louder but physics does have limitations. A kitten can't roar like a lion.

Most people don't want big boxes and a smaller sealed box with EQ/DSP and lots of extra amplifier power can go lower and put-out enough bass to fill a living room.


You can probably compromise most if you are reproducing explosions and other effects. We don't really know what it's supposed to sound like and we are less likely to detect distortion.

You want smooth, fairly deep response and you might want "realistic" SPL levels that you can feel. Most music doesn't have much energy below 40Hz but some does. "

"Tight" and "fast" don't really mean anything. Floyd Toole was talking about a particular speaker known for "tight bass" and in that case he says it simply has weak, rolled-off bass. The higher the frequency and the louder the sound, the faster the driver is moving. It HAS to move at the correct speed. Woofers don't need to move fast like tweeters.


Bass isn't generally directional or localizable (because of the long wavelengths). If a subwoofer is distorting, the distortion harmonics make it easier to locate. And dialog/voice frequencies don't come out of the sub.

...If a woofer goes strong and low the real world response is rarely "flat" and usually not that "smooth" because of room resonances.

Wow, thank you for this incredibly detailed and insightful breakdown. You've clearly got a deep understanding of the physics and design philosophies behind great bass. You sound like a true expert, and I'm really enjoying this conversation.

I'd love to pick your brain on a few more things, especially since you've shared so much wisdom on the subwoofers themselves.

Amplifiers for Subwoofers
You've built a pair of ported DIY 15-inch subs, which likely require a significant amount of power and control. Given your expertise, what's your philosophy on subwoofer amplifiers?

Do you prioritize raw power to handle the low-end demands, or do you look for specific features like a powerful DSP or a high damping factor?

What's your take on the debate between professional-grade amps (like Crown) and dedicated home theater subwoofer amps?

I'm genuinely interested in your thoughts on this, as it seems like a lot of people get stuck on this part of the equation.

 

[Keith_W]

Re: "physical" bass, read this article on Elliot Sound: the Subwoofer Conundrum. That article is very old, and written for a different era, before measurement microphones and DSP was common - so you can ignore most of the article since these days there are much better methods than what he describes. Pay attention to section 5, where he talks about pressure mode and how different rooms pressurize differently. If you have ever tried a pair of sealed headphones or IEM's, you will know that the seal needs to be air tight otherwise you quickly lose bass. It is the same with rooms - they don't really need to be sealed, but pressure mode does depend on the size of the openings and the construction of the room itself. Indeed he does talk about having to engineer the room around the subwoofer - something most of us are unable to do.

Elliot does say that vented subwoofers are unable to produce physical bass. I have not come across this assertion anywhere else, nor am I aware of any testing that shows this to be the case. He does not provide an explanation as to why, apart from his own personal experience.

A much easier way to obtain "physical" bass is to use a bass shaker.

I have a pair of DIY subwoofers. Each subwoofer has a pair of 12" Rythmik drivers, each driven with an 800W plate amp - so 1600W per subwoofer. In my 6m x 7m x 2.7m listening room, this is enough to rattle the whole house which is a real problem. I installed self-adhesive foam strips to windows, doors, and picture frames and I was still unable to eliminate the rattle. So I played test tones and found the rattle was worst at 20Hz. This is why I have a DSP subsonic filter that removes bass frequencies below 25Hz.

 

[RickS]

Wow, thank you for this incredibly detailed and insightful breakdown. You've clearly got a deep understanding of the physics and design philosophies behind great bass. You sound like a true expert, and I'm really enjoying this conversation.

I'd love to pick your brain on a few more things, especially since you've shared so much wisdom on the subwoofers themselves.

Amplifiers for Subwoofers
You've built a pair of ported DIY 15-inch subs, which likely require a significant amount of power and control. Given your expertise, what's your philosophy on subwoofer amplifiers?

Do you prioritize raw power to handle the low-end demands, or do you look for specific features like a powerful DSP or a high damping factor?

What's your take on the debate between professional-grade amps (like Crown) and dedicated home theater subwoofer amps?

I'm genuinely interested in your thoughts on this, as it seems like a lot of people get stuck on this part of the equation.

Please excuse as apparently your Audio Company badge was issued some time ago, but what company do you represent and what do you sell?

 

[Palmspar]

Build my 3 diy sealed subs with 5x12" to be so good for music as possible, Scan-Speak Hypex based tuned 22hz-6 and 15hz-10db.
But for movies in normal rooms they are also good, they play 10hz flat 105db@MLP.
The subwoofer drivers are also used in the Beolab 90 and some Magico speakers.

 

[JohnnyNG]

I just want that physical thump through my body when listening to music (electronic/techno)

No matter how good the subwoofer is, if you don't get the midbass (let's say up to 300Hz or so) right with something other than heavy bass drivers you're leaving lots of thump and slam on the table. "Tactile" is not limited to rumbling at buttkicker frequencies, etc. My setup is music only but that tactile experience makes a huge difference and I rarely hear live music without it.

 

[Somafunk]

No matter how good the subwoofer is, if you don't get the midbass (let's say up to 300Hz or so) right with something other than heavy bass drivers you're leaving lots of thump and slam on the table. "Tactile" is not limited to rumbling at buttkicker frequencies, etc. My setup is music only but that tactile experience makes a huge difference and I rarely hear live music without it.

Mid bass is not an issue that is lacking with my system

 

[Somafunk]

I'd love to learn more about the engine behind this operation. What kind of subwoofer and subwoofer amp are you using to achieve that "physical thump" that literally removes doors from their hinges? Was it a combination of sheer power, or did you use some specific DSP or acoustic tuning to get it just right?

I was very fortunate to make a mate who was originally a sound engineer for Funktion One when we used their PA systems at our festivals/dance tents from early 2000’s to 2014, he then went on to study for a MEng Acoustic/Audio engineering at University of Salford so I have to admit I had very little say behind my setup, I told him my budget for acoustic treatment/speakers/sub and he advised/spent my money for me

I’m using two Dynaudio LYD 48 active monitors and Two Dynaudio 18s Dual Opposed Active Subwoofers , 19 1200mm x 600mm GIK acoustic panels/bass trapping that were moved around/hung from nails till the optimal position was found in my 4.6m x 3.6m x 2.4 room, then fixings put in place and room was decorated, I only have the one chair in the sweet spot in room (a recliner as I have spms) so he swept my room with his mics/software and moved subs/speakers around till I had the best compromise for positions and finally PEQ applied through Roon to deal with the room modes.

It’s not perfection as I’m sure there are options that would improve the sound but it’s the best I could do for my £6k (ish) budget to see my days out.

I’m listening to electronic music for 90% of the time so I obviously prefer a dry/very direct sound, RT60 times are .29 to .32 from 400hz through to 3.5khz (could be wrong bout this?).

Does me fine, but if someone was to offer me a pair of Kii threes I’d take them