The (dubious) usefulness of subwoofers - opinions needed

[FeddyLost]

Hello everyone.

I need to get some opinions from experienced people.
I'm sluggishly think about augmenting my stereo (currently) setup with at least one decent subwoofer. Maybe 2 subs for DBA or 2.2.
My main concern is simple - will it really make enough difference to call this upgrade with all expenses and hassle and calibration work justified?

I mean, currently I have PSI A-25 mkI with free field F6 of 32 Hz and all distortion at 90 Db/m below 2,5%.
My room is small, and first axial mode is around 37 Hz, so below +-1,5 Db flat FR shelf of speakers I have pressure zone.
Listening SPL usually significantly less than 90 Db/m per speaker, so typical distortion is below noise floor.
With some installed acoustic treatment and AOI feature of PSI I don't really feel any issues with bass reflex port (like slow and boomy bass).
I don't really care about 20 Hz and would like to have faster, cleaner and tighter bass if that can be achieved with sealed subwoofer(s) support. (I like happy galloping triplets and blastbeats very much and prefer dry sculptured bass if record have it... ). Flat 20 Hz will be kind of bonus, but it's definitely not a goal.
With all these data I'm really in doubt if subwoofer support will have any real profit over i.e. membrane bass traps for RT reduction (which definitely works well).

Would like to know opinions about that and real worl experience if someone have such...

 

[FrantzM]

Hi

Integration of subwoofer with any speakers is tricky, call it, difficult. It may take months, require measurements and learning how to interpret them. Cost is not an issue for measurements, $100 for a good microphone, whatever you decide to donate ($0 to ??) for the spectacularly powerful REW software. Learning how to use REW and the microphone, using the measurements for integration will not be easy...
Finding the right crossover appliance is not trivial .. Once you get past these hurdles. subwoofers bring a lot on the table, Any speaker in any room, the use of properly and correctly integrated subwoofers significantly enhance the quality of the reproduction. I consider subwoofers: mandatory. Not a matter of getting to 20 Hz, simply that, IMHO accurate music reproduction, requires subwoofers, regardless of the intrinsic capacity of the main speakers.


Peace.

 

[Elk]

As you surmise, it may not be worth your while. The PSI A25s are a 3 way speakers and won't benefit much from the reduction of frequency modulation in the mids as much as a 2 way speaker would, nor is low frequency response much of an issue.

However, adding sub(s) will allow you to control the room's eigentones, or standing waves, at the listening position, or listening positions, better than the PSIs alone. One sub is useful if there is only one sweet spot needed, at least a pair at mid points on opposite walls if even bass throughout the room is desired. DSP added would put the icing on the cake.

 

[Hipper]

I've no experience with subwoofers or membrane bass traps (I presume you mean the ones targeted to a particular frequency?). What I have experience of is large absorbent bass traps and an equaliser.

Even a large number of absorbent broadband bass traps will not solve all the bass issues. I needed to use EQ to complete the task. What the bass traps do do, spectacularly well, is reduce decay times and I think this makes a bigger difference then I appreciate. I posted some REW graphs here, post 60:

https://www.audiosciencereview.com/.../share-your-in-room-measurements.13540/page-3

This will give tighter bass.

I did look into membrane bass traps but first I decided to try to find exactly where I should place them by playing the naughty frequency and listening and measuring where it was loudest. I was unable find the locations and so didn't buy them.

 

[sigbergaudio]

I doubt anyone will look back after getting properly integrated subwoofers in their setup, but it will require some time and knowledge to properly setup and integrate. There are however products to help you with that, either having an amplifier with built-in room correction, or stand alone solutions like the Antimode 8033. And ideally you should have the ability to highpass your speakers.

 

[Slayer]

First off a well set -up and integrated sub or subs will be beneficial to almost any system. Dont get caught up on the ported vs sealed sub debate. A modern ported sub can play just as fast and tight as a sealed sub. Ported can actually offer more benefits, being able to play the same amount of spl using less power.
A sub is not or should not be thought of as bringing that boomy bass. That really only happens with low-end low quality subs, better known as one-note wonders. If this is what you have heard or are concerned about hearing, it really only happens in systems that are not properly set-up, or some young person who is into that and thinks that's how it should sound.

A properly set-up sub or subs will be a huge sound improvement. One- you can reduce the low frequencies required going to the main speakers, which in turn will take a huge amount of stress of the main speakers amplifier.
Most importantly, when set-up and dialed in correctly, bringing subs into the mix, will help anchor in the soundstage, staging will be deeper, darker and wider. It will also bring out more clarity to the main speakers. The plucking of guitar strings will have more realism, piano key notes will carry more weight and so on.

In my 2.1 system, I run 3 subs, while a little time consuming to dial into perfection. It Is probably one of if not The Best addition to the system.

 

[levimax]

What kind of music do you listen to? For a lot of music your current speakers will work fine.... for EDM or similar you absolutely need subs to get the full effect.

 

[jtwrace]

http://www.gedlee.com/Papers/multiple subs.pdf

 

[jtwrace]

 

[Thomas savage]

Be happy dont bother .

 

[Beershaun]

I have subs for each of my systems and I won't go without them anymore. I'll go further than the folks above and say even a simply integrated sub brings a big improvement in low frequency volume and balance. It's also relatively cost effective to get a high quality powered sub into your system vs. trying to get the same from a "full range" speaker. Being able to dial in the power/volume separately for low frequency is really a nice improvement since our hearing is much less sensitive at those levels. Also it gives you much more flexibility to place the speaker in the best spot in your room for those frequencies.

 

[axbarker]

First off a well set -up and integrated sub or subs will be beneficial to almost any system. Dont get caught up on the ported vs sealed sub debate. A modern ported sub can play just as fast and tight as a sealed sub. Ported can actually offer more benefits, being able to play the same amount of spl using less power.
A sub is not or should not be thought of as bringing that boomy bass. That really only happens with low-end low quality subs, better known as one-note wonders. If this is what you have heard or are concerned about hearing, it really only happens in systems that are not properly set-up, or some young person who is into that and thinks that's how it should sound.

A properly set-up sub or subs will be a huge sound improvement. One- you can reduce the low frequencies required going to the main speakers, which in turn will take a huge amount of stress of the main speakers amplifier.
Most importantly, when set-up and dialed in correctly, bringing subs into the mix, will help anchor in the soundstage, staging will be deeper, darker and wider. It will also bring out more clarity to the main speakers. The plucking of guitar strings will have more realism, piano key notes will carry more weight and so on.

In my 2.1 system, I run 3 subs, while a little time consuming to dial into perfection. It Is probably one of if not The Best addition to the system.

After many years I started the subwoofer journey and wished ~I had started earlier. I now have an SVS SB 4000 and an SVS Ultra 13 upgraded operated sealed. I listen to 2.2 music and it brings a wealth of additional information, BUT - must be set sensitively, and listened to over time. Wring settings and its a backward step. Good settings and its a different world.

 

[Slayer]

One thing i should have added is, do not buy a sub without having adjustable phase control. The zero or 180 switch is a joke. I can't emphasize enough how important it is getting the phase set correctly. None of my subs ended up being Zero or 180, so i just want you to understand how important it is to have an adjustable phase control.
Proper phase is far more important than worrying about sealed vs ported, in achieving as you said faster, cleaner and tighter bass.
Make the plunge and go for it. I think you'll be more than happy once you do.

 

[sigbergaudio]

One thing i should have added is, do not buy a sub without having adjustable phase control. The zero or 180 switch is a joke. I can't emphasize enough how important it is getting the phase set correctly. None of my subs ended up being Zero or 180, so i just want you to understand how important it is to have an adjustable phase control.
Proper phase is far more important than worrying about sealed vs ported, in achieving as you said faster, cleaner and tighter bass.
Make the plunge and go for it. I think you'll be more than happy once you do.

This depends on your setup. If you have a sealed sub and sealed speakers you are less likely to have phase issues, and this also depends on crossover slopes, whether you're highpassing mains or not, whether you have room calibration capabilities in amplifier/processor, how your sub is placed in the room, etc etc.

Phase is also frequency dependent, so you won't necessarily get perfect phase even with a phase control.

 

[dasdoing]

imo, if you have clean and loud 30Hz , you are done for music. that is for modern pop/hip hop. depending on the style even that is overkill.
with that beig said, I have clean output to 13Hz-ish and I don't regret it lol. but it isn't realy needed

 

[FeddyLost]

Any speaker in any room, the use of properly and correctly integrated subwoofers significantly enhance the quality of the reproduction

Could you clarify your best improvement experience with measured terms?
Of course, if one have small classic (uncorrected) ported 2-ways, proper augmenting them with pair of 12+ inchers will be beneficial, but pair of ported 10" with corrected impulse ... I don't know for sure.
Room interaction and placement looks like more realistic reason in my case.
I hope to bring BIR issue into sub or crossover region and correct it somehow in software. It might help with better, more normal-life-friendly placement.

it may not be worth your while

With pair of decent 12-15 inchers expenses would better bring spectacular difference.
Even reselling losses will be substantial.

I was unable find the locations and so didn't buy them.

Pressure zones = room corners.
I plan to fill at least 2 frontal corners with limp membrane traps tuned to around 50 Hz (strongest diagonal mode) with decent damping for wider working band. I need to calculate price of these ... Maybe it will be enough.

And ideally you should have the ability to highpass your speakers

Either LF level potentiometer or software processing.
In principle it's not a question, because woofer works up to ~ 550 hz and releasing some of low end duties might clean up some midbass and low mids.
Unfortunately, i can't predict how much this will improve total sound.

Also it gives you much more flexibility to place the speaker in the best spot in your room for those frequencies.

That's also one of the reasons.
Current placement is kind of "room dedicated to hifi" and not very suited for life.

do not buy a sub without having adjustable phase control

I think about ML Dynamo 1100 or 1600. They are DSP tuned with variable phase.
Anyway, my source is pc-based, so I can use software processing.

Phase is also frequency dependent, so you won't necessarily get perfect phase even with a phase control

If crossover will be low, i hope it will not introduce issues when FR is smooth.

imo, if you have clean and loud 30Hz , you are done for music

How clean and how loud?
Some bands use cool LF effects, as I've read. Maybe it will add some emotional improvement.

 

[sigbergaudio]

Could you clarify your best improvement experience with measured terms?
Of course, if one have small classic (uncorrected) ported 2-ways, proper augmenting them with pair of 12+ inchers will be beneficial, but pair of ported 10" with corrected impulse ... I don't know for sure.
Room interaction and placement looks like more realistic reason in my case.

Either LF level potentiometer or software processing.
In principle it's not a question, because woofer works up to ~ 550 hz and releasing some of low end duties might clean up some midbass and low mids.
Unfortunately, i can't predict how much this will improve total sound.

If crossover will be low, i hope it will not introduce issues when FR is smooth.

Just addressing the comments/questions where you quoted me:

To my mind there's almost no speakers who can deliver bass with the same authority than one or more subs. I used to have tower speakers with 4x6.5" in each speaker, and still crossing over the subs at 100-120hz will give more impact and better transient response.

And yes, room interaction and evening out frequency response is also valid reasons.

Crossing over low may reduce the probability of phase issues, but it will also reduce the frequency range where you can clean up the frequency response with the help of the subwoofer.

"Could you clarify your best improvement experience with measured terms" - not sure exactly what that means, but you are way more likely to get an even frequency response from 100hz and down with one or more subwoofers than with your speakers alone.

Here's my main living room (two subwoofers):

Here's our test room (one subwoofer with Antimode 8033):

 

[pozz]

Easy experiential check: music with low notes. Without a sub & setup some part of the bassline will just disappear.

 

[Beershaun]

Also there is the simple physics that a 12" driver will have much less movement to create a low frequency at an audible level and therefore better linearity and much less distortion. If you read most of Amirs speaker reviews you see all the woofers fall apart in the low frequency region and distortion spikes up quickly there first. A 6" woofer just has to physically move further to reproduce the same note as a 12". And then there are the much higher power needs to create those notes at audible levels.

 

[FeddyLost]

I used to have tower speakers with 4x6.5" in each speaker, and still crossing over the subs at 100-120hz will give more impact and better transient response

I can't say for sure, but if we compare something like Kef Ref 5 with 13" subwoofer, most LF output till ~70 Hz in case of KR5 is coming from the ports with inevitable GD. I can't imagine sealed 4x6,5" tower, sorry.
And please don't forget oversized (typically 500+ W RMS) subwoofer amp, directly pumping the low inductance voice coil vs typical stereo amp up to 250W/ch into big HP chokes, parallel woofers and resulting midbass impedance around 2,5-3,5 Ohm.
So, I don't think this comparison is fully applicable in my case.

but you are way more likely to get an even frequency response from 100hz and down with one or more subwoofers than with your speakers alone

That's really strong reason. Most even LF is kind of controversial with best imaging and soundstage as I've found during speakers' rigging.
But if I'll have to EQ resulting responce anyway ... maybe it's not so crucial.

music with low notes. Without a sub & setup some part of the bassline will just disappear

It depends on exact record. If we use something pop/rock with standard bass tuning, something like 35 Hz flat is more than enough.
Modal and BIR issues are much more audible and much more destructive for bassline.
If we are mixing some epic soundtrack, for sure we need flat 20 Hz and even lower.

is the simple physics that a 12" driver will have much less movement to create a low frequency at an audible level and therefore better linearity and much less distortion

I know this already. That's why I've mentioned my typical SPL and distortion levels.
I'm not sure if i.e. 12" subwoofer(s) augmentation will make distortion numbers better, and we are not so sensitive for LF distortion in real music signals, as I remember.
So, it's not a very good reason.