Will I benefit from a subwoofer with 20Hz speakers?

there was a great thread a few years ago about using 2 subs with tower speakers...part of the question is do your main speakers actually deliver 20hz at the listening position at full listening volume - that is very rare - most measurements are at low volume, very close to the speaker...

Hey, I wrote a blog about how I made my decisions.

The main lesson I want readers to get from this is that speaker or subwoofer specifications don't mean anything when you get them into a room. 

 

 

We might be able to help you but first you have to tell us what problem you are trying to fix. What are you missing?  What’s bordering you?  Do you have enough bass?  Help us help you. I hope I don’t come out as being brash. The subject is very deep and it would help telling us what your concerns are. Thanks. 

Look up "swarm subs"

I just re-read that you have measurements and use miniDSP.

Generally speaking to my mind, room correction systems tend to be too bright.  If you have the ability to control the tilt downwards try that.

After you get there, a boost in the bass (below 100 Hz) of around 4 dB is a good thing. The problem is if you aren't flat to begin with. 

Of course, all room correction works best with room treatment.  Take a look at the room simulator, below and see if your measurements are coinciding, and then we can talk about potential fixes.

https://amcoustics.com/tools/amroc

20Hz @ 0 db loss?

"The speaker's published frequency response is 41-20,000Hz. I presume this is achieved in an anechoic chamber. In my room however, it goes down to 20Hz, at least according to the Dirac measurements. In fact, I needed to flatten the curve and  reduce by 5-20 DBs between 20-100Hz due to the room effect."

Nice looking speaker. 

You have a magic room. The speaker defies manufacturers reasonable/real world  low frequency claim? Hmm...

I took a look at the website. This one is over the top:

 

Here is a photo of my measurements (took me forever to figure out how). 😁

They are taken from the listening position. As you can see, I had to even reduce the low frequencies by quite a bit. 

 

 

 

Here is a photo of my measurements...

Well to answer your question. Yes you could live without a sub on that system. You have most everything covered. That is not to say there is not more to get but you would not be missing much. 

 

Thank you for this Erik. I have never used this, so I will spend some time going over it. Here is what came up based on my room size of 16X18X8 feet. https://amcoustics.com/tools/amroc?l=487&w=549&h=244&r60=0.6

The short answer, is definitely "yes", add a subwoofer.  Don't over analyze it.

Well that's not bad.  I think you left the bass a little lean. 

Between 20 Hz and 100 Hz add a low shelf of about 4 dB.

from 100 Hz to 16 kHz go for a steeper slope, so 16 Khz is about -5 dB relative to 500 Hz.

Yes, subwoofers can be glorious but your problem right now is room balance.

Also, if you are doing this all without any room treatments it's not going to sound as good as if you worked together with them, especially in the bass.

Assuming 18ft between front and back wall your room will amplify 1125/36=31.25Hz and multiples (62.5Hz, 93.75, 125Hz etc.).  31.25Hz is alway welcome, but multiples require room treatments.

A good Subwoofer will be far more articulate and controlled and far better punch such as Svs 4000SB  no contest for just over $3 k a pair if you get them on sale from the outlet. The Cabase no way it get 20 HZ with impact reaching 20 hz for a millisecond won’t cut it ,my brother has bigger Wilsons and still has these same 

Svs subs  tuned with their excellent App,Free  REW bass program ,and you buy a DSP Mike ,after learning and taking a few readings you sent to SVS  and they tell you exactly where to set the parametric eq on the app to truly flatten room bass nulls and tune the Bass to your room , night and day better Bass, Svs pays shipping ,a 45 day trial 

and even return shipping $100% refund if not happy and 5 year transferrable warranty ,a great company to do business with.

Yes you need subwoofer without doubt there be shadow.

there's no way speakers that are rated at 41 HZ are going to go down to 20 HZ in your room what kind of measurements are you using?

there's no way speakers that are rated at 41 HZ are going to go down to 20 HZ in your room what kind of measurements are you using?

The words of those who don't have a lot of practical😀 experience. 

All a sub would do is take a load of the mains and introduce complexity into the space.  Quick trick to try is Eriks' eq suggestion. *S*

I could easily live with that curve as is, personally.

Lucky you. ;)

@tablejockey , I'm sorry but la Sphere looks too much like a next millennia Dalek.
I don't like anything that looks like an eye that never blinks trying to hypnotize me with music...and a ball on a spring is....

Hard to take seriously....Seriously. *L*

Thanks, anyway...J

I've found the optimal room location for the main Speakers ability present a sound stage is usually not one of the rooms  optimal bass modes.There are simply too many room and system variables as well as your personal taste. 

Map your rooms bass modes using the crawl test standing up. Then order some long XLR or RCA interconnect form Blue Jeans or Mono Price.

If your in the U.S. SVS Subwoofers offer what seems to be a simply painless trial period.

I believe their products provide a functional amount of remote equalization, optimization, and gain along with three customizable memory presets that might better match your main speakers low frequency presentation.

Subwoofer single processing is vastly different and typically limiting. Best of luck with it.  

@tablejockey I have heard the smaller Pearl speakers that look the same. A few thousand watts of class-d amps makes sure they are VERY dynamic!

I am not sure they went down to 20 Hz in that room but the bass that I heard was Impressive. Drums were really good. Of course they managed voices and other things well also. Just $30k.

Hi @dmilev73, to echo 1 or 2 posters above,

• No, you definitely do not need subwoofers in your room
• I would lift the 20-30Hz by a few dB and lose 6dB 90-60kHz, more or less as per @erik_squires wisely suggests above
• Bass absorption looks like a plan: you have serious modes in the early 30 Hz & a suck-out a little over 100...

I like those speakers!

To get a better picture of what's going on use REW and do a measurement with Dirac on and off.

Speaker manufacturers need to quote frequency range within decibel limits.

If Cabasse quote 41Hz at the bottom end it might be -3dB or -6dB, or worse.  Whatever, at the usual rate of roll-off there will be nothing at 20dB.  If OP is hearing a significant signal then it might be room effect but more likely check his Dirac.

For those interested bottom B on a Steinway Model 6 is 31Hz.  The bottom of a string or electric bass is 41Hz.

Those wishing significant musical output down to 20dB definitely require sub-woofers with these Cabasses.  I wonder what instrument they are listening to.

I usually find if someone is asking if they need subs, they are not satisfied with their current bass...

How much music content goes BELOW 20 Hz ?

20Hz?

Give me the titles of all 20Hz music you listen to and I will solve your issue, I am sure.

@asvjerry, For a 21 inch woofer I'd have to give them a try!

"I'm sorry but la Sphere looks too much like a next millennia Dalek."

asvjerry- yes, I'm afraid la Sphere is a little much for my tastes. Tough to get it to fit

with the decor, or get approval by the "boss."

They look like something from Hef's mansion in 1986.

Low B on a 5 string electric bass is 31hz (ref A440), Jaco on Cotton Ave tuned his e string way lower than low b on the intro. Synth produced bass ...well that's another story and some of it is really good like Bela Flek etc...

Yea, I don't think you can have the Sphere if you're married... 😅

Having read many comments on this discussion forum I can say that about the only thing that most people agree on is that REL subs are really good. I have yet to read a negative comment about an REL sub (let the negativity commence). I say go for it.

From my experience with all my systems over the years,

(answers to your two questions in the second paragraph)

1 Yes

2 Yes

Looks like the website says frequency goes down to 20hz. Where did the 41hz number come from?

Maybe RELs really are good but from my own experience their customer service sucks. Phone calls never returned. Emails answered then told they'd get back to me but never do. Text messages back and forth promising me answers that I never get. A different mfg for me next time.

Your 41HZ data is incorrect. But tell me? Do you not expect there to be dynamics in sound? Are you trying to tune out dynamic pieces so that everything plays within the same 1-2 dB range? Music is a lot different than running a tone generator through your system from 20-20KHZ at at constant decibel level and looking at the graph for peaks and valleys built into the crossover network and then trying to correct it. 
 

But yes! By all means, add 2 subs to your space. Everyone should, whether they know it or not. 

Here is a review of the speakers. In the 3rd paragraph it mentions the frequency range. 

I also included a couple of screenshots conforming it is 41 Hz. 

 

https://www.ultraaudio.com/index.php/equipment-menu/356-cabasse-pacific-3-loudspeakers

 

 

https://postimg.cc/HVPKXbvs

 

 

 

I bought the MiniDSP and returned it before the 30 day trial was up.  All the components in my system are many times the price of the Mini and it sounded like I had a really cheap preamp in the system when I put it in.  It gave me a wonderfully flat frequency response, but I hated the way it veiled the overall SQ.  I’m surprised so many people like it.

@erik_squires I really would like to take your words for it and tune my 44hz and 39 hz (+-3db) bookshelfs down to 20hz (flat like you have shown or -3db is fine). This really sounds a bit too good to be true to be honest. But before we invest further for expensive GLK panels and treat my room as you did, is it possible for you to "demonstrate" the sound reproduction from your room by some real-life recordings? I think, with all the measurement equipments you have for DSP, doing a quality recording is not that hard, right? Are you able/willing to do that for the good of the group?

https://speakermakersjourney.blogspot.com/2021/12/room-speakers-eq.html

@lanx0003

The main thing to keep in mind from my blog is that it’s based on creating a fix appropriate to the measured room. Each room will be different.

I also didn’t really attempt to boost the low bass by itself. Clipping the peaks and then just adding a bass boost with a shelving filter is not the same as trying to push speakers where they can’t go. If your speakers are down 18 dB at 30 Hz and keep going down EQ is not going to solve your problems. :)

Also, as I explained, for my Jazz/Classical mid volume listening needs I'm OK.  If you like to push the volume then even with these results a subwoofer will become more important to you.  My choices were based on measurement and values/needs.  I hope the blog gives you an example of how to go about figuring out what you need and what's important to you.

That was what I was saying "it is too good to be true" (without the aid from sub). I believe you know quite well that, in order to boost 6dB, you need to double the volume. So I wonder why do you even make fun 😀 of people when they question that as below. It is simply not doable either practically or in theory. That also lead to my next question in your post where you mentioned: "... Take my modest speakers. They use 6.5" woofers and a ported cabinet. Would you guess they went down to 20 Hz? They do..." How you achieve a flat response down to 20 Hz there? What is the frequency rating for your modest speakers (Squires SNR-1?)?

 

there’s no way speakers that are rated at 41 HZ are going to go down to 20 HZ in your room what kind of measurements are you using?

The words of those who don’t have a lot of practical😀 experience.

How you achieve a flat response down to 20 Hz there? What is the frequency rating for your modest speakers (Squires SNR-1?)?

Please refer to my blog!

 

OP: 

 

@dmilev73 May I have permission to use your frequency response picture on my blog??

PS - The SNR-1 would be rated around 40 Hz anechoically. 

@dmilev73 May I have permission to use your frequency response picture on my blog??

 

@erik_squires 

Sure Erik. 

Is there a good test measurement app for Mac?

@coachpoconnor  Room EQ Wizard is the standard for free tools, and it should run on a Mac.

I really would like to take your words for it and tune my 44hz and 39 hz (+-3db) bookshelfs down to 20hz (flat like you have shown or -3db is fine). This really sounds a bit too good to be true to be honest.

 

@lanx0003 - I don’t know what you’ll be able to achieve because it is so very room/speaker/placement specific, I make no guarantees that you can take this recipe, follow it 100% and get usable 20Hz. Really all depends where you are starting from. The initial measurements from this OP and my experience in my room which I wrote about showed we both had usable output at 20 Hz. We got lucky. But the thing is that rooms and speakers are random.

I will say this however, almost every time an audiophile adds bass traps and some room treatment to a speaker they are amazed at how much bigger their speakers sound. That is something I can almost guarantee will happen. At the end of that you will be much happier. Now, will it be so great you don’t want a sub? I do not know, but I know 100% that if you do all this and then get a sub you will enjoy the sub a lot more and have a much easier time integrating it with your main speakers.

What I know is a really bad idea is to look at a speaker spec sheet and think "Oh, OK I know what’s going on in my room" because I promise you, you do not.

Overall what I want you to do is measure first and then decide where to go. This I am also extremely confident in being a great approach.

There are the rare cases when bass slopes downwards from 80 Hz or so and there's no significant room modes.  In these cases, bass traps should wait for a sub. 

Eric, I do not wish to prove you wrong.  In fact, since I know your existence in the forum and read several post of yours, I always respect and consequently place more weight on what you have advised or recommended to improve my system.  So far, except last time you said to toe-in speakers and cross in front of you that I found by doing so shrinks the width of soundstage, everything else is spot on.  Unfortunately, this is another incidence that I was (and I believe some others were) not convinced.  Let me explain by telling you my experiment first.

I use foobar2000 as a player and under the "View" "DSP" you should be able to find "Equalizer."  The reason I specifically refer to this particular EQ tool in foobar2000 is because I found this is probably the best EQ among all the players I have experience with.  I trust the fidelity of this tool.  The lowest frequency this EQ can go is 55Hz and you could adjust all bandwidth up and down by 20dB.  I play a track entitled Keep A Secret by The Whitest Boy Alive from their album Rules which begins with heavy weighty drum beats.  Then I gradually ramp up the 50Hz-156Hz bandwidths in a linear fashion, i.e., starts with +1dB at 156Hz, +2dB at 110Hz, +3dB at 77Hz and +4dB at 55Hz and ramp up by a certain level while keeping the slope linear.  When ramping up the 55Hz to roughly halfway (+10dB), I have already hear distorted bass notes.  I stopped with the worry ruinning my speakers.

The reason I did this experiment is because I suspect that what you and the other forumer have measured in your room as shown in SPL down to 20Hz might be some highly distorted noise, not the pleasant musical notes any more.  That is also why I am asking you to provide some quality recording to the group demonstrating what we are going to hear when you tune the speakers from the rated frequency (say +40Hz) down to 20Hz.  I could be wrong and I wish I am wrong.  I wish the tuning / DSP is successful out of the room treatment so we could all enjoy/benefit from this experiment.  I hope I make my point this time. 

I will play the devils advocate here. While adding a sub has the potential to add LF quantity and / or quality, it will invariably take away from the signal strength going to your main amp / speakers. That is, you need to make compromises at the low signal level, which might be quite steep especially when the subs plate amp with super low input impedance guzzles the current away from a tube power amplifier with high input impedance.

In easier to understand language: most of the energy that drives your system will be shunted to drive the subs, and your amp driving the main speakers will be starved and get only the meager leftovers that the sub graciously allows.

I have invariably found that adding a sub always has noticeably degraded midrange and high frequency quality in my systems, and the gains at the added bass level were not big enough to balance out the losses in the main frequency range.

I use very high efficiency speakers and straight path / no feedback system approach. However, when you have a preamp that has an added stage (or stages) to provide current drive for the sub(s) then this is a non-issue. 

Yet, the problem of those extra stage(s) eroding low level signals still remain, so the main amp will receive compromised signals regardless a sub is connected or not. No free lunch, but we can plan when we understand the menu.