Everything I have to say about the Distributed Bass Array I wrote about here, and it is as true today as when I wrote it:
Will I benefit from a subwoofer with 20Hz speakers?
My source is a minidsp shd studio with Dirac going into Denafrips Gaia DDC to Denafrips T+ DAC to McIntosh 601 Monoblocks to Cabasse Pacific 3 speakers. 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.
So, considering I already go down to 20Hz, is there anything else 1 or 2 subwoofers will do for my system? Would it create a more consistent low frequency field? I see many people adding up to 6 subs, so I wonder what I'm missing.
Thank you for your insight!
Showing 19 responses by erik_squires
My point, and I made it after my head got hot, is that rather than demand I do more work, others should instead follow the discussion and contribute their own findings. Honestly, I am super curious about seeing data from audiophiles comparing their speaker’s published spec and in-room response. I would learn a lot from that. Very little benefit, IMHO, would come from me recording my system, and honestly, I don’t have a lot of time and energy for this. The more others contribute their experience the better the elephant will look. I am by no means anti-sub. I love subwoofers, but consumers should be clear-eyed about where their system is starting from and what problems or benefits they hope to achieve. I have _never_ seen anyone regret analyzing and treating their room before adding a sub, but I have seen some decide not to sub. |
@lanx0003 - The day you pay me to do this is the day you get to complain of what I have or have not done. I ignored you because I have other things to do, and other priorities in my system, which will continue to be true. Since I make no money either way based on whether or not audiophiles take my advice or not, make of my postings what you will. If you think I am in error I suggest you post your own findings, and actually do something instead of complaining that I haven’t done enough for you, because the level of obligation I have to you or anyone else on this site is ZERO and I'll be damned if you or anyone else on this site gets the impression you have any say so in how I spend my precious free time.
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BTW: To all the nay-sayers, please take a look at the OP’s data. Notice how the original measurements showed output at 20 Hz very close to the output at 1 kHz. This is despite his speakers being rated to -3dB at 40 Hz. This is a very similar situation to the one I wrote about in my blog and why I keep saying measurement is important, and we may be adding subs for the wrong reasons. Let the OP clean up his bass first, and then decide, based on his own needs and values if a sub is worth the trouble.
In terms of what this SHOULD Be, I am going to go with Floyd Toole and Anthem's ARC room gain recommendations. Below 100Hz there should be a shelf of around +3 to +6 db. Basically this is "salt to taste" when it comes to bass levels, and follows my overall process:
1 - Measure 2 - Clean up 3 - Re-shape |
OP: Sometimes speakers image better crossed in front. Depends on a lot of factors, but what this tries to do is minimize early reflections from the side. If you don't have early side reflections this can't provide any benefit, but being only important in the mid-hi frequency range it's OT for this conversation. |
Thanks for taking my comment out of context, @lemonhaze My meaning was that most audiophiles should not take the -3 dB point of a speaker and think that it means much once it is in a room. While the physics of room modes is understood, the final -3 dB point of a speaker in a room is not something anyone can gauge well by back of the envelope calculations. That is what I meant by "random" and why I encourage measurement as a much better place to start than speaker specs. Room mode simulators like the great one from AM Acoustics are fantastic tools which should be leveraged when considering room treatment, and I encourage it’s use as well. |
No, this isn't a thing. With preamps easily able to under 1 kOhm loads, and amps presenting 25k Ohms and higher loads there is a barely measureable change to the preamp output at the same setting. Do the math. Assume a perfect voltage source with a 1 kHz output impedance. Takes a lot of 25kOhm amps to cause a change. |
@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. |
@coachpoconnor Room EQ Wizard is the standard for free tools, and it should run on a Mac. |
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. |
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. |
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. |