So, you have a multiple subwoofer system, and it measures perfectly. But what do you actually hear?
I did this exercise today. I built a system that was designed to achieve a measurement, because the technical side was interesting to me. But in the process I haven't re-checked to see how much difference there is, or what the perceptible difference actually is. For my test I enabled and disabled the DSP settings used to optimize my system, so it is all subs optimized, and all subs not optimized.
My answer is my optimized subwoofer setup gives me more detail and transparency from sub frequencies into the low mids.
I'm curious to know what you guys hear that is the biggest difference to you. Is it very noticeable, or more subtle? Which do you like better subjectively? And what configurations are you comparing?
I did this exercise today. I built a system that was designed to achieve a measurement, because the technical side was interesting to me. But in the process I haven't re-checked to see how much difference there is, or what the perceptible difference actually is. For my test I enabled and disabled the DSP settings used to optimize my system, so it is all subs optimized, and all subs not optimized.
My answer is my optimized subwoofer setup gives me more detail and transparency from sub frequencies into the low mids.
I'm curious to know what you guys hear that is the biggest difference to you. Is it very noticeable, or more subtle? Which do you like better subjectively? And what configurations are you comparing?
Last edited:
That is what we are measuring and what we are trying to eliminate.
But if we put the measurement mic away and just listening to the before and after, what do you actually hear when you listen to the two objectively?
Is it a big difference, or a small difference? Are there things about the non-optimized setup that you actually like? Stuff like that...
It’s the coupling of the low frequency and midbass to the 3D space….once even distribution of waves are achieved, the entire soundstage subjectively seems much less congested.
I have recently used a 12" ported sub together with an 8" sealed box. The efficiency of the ported one is higher so its gain is turned up somewhat less. The two together seem to enhance the perception of the low bass beyond each individually. Both are low-passed at 100 Hz, second order. But I have not experimented too much with placement. They are used with 2-way mains also crossed at 100 Hz. Separately, my 4-way speakers each have a 6.5" sub (down firing) in addition to 7" woofers. Two subs in this context are better than one.
I think there are advantages to using subs with different designs like sealed and ported. Or atleast in my design I made that choice intentionally. Thanks.
I'm just pushing for a more subjective statement! Stuff like without optimization it sounded boomy, fatiguing, etc.... Or maybe optimizing was mild improvement or a massive improvement?
Personally I'm thinking about how my system has developed and how much audible improvement I found with each iteration, starting back when I upgraded from 2.1 system to "cheap" stereo subwoofers. (They cost around $400 each around 8 years ago.). Two mediocre subs was way better than 1 under sized sub. Then my DIY sub prototypes revealed how boomy and bad the cheap subs really were. I felt like it was the first time I'd been able to hear every bass guitar note.
So the subs I built are a huge benefit even without optimization. On the other hand, adding the optimization, in my house, is a small enough difference that I have to think about it. No regrets about doing it, but I'm just evaluating how perceptible the upgrades are.
Was I too subtle? If it's right, you just know. (..and yes, multi-subs can work if you do it right...)
I don't have it, but I am interested in what Geddes has to say.
My idea for posting was about correlating our perception to the measurements. We're all getting great measurements, but what does it sound like? What did it sound like before? What do we like? So it's about psychoacoustics. Isn't that a bit more Floyd Toole?
As a person who is invested in a multiple sub system, which is still evolving, I just thought it would be an interesting conversation.
Having multiple subs allows for stereo subs. For me this was a surprisingly big improvement over a single mono sub and even dual mono subs.
I had dual mono subs in my system for about a year, then got another active XO so I could run the subs in stereo.
The sound stage opened up a lot and there were improvements in detail and separation well into the lower mids.
After all, stereo music is meant to be heard in stereo, over its full frequency range.
I don't think measurements apply here, just the good old ears.
Last edited by a moderator:
2 cents worth ...
If you have a non-symmetrical room & furnishings, there is a definite advantage in having two subs. > L & R.
The left & right room modes won't be the same, thereby achieving a sort of 'peak & dip averaging'. (smoother)
Also as I have definitely found in recent times, bass is no longer strictly mixed mono - center panned.
This applies to BOTH music & movies. This alone is a very strong case for dual subwoofers
If you have a non-symmetrical room & furnishings, there is a definite advantage in having two subs. > L & R.
The left & right room modes won't be the same, thereby achieving a sort of 'peak & dip averaging'. (smoother)
Also as I have definitely found in recent times, bass is no longer strictly mixed mono - center panned.
This applies to BOTH music & movies. This alone is a very strong case for dual subwoofers
fredygump: IMO it very much depends on the circumstances; if you are fortunate enough to have a room that suits the position you want/need your main speakers (and the frequencies they play down to) and ditto for any single or stereo subs then you may not hear much difference. Epecially if you only need things to sound right in one listening position.
But if you have a less cooperative room or (like me) expect your system to work in different rooms with different room effects, then handing over the lower notes to multiple subs brings much more flexibility. Being able to position the sources, and having them spread around, is the most control I can reasonably get; much more than DSP alone. If your room is less than ideal, they can achieve a more even sound throughout, in particular offering the ability to reduce boomy room resonances and locations. EDIT: Obviously you need to get them integrated with the main speakers well - any badly integrated system can make things worse. Or if you cross too high then they need to be near the mains, which robs you of placement flexibility.
I've come to realise that at such low frequencies I'm largely at the mercy of whatever the room wants to do (even room treatment is difficult to make effective that low). So where I can't control that, I want to be able to control the low-frequency source locations instead. I'm currently without any subs (life threw a curved ball) but multiples are the way forward IMO if you want or need more control, so I will be getting some again and I won't go back to using just a single one or using stereo ones that need to be near the main speakers.
But if you have a less cooperative room or (like me) expect your system to work in different rooms with different room effects, then handing over the lower notes to multiple subs brings much more flexibility. Being able to position the sources, and having them spread around, is the most control I can reasonably get; much more than DSP alone. If your room is less than ideal, they can achieve a more even sound throughout, in particular offering the ability to reduce boomy room resonances and locations. EDIT: Obviously you need to get them integrated with the main speakers well - any badly integrated system can make things worse. Or if you cross too high then they need to be near the mains, which robs you of placement flexibility.
I've come to realise that at such low frequencies I'm largely at the mercy of whatever the room wants to do (even room treatment is difficult to make effective that low). So where I can't control that, I want to be able to control the low-frequency source locations instead. I'm currently without any subs (life threw a curved ball) but multiples are the way forward IMO if you want or need more control, so I will be getting some again and I won't go back to using just a single one or using stereo ones that need to be near the main speakers.
Last edited:
I basically wrote what you just said here, so I have no clue what you're looking for? 🤔
@fredygump
I wrote my little soiree on my room setup and multisub setup a few years back along with pictures and measurements (posts 55 and 59 from that link).
And to quote my subjective listening experience, written with the eyes of a 6 Looney Tunes like reviewer with flowery prose:
Well, I tried to be flowery, but it’s tough to find new ways of saying the same thing over and over again!
Best,
Anand.
I wrote my little soiree on my room setup and multisub setup a few years back along with pictures and measurements (posts 55 and 59 from that link).
And to quote my subjective listening experience, written with the eyes of a 6 Looney Tunes like reviewer with flowery prose:
The use of low inductance ultra low distortion subwoofer drivers of very high efficiency (93-96dB) is the key to having a very fast midbass that is at least as good as open baffle subwoofer designs (like GR Research/Rythmik) but with distinct advantages in attack, ultimate SPL capability, and deep bass extension. Motor design is paramount and absolutely everything. Building boxes is super easy and requires little knowledge for the diy’er. I auditioned several prospects and thankfully several pro audio companies design some of the finest woofers that are 15 inches and greater (i.e. B&C, BMS, LaVoce, Ciare, Funk, Faital Pro, etc…). Most "hifi" woofers are either designed for great midbass or great bass (extension) but usually not both. Several are just too small with tiny piston areas and swept volumes. Compartmentalizing the advantageous motor designs for midbass and then adding 1 or 2 other “conventional” woofers designed for low bass extension is an excellent compromise.
That being said, my 'bass system' is somewhat the exception to the rule (i.e. I didn't want to compromise
The placement of subs cannot be done without didactic in room measurements such as those afforded by John Mulcahy's excellent REW program. I am greatly indebted to him and his free software design. By using an asymmetrical multisub setup as well as room treatments (while being able to harness the technological advancements of stringent motor design that is typically reserved for the finest systems and large venue installations) one should be able to easily address modal issues, SBIR, and in particular, the "modal region."
I firmly believe that a properly designed low frequency setup is at least 30% of the playback performance as it has distinct effects in not only bass perception, realism but sound staging and imaging as well. This may not be obvious to a lot of folks. It's not about 'thumping' bass, it's about finely delineated bass detail that can be appreciated even at the highest SPL levels. Properly done, it affords a 'realism' to any 2ch playback system.
Best,
Anand.
Well, I tried to be flowery, but it’s tough to find new ways of saying the same thing over and over again!
Best,
Anand.
Last edited:
