Near Field and Subwoofers

[test1223]

Firstly, if I have two subs, one for each monitor, and placed near them, should that solve directionality issues?

You won't get envelopment with standard near field speakers and placement therefore the second subwoofer is not essential in this regard.
Placing the subwoofer next to one of the speakers or between both is the best placement.

If a sub is close to your listening position, does that remove or reduce the impact of the room in what you hear, in the same way that having monitors in near field does?

The placement closer to the listening position will only decrease the influence of the room by a smaller amount, since the wavelength are to long so that the room modes and reflections are still very relevant.

A near field dipol subwoofer is the way to go to reduce the influence of the room by a large amount. There is no such commercial design out there that I am aware of. So DIY is the way to go here. The simplest design is a naked driver which has to point at your listening position. Have a look at diy audio forums if your are interested. Without measurements you won't get good bass anyways therefore DIY is not that far away. The downside of such a dipol subwoofer is that you don't have any deep bass outside your listening position and you need a very big woofer and a very quiet subwoofer amp otherwise you hear the hiss. The placement is also tricky in a typical computer desk setup. The benefit is that you get very very clean and "fast" bass and there is almost no bass in the room therefore you don't bother any neighbors with your bass. You have to be aware that the transition to a standard boxed bass can be difficult since you might hear the degradation in sound quality due to the jump in more room interaction and potential enclosure issues.

The monitor/sub combination I’m looking at is the JBL 308p Mk.IIs and 310s. The sub was designed specifically for use with these monitors, and has an 80hz crossover setting, again recommended and designed for this combination.

Given JBL’s pedigree, and the fact that the monitors (and subsequently the sub) are designed for near field listening, I’d hope they had the crossover perfect.

The JBL 308 are good speakers with a good tonality but will potentially hiss a bit and they are not "crystal clear" due to a bit higher intermodulation distortion compared with other (more expensive speakers) and they didn't provide the image and other advantages of a coaxial speaker. I personally would choose a coaxial speaker but such designs also have disadvantages and there aren't perfect speakers. Speakers like the JBL308 provide a very good value for the price.

 

[ozzy9832001]

I tried a sub behind my listening sofa and it integrated surprisingly well. I couldn’t locate it as behind me. If I use a sub again someday it will likely go in the same location, and for one of the reasons cited by Floyd Toole: our bedroom is above my listening room and sometimes my wife is sleeping when I’m listening. A closely placed sub will mean it’s not as loud and that much less likely to disturb her.

I found this to be true as well. It also gave a better 3d sense as well. It's difficult to explain. Maybe it's because I knew it was behind me. Cabling wasn't a good option or I would have left it there. FR was the same in either position, maybe slight variations. Someday, when I have the drive, I may invest in a much longer cable and see if I can't route it right. Overall, I actually liked it compared to being right in front of me.

 

[ozzy9832001]

So the idea of near field listening is that, with traditional seating distances, you’re listening to a combination of the speaker and the room. But the closer you sit to the speaker, you’re changing the balance - effectively making the speaker louder and the room quieter. The knock-on effect is clearly that your room won’t matter (at least not as much), and so you don’t need to worry as much about acoustic treatment, etc.

Okay, I’ve got that.

But what about subwoofers, non-directional, and possibly under a desk? Do they follow the same rules? If you sit closer to your sub do you hear more of the sub and less of the room, with the sub contributing more and the room less?

Or do subs effectively not count? Can you ‘ignore the room’ from your main speakers, but have to treat the subs no differently to if you weren’t sat do close.

I’ve used the inevitable level of imposed ‘internet shorthand’ there.

The only issue with nearfield listening is: listening position. I find less options when in the nearfield and it's less forgiving. To me, I really don't find a benefit to crazy subs that go down to 20hz. My sinuses and ears are messed up, so LF sound tends to "rattle" in my head (anything under 60hz). However, a sub is massively beneficial for handling room modes and smoothing out the response. Also, having a sub with good crossover options is super important.

 

[Yorkshire Mouth]

You won't get envelopment with standard near field speakers and placement therefore the second subwoofer is not essential in this regard.
Placing the subwoofer next to one of the speakers or between both is the best placement.


The placement closer to the listening position will only decrease the influence of the room by a smaller amount, since the wavelength are to long so that the room modes and reflections are still very relevant.

A near field dipol subwoofer is the way to go to reduce the influence of the room by a large amount. There is no such commercial design out there that I am aware of. So DIY is the way to go here. The simplest design is a naked driver which has to point at your listening position. Have a look at diy audio forums if your are interested. Without measurements you won't get good bass anyways therefore DIY is not that far away. The downside of such a dipol subwoofer is that you don't have any deep bass outside your listening position and you need a very big woofer and a very quiet subwoofer amp otherwise you hear the hiss. The placement is also tricky in a typical computer desk setup. The benefit is that you get very very clean and "fast" bass and there is almost no bass in the room therefore you don't bother any neighbors with your bass. You have to be aware that the transition to a standard boxed bass can be difficult since you might hear the degradation in sound quality due to the jump in more room interaction and potential enclosure issues.


The JBL 308 are good speakers with a good tonality but will potentially hiss a bit and they are not "crystal clear" due to a bit higher intermodulation distortion compared with other (more expensive speakers) and they didn't provide the image and other advantages of a coaxial speaker. I personally would choose a coaxial speaker but such designs also have disadvantages and there aren't perfect speakers. Speakers like the JBL308 provide a very good value for the price.

Damn good reply - lots of great information there, logically explained.

Muchos thanks.

 

[192kbps]

Near-field sub is the strategy Dr. Toole is going to employ when he moves into his new condo.

Do you have any more information about near field subwoofing? It looks amazing.

 

[NTK]

Do you have any more information about near field subwoofing? It looks amazing.

You'll need to ask Dr @Floyd Toole how he is going to implement his nearfield subs in his new condo. The only other info I have is from his post in AVSForum on his earlier (>50 years ago) nearfield sub implementation.

https://www.avsforum.com/threads/how-to-choose-a-loudspeaker-what-the-science-shows.3038828/page-264#post-58636456