Advice on adding a subwoofer

[andrew]

I'm looking to add a subwoofer, or two, to fill out the 20 to 80Hz portion of a stereo system that resides in small 16' x 12' room that has combination of Helmholtz and super chunk bass traps. The chain is music server -> pro-audio interface -> (.80Hz) line level to stereo speakers + -> (<80Hz mono) line level to subwoofers with filters generated via Acourate. I am, most often, the sole listener so I'm hopeful that I can get away with a single subwoofer that is EQ to the one listening position but open to adding a second should this be required and budget available. So, then, my question is how one goes about finding a suitable subwoofer given that home auditions are unavailable and store demos impacted, largely, by position and integration. Most of my functional requirements are met with common brands given that I'll be managing the x/o and EQ off-board but I'm unclear about sound quality. Is this purely a function of comparing output levels and distortion at a nominal output level (see data-bass measurements e112) or is it a case that there are other factors to be taken into account? (A fair number of reviews, for example, seem to hint that for music JL Audio subs perform a level above the top of the line SVS subwoofers which in turn out perform PSA subs .)

 

[RayDunzl]

I went cheap, 4 Dayton Audio Sub-1500, with miniDSP and AcourateDRC in control.

Obviously, that disqualifies me for giving any audiophile advice.

 

[DonH56]

Thermal distortion and compression also comes into play, as does port noise, but certainly simple THD/IMD tests are revealing. My subs are Rythmik, using a servo design similar to what I used in a design of my own decades ago (should have patented the servo circuit, darn it!) The servo lowers distortion and controls thermal effects rather nicely. That said, chances are any decent subwoofer would do. I did choose Rythmik over JL, Velodyne, Paradigm, and a couple of others for its performance and value.

 

[andrew]

Another part of the puzzle is that there seems to be a race to big subwoofer drivers which I get int terms of ability to move air. That said, I’m tending to think of 12” drivers as the size and weight of well built 15 to 21” driver subs makes them difficult to place and move. And if one compromises on cabinet construction then I’m guessing that that in turn raises the distortion (albeit small compared to room)

 

[Dilliw]

Is the sub for music, A/V, or both? That's the first point and determines if you go sealed, ported or some other configuration. Second decision will be if you are going to run one sub or multiple. Even in smaller rooms I think two subs sounds better but then you are adding complexity. Finally you need to decide what type of connection and/or crossover you are going to use.

My music room is smaller and everything must be wife approved so I run a single SB1000 SVS via speaker level input. My friend runs two of Ed's "bucket subs" off a Crown XLS amp and that sounds better but then you are adding another box and another component.

Compromise, compromise.

 

[DonH56]

Is the sub for music, A/V, or both? That's the first point and determines if you go sealed, ported or some other configuration.

Why? Each type has pros and cons that are relatively independent of what you are playing through them. The room, listening position, physical space for the sub, cost, and preference probably has as much or more to do with the choice of sealed vs. ported (or IB or whatever). Sealed may go lower in the room, ported usually provides more output over the tuning frequency but chuffs when overdriven and takes a bigger box, etc.

Second decision will be if you are going to run one sub or multiple. Even in smaller rooms I think two subs sounds better but then you are adding complexity. Finally you need to decide what type of connection and/or crossover you are going to use.

Arguably two or more subs help even more in a smaller room as modes and SBIR can be worse. Most subs and AVRs have crossovers built in but agree knowing what is driving the sub(s) is needful.

Compromise, compromise.

Yeah, always... - Don

 

[Dilliw]

Thanks Don. Yes I agree that there are many factors but my simplistic approach is based on price points I guess. You can overcome the advantages/disadvantages that you describe with money but you get more rumble for the bucks with a port.

 

[1Fun5oh]

There are alot of subwoofers out there. I have an SVS SB13 Ultra sealed sub for home theater but I fill space in an open floor plan living room. ported would have been better but...... The accuracy of sealed is amazing, the power of ported is amazing at port tune. For budeget do SVS SB1000, RSL speedwoofer, even Emotiva. My original sub was an Infinity 12 about 12 years old now. Look at specs first. Look at Audioholics website for reviews. As always personal taste is key. Good luck.

 

[DonH56]

Here at ASR we'd like to think there are other keys to help in your decision...

 

[andrew]

Why? Each type has pros and cons that are relatively independent of what you are playing through them. The room, listening position, physical space for the sub, cost, and preference probably has as much or more to do with the choice of sealed vs. ported (or IB or whatever). Sealed may go lower in the room, ported usually provides more output over the tuning frequency but chuffs when overdriven and takes a bigger box, etc.

I'll be going sealed on the basis that a combination of the room and WAF disqualifies larger ported subs, and, finally, massive output isn't a major requirement in this music based system.

Arguably two or more subs help even more in a smaller room as modes and SBIR can be worse. Most subs and AVRs have crossovers built in but agree knowing what is driving the sub(s) is needful.

Plan is to start with two subs on front and back wall with an option to add more if this is required. The default plan is to use computer source + multi-channel interface or mini-DSP to send high-pass to mains and (mono) low-pass to subs, as well as to equalise. That said, the on-board DSP built into the JL Audio Fathom range is appealing as a simple solution.

One other, interesting observation, is that I've read a number of reports of people selling off larger subs used in smaller rooms on the basis that they are "overpowering the room". My guess is that this might be from parking a large sub in a corner, gain matching, and then having huge modal issues - and would be solved via addition of another sub or subs rather than downsizing to a smaller sub.

 

[mitchco]

Hi Andrew, I wrote a long article on Integrating subwoofers with stereo mains using Audiolense. The music subs are Rythmik L12's and more than enough for music and light duty HT in my 30 x 16 x 8' listening room.
Kind regards, Mitch

 

[uscmatt99]

I’m very happy with Seaton Submersive subs. Been using them for home theater for several years. They measure well and the dual opposed 15” drivers with sealed design may be good for your needs. Headroom is not an issue. Hopefully one would be enough to get an even response at the listening position given the treatments you’ve employed.

 

[andreasmaaan]

Your plan to buy two subs rather than one is sound - one sub systems tend to be a recipe for modal chaos imho.

Unfortunately I can’t advise on what model to go with, but since you’re using a DSP anyway, would DIY subs not be under vague consideration? Especially straightforward to build if you go with the sealed option...

 

[andrew]

I went cheap, 4 Dayton Audio Sub-1500, with miniDSP and AcourateDRC in control.

Obviously, that disqualifies me for giving any audiophile advice.

Thanks, Ray. I just read your thread on whether it would make sense to add subs given that your system, at that time, measured flat with the exception of a dip at 48Hz. What, in retrospect, was the impact / benefit of adding the subs?

 

[andrew]

Your plan to buy two subs rather than one is sound - one sub systems tend to be a recipe for modal chaos imho.

Unfortunately I can’t advise on what model to go with, but since you’re using a DSP anyway, would DIY subs not be under vague consideration? Especially straightforward to build if you go with the sealed option...

Yes, here in Australia, the price of subs is a lot higher than in North America so DIY is an option but, without a lot of experience, I’m unsure how I’d get a finish that was good enough to win-over approval for placement in the room (a big black DuraTex painted box isn’t going to work). The point that, if I’m going to use off-board DSP then there is no need to pay a premium for on-board DSP is understood.

 

[nefilim]

there are a lot of resources on this forum (look up dallasjustice's posts).

there is a strong case for more than 1 sub, see some theory here:

http://www.gedlee.com/Papers/multiple subs.pdf (some thoughts by Dr Geddes following his PhD many years ago on this subject)
https://www.harman.com/sites/default/files/multsubs_0.pdf (Harman's Todd Welti's take)

be warned, it's a rabbit hole but you're already pretty far along if you're doing your own convolution filters

 

[Fitzcaraldo215]

I don't disagree that 2,3,4,6,8 subs is better than one. I am quite happy with just one, however, a nice one, a JL f113. I think the biggest advantage of multiple subs is more evenness of response around the room. I don't need more headroom or dynamics. But, that would be wasted on my tin-eared wife in the next chair, and response at my sweet spot position seems quite well EQed.

I have never owned one, but if budget is an issue, I might at least look at Hsu. They do not seem to measure badly, and they have a lot of configurations/form factors.

BTW, I totally agree with @DonH56. Sound is sound. Music or movies matters not. And, a sub hugely adds to my day to day enjoyment of music, yet you don't know it is there unless the program material demands it.

 

[Kurtis34]

I'm looking to add a subwoofer, or two, to fill out the 20 to 80Hz portion of a stereo system that resides in small 16' x 12' room that has combination of Helmholtz and super chunk bass traps. The chain is music server -> pro-audio interface -> (.80Hz) line level to stereo speakers + -> (<80Hz mono) line level to subwoofers with filters generated via Acourate. I am, most often, the sole listener so I'm hopeful that I can get away with a single subwoofer that is EQ to the one listening position but open to adding a second should this be required and budget available. So, then, my question is how one goes about finding a suitable subwoofer given that home auditions are unavailable and store demos impacted, largely, by position and integration. Most of my functional requirements are met with common brands given that I'll be managing the x/o and EQ off-board but I'm unclear about sound quality. Is this purely a function of comparing output levels and distortion at a nominal output level (see data-bass measurements e112) or is it a case that there are other factors to be taken into account? (A fair number of reviews, for example, seem to hint that for music JL Audio subs perform a level above the top of the line SVS subwoofers which in turn out perform PSA subs .)

@andrew did you find a good sub? How much was it?

Sorry for being off topic. I'm looking for a good sub for my truck and can't wrap my head around which would suit me best.

Do I need to spend over $1000 to get some decent sound? I've been reading the reviews all over the internet and I didn't get closer to finding a solution. Plus most reviews are hype. Blatant copy of manufacturer's features that's it. Now I've found a different site which writes more on our language. Still there are 10 subs on the page and it's hard to choose. I've founded on the best subwoofers for cars site. What I loved about the reviews were that he highlights many negatives. Best of all they are not watered down.

What are the most important things when you're looking for a sub? Any tips?