Subwoofer Selection Criteria

[watchnerd]

@watchnerd if I were you I'd probably go for bigger subs placed in corners over smaller subs placed between the speakers. According to Harman's subwoofer placement paper, both configurations give fairly similar results in terms of smoothness of response and sound power, which means that the greater surface area of the larger subs should probably be the decisive factor.

I've got 15" clearance for a "between the speakers" placement, which would also fit in the corners. Lots of 12" systems at that width.

If I max out on the corners, I have 18" clearance. Too large for between speakers. Lots of 15" systems around that width.

Room volume is about 3500 cubic feet / 100 cubic meters.

I'm thinking 2 x 12" may have enough output (note: music only, no movies), is "big enough of an upgrade" relative to the 7" in my mains, and would allow me to try both corner and between the speakers options and pick whichever works best.

 

[watchnerd]

3 subs following Geddes are better than 2. 4 is the threshold of diminishing returns for Welti et Devantier. Geddes approach favors a quasi random positioning of the (at least 3) subs. Geddes almost advocates different sealed or passband subs.

By passband sub do you mean ported or line a transmission line?

And you saying he recommends mixing subs of different types?

 

[watchnerd]

i second rythmik. very clean and effective, great value. made in my hometown. attend to ground loop issues, however.

These look like a very compelling option if one is doing room correction, bass management elsewhere.

For me, personally, I'm probably shopping for something with room correction / EQ built-in, ideally with wireless and or phone app config.

 

[andreasmaaan]

I'm thinking 2 x 12" may have enough output (note: music only, no movies), is "big enough of an upgrade" relative to the 7" in my mains, and would allow me to try both corner and between the speakers options and pick whichever works best.

I agree. Whether you go with 2x12” or 2x15”, there’ll be a significant improvement. If 2x12” allows you more scope to experiment with placement, perhaps it’s worth it.

 

[Willem]

Room eq built in reduces your options enormously. I would prefer an external unit like the Antimode 8033. It is dead easy to set up, and more advanced than most built in solutions.

 

[FrantzM]

Room eq built in reduces your options enormously. I would prefer an external unit like the Antimode 8033. It is dead easy to set up, and more advanced than most built in solutions.

+1

I don’t know anything about the anti mode unit. I am thinking that things like Acourate or Audiolense are the most flexible and potentially higher performance . IMO they are also more difficult to master . I’d go miniDSP for the ease of use.
Still, for the results that can be achieved with these DRC software solutions. I believe they’re worth the (immense) hassle of learning them and using them.

P.S. Read about the antimode box. It seems to be a very good solution. How it compares to other solutions? I don't know.

 

[Willem]

The Antimode is a litle box that you connect out of sight in between the amplifier and the sub(s) and comes with a measurement microphone. It produces a series of test tone sweeps, and automatically decides what narrow filters are necessary for the best result. So after only a few minutes you are done without any hassle. Since it is not a software solution it will work with any system, playing vinyl, cd's or whatever. If you like to tinker, you can use it to have a low cut filter, or a small bass boost. It will only equalize your subwoofer(s) and leaves the mains speakers unaffected, which in many cases is just as well.
DSpeaker also makes rather more expensive units that will equalize full range, if you are keen.

 

[dkinric]

These look like a very compelling option if one is doing room correction, bass management elsewhere.

For me, personally, I'm probably shopping for something with room correction / EQ built-in, ideally with wireless and or phone app config.

https://www.martinlogan.com/en/product/dynamo-1600x
About 18" cubed

 

[watchnerd]

Room eq built in reduces your options enormously. I would prefer an external unit like the Antimode 8033. It is dead easy to set up, and more advanced than most built in solutions.

Huh?

Built-in room EQ expands options.

I can still use Antimode or whatever if I don't like the built-in EQ.

Plus, most of the built-in EQ models seem to have wifi subwoofer controls, which is useful in any scenario.

 

[watchnerd]

Ported vs sealed?

How important is this?

I see some recommendations to use sealed for music and ported for movies.

But this seems overly simplistic, especially when my mains are ported.

It seems like the tradeoffs between the two should be more around easier wall proximity vs output / sensitivity, as opposed to music vs not. After all, one can tune a reflex box with a low Q of .5 or .7, to make it either "tighter" or "boomier".

Or am missing something important?

 

[watchnerd]

https://www.martinlogan.com/en/product/dynamo-1600x
About 18" cubed

If picking amongst the MLs, I'd probably go for the 1100X so I'd have more placement flexibility. 18" width, for me, means corner placement as the only option with WAF.

 

[DonH56]

Sealed systems never "unload" the driver; the box always provides some resistance. At and below the port tuning frequency, the driver is essentially "unloaded" and just flaps in the wind, leading to high distortion and that infamous "chuffing" noise you can get from ported speakers. A proper design will have a large and smooth enough port to avoid chuffing, and filter to prevent or control undesired low-frequency signals. A ported design's output drops off rapidly below the port tuning frequency; a sealed system drops more slowly. That means in a sealed room you can generally achieve deeper response due to "room gain" reinforcing the subwoofer's output below the -3 dB point -- it will play deeper in a closed room than a ported system with the same -3 dB point. The constant loading also generally means a sealed design will have lower distortion and better time response. But, ported designs generally have higher output, since the port contributes to the output as well as the driver, so more output with less power means potentially lower distortion since less power and driver excursion is required. But the box is generally significantly larger to provide the same LF corner as a sealed system.

Rythmik and other designs with a servo circuit can better control the driver, ported or sealed, so distortion can be comparable between the two. Then it comes down to aesthetics (size) and in-room response desired. I chose sealed for the smaller size, slightly better performance (probably inaudible but what the heck), and additional room gain. In my modest sealed room I gained about an octave, so my in-room -3 dB point is about 7 Hz instead of the sub's native 14 Hz.

Having ported mains or not should not matter if you are rolling off their response well above the port tuning frequency. That is what I recommend, along with real experts like Dr. Toole, but again that comes down to preference and the characteristics of your speakers, room, etc.

HTH - Don

 

[andreasmaaan]

You’re about right @watchnerd. The caveat is that no matter how “tight” you tune a BR box, you’ll always end up with a steep roll-off below the tuning frequency.

To summarise the other differences, BR boxes tend to allow for significantly higher SPL/lower distortion/less excursion at/above the tuning frequency, but produce much higher distortion/greater excursion below the tuning frequency - unless high pass filtered, as is usually the case with active implementations (although I haven’t kept up with home audio subs so I’m thinking here about pro subs when I say they are usually high pass filtered).

 

[watchnerd]

additional room gain.

Additional room gain because you can put them closer to the wall?

 

[FrantzM]

Sealed systems never "unload" the driver; the box always provides some resistance. At and below the port tuning frequency, the driver is essentially "unloaded" and just flaps in the wind, leading to high distortion and that infamous "chuffing" noise you can get from ported speakers. A proper design will have a large and smooth enough port to avoid chuffing, and filter to prevent or control undesired low-frequency signals. A ported design's output drops off rapidly below the port tuning frequency; a sealed system drops more slowly. That means in a sealed room you can generally achieve deeper response due to "room gain" reinforcing the subwoofer's output below the -3 dB point -- it will play deeper in a closed room than a ported system with the same -3 dB point. The constant loading also generally means a sealed design will have lower distortion and better time response. But, ported designs generally have higher output, since the port contributes to the output as well as the driver, so more output with less power means potentially lower distortion since less power and driver excursion is required. But the box is generally significantly larger to provide the same LF corner as a sealed system.

Rythmik and other designs with a servo circuit can better control the driver, ported or sealed, so distortion can be comparable between the two. Then it comes down to aesthetics (size) and in-room response desired. I chose sealed for the smaller size, slightly better performance (probably inaudible but what the heck), and additional room gain. In my modest sealed room I gained about an octave, so my in-room -3 dB point is about 7 Hz instead of the sub's native 14 Hz.

Having ported mains or not should not matter if you are rolling off their response well above the port tuning frequency. That is what I recommend, along with real experts like Dr. Toole, but again that comes down to preference and the characteristics of your speakers, room, etc.

HTH - Don

In my modest sealed room I gained about an octave, so my in-room -3 dB point is about 7 Hz instead of the sub's native 14 Hz.

WOW!!!

I hate you Don! Need to find a way to audition your system

 

[Dimifoot]

When running multiple subs, should they be of similar design or it doesn’t make a difference?

I mean all subs ported, or all subs sealed / vs some of them ported-some sealed

 

[March Audio]

When running multiple subs, should they be of similar design or it doesn’t make a difference?

I mean all subs ported, or all subs sealed / vs some of them ported-some sealed

I have not tried disperate subs, my 4 are the same, but logic would dictate to my mind that they should be same.

 

[Dimifoot]

they should be same

Same as identical, or as same design (ported/sealed)?

I wonder if Room Eq will have issues trying to do multi sub management with dissimilar designs ?

 

[andreasmaaan]

When running multiple subs, should they be of similar design or it doesn’t make a difference?

I mean all subs ported, or all subs sealed / vs some of them ported-some sealed

Geddes’ view is that they needn’t be identical. I think that’s correct insofar as the Geddes setup approach is concerned.

However, logic would dictate IMHO that identical subs would at least offer greater flexibility, as non-identical subs would take certain setup approaches completely off the table, and would make certain other approaches more difficult to varying degrees (depending on the differences).

 

[March Audio]

Same as identical, or as same design (ported/sealed)?

I wonder if Room Eq will have issues trying to do multi sub management with dissimilar designs ?

identical IMO, unless you are going to accurately (close measurement) correct each one, and even then I foresee problems.

BTW here are a couple of plots of my 4 subs I generated tonight after my latest iteration (playing and fiddling with the set up again) The XO is at 60Hz.