Subwoofer Selection Criteria

[FrantzM]

I've shied away from Mini DSP because it sort of kills the point of having my all-in-one-box Devialet Expert system, and I wouldn't have an easy way to apply it equally (without major PITA) to both vinyl and digital streaming.

But the Martin Logan Dynamo looks intriguing.

I'll admit, though....having owned ML electrostats for 10+ years, 2 different models, and now moved back to dynamic speakers, it would seem weird to go back to ML for a sub...to use with someone else's speakers.

Also how well does the ML auto EQ work if you have 2 subs?

Correct me if I am wrong but you could output a signal from the Devialet to a miniDSP. IIRC the Devialet can do the high pass crossover and let the miniDSP do the DSP'ing.... An elegant solution if you ask me plus I doubt the built-in DSP in the Dynamo to be as flexible as any miniDSP model.

 

[watchnerd]

Do you have some idea what your SPL requirements are?

And have you decided whether it’s important to you that the sub be sealed as opposed to ported?

My typical listening level probably averages about 85 dB at the listening seat, which should be about 100 dB at the speakers. Add in some extra for peaks and overhead, call it 110?

Sealed is probably preferred so I can put it closer to the wall without worrying about blocking a port.

 

[watchnerd]

Correct me if I am wrong but you could output a signal from the Devialet to a miniDSP. IIRC the Devialet can do the high pass crossover and let the miniDSP do the DSP'ing.... An elegant solution if you ask me plus I doubt the built-in DSP in the Dynamo to be as flexible as any miniDSP model.

The crude set up I'm doing right now is using the Devialet to do the high pass and letting the sub do it's own low pass filtering.

So, yes, that could work. But I'm not sure it would be better, from a usability POV. MiniDSP is powerful, but I find the process and user interface (connect the box to a laptop, use their horrible UI) to be clunky. I like the idea of having on the fly dynamic management from a smartphone app.

Of course, that might suck in other ways, too. But ARC Mobile seems to get reasonably favorable reviews from the stuff I've read.

If it's lousy, I can always add in MiniDSP later.

 

[dkinric]

Are you running the Dynamo woofer down or woofer horizontal?

Downfiring, looks clean and I have a carpeted room, so it works well. Designed to be used in either orientation though, as "legs" can be installed either way and it comes with a grill for front firing orientation.

Regarding other comments, yes, the app based solution is very well done. It has always connected quickly, and I have not run into any hiccups at all. It only needs to connect via bluetooth if adjustments are being made. The apps (Anthem for running setup, ML for sub controls) are well designed, and the ability to make adjustments on the fly from the seating position is great.

Sure, a full mini-dsp system would be more powerful and encompass the entire frequency spectrum. However, as you note, it requires a laptop and quite a bit more effort. I'm not discouraging anyone who wants to go down that route, I was strongly considering it myself. However, my experience with the ML sub with it built in is effective, elegant and simple. A great solution for properly integrating a sub with the room and existing speakers.

One can always add a full DSP system later on. ML even addresses this in their literature, suggesting turning off the built-in room correction in this case. You still have the adjustment app though, in this scenario, so it's like a remote control for the sub controls.

 

[watchnerd]

As a follow-up:

Multiple subwoofers seem to generally be better for taming room nodes, but for a similar budget I could get either 2 medium subs or 1 bigger sub.

Other than perhaps maximally low F3, are there other things to consider when weighing, say:

2 x 10” vs 1 x 15”

From a radiation surface they seem almost equal (50 pi sq inches vs 56.25 pi sq inches).

 

[watchnerd]

Downfiring, looks clean and I have a carpeted room, so it works well. Designed to be used in either orientation though, as "legs" can be installed either way and it comes with a grill for front firing orientation.

Regarding other comments, yes, the app based solution is very well done. It has always connected quickly, and I have not run into any hiccups at all. It only needs to connect via bluetooth if adjustments are being made. The apps (Anthem for running setup, ML for sub controls) are well designed, and the ability to make adjustments on the fly from the seating position is great.

Sure, a full mini-dsp system would be more powerful and encompass the entire frequency spectrum. However, as you note, it requires a laptop and quite a bit more effort. I'm not discouraging anyone who wants to go down that route, I was strongly considering it myself. However, my experience with the ML sub with it built in is effective, elegant and simple. A great solution for properly integrating a sub with the room and existing speakers.

One can always add a full DSP system later on. ML even addresses this in their literature, suggesting turning off the built-in room correction in this case. You still have the adjustment app though, in this scenario, so it's like a remote control for the sub controls.

Are you using a high pass with your mains?

If so, how did you decide where to do the rolloff?

 

[Willem]

Some subs are better than others, but two things are probably more important:
1 integration with the main speakers. For best integration I like to play the main speakers at full range and only use a low pass filter on the sub. If this is what you do, the crossover should often be quite low (33 Hz on my main spakers). Not all subs allow this. The slope of the attenuation may also be important. Often a 12 dB 2nd order slope is best for sealed main speakers, whereas a 24 dB 4th order slope is often better with ported main speakers.
2 integration with the room. Subs usually generate pretty massive room modes, i.e. peaks and dips at the low resonant frequencies of the room's dimensions. There are three ways to combat this. The first is bass traps, but at low frequencies those are quite massive and domestically not necessarily acceptable. The second is to use multiple smaller subs that compensate each other's behaviour because they are in different locations and hence excite different room modes, and produce good results over a larger listening area. Four is probably best, but two is often almost as good. The Audiokinesis Swarm system is a good example of the benefits of four subs. Finally, there is the options of dsp room equalization. I have been very pleased with the easy to use automatic and affordable DSPeaker Antimode 8033. This can flatten the response very effectively, but with only one sub the benefits tend to be highly localized and limited to one listening position. So all in all, the best solultion is probably to use two subs combined with the Antimode 8033 or a similar system. The best size for the sub then depends on the size of the room and the kind of music or movies you want to play - plus your budget of course.

 

[watchnerd]

The best size for the sub then depends on the size of the room and the kind of music or movies you want to play - plus your budget of course.

I don't use my system for movies, but can you elaborate on the music type thought?

I spend <1% of my time listening to music that has what I would call extreme bass (pipe organs, EDM synth), with most of my music using having the deepest notes defined by a piano (28 hz) or a bass (6 string 31 hz, 4 string 41 Hz), timpani (65 Hz tuning), and kick drums (20-100 Hz).

 

[Willem]

There is quite a difference between baroque harpsichord and a late romantic symphony. Unless your room is very large, even two sealed SVS SB1000 subs will do quite a lot. If it is just for music I would avoid ported subs. But do not leave out the Antimode 8033 or similar.

 

[watchnerd]

There is quite a difference between baroque harpsichord and a late romantic symphony.

Lukewarm on and seldomly listen to harpsichord (maybe once a year), whereas romantic symphonies are probably 30% of what I play on my big system, jazz 60%, rock/world/other 10%.

 

[watchnerd]

Unless your room is very large, even two sealed SVS SB1000 subs will do quite a lot. If it is just for music I would avoid ported subs. But do not leave out the Antimode 8033 or similar.

I thought the SVS SB1000 would have been a 10". But it's 12"....although a tiny one!

As for Antimode, are they still in business? Their website ( http://www.dspeaker.com/ ) seems unreachable at the moment.

 

[RayDunzl]

Their website

works for me (without https)

 

[watchnerd]

works for me (without https)

Huh, works in Safari, but not in Chrome for me.

 

[dkinric]

Are you using a high pass with your mains?

If so, how did you decide where to do the rolloff?

No other adjustments. The speakers are bookshelf, I run them full range on Direct mode, as my amp has no bass management. The design philosophy of the amp is high quality components and beefy isolated power circuits with simple, short, isolated signal paths, so that's what I honor. This works well for me as the speakers play clean at all volumes I've thrown at it. I let the sub DSP decide where to weigh in and take over the lowest frequencies.

There are arguments to be made for putting a floor on the lowest frequencies to one's mains, allowing them to concentrate on the higher frequencies and maximizing the power of the amp there, and letting the sub do the rest. There is also an argument that the simplest circuits sound best. At this level of kit, it just depends. My system has no issues with power or low end distortion, so I keep it simple. It works well for me.

 

[watchnerd]

No other adjustments. The speakers are bookshelf, I run them full range on Direct mode, as my amp has no bass management. The design philosophy of the amp is high quality components and beefy isolated power circuits with simple, short, isolated signal paths, so that's what I honor. This works well for me as the speakers play clean at all volumes I've thrown at it. I let the sub DSP decide where to weigh in and take over the lowest frequencies.

There are arguments to be made for putting a floor on the lowest frequencies to one's mains, allowing them to concentrate on the higher frequencies and maximizing the power of the amp there, and letting the sub do the rest. There is also an argument that simple circuits sound best. At this level of kit, it just depends. My system has no issues with power or low end distortion, so I keep it simple. It works well for me.

I'll admit that my initial bias (probably from some combination of AV-centric thoughts on sub processing, plus how I run my nearfield monitors in the studio) is the former: sats should be high passed.

But....

1. My mains / sats (Dynaudio Contour 20) are pretty big for stand mounts, designed and voiced to be nearly full range, have a pretty high excursion driver for its (18cm) size, and my amp has lots of power to spare.

They also don't have the same kind of dynamic range constraints you get with a smallish 5" wall-mounted AV sat.

So that would seem to mean, I don't want subs because my sats have inherently weak bass; I want a sub because my room has issues.

2. Since I'm correcting for the room, and not trying to make up for dynamic limitations of the sats, I can see the case in hypothesizing that a high pass on the mains may do more harm (yet another circuit, albeit DSP, isn't the use case the speaker designers envisioned when they voiced the speaker) than good (hypothetically helping extremely rare cases of headroom limits).

3. Running full range would let me more properly use Devialet's SAM, which seems to make for lower Q / tighter bass.

 

[DonH56]

Worked in Chrome for me.

My experience is the opposite of Willem's nearly every time. I find using a HPF to keep the sub frequencies out of the mains greatly improves in-room frequency response, assuming I can properly position the subs, and getting the high-amplitude deep bass out of the mains greatly improves their performance (lower distortion etc.) plus off-loads their amplifiers for the rest of the frequency range. And I have rarely found that the best place for stereo imaging and such is the best place for the deep bass drivers due to room modes, SBIR, etc.

When running subs in a stereo system without bass management (as I have run my Rythmiks though not now) I used a crossover and adjusted settings on the subs for integration. The Rythmiks include a lot of features to help, including built-in crossover, continuous phase control (huge help), PEQ, and level controls -- all analog. Other subs include DSP control. For crossovers, I have used many, lastly a dbx 223 (analog L-R, 24 dB/octave), but there are choices from th e$100 miniDSP to the $200 dbx to $1000 Marchand to $3000+ Bryston/DEQx etc. crossovers.

FWIWFM - Don

 

[watchnerd]

getting the high-amplitude deep bass out of the mains greatly improves their performance (lower distortion etc.)

I'm going to try to ask this in a way that doesn't sound pedantic, as I mean it seriously:

For a given main, what qualifies as deep bass?

Because every driver has excursion limits / F3 / Fs resonances, what qualifies as "deep bass" will very from one main to another.

Would it be safe to assume:

=< F3: deep bass, high distortion >F3: gray zone, middle distortion >2 x F3 (an octave higher): safe, low distortion zone

 

[Soniclife]

1. My mains / sats (Dynaudio Contour 20) are pretty big for stand mounts, designed and voiced to be nearly full range, have a pretty high excursion driver, and my amp has lots of power to spare.

They also don't have the same kind of dynamic range constraints you get with a smallish 5" wall-mounted AV sat.

So that would seem to mean, I don't want subs because my sats have inherently weak bass; I want a sub because my room has issues.

Measure your mains in nearfield, distortion probably increases rapidly from around 100hz down, and will be worse with SAM. Also measure headroom as you crank up the volume, find where they start to compress, and what the distortion is like then. My Sonus Faber guarneri evolution have similar sized everything to your speakers, I'm finding a sub is magic, and crossing them over is great, I have more work to do to get them perfect, and a proper sub purchase is on my list.

 

[watchnerd]

Measure your mains in nearfield, distortion probably increases rapidly from around 100hz down, and will be worse with SAM.

SAM increases distortion? I thought it was supposed to lower it?

Damn Devialet and their mysteriousness....

 

[Soniclife]

I thought the SVS SB1000 would have been a 10". But it's 12"....although a tiny one!

The 2000 is also very small and presumably higher quality.