Subwoofers with room correction built in?


Who has experience, good or bad or whatever, with the built-in room correction/DSP/EQ that newer subwoofers (except REL) come with these days?  I’m excited to try the system built into an ELAC sub 3070 that’s coming my way soon, but I want to be realistic.
Thanks.
redwoodaudio
Well, I'm a few days into using my new Elac 3070.  The auto-eq feature smooths things out a little, but in my room it does not appear to make all that much of a difference.  The room has rarely caused me problems with other gear and setups.  Overall, love the app-based interface of this subwoofer but most of all the excellent bass foundation it provides.  Currently crossing over the sub at about 60-70hz with my my Graham Audio LS5/5s.  
I find the processing parameters offered with many of todays consumer subwoofers built in room correction / optimization quite limited. 
On the other hand unless you've heard the affects of a suite of manually adjusted parameters I think you'll be quite satisfied with the before and after the Elac smart phone application appears to offer.
Any sub is more fun than no sub.

Welcome to the deep end, have fun with it
@redwoodaudio said: "This is an interesting option from Underwood hifi by DSpeaker: 8033 SII subwoofer equalizer. Just for the subwoofer."
That’s the unit I mentioned upthread. It is inexpensive, comes with a calibration mic, allows you to do repeated cycles with different mic placement and enables you to DSP just the subwoofers. That’s what I use with the 15 inch Rythmiks. I run it through another line out on my line stage. The main speaker system is not getting any signal from it and remains entirely unprocessed.
Very effective, both in terms of performance and cost, especially since I’m running those subs very low-- as mentioned, roll them off at 55hz on a 24 db/octave slope. The trick is dialing in the main speakers and woofers once the DSP does its thing- manually adjusting gain (including through use of a good SPL meter), phase, roll-off of the main speakers, their crossover point, etc. Still takes time and effort, and no remote, but it works well for me.


Really like my MartinLogan 800x. I didn't find the anthem did a whole lot after I ran it but it along with the ML app allowing for wireless access to fine tuning the sub made it much better then my previous ML 1000w sub. Way less boomy and didn't keep the kids up in the evening anymore.
@twoleftears yeah, that review got me thinking about this concept again... I found it quite encouraging, but wanted a bigger sub that I could get a deal on.
Check out Herb R's review of the SVS 3000 MIcro in this month's Stereophile.  He spends a good deal of time on the phone app and the many variables that are constantly adjustable via the app.
@bigwave thanks for the heads up about this brand, even though they're currently out of commission
@audioquest4life the elac EQ uses your smartphone mic, but directs you to take a nearfield and then a listening position recording by which to calculate the frequency curve. i’ve seen it demonstrated online and it seems pretty snappy. and yes, velodyne is a little under the radar, but they seem like they mean business with regards to subwoofers. they’ve been doing this built-in EQ for a while it seems.

@mijostyn
The absolute best way of going about this is to get a DSP preamp like the MiniDSP , Anthem STR or DEQX Premate
I have a great dac and preamp and don’t want to do the ADC and DAC through these alternate components for my full signal path. If it was just in the path between my preamp and sub, it would be more appealing. we’ll see how the elac’s EQ does by itself first, but I’m open to tweaks.  This is an interesting option from Underwood hifi by DSpeaker:  8033 SII subwoofer equalizer.  Just for the subwoofer.  
@mijostyn…+1,

Most often folks neglect the listening position altogether when going through the time and expense of setting up subs in the corner or alongside walls. It defeats the purpose for the ideal end state. 

I am close to that level of tweaking “get a DSP preamp, MiniDSP, etc.” except not building a passive sub with an external amp like you did. Perhaps, you can sell your DIY kits for the masses:)😀👍
redwood, room control is really speaker control. You are adjusting the speaker to suit room acoustics AT THE LISTENING POSITION. Everywhere else in the room the correction will be wrong. You still have to do your best to improve room acoustics. The Room control in subwoofers is extremely basic. It can only adjust frequency and phase. It can not correct group delays and most subwoofers have low pass filters only and not two way crossovers. These are two serious flaws if you are looking for the ultimate bass. Having said this a sub with room control is better than without and using two of them will be an improvement in most systems
The absolute best way of going about this is to get a DSP preamp like the MiniDSP , Anthem STR or DEQX Premate. Then build a passive sub from a kit. PartsExpress has a lot of them. Then get a commercial sound reinforcement amp with a high damping factor >500 and a lot of watts.
I like QSC products over Crown. With a system like this you have digital control over everything including the crossover. If electronics are so susceptible to vibration why would you want to put them inside a subwoofer?  
Yes, from what I understand the Martin Logan app is smart enough to "know" that not all phone mics are created equal so it first measures your phone mic then you can continue with the calibration. Pretty cool. But, yeah, the Perfect Bass Kit is better.
Martin-Logan X series can be used with a smartphone app that is OK. Much better results w Perfect Bass Kit.

The smartphone app is good for tweaking phase and level to fully integrate with mains.

In two years, the only negative is they are light and require mass atop them if they are on a compliant floor, i.e. media room above a triple garage with an unsupported ceiling. see http://www.ielogical.com/assets/Audio/SubWeight.jpg - somewhat low WAF factor
Syzygy subs, we’ll built & have EQ, works extremely well. Out of business but still may be able to find. 
One thing about auto EQ, unless a separate microphone is included with a long cable reach, Auto EQ will only use the subs built in microphone and EQ the bass for its resting location, not the listening position. Although, it will be better than not doing anything at all, in terms of bass EQ, you made still need to fiddle with the settings if the listening position does not sound right. That’s the thing about integrating subs into any listening  environment, you can adjust by ear, and/or adjust with measurement tools. 
More subs, as others have stated, and scientifically proven, will help to alleviate room anomalies by allowing a flattened low frequency response as long as the multiple subs are not exciting the same room mode, then you have to vary the positions of the subs within the room to help alleviate that issue. At the end of the day, auto EQ should help a lot compared to not doing anything at all, but with the caveats I stated above the measured frequency response at the listening position. 
What are your room measurements? I can send you a room mode calculation which will depict the room modes. It’s not a real live measured response but a scientific approach based on volume and size which normally is pretty accurate. Other factors could play into room modes, furniture, design, construction, etc, but, this approach gives one an “idea” of probable room modes before doing anything. 
The only subwoofer that I know of and have experience with that had auto EQ was the Velodyne Digital Drive 12. It worked pretty good. Velodyneacoustics are now located in Germany, but have distributors in the U.S.A. 
That is a true self contained self auto EQ solution which does not require external measuring software or external DSP hardware. It’s all built in and plug and play.  Hmmm, makes me think of exploring the Velodyne subs again. I sold them when we moved due to lack of space and at the time, Velodyne was restructuring and availability in U.S. was non existent. That has changed due to new European ownership. 
Depending on where you are located in the U.S., I located several dealers. 
https://www.velodyneacoustics.com/en/experience/#nordamerika



@deadhead - I just didn’t want to spend the $ for JL right now, but I know it’s got a well regarded DSP.  Maybe someday.
@jrpnde - I’ve had subs in my system before, but that was before I had my system dialed in he way it is now.  I had in order rel t9i and rythmik 15, both nice subs, but manual adjustments were just too much trouble, even after taking a methodical approach. My current speakers are great (graham audio ls5/5), but I want the full dynamics in the music to come through as much as possible.  The built-in sub EQ seemed ideal to save some hassle this go-round.  Found a great deal on the Elac, would have considered some of the others mentioned here so far as well.  If you want to know more, see my system page.
I'm partial to Bowers & Wilkins DB4S.

https://www.bowerswilkins.com/home-audio/db4s 

1000W Class D Hypex amplifier
Aerofoil™ bass cone
Digital preamplifier with Dynamic EQ
App-based set-up and BT-LE control
10Hz – 350Hz -3dB
8.5Hz - 500Hz -6dB

DB Series subwoofers provide optional equalisation presets designed to suit music and movie programme material. Custom equalisation via a five band equaliser is also provided.

I'm not sure about the feet supplied, but SVS SoundPath Subwoofer Isolation System is easily fitted.

No worries with the music and as for movies... well let's just say it can handle anything thrown at it.
I had an old velodyne that I replaced this year with a JL Audio 110 with their DSP. Without the DSP it was obviously better, but when I set it up with the DSP,  to me it went up another big, very noticeable notch.
   You didn't mention much about your overall system or if it is your first venture into adding a sub to your system? One of the most challenging projects of all. If this is your first attempt of adding one or not, room correction may be important but not the primary concern.
   So many factors to consider......room acoustics, placement of sub(s), etc. Seems that getting the basic performance should be of primary focus before fine tuning with room correction. You may want to seek advice from millercarbon who has lots of good advice about subs, especially the use of multiple subs.
   Please don't infer that I think you're new to subs but your original post didn't give many details. Not intended as an insult but there is quite a lengthy article about subs if you're patient enough to read it.
http://www.soundoctor.com/whitepapers/subs.htm

Vandersteen Sub 3 11 band EQ same adjustable as Quatro,Kento and 7s

Enjoy the Music 

Tom
True room correction is not totally true even in a preamplifiers 
it Averages , Svs has several ANalog Devises 52 bit processors a great app , and you can fir free down load a subwoofer room correction program ,just buy a USB Mike ,  call Svs they can educate you on it to truly flatten your room acoustics 
2 subs are by far better then one also.
From what I've read, you should run something like REW to verify the outcome. You may end up with better or worse results than setting the subs up manually using tools like REW. I wouldn't assume it's going to be better just because is done automatically.
For home theatre, I run Anthem ARC, but don't really care what happens with auto correction. Personally, for music, I don't see the benefit because I'd use REW anyway. 
@docknow and @doctors11 -- I hadn’t considered a Martin Logan sub -- thanks for the tip. Glad to hear the room correction is seriously helpful.  Interestingly, the balanced force sub has two drivers in opposition like the elac.
The Anthem Room Correction on my Martin-Logan Balanced Force 210 sub is nothing short of outstanding.  The difference between no correction and corrected is the difference between bass that goes in and out, depending on the note, and sound that is equal in volume as the bass player goes up and down the neck.  Quite beautiful.

I only have one sub though.  Perhaps it would be less noticeable with a DBA.
No experience but lots of reading with almost universal love...the Dynamo series from Martin Logan. Anthem Room Correction built in. Full app control.
Well the just of it is, the ones I built work great and the plate amps your asking about are very close. It's worth your while. Along with room treatment, DSP is a great tool and pretty easy to use..

Mic position is the key if you ask me? Right where your head is going to be.

I'm not saying you'll like the way it sounds though.. Really some people just don't like the sound. It doesn't account for OUR ears sensitivity or the lack of it.

Better off with it, than without it. That's for sure.. I use the PEQ function for a 50 and 70 hz bump works great..

Enjoy
It's good to know that there are external DSPs that can be had for reasonable prices, but right now I'm primarily interested in hearing from those who have had subs w/ the feature built in.  Anybody else care to share?
I’ll echo the last two posts and add that even the cheap 8033 from Dspeaker, which is only meant for subwoofers, works well, particularly if you dial in the woofers as much as possible (placement, crossover, gain, phase, etc.). I run such a unit from an additional line out on my line stage to feed the Dspeaker, which controls a pair of Rhythmik 15 inch subs. Those subs are not crazy money and really blend well with my hybrid horn set up. Note that the 8033 sums the bass for two outputs so no stereo subs (unless you have two 8033s or buy the fancier Dspeaker unit mentioned above). I don’t really care about that because I’m mainly playing LPs most of which are summed bass anyway and I'm rolling off the subs at 55hz on a 24db/octave slope. Pretty cost effective way to get synergy with a horn/hybrid that does not sound like two systems playing at the same time. It is seamless.
+1 @musicaddict Though I tend to buy from miniDSP.  Also, DSP works MUCH better if you have good room management.
For less than $1k you can get the DSPeaker Anti-Mode 2.0 unit with built-in room correction and DSP equalization modes. Other units are out there but I'm not that familiar. These units can be used with your main speakers, in addition to your subwoofers, to take out certain problem frequencies. Some will go to their graves fighting DSP tooth and nail but I would not remove mine. The improvement to the sound of a good system is night and day, no kidding.
I am hopeful you can make most self-adjusting subs work.

The parts they seem to do well is room integration and main speaker integration.  The part that is sometimes in question is the bass ends up too dry, which can be fixed by gently boosting the lowest Hz, 16 to 25 Hz and letting it slope downwards about 1 to 2 db/octave until it reaches the main speaker crossover frequency.
@oldhvymech - my DIY skills are pretty limited so far, but I'm sure this would be a worthwhile approach.

@erik_squires thanks. I know JL is the real deal, but I have high hopes for the elac due to Andrew Jones involvement. 
Given the trouble audiophiles have in correctly integrating a room, I highly recommend this approach in general.

The one thing to keep in mind is that auto setting software is not all the same. I really like the way JL audio's built in software sets their subs, but they are super pricey. You definitely should listen before buying if you can, otherwise it's worth keeping an open mind and being prepared to tweak.

A gently descending curve from 20Hz to 80 Hz to my mind sounds much better than flat.
I've been using plate and external XO with 12K class d amps with all the goodies for over 6 years. 

DSP with
Delay
Threshold
GEQ
PEQ
3 channel summation
OTF (on the fly) correction
Active tracking, in real time, on a laptop.
Multi XO with 6, 12, 18, 24, 48db (2496 OXO not the plate amps)
Mic input 

Note 1. 2496 Behringer is Daisy chain via Cat 4-6 (EASY to set up a perfect DBA or Swarm VII) I'm not sure how many you can daisy chain, 128 at least. with 6K class d amps. ALL with full blow DSP engines.

Note 2. The plate amps are not quite as loaded with goodies as the active 2496 OX but they sure do work well.

https://www.parts-express.com/Dayton-Audio-SPA500DSP-500W-Subwoofer-Plate-Amplifier-with-DSP-300-801...

This plate amp has two big brothers a 1200 and 2400 model. Every now and then they produce the 1200 and 2400. I use their SPA non DSP plates amps too. Good amps.. They have correction just not DSP. No active correction or remote correction.

I've had the same rooms for 40 years.. Ya just know. Push that button and turn that knob.. :-)

Enjoy your newbie.. I'm glad the price didn't go out of sight. Everything else did..

Regards