For those of us with subwoofers, I'm curious whether you thought integrating it was easy or difficult. That's it.
Of course, lots of DBA people will chime in. No problem but please ask that everyone stay on topic. If you want to discuss all the pro's and cons of DBA take it to a brand new thread. Thank you.
The focus here is just to ask how many people had easy or difficult times and what you thought was the difference.
Not difficult but it is a process and the more of a perfectionist you are the more knowledge and tools you will need.
Depends greatly on the subwoofer (RELs are by far the easiest because of their passive radiator) and the speakers (speakers with lower output are harder to integrate unless you plan to high pass, which I will not do.
Two subs are more difficult, especially if you don't know the proper method, but the results are better.
I would not integrate a subwoofer without a using some form of measurement tool- e.g. a microphone, RTA software and full bandwidth pink noise tracks.
I’ve run a single sub + 2 desktop main speakers for ~15 years. Until ~5 years ago the mains were powered; then I switched over to a series of passives.
For me, the hard part of subs wasn’t placement--I only had one placement option, and luckily all the subs I’ve tried sounded good in that spot. Specifically, in my nearfield setup (home office), the sub’s effect sound flattest/best in the listening seat equidistant from the speakers. So I lucked out there.
But for me, the hard part was getting a high-pass filtered signal to the mains. Some subs have built-in crossovers that can do this. Sometimes those crossovers are high quality and sound good; other times they’re trash and sound bad (I’ve had both). I solved that issue for once and for all by picking up a transparent, high-quality external electronic crossover ((Marchand XM-66 in which the high- and low-pass filter slopes 24 dB/octave).
The other hard part is matching the sub’s output level to that of speakers. I found two things that help:
I get better results by far when using sealed/acoustic suspension speakers. They sound better here, and have the benefit of having a real drop-off out output at the resonant frequency. I count on that when setting the crossover
And it helps to cross over to the sub at the lowest frequency (that is comfortably above the -3 dB drop-off point of the mains).
Would all this apply to a far larger, high-end system in a living room? Yes, but also no, because there the physical placement of the sub (or subs) would consume much time & effort.
@atmasphere- hi atmasphere, I was wondering, which of your two set-ups, with the DBA and the single sub, do you feel sounds better? And, of subs in general, do you believe forward-firing subs produce more accurate lows than downward-firing ones? thanks much!
@kevnThe DBA setup is more accurate. The single sub suffers a bit around the edges of the room where it gets too much reinforcement. Forward or downfiring has no effect (in practice) simply because in most rooms the bass is entirely reverberant by the time you hear it due to the wavelengths involved (at 80Hz the wavelength is 14 feet).
@jrpnde, nice article and very correct. A sub not only has to match the mains in frequency response but also in time. This is the problem with DBA's. They do a great job of evening out the bass response throughout the room. But, they are not necessarily and probably not matched in time with the main speakers. You have to be in phase and in time with the main speakers or you have essentially an echo. Bass transients like bass drums lose their impact. The buzz in bass strings disappears. The only way you can do this easily is with digital signal processing. The Anthem system was mentioned above. MiniDSP makes the least expensive unit that I know of. There is Trinnov, DEQX and Lyngdorf. People who are digiphobes need not apply and more than likely would be better off without subwoofers. You can not recreate a live performance without subwoofers. To do it right takes much more driver surface area than you would think. Residential rooms stifle bass. Add a processor to this and you have considerable expense. If you can not do it right you are more than likely better off from a sonic perspective not to do it at all. You can kiss the live performance goodbye but this is not what most people want anyway. They want a more polite system that is very detailed. They rarely listen over 85 dB and bass loses it's energy at this volume subwoofers or no.
Another important aspect of subs is that they take the load off the main speakers which can make serious improvements with their performance in terms of distortion and headroom. Good subs do not low pass at 40 Hz. They are used in conjunction with a high pass filter on the mains and cross between 80 and 120 Hz then time corrected usually by delaying the signal getting to the main speaker so the group delays match at the listening position. You have no idea what is happening unless you measure it. If you think you can do it by ear, good luck to you. Getting it right would be like winning the lottery. Like everything else in this life there are no cheap easy solutions only people who want to sell cheap easy solutions.
Just want to repeat my request to please keep the thread on topic by focusing on:
Personal experiences
Difficulty of getting to done.
If we veer too much into theory and pro’s cons of any particular solution this thread will rapidly degrade. Fortunately those interested in debating the pros and cons of any particular solution can pursue that by creating new threads.
nice article and very correct. A sub not only has to match the mains in frequency response but also in time. This is the problem with DBA's. They do a great job of evening out the bass response throughout the room. But, they are not necessarily and probably not matched in time with the main speakers. You have to be in phase and in time with the main speakers or you have essentially an echo. Bass transients like bass drums lose their impact. The buzz in bass strings disappears.
@mijostynThis is mostly incorrect unless you let the subs run up too high. At lower frequencies the 'time alignment' thing isn't an issue simply due to the length of the waveform. At 80Hz its 14 feet long and that means in most rooms its bounced off the wall behind you before the you can even know what the bass note even is (it takes a few iterations of the note before the ear can identify the frequency). By the time you've identified the note, the bass in the room is entirely 100% reverberant- there's no time thing. So yes: ALL bass in regular size room below probably about 80Hz is an 'echo'.
FWIW this is the case whether you have a single sub or a DBA or anywhere in between.
I play string bass; have since I was in 6th grade. The 'buzz' in bass strings comes from harmonics of the instrument, not its fundamentals; the former are handled by the main speakers.
A DBA has no adverse effect on bass impact (if you have a standing wave at the listening position it can certainly improve it); at any rate regardless of the subs you have if they (or it) allow proper bass at the listening position then the bass will be the same in either event regardless of single or multiple subs.
@atmasphere I absolutely agree, if you are crossing over at 40 Hz. If you are trying to "unload" the main speakers from having to make bass which is particularly important for speakers with smaller woofers, full range drivers and ESLs you have to cross up around 100 Hz . For over a decade I was crossing at 120. The wavelength at 100 Hz is about 10 feet depending on your altitude. Worse even if you are using a steep slope there can be useful output up to 200 Hz. These wavelengths fit into all residential rooms except closets. A lot of the detail in bass and slam comes from this range. I can show you in an instant playing a repetitive bass drum kick switching the delays on and off. I do have a special situation as I designed the house and this room was purpose designed to be a media room. All the speakers and subs form linear arrays and are very directive. There is very little room interference. I essentially have no back wall. It is all broken up opening into other rooms and hallways.
Hoping to order my MA2s in a month or so. I'd say we are 95% of the way there.
@atmasphere, I forgot to mention we are talking about two different buzzes. I mean the vibration you feel as if you feel the string moving. The buzz you are talking about is the icing on the cake. It comes I think from the string vibrating against the fret board. I love listening to Dave Holland as he makes a lot of that noise playing. I just saw Marcus Miller and Mike Stern at the Blue Note in NYC and I was about 15 feet away from Marcus, best electric bass I ever heard. Now I have a new target to shoot for. I wonder why humans love having their insides rattled.
I have just this week been looking at some changes to my sub situation. My main speakers with two 9-inch drivers each in a very inert acoustic suspension cabinet perform very well with bass down to around 40Hz. I have been very happy with the sound resulting from rolling in two subs and cutting them off at around 40 Hz.
In discussions with the manufacturer of my speakers, he believes what I am doing is fine, but that I could gain improvements with a high pass filter set for 45 Hz, which could reduce doppler distortions resulting from the woofers reproducing lower midrange frequencies up to 360 Hz while at the same time trying to reproduce very low frequencies in the 30-45 Hz range. Marchand is in the process of building a passive balanced HP filter for me.
It is also my speaker/sub manufacturer's experience that two subs run in stereo (which is how I use mine) are superior to one mono, or running two in mono. He believes we can localize stereo sounds in the low bass to some extent making it worthwhile to run the subs in stereo. Regarding more than two subs, it is his experience that adding a third sub run in mono and located in the back of the room can provide significant improvements in bass, while going from three to four subs is much less of an improvement. He recommends adjusting phase using a trial and error method from the listening position. I have been planning to add a third sub but haven’t yet found one of the SW-12s that I use anywhere close to where I am located.
My main speakers use dual 15" drivers each. They can shake the house pretty well; everywhere except the listening chair 🙄 So I added a pair of subs, thus creating a DBA because the subs are asymmetrically placed. Now I get the same bass impact (and 'buzz'...) at the listening position that the rest of the house gets.
@atmasphere, you put your listening position in a null spot! You evened out the amplitude response in the room. It would be interesting to measure the group delays of the system before and after you added the additional subs. At what frequency do your 15" woofers cross to the midrange horn?
Yes: 'Nulls' are caused by standing waves. It was exactly the only spot in the room the listening position could be located. Move three feet in any direction and no problem. I am very lucky in that my GF likes the stereo quite a lot (helps when it sounds good) so its in the living room rather than a mancave.
The 15" drivers cross over at 500Hz. They are field coil and quite fast, but so is the midrange driver.
My tapped horn subs, two of them, are big at 20 cf. per cab (and each weighing around or +200lbs incl. the driver, built in BB 13-ply), and handling such behemoths certainly isn't easy.
Once positioned is their respective corners (a placement chosen to flank the mains symmetrically and to take advantage from boundary gain) integration with the mains and overall acoustics from hereon has been a work in progress, mostly with regard to finding the proper delay setting as this has been done by ear (sorry, @mijostyn).
Tapped horns as well as the more classical front loaded horns can be tricky to hone in on wrt. delay (unless done with microphone + software), because there's not really a wave front outset to visually outline as a starting point, if you would, the way you can with a direct radiator. Some delay compensation with horn-based subs is a necessity, and knowing the horn path length helps, but with a tapped horn the front wave isn't initiated at the front nor back wave of the driver (positioned at the tap/mouth of the horn), but somewhere between the front side of the driver and the mouth.
Different delay settings have been been tried out via different presets, with a very good balance and mid bass energy now found. I have had my speaker setup (though with other, passively configured mains) measured out in both the time and amplitude domain and corrections done via software, but with my current actively configured setup I've only applied PEQ corrections (aided with measurements; completed by ear) on the top horn section via my Xilica DSP. A more complete software correction in both the amplitude and time domain may be implemented down the road.
To conclude: integrating my subs hasn't been downright easy so far, but having high-passed the mains beyond 80Hz, actively as well with subs sporting low group delay, decent phase behavior and no overhang, while having a professional, elaborate digital cross-over tool like the Xilica makes it a fairly straight forward process and a great way to harness the potential even further. Had I used digital correction tools to begin with the process would've been easier for sure.
As is the results are great; of-a-whole coherent sound, and totally effortless.
@atmasphere, WOW, that is high up but not unusual for efficient speakers. They probably need the radiating area to keep up with the horns. Between 200 and 500 Hz is a big chunk of very important midrange. Relieving those 15" drivers of 80 - 100 Hz down would clean up your midrange quite a bit. When you play the system as loud as you are comfortable with, something with a decent bass line and a bass drum, can you see the excursions? If you cannot see it doppler distortion is probably not audible. If you can see it , it probably is. The kicker here is my experience is with full range ESLs. Do the same criteria apply to cone drivers. I do not see why not. The driver with the smaller surface area has to take a longer excursion.
@phusis, you must have a huge listening room. check out the DEQX web site. They are just now releasing a new set of gear and it is really serious stuff. You get either a Pre4 or a Pre8 and you will be in hog heaven!
Basically it's what I have now (i.e.: fully programmable and nothing between the amp and the driver), but as an all-in-one unit this beautifully realized (or so it certainly seems) it's an item I'd like to acquire for sure.
@phusis I though I was going to get a Trinnov Amethyst until this came along. The Trinnov's bass management is too basic and does not give the kind of flexibility I am use to. I have asked for the DEQX Pre8 manual so I can get an idea how it is programmed and will choose once I see it. If DEQX continues to organize things as they have in past units, the new ones will be fine. In trying to make the situation as simple as possible, some companies are making it impossible to fine tune a system. The other problem with the Trinnov is that it does not have a USB audio input. The DEQX has one.
Please let me know what you find out when having gone through the Pre8’s manual. I have no experience with the previous line(s) of DEQX units, nor the Trinnov Amethyst for that matter, but learning of your findings would certainly give me a bearing on whether to seriously consider the Pre8 as a future acquisition. My Xilica digital XO has given me a taste of flexibility and rather elaborate settings to work from, so I wouldn’t want to give that up with a new unit either. Connectivity range with the Xilica is a bit limited though, so seeing that being given a boost wouldn't hurt, and fortunately the Pre8 has that to offer.
One thing that made setting up a pair of subs much easier for me was to put a 2’x4’ x 6" Owens Corning 703 fiberglass panel in each front corner. I plan to add a second pair in the rear wall corners.
I also have successfully used an Anti-Mode DSPeaker to help with room correction. Ultimately it was a matter of trial and error and making sure I didn't become obsessive.
Bass traps, properly used, are magical. I use them both for subs and for two ways and it never ceases to amaze me how much better my life is thanks to them. I simply lack some of the main bass issues (sub or no) others might contend with.
Super easy for me. I have a pair of Vandersteen 2wq and a pair of dunlavy Athena’s. Tons of time getting the Athena’s dialed in. Put the subs fairly close to the mains and not symmetrical in the room or relative to the mains. Started with the cheaper Vandersteen high pass filter which was pretty good but then made a charged balanced high pass filter with Milflex caps. Had to run two caps in series to get the right value so no need to double up on caps to implement charge balance….yes the battery makes a huge difference. My system has much more detail and separation than before, cymbals sound much more correct, smooth with no fatigue even though the top end seems more extended. Don’t even notice the subs except for the significantly added body and impact in the bass…still sounds like, well no speakers most of the time but the subs definitely do not stand out…fully integrated. While the added bottom end (80hz and down) is very nice the biggest benefit came from removing the low bass fro the amp and mains load. High passing the mains is the only way to go
One super easy integration, one not so much. The easy one was putting an old sub from Radio Shack in through the B channel of a receiver. I just placed the sub to the left of my rack and it improved the sound quality drastically. The second time I had a problem as far as where the subs should be placed because the two subs I had were designed to go in the corner of a room, but the wall where my unit was placed, is also where the front door was. I was loathe to place the one sub where the door would hit it. As it happened, a huge fire solved the problem for me. I now have a system with no subs at the moment.
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