My experience adding subwoofers to 2 channel


My Kappa 9 speakers are rated to 29hz and they sound pretty good in my 18x24 room...powered by McIntosh mc1.25 amps...l was looking for another layer of bass to enhance the sound..my first experiment l took my SVS pb16 ultras from my theater room and tried them first...it sounded terrible,didn't blend well..couldn't hear a difference until you turned in up then it rattled the room apart........my final experiment worked..l used 4 Velodyne minivee subwoofers(1000 watt rms class D sealed 8 in.) and after hours of calibration l hit it......lve got the bass response that exeeded my expectations. ....l should have done this along time ago....can anybody tell me of another subwoofer that may work even better?
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clio09:
"@noble100, my speakers are the Model 2, mijostyn has the 2+2. I doubt my speakers go down to 28 Hz, but regardless I am cutting them off at 100 Hz. IIRC I think Duke recommends running the mains full range and set the frequency on the Swarm accordingly. If I am wrong about that I apologize to him in advance. I could run my system that way, but I prefer to follow Roger's method and treat the panels as if they were designed to only go down to 100 Hz.

As for your amp, measure it. That will tell you what you need to know."

Hello clio09,
     My mistake.  Your Acoustat model two's specs state they go down to 30 Hz, which means our speakers are even more similar in their low frequency limits than I originally thought, 28 Hz for yours and 35 Hz for mine.  So, I believe everything I stated in my last post still applies.
     I know the xover frequency and volume controls and settings are the key adjustments that need to be set properly for my DBA system subs to blend seamlessly with my main speakers.  I do use Duke's recommendation of running my mains full range and usually set the xover frequency on the Swarm/Debra accordingly, which in my room and with my speakers seems to be about 45 Hz.
     I just tried raising my xover to 100 Hz on my system as a test.   The most noticeable effect this had was to change my system's normally 3D soundstage imaging into a 2D soundstage image.  It flattened out the soundstage similar to the difference between looking at a real life live scene and a video of it.  It was much less realistic and enjoyable.  
     I think I know the cause and effect of this change in perception but want to think about it a bit more thoroughly before explaining it in words.
     In my opinion, the ability of a high quality audio system to create a solid and stable three dimensional soundstage illusion in our rooms through a pair of properly positioned speakers, with the assistance of our brains and a well engineered recording, is one of the most enjoyable experiences to strive for in this hobby.  
     I've discovered that my 4-sub DBA system, by adding the accurate reproduction of the lowest audible bass frequencies it was lacking from about 20-35Hz, significantly enhances this 3D soundstage illusion by causing it to sound even more life-like and palpable. The increased bass detail,the increased bass dynamics and impact that can be felt as well as heard along with this added bass output seamlessly blending with the quality of the rest of the audio spectrum being reproduced by my main speakers also contributes to this realistic portrayal.
     As I've stated, I'm extremely satisfied with my DBA system's performance and my wife's very pleased with its inconspicuous presence in our living room.  I'm not claiming a 4-sub DBA system is superior to a line array bass system in bass performance but it certainly is when judged in the living room inconspicuousness and swimsuit competition stages of the sub system contest.

Tim
Tim, If you have been following those of us with panel loudspeakers who have a lot of experience with sub woofers, there is a strong belief that removing the very low bass from this type of speaker decreases distortion and increases power handling. With your speakers that have two crossover points at 500 and 950 Hz the effect will not be as pronounced. Clio and I have no cross overs so the effect is over the entire frequency spectrum. You did not roll off the Maggies at 100 hz so now you have the Maggies and 4 sub woofers competing with each other all out of phase. It should be no surprise that it sounded like garbage. But it is a learning experience and you know for sure that approach will not work:)
Clio, Roger is absolutely right. ESLs should not be allowed to go under 100 Hz. To destroy that beautiful mid range with stuff any old crude sub woofer can do is a travesty.
I wouldn’t even consider a tube amp to power subs due to their generally low damping factors and their resulting poor ability to firmly control the movement of dynamic cone drivers, especially the precise starting and stopping required of larger and heavier bass drivers in subs.
Actually this 'precise starting and stopping required of larger and heavier bass drivers' is a bit of a myth. You can get excellent and natural bass out of a tube amplifier if you set things up right. Our amps go full power to 2Hz so no measurable square wave tilt at 20Hz. So often what causes people to think tube amps don't make good bass is phase shift; if there is a cutoff within 1/10th the lowest frequency to be amplified phase shift will be present. This can cause a lack of impact. FWIW, if you overdamp the speaker it will be less able to play bass impact correctly; no speaker needs more than 20:1 damping factor.@mijostyn  Some of those Acoustats were very easy to drive and some weren't. I've never figured out the models, but a customer had a set of M-60s driving Acoustats and the combo was wonderful. The Acoustat was a very nice and IMO an undersung product.

Hello atmasphere,

Thanks for the good info, I learned some good stuff.

Tim