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?
vinnydabully

Showing 7 responses by millercarbon

Its amazing when it comes to bass how much better more is than few. With subs unlike the L/R stereo pair the subs can be completely different and located almost at random and yet still work just fine. So they can be "cobbled together" buying whatever you can whenever you can add and still wind up with excellent results. This might even be the best way to go, because of all the flexibility being able to adjust crossover and level of each individual sub. If you can afford a better sub great, but if you can only afford a cheaper one that's great too because more is always better.
Multiple subs is the way to go. The more the better. Once you get to where you are now though (4) then yes better quality subs will be better. Also having them spread around the room, basically one per wall but asymmetrically not just one in each corner, helps to get smoother flatter response. Where are yours now? 
vinny I think you figured it out- when it sounds like just the mains, that's what you want. Some recordings have great low bass but a lot have very little or none. This makes it real easy to set the subs too high and not realize it until you get the rare record with really good bass. The meter test CD thing can get you close but then I think it just takes a while of listening and tweaking. Duke said the same thing, expect to spend a while fine tuning the levels. Then you put on Welcome to the Machine, Seal, Bird on a Wire, something like that, totally worth it.
The idea mijostyn has (and others, he is far from alone in this) of bass timing being smeared is of course based on the false assumption that human hearing responds to all frequencies equally.

That this is false is proven by a simple experiment in which subjects wearing headphones are played test tones of short duration. This test demonstrates conclusively that less than one full wavelength of low frequency bass is not heard AT ALL. Say again, human hearing does not even register very low bass less than one full wave duration.

Understand what this means? A single 20 Hz wave lasts 0.05 seconds. Anything 20 Hz lasting less than 0.05 seconds will not be heard at all. Sound travels roughly one foot per millisecond. Ballpark. So think about it. Bass can travel FIFTY FEET before we are even capable of hearing it.

So I ask, from the point of view of timing- not frequency response, just timing- how in the world is it possibly going to matter where you put the subs? Any normal size room the bass is going to leave the speaker, bounce off half a dozen surfaces, probably more than once, all before you even hear it.

Yes timing is super important - at high frequencies. I take heat on here all the time for saying speaker placement being off as little as 1/8" matters. But that’s high frequencies. Low bass is completely different.

Just one of several deeply ingrained yet totally false concepts hampering our ability to understand the beauty of the distributed bass array.
mijostyn writes:
I’m afraid millercarbon is spouting off with excuses to support his infatuation with SWARM systems, all of which are entirely unsupported assumptions which in reality are entirely wrong.


This is what psychologists call projection. Whatever you are doing you project onto someone else. Instead of actually listening to what they are saying.

Which if you did mijostyn, what you will read if you can be bothered is pretty much everything I have written is based on my actual experience. There is posted among the many threads my actual experience of actually reversing phase, adjusting phase, and trying different locations.

What actually happens- actually not in your imaginary theory world but a real live room- is when you reverse the phase the drum does not disappear. You still hear it. In fact it sounds almost exactly the same. Not quite. You can’t ever change anything and yet have everything be the same. But you said, "Out of phase and you feel nothing." That could hardly be further from the truth.

Now at this point I have to be clear. I’m talking about the lowest bass component only. Of course if you reverse phase on the main speakers the drum is going to go from being focused and located to the opposite, coming from everywhere. At very low frequencies though, and with four subs- which is what we are talking about- its a completely different story. The kick drum does not disappear to "nothing". Talk about unsupported assumptions!

So much for your projecting your own faults onto me. What about your projecting your own misunderstandings onto the Swarm?

You say everything about the SWARM is entirely unsupported assumptions. In fact the distributed bass array concept is based on extensive real world measurement and experimentation. In sharp contrast to your fantasy of it being all "unsupported assumptions" it is in fact only there because of the measurements. In other words it was not a case of a theory in search of evidence. It was the exact opposite of that. It was a case of testing and measurement and then eventually figuring out how to explain why we get those measurements. And only then what to do about it.

Its Audiogon. Someone is always getting something worse than backwards, then posting authoritatively about it. So nothing new here. But just because others do it doesn’t mean you have to follow them over the cliff.
noble100 says of mijostyn:
Incorrect, wrong and you're mistaken. Millercarbon absolutely knows you're wrong because he had the intelligence and cajones to give it a try.


Yup. And thanks. Finally got the Rosewood veneer on and finished. 

I believe the root cause of our disagreement over the effectiveness of 4-sub distributed bass array systems is your lack of experience and familiarity with them.


For sure. Demonstrably so. Thanks again.
mijostyn states:
The reason clio is now feeling his bass is because his subs are now functioning as one driver and the arrival time (phase) is the same across the entire room.


This is of course impossible.