Nord User Forum

Thanks again for all the input here.

ignoring for a moment the near vs far field issue, it is clear that for reproducing piano, the absolute No.1 is to have the best Hi-Fi reproduction possible.

As an example, I hooked up a pair of high quality speakers that just have a 4" bass driver and the result was astonishing - the closest thing to the pure sound you get with headphones that I have heard yet. No problems reproducing the bass notes. The sound easily fills a medium size room.

I then tried playing a CD through my L1 Compacts - It's Ok but clearly not Hi-Fi. I did find that by reducing the bass at 100Hz (well known problem with these) and the treble at 8 -10 KHz, the sound improved a lot - which gives a pointer to EQ when using my Stage 3.
So clearly there is room for improvement when it comes to small PA. I haven't yet heard the QSC K8.2 but I would be very tempted to put a CD through these as well.

Almost anything to my ears would be better than the Bose L1. All of the suggestions here make sense, I have a pair of the K8.2s. I think even the Alto TS410 or even 408s would sound better. The guitar player in one of my bands brought them to a gig and it was the worst-sounding system I ever heard. It did not go loud enough to hear the vocals at all, and sounded extremely thin. Maybe for a coffeehouse acoustic duo, but certainly not a rock band.

-dj

cphollis wrote:The reason I keep suggesting that design vs a more traditional point-source speaker is that they usually have exceptionally wide dispersion (usually 180 degrees or more) which means that in smaller or irregular-shaped venues everyone will get a pleasant listening experience. Point sources make more sense when the audience is directly in front of you and you want to aim two sound beams to produce stereo.

Well put. The other (very significant) advantage to a line array is that volume drops off linearly with distance rather than proportionally to the distance squared, because the radiation is cylindrical rather than spherical. So, the line array helps to cover the whole room, both side to side and front to back, and best for background music. The point source is better if you actually want the back half of the room to be quieter: when you're playing to a room where folks who want to, can come to the front.

But mind what cgrafx says above:

cgrafx wrote:Arrays lose pattern control below frequencies whose wavelengths are longer than their height. To achieve pattern control down to 200 Hz, a line array must be over 6 feet

Another thing to keep in mind about these line arrays: with the wide dispersion, the reduction in loudness as a function of distance is linear (thanks to being a line array) but the linear coefficient is high (due to wide dispersion). So, one hand (line array) giveth while the other (angular dispersion) taketh away. This is precisely why line arrays are best when you need wide dispersion. At the opposite end of the spectrum, we have PA speakers with relatively narrow dispersion (90 degrees or less), which reduces the coefficent, but that coefficient is applied to distance squared. If you do the math, or better yet, try them out, you find that the narrow dispersion PA speakers can actually have more consistency in volume in their sweet spot than the line arrays. But the sweet spot is nearly directly front of the speaker, which isn't what you want here.

Yet another thing to keep in mind is that, at higher levels, any room (especially a more rectangular one) becomes a transmission line, and none of this dispersal stuff works out the way it does on paper.

If this stuff was simple we wouldn't still be talking about it so much. I've always used small PA speakers or high quality floor monitors (point source speakers) but sometimes in small venues I've bounced one or both off walls, to help with dispersion and limit my floor space. A Leslie sounds great that way, and piano, better than you might expect.

I'd love to try a pair of L1's (or similar) but my budget just isn't big enough, and I don't want to lug that much gear (e.g., the subs). I currently use a pair of QSC K8.2's that I'm very happy with.

JeffLearman wrote:

cphollis wrote:
If this stuff was simple we wouldn't still be talking about it so much. I've always used small PA speakers or high quality floor monitors (point source speakers) but sometimes in small venues I've bounced one or both off walls, to help with dispersion and limit my floor space. A Leslie sounds great that way, and piano, better than you might expect.

Well said!
My problem is that as well as adequate dispersion I'm looking for CD quality from a small PA system.
I find that as a HiFi enthusiast I am almost never satisfied with music coming from any PA system I hear.

For an audiophile, few (if any) PA systems will ever beat a high quality studio monitors or top-shelf home hi-fi setup. PA speakers are designed for high efficiency, so they can get more volume for a given amount of wattage.

To be twice as loud you need roughly 10dB more SPL, which takes TEN TIMES the wattage. So, those studio monitors that have 82 dB SPL efficiency will be less than half as loud as typical PA speaker, which tend to be in the 98 dB SPL efficiency range.

So, PA speakers are a compromise. They're not aiming for the same target as a studio monitor or high-end home stereo.

If you don't have budget limits, try RCF TT series speakers. I haven't heard them myself, but the broad consensus is they're among the best you can find.

I have a pair of QSC K8.2's. My favorite speaker demo is Aja by Steely Dan, and they sound good to me through the QSC's, but I'm 65 with typical hearing degradation for my age and s*x (can't hear much over 8K anymore, and the top three Hammond tonewheels don't really sound like notes.)

"To be twice as loud you need roughly 10dB more SPL"... Isn't this 3dB instead of 10?

Graspieper wrote:"To be twice as loud you need roughly 10dB more SPL"... Isn't this 3dB instead of 10?

There is a big difference between sound pressure (dB) and perceived loudness to the human ear.

If I have one speaker at +120 dB and add a second one, that would be +123 dB with twice as much sound pressure. But our ears don't perceive two speakers to be twice as loud as a single one. Put four such speakers together (123+123=126 db) and now you're getting closer to being perceived as louder, but not twice as loud. Eight such speakers would deliver ~129 dB, and more people would perceive that as "twice as loud". But to do so you have to generate 8x the sound pressure!

I believe the +10 dB figure is a bit on the high end, as volume sensitivity to sound pressure varies by individual. My ears, for example, will perceive +6dB as "twice as loud". Lead guitarists and drummers may need as much as +12db or more, given my experience.

As cphollis said, loudness is subjective. 10dB is the usual rule of thumb. Some say 6dB sounds twice as loud. I've never heard anyone say that 3dB sounds twice as loud.

And, as usual, it's really not quite that simple. Again it varies from person to person, but a 10dB level change at 60dB isn't necessarily the same subjective difference as at 800, 100, or 120 dB, because our ears and brains are complicated. I haven't seen any literature on this, but I also suspect that the perceived difference depends on how long you've been listening at that level, because our ears and brains adjust. Ever notice that scrunching in your ear? It's a muscle tightening things so that you can hear louder stuff -- it really changes the EQ curve of the sound going into your cochlea, but most of us don't perceive an EQ change because our brains are adjusting. But while subjective loudness isn't perfectly linear with dB, it's a pretty close approximation and good enough to be able to make predictions (like, "Will it be loud enough?")

To lead guitarists, that prediction is easy, the answer is always "no."

I googled and found LOTS of references stating that 10dB was "twice as loud." But I've also seen common errors cited in many google results so I kept looking. This one from UCSD sounds like a better summary of experiments: twice as loud is in the 5-10dB range; most people felt that 5dB was less than twice as loud; most people felt that 10dB was at least twice as loud. So, I guess I've been propagating a myth. Or, at least, a "near-myth."

http://musicweb.ucsd.edu/~trsmyth/loudn ... ce_as.html

I have both QSC CP8 and 8.2. At medium to low volume I hear no difference. 8.2 = more headroom and annoying fan noise audible at low volume.