Used 4 towers & 8 subs today

I DJ'ed an outdoor college spring fling dance today (450 students) and I am now so sold on this Bose system that I can't put it into words!
4 towers and 8 subs is simply a wall of sound.
I went out 400 feet and this system was still still rockin the house!
I was at 80 % volume and was hitting 117db's.
Mike

Attachments

Photos (7)
Original Post
U rock, Mike! Tell us more. I've never been out 400 feet at a live event, so I'd like to know what it sounded like out there. Also, how far away were people dancing? Were you in stereo? How wide was the audience? Any problems? Echoes off the buildings? You've really pushed the system to a new place and I think a lot of folks would like to know what you found. Please share.
Chris

(Edited to remove questions answered by replacement photos.)
All these pictures were shot one hour before the event start time.
They danced right in front but I was playing for the whole area also.
At 400 feet it was wedding reception volume
At 200 feet it was ACDC volume
At the stage I was looking for Robert Plant to show up!
I was looking for the top but never even came close.
I was running in stereo and only had a 16' stage.
The area was 600 feet wide and I had awesome sound everywhere.
Not once did I hit red.
I thought if a band can jam with 4 of these units then why not a DJ?
Mike
That is the SKB mini gig rig setting on a SKB roller amp rig.
Yes this is all my equipment.
I just had custom stage risers made for my Bose system so my next event like this I will be able to put a 15' gap between the left and right towers.
The bass was awesome in the whole area.
My settings are preset 00, low on remote @ 3 o'clock,master 12 o'clock,OL 2 o'clock and the rest @ 12 o'clock and my mixer runs flat with IMP pad's-20's installed at mixer.
My PS1's have the trim settings at 8,,,,I have perfect gain and without that this system will not perform as intended at these higher levels.
I use a Rane MM8z Mojo mixer and I use two IMP-20 pads (left and right Channel) to pad down the signal.
This allows me to set perfect gain and with my system thats puts the trim setting at 8.
I have not seen red since and the sky seems to be the limit now (lots of headroom)
Cool pics!

A comment & a question:

quote:
Originally posted by Mike Early:
The XLR Y was used on each side at the end of my XLR cable but just before the first PS1 unit.

You could eliminate the "Y" by just taking the Line-out from the "inner" systems to the "outer" system (use the 5' cable you have in place now, just eliminate the Y). The only drawback is that the Trim on those "outer" systems would be different that on the "inner" systems to give the same volume.

Question: Did you get much in the way of phase cancellation out in the listening area? You are overlapping the sound field with two identically-driven towers. Outdoors, it might not be as much of an issue as it can be indoors (where reflections can make those "phase cancellations" worse).

One suggestion, when the location warrents it, might be to angle each pair of towers (on the same side) at ~45 degrees off center (in opposite directions, of course): That ought to both reduce the potential phase cancellation AND give you a wider field of coverage (e.g.: 260, rather than the nominal 170).
I use the Y's to have the exact same line level to each unit.
If I did it your way then there is a 4db kick to the next unit and I don't want that.
These PAS units don't suffer the phase cancellations like conventional speakers do.
I had confirmed this with 4 different Bose techs.
They all said to have at least a 4 foot gap between them.
I have heard nothing but great sound in this configuration.
You can use these systems any way you choose, but you can't change the laws of physics. Chris-at-Bose always says to just try it & listen. That's your best guide. Every situation is different, although there are some basic guidelines.

I think there probably was phase cancellation in several places in the audience, but no one knew that's what it was. YMMV.

Tom
Sorry to come off sort of belligerent, but I get frustrated when I see people not grasping the design & intent of this system. The forums have gone a long way to teaching the "proper" way to use these systems. I realize there are money constraints for everyone & many other variables that affect how people choose to use these. There are also exceptions to every situation as far as acoustics & dispersion, etc. Sometimes I think people use these systems in a different way just to prove something - what, I don't know. We are all individuals & like to arrive at good sound in our own way, but I still say you are inviting problems when you stray too far from the accepted way to use these & the accepted rules of sound reinforcement.

I apologize for my passion, but sometimes some of us have to say what's politically incorrect for the engineers at Bose to say.
quote:
you are inviting problems when you stray too far from the accepted way


With all due respect, Tom - if the Bose engineers hadn't confronted the "accepted way" that things were, none of us would be here... because the L1 would not exist.

It's good to think outside the box.
quote:
Originally posted by Mike Early:
These PAS units don't suffer the phase cancellations like conventional speakers do.
I had confirmed this with 4 different Bose techs.
They all said to have at least a 4 foot gap between them.
I have heard nothing but great sound in this configuration.


Mike, who told you that 4 feet was the magic distance?

Chris-at-Bose, were you in on this?
quote:
Originally posted by Mike Early:
I'll take the 5th,,,,,,,sounds like you carry a gun!


Sorry, Mike. I'm just having a stressful day & am coming off very heavy handed. I should probably have just gone fishing, but I have several deadlines & I can't stay off the forum.

I really would like to know where you heard about the 4-foot rule. I've never seen that, & I'd like to get some real data. I'm hoping Chris or Hilmar might have some more concrete thoughts. I've a feeling it's not that cut & dried.
Hi Mike, Tom, jfc and others,
Sorry that I've taken a while to reply on this thread. My wife and I took a long weekend at our cabin in Maine--no internet access there. Ken and Tom sent emails to alert me, but I didn't see them until after I got back. And I needed to get my facts straight before making this long post. (always a good plan)

Let me summarize what I have heard so far. As jfc noticed, Mike's good experiences with four L1s in stereo are in contrast to our stated rule of avoiding distributing a single source to multiple L1s. And this rule also contradicts what Mike has heard from four Bose people, that it is okay to distribute to two speakers if you observe a 4 foot minimum spacing between them.

Let me tackle the "4 foot rule" first. Tom would like to know where this comes from. You may find the answer amusing. First of all, I found no reference to a 4 foot minimum spacing anywhere on the forum, other than in this thread, and it does not appear elsewhere on the Bose web site that I can find. So far, so good. But, by coincidence, the number is familiar to me in another context. More than 15 years ago, Ken and I worked in the installed sound part of Bose Pro. Dealers were beginning to hang clusters of multiple 402s, 802s, etc. because it saves them money to use fewer hang points. We were very concerned about coloration from interference, in other words the "phase cancellation" often referred to on the forums. (I don't like the term phase cancellation, but that's another story.) Ken and I decided that those speakers needed to be no less than 4 feet apart, or the amount of coloration would be unacceptable in some seats. This gradually became something of a standard distance, which is too bad, since it represents the worst coloration we were willing to tolerate. And I remind you that this rule applied to directional speakers aimed in different directions and falling off with distance at the normal 1/r^2 rate.

Interference between line arrays would be more severe. In fact, the current Bose design rules for installing MA12 line arrays recommend NOT putting them in the same cluster at all, ever. For distributed systems, they plan to recommend a spacing between line arrays of between 6 and 15 meters! (20-50 feet) So the amusing part is that the source of the "4 foot rule" appears to be Ken and me, although the rule was never meant to apply to line arrays. The four Bose people who told Mike that 4 feet was okay were "incompletely informed" and assumed that the rule we taught them applied to line arrays as well. I've spoken to our head of training for North American Pro to let him know that the curriculum needs to be more explicit that the spacing rules for line arrays are different, not 4 feet. (Mike, if you remember the names of any of the four folks you spoke with, please send me the names in a PM, so that I can be sure to teach them about the different rules for line arrays. No, they aren't in any trouble, Bose isn't that kind of workplace. Help me fix this if you can.)

So much for the 4 foot rule. It works for 802s and such, but it does NOT apply to line arrays. (All the way from Colorado, I can hear Tom breathing a sigh of relief. Smile But maybe now Mike is shifting from foot to foot? Frown )

(continued on next post)
This brings us back to the other question: Mike has heard good results many times with his 4xL1 system driven in stereo and this goes against our rule about not distributing a source to more than one L1. To be exact, he's feeding the stereo left channel to two L1s and the stereo right channel to two other L1s. I think his result is interesting and there may be something new for all of us to learn here. But if Mike can live with a bit more suspense, I first want to contrast his listening results with those that gave rise to the "don't distribute sources" rule.

In the early days of the L1, the team tried many different ways of using it, including distributing sources to multiple L1s. Hilmar is one of those who heard this personally and his experience is typical. He tells me that the sound was quite muffled and unclear and the localization was vague. The degradation was not subtle. These tests gave rise to the "don't distribute sources" rule before the system was even on the market. The rare bad listening experiences reported on the forums often seem to trace back to violating this rule. I agree with jfc that the recent disappointing results at The Girls demo in Mayfield/Cleveland are almost certainly due to this phenomenon. The audible complaints there match Hilmar's descriptions quite well and the routing of sources violated the rule. So why isn't Mike also suffering? (or are you now just a little bit, Mike? Confused )

Well, I wonder if something different is going on with stereo-mix program material than with raw instrument and mic inputs. After all, stereo material includes some content panned to the middle and this content is ALWAYS distributed to two speakers (L&R of course) and that also violates the "don't distribute sources" rule. This paradox has always bothered me. If our rule is so important for good sound, how can we expect stereo to sound okay off the midline between the L&R speakers? We know the stereo image is messed up off the midline, but the over all sound seems acceptable. So if stereo can be an exception to the "don't distribute sources" rule, then why can't Mike use two left speakers and two right speakers? These ideas don't all mesh together nicely, do they?

I think we need to do some experiments to find out more. Mike, I'm hoping you will be interested enough to try something easy and let us know what you hear. (It might even save you some money.) Maybe we'll try the same thing here at Bose and compare notes on this thread. Leaving aside the stereo-mix issue as a harder problem, I'd first like to know if Mike gets better or worse results if he turns off two of his four L1s. Of course, the experiment is not quite that simple. We want the 8xB1s to keep playing in both cases. What we really want to compare is Mike's current setup vs. a stereo system with one L1 and 4 B1s per side. The normal way to set up such a system would be to drive the 3rd and 4th B1s on each side using Packlite amps. But since Mike doesn't have Packlites, he can do it the old-fashioned way and use his other PS1s as if they were Packlites. The wiring change is easy. Just unplug the line-in from one of the PS1s and run a cable from the bass-line-out of the other PS1 to the Amp-3-in of the PS1 you just disconnected. Do this on both L and R sides. Done.

Now for the listening protocol. Interference changes as one walks around from the front to the side, so that's how the listening should be done. Do this for both versions of the system, using the same song or songs in both cases. If you have recorded announcements, try them too. Are there any differences in sound quality? Muffled? Another thing to check is maximum output. You might think that you'd lose some when you shut off two L1s but it can't be more than 3 dB at most, and it could be as little as none. I really don't know which approach will be better over all. That's why it's an experiment. Maybe Mike has a got a good exception to the "don't distribute sources" rule. It's your system, Mike--which do you prefer?

Mike, I hope you'll try this little test just before or after one of your weddings and let us know what you find. In one case, you may show us that your current system is better than what we would recommend and that we need to rethink our rule a bit. In the other case, you may get an even better system and make some money by selling two L1s and buying two Packlites. And where would you sell those L1s? (wait for it ... ) Well, I know this band in Cleveland, see, and they really need a lot of L1s, but they don't quite have the cash for new ones. Big Grin Maybe everybody will win.

Take care and keep posting,

Chris
The difference between two towers and four as I use them is night and day.
I have never heard any cancellation in the six events with the four towers.
I am stumped on this one?
I bought four towers to DJ my 1000-1500 person outdoor events but if two towers and eight subs will give me the same db levels then why did I buy the two extra towers?
Yet when I run the four towers and eight subs the increase in output is awesome and it goes from a DJ rig to a concert sound system and I do not hear any type of phase sound issues.
I use two towers and eight subs all the time so I know the difference between that and the four towers and eight subs.
Maybe I do have phase cancellation and don't know it?
Hi to everyone.

I thought it might be easier to visualize and discuss this with some pictures.

If you want to discuss a different layout, just click on the one closest to what you want to discuss. This will take you into The Sketcher, where you can drag things around.

Be sure to add some comments so we know what makes your variation interesting.

Save your changes in the Sketcher, and I'll post it here for you.

Case 1

-- click image to make changes to the live version --

Case 2

-- click image to make changes to the live version --

Case 3

-- click image to make changes to the live version --
Mike, I'm stumped. It sounds like you've tried what Chris is asking for as a test. I have 4 systems as well & am anxious to get a place where I could test it & see what I hear. I'm not afraid to find out the rules are messed up & there's something altogether wonderful going on here, but it doesn't fit what I've found from experience. We need some tests, & I'm anxious to see what Chris finds as well.

Chris, care to make a model?
My .02 I would think the cancellation effects will be much less noticeable with many types of typical "dance" music than with say a solo vocal.

I'v heard many sound systems be acceptable with musical instruments and the vocal sound totally terrible.

Very interesting thread here! Anxious to learn.
Hi Mike,
Cool! Of course you would have tried two L1s vs. four already--what was I thinking? And I don't doubt your judgment one bit, so there IS something exciting for the rest of us to learn here. (I love surprises in engineering, so illuminating!)

Physically, interference has to be happening in your setup, but I do NOT doubt your ears for a minute, Mike. We all make our living from sound and we all know what we hear. Over many years, every time I have been tempted to reject a listening report of someone who disagreed with the rest, I've found that their report was solidly based in fact and that the rest of us would hear and say the same things if we replicated what the first person was listening to. Passionate exceptions like you are incredibly valuable to the community, Mike--thank you for sticking to your guns.

I want to try your setup here in our lab right away, but we have something special set up for today, so it might not happen until after the holiday. Maybe Tom will beat us to the punch here and publish first. But I'm still hoping I can sneak in there late today. We'll follow the layout in your wedding picture above and let you know soon what we find. If at first it looks like we're getting something different from you, we'll compare notes offline until we can jointly understand what is going on. (Tom, same goes for you, please--if you get a different result, PM Mike and compare notes to be sure you're doing everything the same way he is. That's the way polite and effective science is done.)

Thanks again, Mike. For me there is nothing more fun than knowing I'm about to learn something new and important. Stay tuned.
Chris
As a potential buyer, this thread is very interesting to me. I don't plan on buying more than two towers and four subs but this is still very interesting. In the future I may want to upgrade my system and it would be great to know if Mike's configuration is "sound" (pun intended). Smile

Would there be any problem placing two L1s between 40 and 80 feet apart? It sounds like from what Chris-at-Bose is saying is that 20 feet apart could be the minimum recommended distance.

Add Reply

Likes (0)
Having trouble signing in?

We recently updated our sign-in procedure and if you have old sign-in data cached, this can create a problem. Please:

  1. Clear your browser cache and cookies
  2. Then close the browser (not just the window)
  3. Open the browser and try again
Thank you

Please make sure that your profile is up to date
×
×
×
×