Post by: Steve Moland on December 02, 2010, 04:12:52 PM
At times I need a set up inside in rooms or halls with great to terrible acoustics. I got a pair of Bose 802 II which just don't sound as good as others I've seen in similar situations but at the time I did not know I'd needed to ask this question.
The back of the speakers say, must be used with and 802 C system controller or 802 E Equalizer. Does that really mean what is says? and if I do need the controller, what's the logic. I can't find any description anywhere which tells me what is going on.
All the individual speakers in the units work and sound fine up close. Together the are not as clear as I've heard. If anything they lean toward bass which seems strange because the multiple speakers in the cabinet are only 4 or 5 inch.
Post by: Bennett Prescott on December 02, 2010, 04:27:55 PM
| Steve Moland wrote on Thu, 02 December 2010 16:12 |
The back of the speakers say, must be used with and 802 C system controller or 802 E Equalizer. Does that really mean what is says? and if I do need the controller, what's the logic. I can't find any description anywhere which tells me what is going on. |
Yes. You need the controller if you want any highs or lows out of the box. The design itself relies on extensive equalization.
A quick web search found this:
20 Hz = -5 dB
30 Hz = -1 dB
40 Hz = +3 dB
60 Hz = +14 dB
100 Hz = +5 dB
200 Hz = +1 dB
600 Hz = 0 dB
800 Hz = 0 dB
1 kHz = + 1dB
2 kHz = + 4 dB
3 kHz = + 5 dB
4 kHz = + 8 dB
6 kHz = + 11 dB
10 kHz = + 15dB
15 kHz = + 17 dB
http://www.audiorail.com/802_controller.gif
Post by: Chris Hindle on December 02, 2010, 04:28:16 PM
There's some pretty serious Ju-Ju going on to make a bunch of 4" speakers "work" together.
Post by: Chuck Fudge on December 02, 2010, 04:34:50 PM
Post by: Dick Rees on December 02, 2010, 04:37:28 PM
No lows
No comment
Post by: Steve Moland on December 02, 2010, 04:39:33 PM
| Chris Hindle wrote on Thu, 02 December 2010 15:28 |
Yes. There's some pretty serious Ju-Ju going on to make a bunch of 4" speakers "work" together. |
I thought it might be like that but the cabinet only has one input. Well it has two actually, a 1/4 and an XLR which I assumed was only an option as to which kind of cable one preferred.
I guess if there were two inputs like I've seen on some cabinets, one for the highs and another for the lows, I can see that something external has something to "mix" with. With only one wire I don't get it.
Post by: Steve Moland on December 02, 2010, 04:42:46 PM
Post by: Bennett Prescott on December 02, 2010, 04:44:19 PM
If you have been running them with no processing whatsoever, no wonder you think they sound dull.
Post by: Dick Rees on December 02, 2010, 04:45:40 PM
| Steve Moland wrote on Thu, 02 December 2010 15:39 | ||
I thought it might be like that but the cabinet only has one input. Well it has two actually, a 1/4 and an XLR which I assumed was only an option as to which kind of cable one preferred. I guess if there were two inputs like I've seen on some cabinets, one for the highs and another for the lows, I can see that something external has something to "mix" with. With only one wire I don't get it. |
It's called "equalization" and is one of the basics of any live sound system operation. You've got some serious research to do. There is a lot of information on manufacturers websites. You could start by reading the sticky topics in each section of the Forums. Find out what components comprise a sound system, then look them up in the various manufacturers sites. Find out what they do. Ask more questions. We were all in your situation at one time or another, some of us as junior high kids, some of us as adults DJ'ing for spare cash.
Rotsa ruck.
Post by: Chris Hindle on December 02, 2010, 04:51:01 PM
| Steve Moland wrote on Thu, 02 December 2010 16:39 | ||
I thought it might be like that but the cabinet only has one input. Well it has two actually, a 1/4 and an XLR which I assumed was only an option as to which kind of cable one preferred. I guess if there were two inputs like I've seen on some cabinets, one for the highs and another for the lows, I can see that something external has something to "mix" with. With only one wire I don't get it. |
No. The 2 connectors are paralleled together.
Choice of 1/4" or XLR connector.
They are "full range" cabinets - no Bi-Amp needed.
Bose EQ is not a suggestion, it is a requirement.
Post by: Steve Moland on December 02, 2010, 05:04:37 PM
In the mean time I believe I gathered enough "faith" here to get the controller on that basis alone.
There is one thing that crossed my mind though. All the small speakers in the cabinet look the same. Any chance they are actually different and respond to different frequencies. That is a simple thing I can picture. Failing that, I'm off to chase Ju Ju.
regards
Steve
Post by: Mac Kerr on December 02, 2010, 05:12:39 PM
| Steve Moland wrote on Thu, 02 December 2010 17:04 |
There is one thing that crossed my mind though. All the small speakers in the cabinet look the same. Any chance they are actually different and respond to different frequencies. That is a simple thing I can picture. Failing that, I'm off to chase Ju Ju. |
All the speakers respond to the same signal. There are 8 1Ω speakers wired in series to make 8Ω. On old ones there may be 8 8Ω speakers and an 8Ω light bulb wired in series/parallel to make 8Ω. There is no way to get a different signal to any given speaker in the chain.
The system controller is an eq that goes between your mixer and the amp that is driving the 802s.
Mac
Post by: TJ (Tom) Cornish on December 02, 2010, 08:54:57 PM
| Steve Moland wrote on Thu, 02 December 2010 15:39 | ||
I thought it might be like that but the cabinet only has one input. Well it has two actually, a 1/4 and an XLR which I assumed was only an option as to which kind of cable one preferred. I guess if there were two inputs like I've seen on some cabinets, one for the highs and another for the lows, I can see that something external has something to "mix" with. With only one wire I don't get it. |
By the way, the XLR connector on the back of a passive speaker is a very outdated thing. 20 years ago there weren't many choices for high-power speaker level connectors, so all sorts of weird things got used, including XLR connectors, which are typically used for "mic" or "line" level signals - before the amplifier.
Don't make the mistake of using an XLR cable from the store as a speaker cable - the wires aren't big enough. For that matter - don't use a 1/4" instrument (guitar cable) either for the same reason - get a real "speaker" cable.
Post by: Mac Kerr on December 02, 2010, 09:09:29 PM
| TJ (Tom) Cornish wrote on Thu, 02 December 2010 20:54 | ||||
By the way, the XLR connector on the back of a passive speaker is a very outdated thing. 20 years ago there weren't many choices for high-power speaker level connectors, so all sorts of weird things got used, including XLR connectors, which are typically used for "mic" or "line" level signals - before the amplifier. Don't make the mistake of using an XLR cable from the store as a speaker cable - the wires aren't big enough. For that matter - don't use a 1/4" instrument (guitar cable) either for the same reason - get a real "speaker" cable. |
FWIW, "back then" good quality mic cable was 18ga. When you doubled up the 2 hot conductors you ended up with about 14ga, the heavy braided shield was already about that. Since a really high powered amp was 200W it was not such a bad scheme.
Mac
Post by: TJ (Tom) Cornish on December 02, 2010, 09:14:44 PM
Post by: Steve Moland on December 02, 2010, 09:57:15 PM
Because I'm always doing long runs between amps and the chain of speakers, I use 12 and 14 gauge. I made my own 12 gauge ones because they were way too expensive to buy.
Post by: Canute J. Chiverton on December 03, 2010, 03:06:08 AM
Post by: Ivan Beaver on December 03, 2010, 10:54:33 AM
| TJ (Tom) Cornish wrote on Thu, 02 December 2010 21:14 |
So what's the damping factor of 50' of modern 22-ga XLR cable? |
Around 5 if you use the 2 hot conductors.
If you tie them together and use the shield (assuming a decent size-but now they are nowhere as large as they used to be, you might near 10 for a damping factor.
That is assuming an 8 ohm loudspeaker load,
Post by: Greg Cameron on December 03, 2010, 11:48:13 AM
| Ivan Beaver wrote on Fri, 03 December 2010 07:54 | ||
Around 5 if you use the 2 hot conductors. If you tie them together and use the shield (assuming a decent size-but now they are nowhere as large as they used to be, you might near 10 for a damping factor. That is assuming an 8 ohm loudspeaker load, |
Maybe the next sub "shootout" should have a side bar listening contest, "22AWG vs. 10 AWG into a 2Ω load with 100' of wire." Frequencies of 80Hz and below of course. See if people can hear a difference
Greg
Post by: Brad Weber on December 03, 2010, 12:21:54 PM
| Steve Moland wrote on Thu, 02 December 2010 16:12 |
At times I need a set up inside in rooms or halls with great to terrible acoustics. I got a pair of Bose 802 II which just don't sound as good as others I've seen in similar situations but at the time I did not know I'd needed to ask this question. |
That you need the Bose controller or something providing the equivalent processing has been well addressed, but I wanted to add that due to their overall wide horizontal and vertical pattern and with significant lobing starting in the speech/vocal range, the 802 may not be the best choice for challenging acoustical environments. The processor will not fix that, in fact the boosts at low and high frequencies could exacerbate any related issues.
Post by: Steve Moland on December 03, 2010, 12:38:56 PM
Yes I can see the issue. Fortunately where I'd use them any sound is better than nothing, but I would like the best I can get and I'm willing to toss a bit a money at trying my best.
I've messed around with the equalizer slides on the my amp in those situations and you are right, almost nothing ends up good and it's often a choice of choosing the least worse setting.
Normally I can drive my van and trailer to almost every place I'm going to be using my gear outside, so I don't have to load stuff on a hand cart or dolly.
When I do pre-race or post-race awards it's often inside where I don't want to make too many trips with a dolly and the most of the speakers I have are odd shapes which don't pack/stack too well. (Peavey PR12, PR15 & Mackie 450s)
The Bose units (with cover/handles) are essentially square and cooperate well with other gear on the dolly, and they are light too.
Very often, I'm there once an event decides they don't emcee very well themselves and a bullhorn is a cruel joke on those they need to communicate with.