Hey there,

I've got a restaurant AV system that has 6 zones of audio and the owner wants to have a local input in for acoustic guitar/vocal performances. They will not provide their own PA but they will supply their own mixer(or we can provide) so I was figuring on wiring for (2) local TRS jacks wired back to a JBL CSM-xxx into a Crown Amp. I'm looking for advice on speakers, head end mixer, and 70v vs 8/16ohm. There will also be integration of local DMX music server/Custom Channels remix via Sonos. Any advice would be appreciated as I've primarily done residential.

Thanks!

Commercial units, go mono, 70 volt.

People who plug things into amplifiers can be relied upon to drop mics or guitars and thrash good commercial speakers with the resulting power transientst. There's a reason for band equipment: it's so normal commercial (and, God help us, residential stuff) doesn't get blown up by normal stage idiocy.

You've seen the appropriate products mentioned here many times. Just don't ever consider resi equipment; ignore 8 ohm product; get stuff made for musicians when you're using it with musicians.

What Ernie said. I have a couple systems like what you've described. 70v with a connection for a DJ or local band to connect their mixer. And if possible, cut that input on your system back just a bit to keep some middle aged moron that's trying to still pretend he is 16 from blowing up your system. The kids you can threaten and make them listen.

That's perfect. I'll have to remember that! It always worked with my kids....

Once my daughter got rare permission to go with a friend to a school dance, and we insisted that she go into the dance, then go home from there. A half hour into the dance she butt-dialed me, obviously outside with other people, and the phone call stayed live until we picked her up... Man, she felt the Ern that day!

Malcolm013,

If you search the forum for dBx 1260, you'll call up a lot of good ideas. You can provide local volume controls, input selection, and inputs for an external mixer as needed for each zone. There is no need for the restaurant staff or the visiting musicians to touch the central equipment. You can program the dBx units to compress, limit, equalize, etc. and keep these settings beyond reach.

There may be some initial sticker shock for the client, but it is worth the cost. They will be buying the system once, rather than "saving a bundle" over and over as they blow-up inappropriate equipment.

By the way, one of the greatest "hazards" for systems such as this is the night cleaning crew. They'll turn things up to "12" or "13" while they work. A processor, such as the 1260, will keep this crew in check.

They may be playing acoustic guitar, but if said guitar has a pickup/transducer system, you WILL need to limit the low frequencies because at some point, some idiot is going to slap or thump the top of the guitar or the strings and the speakers that might work really well for music sources are going to puke. Music reproduction systems ARE NOT the same as what is needed for musical instruments. If I had to do this, I would have a dedicated amp and speakers for FOH and use a separate tap for the smaller speakers that uses a specific equalizer setting for live music. Rather than using TRS, it might be more versatile to install a wall plate with TRS and XLR- there's no reason to assume someone will come in with all of the cables and adapters needed to work and if a small mixer is placed ahead of the wall plate, nobody needs to go to the back room to make changes to the sound- it might not be part of the design, but at some point, you know someone will show up with more equipment than two jacks will support.

I would go with one of these DBX units and send the output to your system configured with some form of compressor/limiter on the main system output.

Feedback WILL be a problem with acoustic guitars and a vocal mic.

[Link: dbxpro.com]

I would suggest a small symetrix unit, like the Jupiter.
It is a full remote mixer, but you can set up and leave presets for the system to operate when not using the stage inputs. Either by timer so the staff does not have to do anything in the morning, or by wall button.
All compressor, limiters, anti-feedback is all included. Just load a suitable template into the unit.

you may want to visit with a supplier who can assist with this. Lots of excellent advice above, but tons of questions remain. My favorite supplier can facilitate this type of installation...

When I was green in the pro audio world, I had the opportunity to assist in setting up sound for a state beauty pageant where every girl's mom was in our face telling us how to run sound. I learned some key elements of live sound.

Before the gig, we took a microphone and faced it square into the monitors, manually tuned out the worst feedback frequencies, and set our max levels for monitors AND front of house. When we were asked to turn it up for the precious performers, we stuck to our max levels. Period. No feedback for the entire show.

Some thoughts:
-The DBX product is great for your venue. It has a feedback eliminator which can automatically achieve the same goal, but sometimes it removes so many frequencies that the vocalists sound like aliens. You may need to go with manual eq adjustment and ignore the eliminator.
-High pass filters are a must and setting max levels will be required.
-Place the head end equipment in a LOCKED wall mount rack in the office.
-Plan $ in your proposal to attend some performances to help them tweak the real experience.
-The stage area should include a small 4- 8 channel mixer for a guitarist, 2 mics, and backing tracks.

My advice is to get a big deposit up front! Worse payment risk of any segment we have ever serviced. A lot of restaurants are even on COD with their food suppliers.

Call The Music People- great distributors for this.

Thanks for all the advice!

And churches. I talked to another installer who put networkable DSP devices and a wireless access point in his racks, primarily for setting the system up, but in one case of non-payment and all phone calls going unreturned from a church, he drove by on a Sunday and opened up his laptop... It was amazing how quickly their phones began working again!

I installed a similar system in a restaurant so that myself and another guy, who could read my instructions, could use it in addition the our stage system to carry sound through out the restaurant. It worked well for a year or two before some moron plugged speaker level outputs from an amp and fried a lot of things in the process. My point being, I should have used XLR/balanced inputs. An idiot will figure out a way to screw things up. Don't make it any easier for them! As was mentioned above, put some DSP in place for some protection and automation for the system. I might also suggest an isolation product between the stage and the house system. You never know what crap gear might get plugged in.

Anything Harman.