It is currently Sat Jun 15, 2019 4:34 pm

All times are UTC - 7 hours



Post new topic Reply to topic  [ 6 posts ] 
Author Message
Post subject: Backwash
Posted: Sat May 16, 2015 7:15 am
Offline
Aspiring Musician
Aspiring Musician

Joined: Wed Feb 16, 2011 7:24 am
Posts: 422
Most people don't have this problem. Since I do sound for contra dances, and there's a caller giving instructions to the dances over the sound of the live band, the band wants to hear themselves and they don't want to hear the caller, so the monitor mix needs to be radically different from the house mix, and the bands HATE it if they have to listen to the caller too loudly.

Fender advertises something like 130 degree spread of sound from these speakers, but in truth, it's closer to 360. The tweeter is louder out front than around back, but the midrange is really almost as loud radiated through the aluminum housing of the tower at the sides and back as it is coming out the front. The bands hate this, though the sound out at the dance crowd is wonderful.

So, I draped the carrying case for the tower over the back of the tower and the band stopped complaining. It makes a big difference.

It doesn't fit perfectly, because of the bottom of the tower, so I'm going back to the same tailor shop that fixed the location of the pads on the carrying cases for the towers and I'm asking them to make me a hood for the towers made out of the quilted material that moving companies use for the blankets they use for padding. That should be sturdy enough, compact enough and acoustically effective. I'll report back, in case anyone is interested.


Top
Profile
Fender Play April 2019
Post subject: Re: Backwash
Posted: Tue Jun 02, 2015 6:01 am
Offline
Aspiring Musician
Aspiring Musician

Joined: Wed Feb 16, 2011 7:24 am
Posts: 422
I got a mover's blanket made from recycled bluejeans, cut it up and hand-sewed what is essentially a large sock to cover the tower, with a long, rectangular hole for the speakers. It covers all the aluminum housing for the speakers.

Wednesday, I'll use this for the dress rehearsal for a choral concert that I do sound for each year. It is a very resonant room and feedback has historically been a problem when using a Passport 500 Pro. This will be the first year using the Expos. I'll put them as far back in the hall as possible and use the blankets to dampen the backwash and see if it works.

Speaker placement with the Passport was dictated by clearance for the speaker stand legs. It's a cross-shaped room and they had to go in corners because the side aisles are extremely narrow. The Expos can go much farther back because they are so small, though I'm limited by the length of AC power cables that I have available. I might buy more before the concert...

Plan B is to use my floor monitors, which can be mounted on speaker stands and have active anti-feedback settings built in. While in theory, this sounds like a good idea, that would again enforce speaker placement limits, and it requires me trusting an untested technology, and it requires me to buy another speaker stand tomorrow...

Ahh, the adventures of amateur sound reinforcement...


Top
Profile
Post subject: Re: Backwash
Posted: Wed Jun 03, 2015 8:00 pm
Offline
Aspiring Musician
Aspiring Musician

Joined: Wed Feb 16, 2011 7:24 am
Posts: 422
The new, home-made tower socks worked fine.

This gig is a choir concert in a church. Soloists and announcers walk up to half the distance from the four mics as the choir, and small groups sing their songs in this closer zone.

My pair of Expos worked much better than the Passport 500 Pro I've used in the previous two years in terms of avoiding feedback in a highly resonant hall (a church), likely because their extremely compact design allowed me to place them in the narrow aisle, too narrow for the feet of a speaker stand. The new placement is farther from the microphones and not under the same curved section of ceiling as the mics. Also, the deeper throw of the towers allowed better sound at the back of the hall with lower volume. Very crisp and clear.
I love the Expo. It makes sound louder and clearer without distortion, and it throws farther without deafening the people up close to the speaker. It solves more problems than it creates.
All sound reinforcement involves compromises. I like the compromises the Expo offers me... especially now that I have a dampener for the aluminum tower case. They fold nicely and fit in my mic stand bag with the stands.

In a couple weeks, I'll be using mine in a large Moose Lodge -- a big room with a low, flat ceiling, and maybe a couple hundred dancers. I'm looking forward to using them there.


Top
Profile
Post subject: Re: Backwash
Posted: Fri Jun 05, 2015 10:00 am
Offline
Rock Star
Rock Star

Joined: Fri Apr 08, 2011 5:14 pm
Posts: 3030
Location: Linningrad
Excellent ongoing reviews in real life scenarios. Thanks CC! 8)

_________________
1976 Lefty Precision Hot Rod
2012 Lefty American Standard Jazz
2017 Lefty American Professional Precision
2018 Rumble Studio 40 Combo
2016 Rumble 200 Combo
One day they shall name a GREAT city after me, and they shall call it LINNINGRAD


Top
Profile
Post subject: Re: Backwash
Posted: Wed Jun 10, 2015 11:27 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Sat Mar 22, 2008 10:38 am
Posts: 11085
Location: Canada
linnin wrote:
Excellent ongoing reviews in real life scenarios. Thanks CC! 8)

+1

Good work on the problem solving, ContraCaller.

_________________
Hello, big guitar. Meet my little fingers.


Top
Profile
Post subject: Re: Backwash
Posted: Mon Jun 15, 2015 7:34 am
Offline
Aspiring Musician
Aspiring Musician

Joined: Wed Feb 16, 2011 7:24 am
Posts: 422
So, next gig with the Expos was a contra dance in a long hall with fairly bad acoustics (a very "active", echoing hall), in extreme heat with huge, inward-blowing fans in the windows at the back of the hall. So, at the back of the hall, you are farthest from the speakers, and you have this huge white noise behind you, so with the sound system off, entirely, if you are near the fans, you have to yell to talk to the person next to you.

Sound sub-optimal to you? Yep.

With the Expos set to 50% volume and the line-level mixer's meter showing the sweet spot tagging the amber now and then and never clipping, I could hear fairly well standing near the fans, and it didn't hurt too much standing next to the speakers. The dancers stand in lines the full length of this space between the fans and the speakers.

I got one complaint from a dancer who said the speakers were too loud when she was standing next to them. I explained that I could not turn them down without making it impossible for the people in the back of the hall to hear at all, and she accepted that. Everyone else seemed to think that the volume level was fine.

This is really impressive. I don't know any other speakers that can do this (except maybe other arrays).

As for backwash, the blankets definitely improve the issue, but it's not solved yet. I think another layer will do it. The movers' blankets are simply not quite thick enough. I have more material. Perhaps another layer of the same stuff will do. Otherwise, I'll try for a different outside layer. I hung the tower carrying cases over the back of the towers for the second half of the dance and that did seem to improve things, though probably not as well as something better fitted, as a second layer of blanket would be.

Oh, and I've dissed the sub-woofers on the Expos in the past, and I should apologize for that. I brought along a Gemini 400 watt subwoofer for this gig and experimented with it for the guitarist's foot percussion and his octivizer bass lines in DADGAD tuning, and I got cleaner, clearer, louder, fuller bass out of the two Expos than I did out of the 400 watt subwoofer. I muted it for the rest of the evening. That's a big, heavy box I do not intend to carry around any more.

Anybody want to buy a sub-woofer?


Top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 6 posts ] 

All times are UTC - 7 hours

Fender Play April 2019

Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to: