Do I really need subs?

[Bickster]

Hello to all BFM'ers!

I've been lurking for a few months at the suggestion of Frankenspeaker and am overwhelmed at the depth of knowledge and sharing here. Thanks to all.

I'm a guitar player, tube amp builder, and woodworker from western PA. My band suffers from the "we don't make enough $ to hire pro sound" thing so we bought a Yamaha EMX 5014c powered board with the usual 15" w/horn mains and 12' w/horn monitors. We attempt to play and mix at the same time without much success. Later on we added a cheap Mackie amp to run monitors. Our material is the same as 90% of the cover bands out there. Classic rock, blues, country, and a little surf. Only the drums are mic'ed and some keys added.

My original plan was to go the T39/DR200/WH route with a DCX. After further thought I realized that our Mackie may not have the power. The powered board is 500W/side but doesn't have power amp inputs. I'm struggling to get the other members to spend more cash so I was hoping to avoid a new amp. Then I got to thinking... What do I need to amplify below 100hz? Would a DEQ/BFM top/WH be enough? This is a pretty quiet band. I attenuate the snot out of my 25 watt Marshall plexi clone and still get the dreaded "turn down" look from the rest of the band. Thanks

Bob

[bgavin]

The BFM boxes are more friendly with under powered amps/mixers, because they are more efficient. This means lesser watts will make the same amount of noise as more watts into inefficient speakers.

The DR200 makes a LOT more noise per watt, than a 1x12 + Horn top.
T39 makes a LOT more noise per watt than a typical sub.

If you can live with a lower limit of 60 Hz (kick drum), the skinny T39 subs will do the job. The lower you go down, the larger the box. No getting around it.

[Bill Fitzmaurice]

What do I need to amplify below 100hz?
Bob

Turn on your stereo, play a CD or a song on FM, and turn the bass control all the way down. That's what your PA sounds like with no content below 100 Hz.

[Bickster]

It just seemed a bit foolish to run the 500/side amp for monitors and the cheap Mackie (300@4 ohms/channel) for FOH. Sounds like I'm foolish for worring about it.

I think that I would go with the 20" T39's. Cartage isn't much concern. I like trucks! I hope to do some WH's to get a little more interest from the rest of the boys. DR's or T39 next?

[DJPhatman]

Hi, Bickster, and welcome!

Although I DJ, I use the predecessor to your powered mixer, the EMX5000-12. I am not completely familiar with your mixer, but IIRC, the biggest difference between them is, on yours, the lack of the active/variable subwoofer out option using the mono out. A call to Yamaha's help line will get you a support person who will walk you through how to set up your mixer for what you want to do. I am pretty sure you can use the AUX1 and 2 outs for two monitor mixes with that board. I do know that there is a direct amp in that disconnects the internal amps from the rest of the inputs. Some creative wiring should get you what you need to do, except maybe only having one monitor mix, instead of two. I'll look it up tomorrow and get back to you on it.

IMHO, build WHs first. Then subs, and acquire an active crossover, the best you can afford. If you can budget it in, the DCX/DEQ combo can't be beat for the money. The Mackie amp you have now is fine for either monitor duty, or sub duty.

[bgavin]

Two T39/20" with BP102 driver will do a very nice job for you.
Four, outdoors, will make a whole lot of noise.

I measured 94 SPL at 40 Hz with DaveK's T30/20"/BP102.
Four in parallel is worth another +12dB, taking the system up to 106 SPL, 1w/1m.

At only 100w (half power), four produces 102 SPL at 52 feet, 40 Hz.
This is concert level intensity at the most difficult note to produce.

This is unbearably loud for the onstage talent, or anybody within 20 feet of the subs.

[Bickster]

DJ - This board has a SUB ST OUT but I can't seem to find a way to get back to the amp. I guess I could loop back to an un-used stereo channel and drive the amp that way. It's probably best to call Yamaha. I'm cool with a single monitor mix. That is how were doing it now.

bgavin - I just need to build and try. It is a challenge to wrap my head around the efficiency that these cabinets provide. It shouldn't be! It's not much different than explaining why my 25 watt tube amp is crushing the other guitar players 100 watt transistor amp.

Thanks for your patience!

[Mikey]

my 25 watt tube amp is crushing the other guitar players 100 watt transistor amp

[Bickster]

But his has more knobs!!!

[DJPhatman]

I had a chance to read over the specs and owners manual for that board. There is no way to loop back into the internal amps. Also, the sub out is a stereo mix of all the channels, at line level instead of at speaker level. You could route that signal to a crossover, but you still need amps to drive the speakers. That board is a waste, IMHO. Same with the 5016. Yamaha took away the ability to bi-amp the system, which you can do with the EMX5000 series.

[Bickster]

That's what I thought. Well, its bought and paid for. I'll use aux 1 for monitors thru the boards amp and ST out to a crossover and our Mackie amp. Thanks so much for everyone's efforts.

Bob

[Dave Non-Zero]

Two T39/20" with BP102 driver will do a very nice job for you.
Four, outdoors, will make a whole lot of noise.

I measured 94 SPL at 40 Hz with DaveK's T30/20"/BP102.
Four in parallel is worth another +12dB, taking the system up to 106 SPL, 1w/1m.

At only 100w (half power), four produces 102 SPL at 52 feet, 40 Hz.
This is concert level intensity at the most difficult note to produce.

This is unbearably loud for the onstage talent, or anybody within 20 feet of the subs.

Ive never found my titans 'unbearable' at any distance or any volume. 4xt48 24'' 3015lf loaded clustered and full power, recorded music and live. I would call it a pleasant experience, and look forward to an opportunity to do the same with all 6.

[bgavin]

Unless you are doing sub steering, the intensity increases as you get closer.
102 SPL at 16 meters increases to 120 SPL at 2 meters. Yikes!

Perhaps it isn't as agonizing as high frequency, but that is still a huge amount of acoustic power on the ears.

[Dave Non-Zero]

Perhaps it isn't as agonizing as high frequency, but that is still a huge amount of acoustic power

Yeah, if you sit in front of the subs you can feel your throat close up, and if you try and talk you can tell your voice is modulating. hehe. ok so i am insane, i get it.