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[Art Welter]

Hi everybody, long time lurker but first post:

I was wondering if there is enough engineering to properly build (split) a subwoofer, like a TH118, but in two parts.

John

John,

What you propose could easily be done, but cutting off the lower "empty" portion of the DSL TH-118 still won't "lighten the load" of the top cabinet portion all that much. Other than lift weight, they would be harder to transport, but normally you could leave then assembled.

Using ratchet straps to put the sections together works well, no rattles or buzz if you do it right. I used to use neoprene gaskets in those applications when using over-center clamps or turnbuckles, but when I started using ratchet straps, found they work fine with no gaskets required.

The wave-guides in front of the Keystone "tapped horn" Sub and small format line array cabinets in the picture below add 3 to 6 dB dB SPL to the frontal output, and are secured using ratchet straps. They take up little trailer space, but are the equivalent to doubling (or more) amplifier power with no power compression, and reduce SPL behind the stack by as much as is increased in front.

Art

[Tim McCulloch]

This is a business question more than a technology question be it a band or a sound vendor.  Do you make enough money working in venues with stairs that it warrants building your inventory around ease of stair access?  If you do then by all means buy the types of equipment that goes up steps easily, very small, lightweight gear that trades efficiency in the cabinet for greater power input from the amps and from the wall. If on the other hand the loading in up a set of stairs is merely occasional even if it is high value for exposure or what ever then its time to budget for the added labor to lift those boxes.

This.

I had a big long reply ready to send and yours says it better and in fewer words.

[Stephen Kirby]

Back in my days of selling pianos there were stair climbers that you strapped the piano to and it went up the stairs by itself.  There are multiple variations ranging from caterpillar tread things that charge straight up the stairs to less expensive things that move feet or the wheels to lever up a couple of steps at a time.  Slow but safe.  Expensive, but so it a TH118, or a doctor bill.

[John Ferreira]

Here's the problem that needs to be fixed.

If you're going up stairs with 160lb boxes on your own, you are ASKING to be injured.

In every other aspect of the entertainment business, proper staff is required to move heavy things around.  It's not expensive to hire a grunt or two.  Yeah, it may cut into your profit for the night, but it's cheaper than back surgery.

As I mentioned my subs are around 90lb, not 160lb.

You should never bend your back carrying something heavy; it's always the legs you bend, back remains straight.

Definitely no extra budget for extra people, so looking into technology.

[John Ferreira]

John,

What you propose could easily be done, but cutting off the lower "empty" portion of the DSL TH-118 still won't "lighten the load" of the top cabinet portion all that much. Other than lift weight, they would be harder to transport, but normally you could leave then assembled.

Using ratchet straps to put the sections together works well, no rattles or buzz if you do it right. I used to use neoprene gaskets in those applications when using over-center clamps or turnbuckles, but when I started using ratchet straps, found they work fine with no gaskets required.

The wave-guides in front of the Keystone "tapped horn" Sub and small format line array cabinets in the picture below add 3 to 6 dB dB SPL to the frontal output, and are secured using ratchet straps. They take up little trailer space, but are the equivalent to doubling (or more) amplifier power with no power compression, and reduce SPL behind the stack by as much as is increased in front.

Art

Art 6ddB is 66% more SPL, if we consider double being around 10dB or so.
That's a lot of sound from just extending the enclosure. Again, I'm surprised this type of subwoofer design is not considered more often.

About the weight, 135lb Elite 1000s can be carried up and down stairs. I used to bend back and tilt them on my knees, stair by stair, never putting pressure on a bent back, but let the legs and knees carry the weight.
It is a similar design to the TH118, with the handles and wheels.

So even if the heavier side of the box was 90lb or 100lb, and the other side 70lb or less, it would be okay for a single person to load, using a dolly.

[John Ferreira]

Back in my days of selling pianos there were stair climbers that you strapped the piano to and it went up the stairs by itself.  There are multiple variations ranging from caterpillar tread things that charge straight up the stairs to less expensive things that move feet or the wheels to lever up a couple of steps at a time.  Slow but safe.  Expensive, but so it a TH118, or a doctor bill.

I think you are talking about a Klavier Roller.

[Ivan Beaver]

Art 6ddB is 66% more SPL, if we consider double being around 10dB or so.
That's a lot of sound from just extending the enclosure. Again, I'm surprised this type of subwoofer design is not considered more often.

There are lots of reason it is not considered-and most have nothing to do with sound quality or output.

Many people like the term "double 18", and if it is not a "double 18" then it is no good.

Manufacturers typically don't want to sell more efficient loudspeakers-especially subs.

That is because if the customer wants to get louder-they just buy more subs-so more profit.

Some people buy subs purely on the driver compliment.

They will not pay more for a sub that contains less drivers, even though it may be louder-have less distortion, require fewer amplifiers, be smaller, weigh less, go lower etc.

To them, it is all about how many drivers a cabinet has-NOT the actual performance.

Some people don't like the cleaner sound of a horn sub, they like the distortion you get with front loaded/ported subs.

[Nathan Riddle]

Definitely no extra budget for extra people, so looking into technology.

Maybe I'm not getting something, and please correct me if I'm wrong.

But I just don't understand not having budget for 1x more person to help carry a TH118 on the few(?) gigs that have stairs.

You could literally pay any random person $50 to help carry the sub(s) up the stairs. You could probably get one of the bouncers (or similar) to help out for free.

To me it seems pretty simple. Either get the TH118 so you carry less subs up the stairs. Which has practically the largest SPL for weight (160lbs) for a sub out there (that I know of, correct me if I'm wrong).

OR get subs that weigh less and you can carry yourself. To me, this doesn't make sense either... even the lightest subs (within a certain class, active, 18", etc) are 75+lbs ea. I don't want to carry 75lbs by myself. I'd either higher or ask someone at the venue to help carry the 2/4 subs/heavy items. Heck I don't want to carry my 90lb SRX835p's by myself. I can...but I don't like it for long distances.

So even if the heavier side of the box was 90lb or 100lb, and the other side 70lb or less, it would be okay for a single person to load, using a dolly.

Looks like you use a dolly for the stairs? Again, I don't understand how a dolly would work but subs with wheels(s) wouldn't work? And please don't take this the wrong way, If you have some method that precludes 150+lb subs (with dolly/wheels), but not 100lb subs (with dolly/wheels) from entering the venue please describe it, I'm always interested in learning other member's methods.

Furthermore, the TH118 tilts on 2-wheels. That makes it super easy to get up stairs with one guy because you just pull it up each step. Gotta be careful, but it's not too hard. For larger steps 2-persons can easily pick it up onto stage height or more. Looks like you acknowledge that aspect here.

About the weight, 135lb Elite 1000s can be carried up and down stairs. I used to bend back and tilt them on my knees, stair by stair, never putting pressure on a bent back, but let the legs and knees carry the weight.
It is a similar design to the TH118, with the handles and wheels.

I think I'm hung up on the whole "135lb's" can be carried up/down stairs, but not 160lbs? Also, dollys work but not casters on subs? It's just confusing.

Anyways, I think I'm missing something because of lack of info and once you explain your reasoning it will be clear for all of us, (if I may be so bold as to speak for everyone here).

[Ray Aberle]

As I mentioned my subs are around 90lb, not 160lb.

I think people are fixated on 160lbs because that's the weight of the TH118 you're asking about...

You should never bend your back carrying something heavy; it's always the legs you bend, back remains straight.

Definitely no extra budget for extra people, so looking into technology.

Why is there no budget for extra hands? The client would get to pay for it anyways...

Another way to look at it: You are endangering your personal health and safety to put more money in the client's pocket.

About the weight, 135lb Elite 1000s can be carried up and down stairs. I used to bend back and tilt them on my knees, stair by stair, never putting pressure on a bent back, but let the legs and knees carry the weight.
It is a similar design to the TH118, with the handles and wheels.

Not trying to bust your chops here, because I get your point- you want to figure out a way to continue doing shows as a one-man operation, and not have to hire on extra help. It's admirable, and that's where I was for many years. I'd do weddings, school dances, and even some basic live sound gigs (think Relay for Life events, and similar). Weddings were always 450s/1500s, but sometimes a larger speaker for the tops. There were always bins of cables, lights, DJ mixer, CD decks, etc. And sometimes I'd go crazy with truss structures. And I often did those shows by myself solo.

Trust me, my back is thanking me for it now. Even being AS CAREFUL AS YOU CAN, you can still easily bump something while carrying a load and suddenly knock something out of alignment.

As the company grew, I came to the realisation that I mentioned above: by trying to do EVERYTHING myself, I was simply making my clients rich, and damaging my body. And not just from the labor aspect of lifting and carrying heavy things- the long days as well. "Oh, it's a DAY RATE so I am going to work 7AM to 1AM!" -- Well, yeah, no. Long days, short turn-arounds, and then another long day- again, I was burning myself out, just for the sake of saving the client a bit of money.

Maybe your answer is multiple size packages. Here's your basic rig, and the medium rig, both of which not only can you handle yourself, but are also *sufficient for your current clients.* THEN, have an Advanced Rig, that adds more subbage, whatever, to really WOW your client- but costs more (because of the better subs, of course!) because you're adding a stagehand to do your load in/out labor. I don't know where in the country you are, but here in the PNW, stage hands typically start between $12 and $15 per hour, based on a 4HR minimum call. If you're ordering through a company (or the union), you'll be paying at least $24.50/hour and possibly more, but if you find someone who just works for you (not through a labor company) you could pay them $15-$18/hour, they'll be happy, and your back would thank you. Say it's $18/hr, 4HR minis, $72 load in and $72 load out. This Advanced Rig costs your client an extra $250- $144 of that is labor and the other $106 is for the nicer gear you're bringing- and life is a LOT easier.

-Ray

[Brian Jojade]

Ray, that is extremely well put!

The 'no budget' argument is one that is difficult to understand.  If the customer has no budget for the work requested, why is it your problem to put in the extra work?  Yes, I get it, and have done it in the past, but had someone told me earlier how to NOT do that, it would have made life a heck of a lot easier.

Yes, you have to get used to people deciding NOT to use your services because of the cost. Honestly though,  at some point, a job at McDonalds might pay more and have less stress on you.

Any way you look at it, the event at the top of stairs will cost more. Either you hire help, you spend money on speakers small enough to be carried individually, (requiring more trips on your own) or you invest in equipment moving devices for the stairs to make the lift safe.  The additional cost for this should be the burden of the customer, NOT you!  It's not your fault that they are booking you at an event that is more costly to set up in.

NIOSH has set guidelines for generally safe lifting:

As a basic starting point, one person should be able to lift an object weighing up to 51 pounds:

If the object is within 7 inches from the front of his or her body.
If the object is at waist height and directly in front of the person.
If there is no twisting involved.
If there is a handle on the object.
If the load inside doesn't shift once lifted.

Anything that doesn't fit into that category should not be lifted by one individual without assistance. The risk of injury increases dramatically if you don't follow the rules.

Now, again, with stairs, and the proper equipment, you are not actually LIFTING the entire weight of the object, but need to make sure that you are operating safely moving the items around.  Even with a proper furniture dolly, I would demand 2 people on a 100lb lift.

[ProSoundWeb Community]