Sub-woofer decision....

[DuckJordan]

The floor standing speakers lay on the ground now since I get a better sound for some reason. Three stage wedges sit across the front of the stage in a normal show.

Its because floors tend to re-verb the bass and send the vibrations through the floor making the floor act as a re-verb cone. I have a friend who works with home theater installs. That's why in a home theater a sub that runs on 35 watts of power is really all you need because its using the floor as a reflector cone.

 

[DaveySimps]

Its because floors tend to re-verb the bass and send the vibrations through the floor making the floor act as a re-verb cone. I have a friend who works with home theater installs. That's why in a home theater a sub that runs on 35 watts of power is really all you need because its using the floor as a reflector cone.

This is actually not reverb at all, but coupling of the sub with the floor. You had the principal right, completely inaccurate term. This is why you get(at times) more bass out of stacking two subs together in the center, as opposed to keeping one cabinet on either side of a stage.

~Dave

 

[DuckJordan]

sorry i was in a hurry and couldn't think of the right term.

 

[ROFLCopter]

Has anyone heard of Wharfedale pro audio?

 

[museav]

That's an older pic from last summer.

The floor standing speakers lay on the ground now since I get a better sound for some reason. Three stage wedges sit across the front of the stage in a normal show.

Are the floor and stand speakers both covering the same listener area or does each cover a different area? If they cover the same area you might consider getting rid of the floor standing speakers and investing what you can get for them in better subs and processing.

I think what Sharyn keeps trying to get across is that you have to look at everything as a system. All the speakers and the room itself have to work together to get the optimum result. If the subs can't keep up with your mains then are you okay with reducing the mains performance? Although many sub sensitivity numbers can be rather misleading, if you have a specific amp for the subs then you might have to look at things like the rated sensitivity for the subs to make sure they can provide sufficient output to properly match your mains. Also, don't get caught up in just 15" versus 18", there are a lot of other factors that can go into designing and building a subwoofer.

Have you ever considered putting acoustical absorption on the walls behind the drums or a lid on the drum enclosure? There may be a number of acoustics related things you could do to improve the sound in that space both with and without the sound system.

Perhaps the picture is misleading but you noted that the room is 45'-60' by 140' however the band and system seems setup in a corner almost as though the room is square. If the room really is that large and 140' deep, have you ever considered having an installed system with the speakers flown? You might be able to get much better coverage and get more of the sound aimed at the listeners rather than at the walls and ceiling with such an approach.

 

[ROFLCopter]

I have considered all of those factors, but the trouble is this, the room is shared, my youth leader is very cheap.

I'd love to get some flyable speakers, but I don't think I could sell both pairs of mackies and make out with decent flying speakers. A friend of mine and I were thinking of building boxes to put the pole speakers(or the floor mackies on and use those instead since they are actually three way, but has a blown mid range in one of them which is why they are pretend subs. previous owners, don't ask....). This room used to be a bar and had at least 15-20 24" sized crt tv's hanging from the /\ shaped ceiling, so I know it's strong enough.

I'm working with a church that a couple years ago almost closed it's doors due to financial imbalance, otherwise that room would have a much better system, but the fact is that that room is used by people who don't know a screw driver from a hole in the floor, so it wouldn't be economical at this time. I've been trying for years to work full time there, but it's not feasible for some reason.

The stage is set in the corner because the room is setup as a banquet room of some sort. The booth is angled straight on which hurts alot.

 

[SHARYNF]

Here is what I would suggest

Get the mid in the SR1530 replaced, you should be able to open up the mackie and get the speaker reconed. Give Doug at speakerguy AT earthlink.net or P# 360-271-4262 WA. State a call to get an idea of cost

The Sr1530's cannot be pole mounted or flown, but you could raise them up from the floor. The inexpensive rolling scaffolding that sells for about 150 dollars a section might work

Then I would look at placing the other mackies on stands down on the sides of the room, and get a time delay so that you can time align them

What probably is not clear to you is that when you just place speakers together they start to interfere with one another and you get all sorts of comb filtering

Doing this IMO is going to give you a much better solution, allow for better coverage in a odd utilization of the room, and not break the bank


Sharyn

 

[ROFLCopter]

The Sr1530's cannot be pole mounted

Who told you that?

A built-in pole-mount cup is provided on the bottom

And if there's a built in pole mount, then what's it for? I saw the online manual and it says that the speakers are not meant to be pole mounted, but for the first 7 years of these speakers lives, they were used on some Ultimate speakers stands, which had no problem at all. So that's pretty interesting that they say that.

I know that basically any mackies from the SR and SA era of speakers were never built to be flown, but whats wrong in building a box around the cabinet?

 

[avkid]

The problem with pole mounting these is that most tripod stands aren't rated for the weight.

 

[avkid]

I know that basically any mackies from the SR and SA era of speakers were never built to be flown, but whats wrong in building a box around the cabinet?

Are you prepared for the liability involved?

 

[SHARYNF]

Long story but used to be an investor in Mackie

The cup was designed to be used with a WALL MOUNT the problem with the pole mount is the the ultimate stands etc were just not stable and they had a tendancy to fall over. The cup if I recall is not like on the SRM450 which has a locking mechanism


Building anything that is a box that supports something over peoples heads is very very tricky. Usually not recommended. The problem is you need to make sure that the cabinet is securely mounted to the box, and then you need to make sure that you have built a box that will hold the load at the joints

I have seen some attempts where for instance the mounting was on the side panels of the box and the bottom fell off

Most of the time the issue is that the front of the speaker cabinet with the speakers will not safely support the weight of the speakers if the cabinet is leaning forward OR the speakers them selves are not securely supported.

In the design usually there is a trade off to easy access to the speakers them selves and the integrity of the design.

Basically you need to have a point that will support the full system but also is engineered in such a way (in combination with the cabinet/speaker) that the entire assembly is totally supportive and nothing will be stressed and come loose


So usually I would say DONT ATTEMPT to build a cabinet that is flown

Sharyn

 

[museav]

Who told you that?

And if there's a built in pole mount, then what's it for? I saw the online manual and it says that the speakers are not meant to be pole mounted, but for the first 7 years of these speakers lives, they were used on some Ultimate speakers stands, which had no problem at all. So that's pretty interesting that they say that.

I know that basically any mackies from the SR and SA era of speakers were never built to be flown, but whats wrong in building a box around the cabinet?

This is from the Mackie SR1530z manual:

WARNING: The cabinet has no rigging points and is not suitable for rigging. NEVER attempt to suspend the SR1530z by its handles. The SR1530z should never be pole-mounted.

and

Mounting Methods Floor mount only. The SR1530z should never be pole-mounted. The cabinet has no rigging points and is not suitable for flying. Never attempt to suspend the cabinet by its handles.

[FONT=SQYEZL+Century-BookCondensedIta,Century][FONT=SQYEZL+Century-BookCondensedIta,Century][FONT=SQYEZL+Century-BookCondensedIta,Century]"...not suitable for flying" and "should never be pole-mounted" seems pretty clear and direct. Can't stop anyone from doing either but can say they would pretty clearly be doing so with the knowledge that it is not recommended and at their own risk.[/FONT][/FONT][/FONT]

[FONT=SQYEZL+Century-BookCondensedIta,Century][FONT=SQYEZL+Century-BookCondensedIta,Century][FONT=SQYEZL+Century-BookCondensedIta,Century]I understand that you have limited resources and are trying to do the best you can with what you have. But there is a point where expectations and functionality may have to be compromised to work withing those limitations. [/FONT][/FONT][/FONT][FONT=SQYEZL+Century-BookCondensedIta,Century][FONT=SQYEZL+Century-BookCondensedIta,Century][FONT=SQYEZL+Century-BookCondensedIta,Century]Consider that the SR1530z are supposedly capable of a long term output of 123dB (126dB peak) with a -3dB response down to 50Hz and a -10dB response of 38Hz. For subwoofers to improve on what you already have they would seem to have to exceed those numbers and apparently do so with the existing amplifier (which may be rated 700W @ 8 Ohms in bridge mono mode but would most likely not be operating that way with two subs). I[/FONT][/FONT][/FONT]t isn't just a matter of adding subwoofers but of adding subwoofers that could provide noticeably improved performance over the existing system. It may be possible but balancing getting much improvement with your $1,000 budget may be tricky and, unfortunately, the type of information required to make a valid comparison of product specs is often not provided for lower cost products.

[FONT=SQYEZL+Century-BookCondensedIta,Century][FONT=SQYEZL+Century-BookCondensedIta,Century][FONT=SQYEZL+Century-BookCondensedIta,Century]As to why to group subs, because they reproduce only low frequencies when subs are grouped the sounds from the two subs are within 1/4 wavelength of one another for all listeners, thus they acoustically couple and you get some free increase in the resulting output. In addition, when you split subs apart physically the phase relationship between them varies over the listener area and thus the resulting frequency response varies over that area as well with a tendency to have a 'power alley' with higher levels down the middle (where the distances to, and thus relative phase of, the two subs are more equal) and varying response off to the sides.
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