First Rig - Small Project (HELP NEEDED)

First of all apologies to everyone who is reading this and is thinking "oh god, another one of these..."

Alright. Im looking to build a really simple rig mainly for house parties and what not. Probably won't need to cover more than 50 people. The sort of music that would be played is dance music, so House, DnB (all types), Hard Trance, Reggae and maybe even a bit of Hardstyle.

I've generally been thinking about making a G-Sub as its a simple plan and seems to be ideal for most genres of music, however i've also considered 1850's. Are these subs a good choice? If not what might be a good alternative?
Mid-tops I really don't know a great deal about so what might be recommended to fit the subs?

Last bit which is probably the most vital, what is EVERYTHING you need to make a fully working soundsystem? I only really know:

Subs, Mid-Tops, Cables, Amp, Genny, EQ, Cross-over... That's all i can name...

Sorry for such rookie questions but we all gotta start somewhere right?

Thank you

Hi,

I'd build 2 G subs and then buy 2 used midtops. Something like a 12 + 1" or 15 + 1.5". I'd also use the G subs vertically and put a top hat with short pole between the subs and midtops to get a bit of height, which will help in a house situation.

If your sadistic enough then build your own midtops, but this will require the skill to design a passive crossover, or enough talent to EQ and setup a 3 way system.

If you go for used midtops then you just need 2 amps and a 2 way active Xover. Do a split around 80 to 100Hz. If you want even less hassle, then get amps with Xovers in, set the bass amp with a 100Hz lo pass filter, and the midtop amp with a 100Hz hi pass filter.

Big fat juicy 2 x 31 band graphic between mixer and active Xover or amps if you skip the active Xover, and your good to go.

Rog.

Yeah i wasn't intending on building my own mid tops haha! What do you mean "Something like a 12 + 1" or 15 + 1.5""?

Yeah i was planning on putting the subs upright. Yeah i will find something also to give the mid top a bit more height.

Could i not use one channel on an amp to power the subs and the other for the mid tops? If not why? (trying to learn at the same time... )

Any recommended amps with xovers built in?

Also is there any way of running the rig of standard plug sockets in a house?


Cheers for the help, i really do appreciate it!

What do you mean "Something like a 12 + 1" or 15 + 1.5"?

The first figure, like the 15 or 12, denotes the size of the midbass driver. Either 12" or 15". The second figure is the size of the HF compression drivers exit. Either 1" or 1.5". A 12" midbass driver can work well with a 1" compressions driver and a 15" will need a 1.5" or even 2" compression driver to work adequately.

Could I not use one channel on an amp to power the subs and the other for the mid tops?

Yes this would be fine, but would require 2 amps to do this properly, i.e., in stereo and without running the amps into very low impedances. If your sub drivers are 8 ohms then each cab will be 4 ohms if you wire in parallel and 16 ohms if wired in series, run 2 of these from one channel of an amp and you have a 2 ohm load or an 8 ohm load. If the amp is very strong and your cables thick enough then no problem with the 2 ohm load. You could use 16 ohm drivers to give you a 4 ohm total load or run both subs in series with 8 ohm drivers to give you an 8 ohm load (same as wiring each sub in series with 8 ohm drivers), but you would need an amp with a lot of output into 8 ohms, which is not easily achieved. One amp also gives you no redundancy, if it fails you're out.

Any recommended amps with xovers built in?

There are many, have a careful search to find out which ones will still be working in the near future. Although having Xovers in the amp(s) is the easiest route, if you decide to scale the system up or add other components you will very soon start to see the limitations. I would include a budget digital Xover as this should also be able to provide EQ for the system and time alignment.

Also is there any way of running the rig of standard plug sockets in a house?

Unless your amp or amps are 20Kw each, then you will have no problem running a system for even 500 people from 13 amp wall sockets.

Rog Mogale covered a lot for you !
Here is what I have to add. Due to your max audience size stated, you don't need big cabinets with horns for low frequency section. You are actually in a situation where bass reflex is fine. With good subs underneath, there are numerous commercially available cabinets that are not to pricy that will work very well in your situation.

Cubo subs do however still make a great deal of sense here. They have very high sensitivity and in that frequency range you can usually use all the headroom you can get. Cubos also are very lightweight in proportion to the output!

Avoid tops with Piezo tweeters as they have a harshness that causes a high degree of ear fatigue. In your tops you are going to want the high frequencies to have efficient compression horns.
An equalizer is going to be a must as you will need to be able to easily adapt both to different acoustic environments as well as changes in the acoustic environment. EQs like Rog is recommending are ideal and a lot of those have a summed LFO (low frequency out). That cxan be used until you can afford an active crossover. The option he mentioned about getting amps with active crossovers built in is a good one and not that big of a price jump!

More speakers are destroyed by under powering them then winding up over driving the amp to the point of creating square waves than any other cause. You do still want to match the amps to your speakers closely enough that it is not to easy to overdrive them however!

Trapezoid shaped cabinets have 2 advantages. It is generally easy to fit them in a given space, and they easily couple a pair of cabinets at a slight splay for wider coverage

BTW, your tops are going to have some efficiency drop in their low frequency section if you use bas reflex tops. In that case the LF driver winds up being the driver for your midrange. In a room that is about right for 50 people you are going to NEED a dip in efficiency at around one khz. Otherwise the room will cause you some headaches that are going to be difficult to remove enough with your EQ.
If you are certain you want to build, but not sure you are ready for some of the stuff here, The Bill Fitzmaurice site does offer some good options. It is however not FREE. It isn't expensive either though!
Hopefully you have gotten some insight that will at least advance you to the next level. Unfortunately that may involve more questions!

Cheers for both your replies, i'm starting to understand a lot more now. Still some questions though,

What difference does it make in wiring in either series or parallel?

I will probably consider getting a xover that isn't built into an amp then as eventually i would like to expand this project. I just want to start off with something small.

Im not planning on building any tops, so can you recommend any that i could buy that wouldn't have that dip? Or is there an easy way of fixing it? (If i buy tops they will be second hand).

Also i've heard that using a PD.186's in G-Subs are ideal. If you do agree on this, what amp do you think would be most suitable as im sure there are many options?

Thanks

Tangez wrote: Cheers for both your replies, i'm starting to understand a lot more now. Still some questions though,

What difference does it make in wiring in either series or parallel?

I will probably consider getting a xover that isn't built into an amp then as eventually i would like to expand this project. I just want to start off with something small.

Im not planning on building any tops, so can you recommend any that i could buy that wouldn't have that dip? Or is there an easy way of fixing it? (If i buy tops they will be second hand).

Also i've heard that using a PD.186's in G-Subs are ideal. If you do agree on this, what amp do you think would be most suitable as im sure there are many options?

Thanks

Series wiring increases the impedance load and reduces the power/efficiency of the amp. Parallel wiring reduces impedance load and increases power output...if you don't drop it below the capability of the amp!

As to the crossover question, my point about the EQs is that is going to be vital gear and you should be able to get one with a built in LFO out for no extra charge. That isn't as ideal as a hard crossover, but can be quite useful while you are building up gear!

The point about the dip was that you should be able to view frequency response curves on any speaker worth buying. If you are doing primarily indoor gigs, a dip in the 1khz range is desirable. Outdoor gigs it is not! If they have only a slight dip in that region you should be able to easily EQ them for either.

About 6 7 years ago I discovered that Behringer Equipment is really l;ow priced for what it is because of some prejudice against anything made in China...I also can attest now that every piece of Behringer gear I have purchased has repeatedly proven to outperform gear costing twice as much or more.

Unfortunately most of my Speakers are old, no longer produced gear. I can't give you a specific recommendation there. Sorry! I am working on doing some building myself!

I have never used the specific subs or drivers you are asking about so I cannot advise you there! Sorry. I have seen enough data on the CUBO series that I can easily recommend them .

So in which instances would wiring either way benefit?

Generally dont have anymore questions so thanks for all the help you guys.

Tangez wrote: So in which instances would wiring either way benefit?

Generally dont have anymore questions so thanks for all the help you guys.

In all instances correct wiring is pretty important. Quality and correct gauge wires can make a substantial difference as well. However I think that isn't what you are asking. Amplifiers are rated to a variety of impedance loads. The lower the impedance load the more power they produce, but only to the point where they are capable of maintaining stability. Operating an amp below its rated load is a recipe for disaster.
Most commercial cabinets are 8 ohm nominal load cabinets.
I will use some old amps and cabinets as an example just because I remember the numbers easily and don't have to refer to a manual to verify each part.
In 80s and 90s I used a variety of amps but essentially started off with a pair of Peavey CS400s. Each CS 400 was rated at 125 watts per channel @ 8ohms or 200 watts per channel at 4 ohms. They were noted rated into a 2 ohm load and presumed to be unstable there!
If I was using a pair of 8 ohm cabinets in stereo and used only one of the amps I would connect one speaker to each side. resulting in 125 watts per side or 250 watts total power.
If I connected four 8 ohm speakers to a single amp I would connect 2 speakers to each side in parallel, resulting in the amp seeing a 4 ohm load. It then produced 200 watts per side and a total power of 400 watts. However this does not produce quite as much total gain as you might think. It produces better distribution of power and did not stress each speaker quite as much. Each speaker only sees 100watts that way.
I did have some large, heavy duty and highly efficient cabinets, and CS 400s were capable of being operated in bridged mono mode. In that mode the nominal impedance load was not to be below 8 ohms. However each CS 400 would produce 400 watts into an 8 ohm load.
In that manner I would use one amp as the left channel and the other amp as the right channel. I would then have 400 watts per side, each speaker seeing a full 400 watts. That is 800 watts total power! I also sometimes used a single CS 400 in stereo mode with an active crossover sending a summed LF signal to the other CS 400. This only netted me 650 watts total power, 250 to the tops and 400 to the sub, but was also very effective and worked well in many situations!

Hopefully that helps you see how wiring and correct connection can make a difference, but you must remember NOT ALL AMPS ARE CAPABLE OF BRIDGED OPERATION! Also in bridged mode each side of the amp only sees half of the impedance load. If the impedance load falls to far smoke, fire and destruction can occur!

Sanaway lab grupen copy amps are very good for the price you pay (if you feel comfortable wiring money to China you could get yourself some powerful Amps for virtually nothing!

Then for a crossover, these lot are gunna tell you to get a 3way active.... Go to freedsp<<< they charge 50 euroes for a copy of a dsp (I believe it runs with sigma audio) the only thing is you have to wait two weeks for them to get 20 orders in.

Drivers... Rig resale page on facebook!! If not just search around but you're much better off going with second hand drivers that's in good conditions.

Then for setting up the dsp just download the software and follow instructions, for one 4way stack including dsp, 2 1000w amps maybe 1 2000w @8ohm (btw overshoot with the power of Chinese amps I.e if you want 2k at 8ohm, buy 3 or 4k ) and drivers and cabs if you built it yourself could cost you £400