Loudspeakers Can I get away without a crossover?

zac850

Well-Known Member
Hey,
So I'm a lampie most of the time, but I'm installing a sound system into a small restaurant that wants to start doing dinner theater (don't ask). Problem is, the director also wants to start doing DJ things in there, so I'm trying to make a basic theatrical system also be a DJ system. I'm trying to add in a sub, but the problem is that cross-overs are expensive.

Now, I wouldn't use the sub for their basic theatrical shows of course, but for DJing, if I just ran a full range output from the console to the sub, would it know what to do with the signal or would the sub attempt to vibrate with the high end as well?

Sorry if this is a really stupid question, I usually try and stick to my lighting world, but occasionally I can't.

Thanks in advance,
Zac
 
It depends on the sub. Some subs do have a built in crossover, especially newer active subs. In your case this might be a great thing to look at. To answer your question, a speaker is still a speaker, it will try and reproduce the signal you send to it to the best of its abilities. So, without a crossover (either internal or external), a sub with try and reproduce a full range signal. I would definately say you should have a crossover, especially with the DJ scenerio you listed.

~Dave
 
What's expensive?

The DBX 223 can probably be found for well under $100.

If you're really low budget, there may be something from Behringer in the $50 range.

You can also use a graphic equalizer on the sub and/or main speakers to filter out the unwanted frequencies, and you can balance the sound coming out of the full range speakers. Check out the Behringer FBQ3102 -- it gives you two channels of EQ to balance out your sound, plus a sub out. You get two devices in one :) And I'm sure you can get one of these for under $100 on eBay at some point.
 
you have two issues here, one is to get the low frequencies OUT of the small full range speakers, and the other is to get the high frequencies OUT of the sub.

You need to get a crossover to divide the audio output for the full range and sub. DJ's really push a system especially on the low end. Do not attempt to use a graphic eq for this and expect to get any sort of quality result.

Sharyn
 
Thanks for the DBX suggestion, that would be well within my budget, I'll look into that.

I had a feeling the sub would blow if I sent it a full range signal, I just wanted to make sure.

Thanks for the help,
Zac
 
sub will NOT blow if you set it to full range, it will output a sound that will interfere with the other speakers giving you a poor quality sound. Your real danger is blowing the full range speakers in a dj environment if you don't use the crossover for them

Sharyn
 
Before you go running off buying a 223 or anything else, tell us more about the rest of the sound system and the space, these factors could make a huge difference in how you might want to proceed.

Also, with your obvious budget concerns, what were you thinking for a subwoofer? Did you have any models or budget in mind?
 
Yes, knowing more about the space will help.

I'll also second going with an active subwoofer as it will eliminate the need for a crossover. What kind of budget do you have to work with?
 
Well, the DJ side of it appears to be less important then the theatrical reinforcement side of it, so I actually dropped the idea of the sub for now, and if they start DJing, then I'll get them a sub.

Its a small restaurant, maybe 50 seats, so I don't need anything that powerful. I found some decent macki powered speakers that I'll be hanging, and 2 wireless mics and a small console later I've got a basic sound system for them. DJ system supplies CD players for shows and a DJ system to use for retirement parties or similar things.

Budget was something under $3,500 for that and some lights.

For some odd reason I just kept finding really expensive $1000 crossovers and didn't find the cheeper ones until given a model number.
 
Well, the DJ side of it appears to be less important then the theatrical reinforcement side of it, so I actually dropped the idea of the sub for now, and if they start DJing, then I'll get them a sub.

Its a small restaurant, maybe 50 seats, so I don't need anything that powerful. I found some decent macki powered speakers that I'll be hanging, and 2 wireless mics and a small console later I've got a basic sound system for them. DJ system supplies CD players for shows and a DJ system to use for retirement parties or similar things.

Budget was something under $3,500 for that and some lights.

For some odd reason I just kept finding really expensive $1000 crossovers and didn't find the cheeper ones until given a model number.

This will give you plenty of choices, and plenty of reviews for a lot of the items.
Musician's Friend - Search Results
 
The Mackie's srm 450 is pretty much a middle of the road solution, not a bad choice. You have options re adding subs to them which could expand its use. Once you mention DJ a lot of us instantly think relatively high volume of compressed mp3's with the need for heart bounding bass. the SRM's are a bit weak on the bass and adding a sub reduces the load on the srm quite a bit improving overall performance. There are a lot of alternatives in this market.

Sharyn
 
Of course Mackie powered speakers could be anything from the 8lbs. SRM150 compact monitor with a full range 5.25" driver to the 132lbs., dual 15", three way SA1532z.

Be careful with hanging these. Make sure to use the right hardware and check the speakers, I believe that some of the Mackie SRM models have some recessed rigging points that require non-standard hardware.
 
Fyi, I have the SRM450s, recently hung them (properly), and used these ... the best deal around:

10MM METRIC DIN 580 - EYE BOLT - SP - 20 PACK - eBay (item 110237001289 end time Jul-23-08 10:04:17 PDT)

This listing is for a 20-pack ... check with them to get a smaller pack (I bought in packs of 4 for around $6/pack).

Use a piece of thin cardboard as a squishable washer to allow you to get the eye ring lined up front/back on the speaker with a real snug fit.

The recessed hole is for the rear mount if you hang the speakers rightside up (horn on top). If you flip the speakers upside down, the rear hole will be flush, so a long bolt will not be required. Fyi, the 12" driver grille removes and rotates so you can get the logos facing upright with the speaker inverted.

Have fun!
 
If it's only a 50 seat venue.. it may not need a sub depending on what the people are trying to do... I've had powered EON's do a fair duty with setting up two of them and using them, and although you don't get a rave base... you still do get a nice amount of base out of them... It was enugh to please our rap and techno playing DJ for events...

Another idea might be to find an amp that has a crossover built in (have a couple at the place I am currently at)... and I don't remember them being too expensive...
 
Also, fyi, if you have Mackie SRM450s, they may have a "low cut" filter button on the back of the speaker.

And if you buy a self-powered sub, it will probably have a high-cut filter built in. In fact, if you buy a pair of subs, they usually have full crossovers built in and you can connect the full range speaker through the sub and it will take care of the full crossover for you.

Another option is to look at EQ units with adjustable hi- and low- cut filter features built in. The Behringer FBQ3102 has this.
 
Since you are using Mackies I would look at their line of subs, they have models with 15's 18's and 4 10's, they include a crossover system that allows for the proper split.

If you decide to go with an independant crossover, take a look at used Ashly crossovers that show up on ebay frequently for very cheap. They are very good quality, sound excellent and are quite robust. A lot of them are turning up on the market as sound companies are moving more and more to dsp systems.

In my opinion you probably will want to have both, a crossover should be set primarily based on the speakers inorder to have the best point and slope and usually should NOT be played around with much. A GEQ on the other hand is usefull for altering the overall sound balance and to eliminate feedback in monitors after proper placement

Sharyn
 
Is there any GEQ a step up from Behringer?
Many, for more budget conscious options look at dbx or as Sharyn noted, maybe something like a used Ashly or Rane EQ.

What about powered subs w/ crossover?
Numerous options are available. Typical factors in selection include the output level required, the physical size, the low frequency response desired, flyable or not, how the internal crossover matches with the mains and, of course, cost. So any more input on these and any other relevant factors would help in providing specific suggestions.
 
You can also use a graphic equalizer on the sub and/or main speakers to filter out the unwanted frequencies, and you can balance the sound coming out of the full range speakers.


Wh you install a subwoofer it is always a good idea to remove the higher frequencies from the signal unless it has a built in crossover. A graphic equalizer with a certain frequency all the way down does not eliminate the frequency, rather reduce it by 15dB (+/- a few depending on the EQ). You should look into getting a LowPass (LoP) Filter to put in the sub chain. This is basically what a crossover is but it can also be found in some Equalizers.

All in all here is my advice:
Get a sub similar to the Samson SM.DB1800A ($650-$850) and wire it like this:

Run the Mixer's Main Outs to the OTB Gear (your EQ's, Delay, etc.) to the SUBWOOFER's Inputs (A for left, B for right) and the FOH Amps. This way the sub will give you the tight punch in DJ'ing and the speakers are still full range for the theatre.
 

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