P.A School (General Advice).

[Karlos Santos]

@Mostapha ; Lol at correcting my grammar.

Yeah Mackie and JBL came to mind simply because they were incredibly affordable. In all honesty I didn't even consider QSC until they was mentioned in this thread as they aren't (to my mind) as well known in the UK.
I really like the compact styling of QSC stuff. Even the 18" sub has a small enclosure (seemingly so) and I think this will work well in smaller venues especially weddings.

I agree with the point made above about people wanting to see a proper setup and that small speakers would be interpreted as 'not a real setup' but there's a limit and I think QSC have got this right. Actually part of the USP of what I am doing is a 'real setup'.
I did a corporate event last weekend and people were absolutely gob-smacked that a 'real DJ' had turned up with decks and that I was actually mixing and giving them what they perceived to be a nightclub type service rather that the usual stale guy with laptop job - which goes a long way to explaining why the event was extended by 2 hours and the dancefloor was rammed.

[Karlos Santos]

Just to give my views on a few of Karlos's questions without quotes ('cause I'm lazy )

If the cabs are comparable I would not consider QSC to be an upgrade from RCF (or even Yamaha for that matter). The times I've found myself on QSC systems (K12s or 153s over 181s) I've found them to be quite ordinary and nothing special.

Avoid the Ksubs no matter what. They are absolutely horrible if you are playing any current popular music. "Black Widow" for example has prominent low Ebs (39hz) that drive the whole track. On a Ksub it will sound like someone turned the subs off. "Don't Tell 'Em"... same thing but with low Ds (36.7hz) - and these are just two examples taken from the current top 10 downloads charts.

Quality powered cabs have enough internal DSP to get you 99% of the way there without external DSP like a Driverack or even EQ.

This is another subject completely but since it's been brought up... tops on poles over subs next to the dance area is often exactly where you want them for weddings and other events where you want the sound localized. It also gives a much cleaner look.

Cheers man.

RCF are definitely on my watch list. I just need to compare specs. Yamaha I had not considered at all but now I will.

KSUBS are now out of the equation but thanks for reinforcing it.

RE: DSP, that's what I was lead to believe - thanks.

In my experience the more poles and stands there are the greater the chance of someone falling over one - with you on that. It might not be the best audiophile way to go (i dunno) but for a wedding, it is the way people like it.

[b ill]

In my experience the more poles and stands there are the greater the chance of someone falling over one - with you on that. It might not be the best audiophile way to go (i dunno) but for a wedding, it is the way people like it.

Actually for most club and banquet sized spaces, subs away from walls and corners works best. I think a lot of this stuff spilled over from the home audio guys where wall and corner placement actually is where you want them.

I mentioned Yamaha because you might find it priced favorably in the UK... dunno. But both the DSR and DXR is good stuff- the DXR line just being not as loud and with a less durable finish. You can't go wrong with QSC either, but I wouldn't pay a premium for it.

[soundinmotiondj]

If the cabs are comparable I would not consider QSC to be an upgrade from RCF (or even Yamaha for that matter). The times I've found myself on QSC systems (K12s or 153s over 181s) I've found them to be quite ordinary and nothing special.

All of those manufacturers offer a range of cabinet lines. There is very little "secret sauce" and speakers that are better performers in any number of specs (flatness, overall SPL, power handling, weight, form factor) are sold at premium prices.

The KLA12 is a clear upgrade over the RCF312A or even the QSC K12. The upgrade is in sound quality and in price.

IMO, I prefer the sound of the K10 to the K12 by a small margin, and I prefer both to the RCF312A by another margin. The differences are clear (to me), but may or may not be clear or worth the incremental $$$ to you.

I would caution that listening tests in the Guitar Center demo room are VERY hard to judge.

Avoid the Ksubs no matter what. They are absolutely horrible if you are playing any current popular music. "Black Widow" for example has prominent low Ebs (39hz) that drive the whole track. On a Ksub it will sound like someone turned the subs off. "Don't Tell 'Em"... same thing but with low Ds (36.7hz) - and these are just two examples taken from the current top 10 downloads charts.

In both examples, the KW181 would also be struggling with those same tracks. So would the Yorkville LS801p. So would any number of subs that are reasonable for a "mobile" PA system.

Using a KSUB will certainly not sound like "...someone turned the subs off..." Such alliterative language, while common, is not really helpful when making purchase decisions. It is true that the KSUB is a compromise of form factor and price against performance. Given the OPs intended usage, it is not the worst compromise to be made.

<40Hz content implies one of two things to me: a permanent installation at a club -OR- a box truck and roadies. My current system can achieve "flat to 40Hz" in rooms up to 20k sqft. It takes a 7x12ft trailer to haul it, and 6 man hours of labor to load in, and 4 man hours of labor to load out. I considered a system that would achieve "flat to 35Hz, and -3dB at 30Hz". That system would have required a 24ft box truck, and 8 man hours of labor to load in. Take from that example what you will.

Quality powered cabs have enough internal DSP to get you 99% of the way there without external DSP like a Driverack or even EQ.

This is not true. While powered cabinets do have some internal DSP, the number of controls that are exposed varies widely. The onboard DSP may be sufficient to tune the box, but most do nothing to help room modes, or to compensate for placement decisions (e.g. delay).

One main advantage of a dedicated digital PA manager is that is can be placed in the booth...and not on the back of every cabinet spread around the room. For making tweaks on the fly, this is not an insubstantial benefit.

This is another subject completely but since it's been brought up... tops on poles over subs next to the dance area is often exactly where you want them for weddings and other events where you want the sound localized. It also gives a much cleaner look.

The "look" of the system will be left as an exercise for the reader.

The "localization" of sound for dancing is often at odds with the "general sound field" that is needed for speeches, toasts, announcements, etc. There are trade offs to be sure. By understanding the reasons for the placement advice, it is possible to account for that information when choosing to break those rules in order to satisfy some other constraint...like how the system "looks."

When placing subs, it is best to avoid placement that is 1/4 wavelength from a boundary. For 40Hz to 100Hz, this is 7.5ft to 2.8ft. Placement that is 1/4 wavelength from a boundary will result in a reflected wave that is 1/2 wavelength out of phase with the source. That leads to an effect that is similar to a -24dB notch filter centered on that frequency. So, if "next to the dance floor" is not also "touching the wall", there is a risk of substantially altering the resulting sound field because of the 1/4 wavelength placement.

In addition, placing subs next to the wall has the effect of boundary reinforcement, moving the sub from half-space to quater-space. The net effect of that is about +6dB additional output across the passband that is typical for subs. The "next to the dance floor" position will not typically gain that same benefit. That +6dB advantage applies to all listening positions in the room. +6dB can be achieved by applying 4x the wattage to the same cabinet.

For any point sources of sound, separation by two wavelengths will minimize the destructive interference that is commonly referred to as "comb filtering." For tops that are high passed at 100Hz, two wavelengths is about 22.6ft. My advice is to split the tops by 25ft, as a rule of thumb.

[soundinmotiondj]

Actually for most club and banquet sized spaces, subs away from walls and corners works best. I think a lot of this stuff spilled over from the home audio guys where wall and corner placement actually is where you want them.

You have that backward.

In "large" rooms (50ft square or 2500sqft and up), wall/corner placement of subs is critical for avoiding destructive interference (1/4 wavelength cancellations, comb filtering, etc), limiting the required power (wall loading is +6dB, corner loading is +12dB, and each +3dB you save cuts the required power in half!), and generally keeping the cabinets out of the way.

In small room acoustics, the room modes are a nightmare to understand and account for. Acoustic treatment is the norm. Placement positions tend to be weird ratios of 1/3 the short wall and 1/7 the long wall. Small room (e.g. home theater) is the bane of my existence. One popular cookbook formula is to put the sub where you will be sitting and then crawl the floor listening to the best resulting low end sound....and then put the sub in that spot!

In between is in between. In rooms smaller than 2500sqft it is often the case that "optimal" placement is not possible given the doors, walkways, and other architectural features that dominate the space. Even so, there tend to be "better" and "worse" options....assuming you know what you are looking for.

[b ill]

All I know is that a few years ago (thinking that I must be missing something) I tried wall and corner loading subs in a variety of clubs. The results were always horrible... no punch or definition... just a bunch of low end rumble... and often where I didn't want it (like along side and back walls where people are trying to get away from the noise).

Even in high energy clubs the only place I want the sound to be loud is around the dance area - and the best way to achieve that is to put the cabs right next to it. The servers must be able to hear their orders, security has to be able to do their jobs, etc.

I was told to keep subs at least 8 feet away from walls, but that's easy. I've never been in a room that was so small I couldn't do that. But most of the time these days I'm on club installs.

... and with that I'm out of this conversation. I don't have the time to go any further. I just thought I'd throw out some practical advice from a guy who is doing this full time night after night in a variety of clubs on a variety of systems.

[Karlos Santos]

I value your input b ill. Feel free to keep going.

In fact I value everyones input cus I'm totally new to this. I've been a pro DJ for over 15 years but I have never once had to bother what the PA was made of. I just know/knew when it sounded good or bad

[mostapha]

@Mostapha ; Lol at correcting my grammar.

[QUOTE=Karlos Santos;703059]I didn't correct it, I adapted the quote to get your message across with some stuff missing for brevity.

Yeah Mackie and JBL came to mind simply because they were incredibly affordable. In all honesty I didn't even consider QSC until they was mentioned in this thread as they aren't (to my mind) as well known in the UK.

I like QSC because their amps survive my Fraternity for decades at a time. I replaced an RMX with another of the same thing when it was like 12 years old...because it got left at an out of town party. Just open the case and vacuum out the crap every few years and they're golden. I assume that their powered speakers have similar build quality.

I agree with the point made above about people wanting to see a proper setup and that small speakers would be interpreted as 'not a real setup' but there's a limit and I think QSC have got this right. Actually part of the USP of what I am doing is a 'real setup'.

I think the look often matters more than the sound at these things. I've seen a LOT of bad mobile DJs. Clean cables, a good console/setup, and nice-looking speakers always get compliments, whether the music is good or not. I've talked to people who complimented how 'pro' the DJ looked when his sound was so bad, he was just slamming us with snares all night.

It obviously helps if you're good, and based on reading your posts here for years I'd bet you are. But it does need to look right....almost moreso. Don't forget that they're not clubbers or audiophiles. It sounds like you're going out of your way to sound good, which is good. But if it comes down to not being able to make a choice, I'd go with the better looking setup.

I did a corporate event last weekend and people were absolutely gob-smacked that a 'real DJ' had turned up with decks

That's always a fun feeling. The closest thing to a disappointment about my wedding DJ was that he used VDJ with a cheap little all-in-one thing. But, you know what, it did the mics he needed and worked for him. Everything sounded pretty damn good given the space (basically a hilltop). And the music choice was impecable. You've got the console, and I'm confident you've got the skills. Look good, and you'll be killer.

Quality powered cabs have enough internal DSP to get you 99% of the way there without external DSP like a Driverack or even EQ.

I disagree. I'm honestly not sure what they'd do except tune for a moderate smile EQ and have a soft knee limiter. The EQ helps fix the room when you can't change it, and the most useful "DSP"s I'm familiar with account for delays with weird speaker placement. I think a 2 or 3 "band" parametric EQ would be a great addition....one set with a super-low Q at like 1k just to tune b/t -2 and +2 (smile vs. frown) to account for different volumes, a high shelf, and maybe one or two more parametric bands to deal with problem frequencies in the room would be very valuable.

Actually for most club and banquet sized spaces, subs away from walls and corners works best. I think a lot of this stuff spilled over from the home audio guys where wall and corner placement actually is where you want them.

Actually....corner placement was the result of experimentation and lead to the folded cab sub designs....mostly used in clubs and concert spaces.

The servers must be able to hear their orders, security has to be able to do their jobs, etc.

That's what earplugs are for. They make talking with bass that shoves air into your lungs possible.

IMHO, this is explicitly to be avoided at weddings, corporate events, and basically everything else mobile DJs do. ESPECIALLY on the dancefloor. No one is going to be mad at hearing music at conversation volume at their table, and it should be louder on the dance floor. But, no one should want or need earplugs. At least, that's how I feel about it. And I think room layout plays the biggest part in that. Sadly, that's often up to the event planner and not you.

[DJ SB]

I'll weigh in. I played a venue last night that had 15" Turbosounds as monitors and they were the best sounding PA speakers of that size I've ever heard. I prefer them to QSC and JBL. Might be worth looking in to...

[JuanSOLO]

This has been a really helpful thread, wish I would have seen something like this 4 years back.
I too am looking to upgrade/change systems.

For whatever it's worth I got a Mackie HD (2 1521's and and 1801) system a while back, thinking it was the latest and greatest Mackie.
I chose these due to price, portability, and because my bandmate had the earlier Mackies as such, and they seemed indestructible.
The HD series was NOT what I had hoped for. The Sub continuously craps out, currently it's "clipped" just turning it on.
The 1521's are ok, most people think they sound great, however recording engineers, producers, audiophiles at various events will always say "your speakers sound muddy."

Im definitely looking into the QSC stuff now.

One thing I'd like to say about subs, like 18" subs.
That low end is almost essential for me to feel like I am providing a proper service as a DJ.
Many times over I have gone out without a sub and people will say, "It sounds just fine without it,"
however, it might sound fine, but how does it feel? To me it feels weak.
What I have noticed with using a proper sub is that in some cases the volume may still be low, but felt.
This is perfect for various shows like gallery openings, weddings, or events where for the first 2 hours you're going to be paying music and you want people to be able to talk to each other, yet still fill the space with sound.
Later when you crank it up, things just get better.

A lot of people will say, less than subs' (under 18"), are suitable.
Maybe it's personal preference, but I cant stand the sound and lack of feel, with subs that dont go low low.

I would add on to the idea that when your asking for a hefty chunk of money to show up and "play music,"
dont scrimp on your system. If it's a wedding, usually the couple has spent a lot of money on ascetics, complement that.
It's tempting to buy used gear because the price is much better.
However if QSC offers a 6 year warranty, it's worth the price.
In 6 years I'll easily have made my money back a few times over.
But I'll be throwing away money if something should happen, and with lugging around PA systems, good chance it will.

I too show up to gigs with a semi decent PA, 2 turntables, and crates of vinyl.
People flip out these days and are so grateful for it. They enjoy the nostalgia of records and record players and they feel like Im putting in the work, so they put in the work on the dance floor.
Sometimes I use Traktor, still rocking the decks though, and people still think I'm playing records, even after explaining it.

Lastly, Allen & Heath ZED series is the best mixer at those price points for these types of gigs.