Hi there,

Greetings from down under (Australia). I hope everybody is taking care around the world during these crazy times.

I'm not very experienced when it comes to hardware but I'm trying to decide what the best solution is for my situation and thought I'd get some advice.

I'm an acoustic guitarist (live looping with percussions on the guitar) performing cover songs with a female singer. Our venues range from small indoor cafes to outdoor markets. At the moment, we're also considering the wedding scene, not only offering live music but to also be the one-stop shop solution for all their sound needs (dance party music at reception etc).

The wedding size on average I'd imagine would be approximately 100-150 guests.

I'm just wondering, what PA speaker combination would you recommend that would most suit our needs?

We would like to stick to the QSC range as they appear to be one of the more reliable and worthwhile brands.

From the acoustic duo point of view, I reckon we could get away with just the 2x K10s for our live performances. Portability would be a priority in this case.

However, for weddings, where we want to provide extra low-end when the dance music kicks in, we'll add the KS112 sub to the K10s.

Would this solution (2x K10s + 1x KS112) be enough to fulfill enough volume for all guests to hear all the speeches etc. and enough bass for the front half of the room (where all the dancers would be) or would we need something more larger?

I've also got an AER Compact 60/3 TE to use as a stage monitor

Thanks in advance.

Only you know what level you actually want to achieve - one person's ample is another person's quiet!

That said, for the use you're looking at, I wouldn't hesitate in recommending a pair of quality high end MI 10" speakers - this covers the QSC K series, but also Yamaha DXR & DZR (no 10" DSR option, sadly) and RCF 700 series. They will give a great perfomance for the acoustic & vocal setup you have.

You've already mentioned that portability is key to you - and a pair of 14.5kg K10.2 speakers delivers that. And, while I'm not a massive fan of the mixers in speakers, the two inputs would, at a pinch, allow a guitar & vox setup without even needing an external mixer, albeit with a very basic mix.

While it will vary from room to room, I suspect that the K10.2's 90 degree coverage is likely to suit your needs slightly better than the K12.2s 75 degree coverage.

Subs, The KS112 does a tidy job for its size/weight. Don't discount the KS212C, though - while bigger and heavier, its cardoid pattern will keep your performance area freer of bass spill.

Depending on how much bottom end you want, it's impossible to tell whether the KS112 or KS212 would be enough for you. Though it's possible you'd find the K10.2 delivers all you really need. But, if you want full on club sound, you might need to trade up to a 15/18 sub (or two)

Ideally, as always, find somewhere where you can try the kit to confirm its suitability. If you like the K10.2s, I'd suggest trying them without subs to begin with - you might be happy enough - and avoid another lump of logistics to deal with, though you might struggle with the disco.

Alec summed it up right. One subwoofer isn't going to do much. You should start with at least 2. They are made to be used in multiples to couple and get down low enough to get the job done. Otherwise you need a really big cabinet that still doesn't really handle enough power to do the job with one cabinet unless it is a giant horn like a danley sub. I would get the best tops you can afford now and get subs when you are ready to buy pairs of them. I take 4 18s out with two 12 inch tops to keep up with them safely for dance rooms. You need a lot of cabinet volume to go low. Yet smaller cabinets can handle more power. So manufacturers make smaller cabinets and expect you to buy 2 or 4 of them to perform well to give them the power handling numbers that they want as well.

Only companies that produce a compact 12" powered sub that might serve your needs well are RCF and Turbosound. If you can track down an RCF SUB 702-AS or Turbosound iP12B jump on it. QSC makes nothing that competes in that size.

If you can compromise size, JBL PRX subs are at least lightweight. They're not especially efficient so you'd need an 18" for sure. But I can carry one up a flight of stairs reasonably easily. Expect to have to replace the filter caps eventually though. I'd replace them with Nichicons pre-emptively if I had to own any.

Hi everybody.

Thank you all so much for your priceless advice. It would have taken me forever to work out all this information on my own.

Really appreciate all of AlecSp's insights. Will definitely take your advice with listening to the K10s with and without the presence of a sub. For some reason, I just automatically assumed we would at least need a subwoofer or two to achieve the "disco" sensation for the partying guests at weddings as the night winds down. I doubt we'll be expected to provide a full "nightclub" sound but we would be at ease knowing that our speakers could comfortably accommodate something similar if called upon.

I have definitely under-estimated the range in the K10s especially when it's in "Deep" mode. I guess that's why the "Deep" option is there. Having said that, have many people used this option extensively on the K10s and have any issues with it?

Thanks Chip Dixon for your feedback. We'll definitely consider getting the subs in multiples and couple them with the tops. Funds aren't quite there yet to go straight to 18"s... so might have to be 12" subs to begin with and trade up from there.

It's the disco/club bit that will almost certainly need subs - I'm ready to bet your set wouldn't. But a lot will depend on the level you're trying to achieve. Personally, I'd prefer being at a wedding using 10" over 12" subs for a disco (actually, I'd prefer them not to have a disco at all), rather than multiplle 18" subs. But you've obviously got to cater to your market.

A reason to consider other manufacters would be that QSC's subs are 12" or 18" - they don't have a 15" option.

Do you have the option to try before you buy? Or a focal rental company who could help you come to a conclusion?

For the record, the subs I recommended were for just a single sub. One of them would easily keep up with a pair of K10's. Getting a pair of small subs is nonsense, like expecting a pair of trumpets to do the job of a tuba. You're far better off with one bigger/better subwoofer. But like I said, one of the RCF or Turbo small subs would do the job.

get the smaller tops but add a sub; use two ir mord dubs if you need higher spl - other than for portability, the size of the sub doesn't matter much: it's the max. spl capacity and frequency range which matter.

i got some 12" subs here which go lower than the same manufacturer's 15" subs from the same series and also more modern 12" subs which go lower than a double 18" from a system which was standard in professional live sr for many years...

While true, in general, a small, loud, good sounding sub is VERY expensive

I have also found that while you can indeed make a fine 12" sub given a higher price point that has excellent SPL, the little sub still weighs quite a lot .

FWIW, I found the KSUB to have the following characteristics:

Price 1K (equal to other subs low end MI level subs)
Weight 62 lbs (Fairly light compared to many low MI subs)
SPL 128db (below many low MI subs)
Sound quality (below many low MI subs)

So, this particular sub, I would say is affordable, and portable. It is a bandpass sub which means that it makes a particular frequency loud really well, but they tend to have an uneven frequency response.

Now, having said that, I think it makes a decent DJ sub if you don't need to fill a big space, and you need to carry it in a sedan.

It depends on what your budget is, and how much room you have to carry it.

For nearly the same money, the PRX818XLF will run circles around the KSUB all day long. It also sounds better; however, it is WAY bigger and heavier (although it is pretty darned light for an 18" direct radiating sub).

If you have the room, I would recommend the PRX.

cannot comment on this particular sub as i haven't been using it and generally speaking, i much rather recommend buying used pro-gear rather than new, cheapish prosumer gear!

however, even a relatively wimpy sub can
a) extend the frequency range of most any consumer 2-way speaker towards the lf range
b) add spl capacity
c) take away some of the 'heavy lifting' of the tops
and hence make the entire system more safe to operate over a relatively wide frequency range and at a slightly higher spl level than with tops alone.

but of course, every component needs to be up to the task at hand and match the application/situation; for a techno party, you don't want a simple lofi joghurt cup, you'll want earth shaking arrays of infra subs...

PA manufacturers don't make single subwoofers large enough to go low enough with just one speaker because when you do that it makes it so the speaker can handle much less power when you tune it low enough. So they have people blowing stuff up under warranty. They expect you to buy more than one sub because human hearing is not sensitive at low frequencies. You need a lot more bass to keep up with the mains speaker wise. So one sub would not be appropriate for two mains unless you bought one kickass sub to go with 2 so-so mains. I typically go 2 subs to one mains for dance music. One sub to 2 mains is a mismatch if you are just getting guitar center stuff. I built a double 18 bin big enough to go down to 32Hz for 2 JBL 2241Hs. It is 18 cubic feet. That is what it takes. Single subs often don't want to go below 40hz. You would need 4 of them to go down to 32 hz. But 4 of them is what would match 2 nice 12 inch mains for dance music to be even up to their limits anyhow. So that is why manufacturers do that. One subwoofer usually won't go any lower than the mains any how. So you will get clear midbass in your mains with the one sub. It won't go lower or be louder though.

sorry to say but this is mostly bs!

- using more of the same sub doesn't make them go lower!
- most any cheapish sub indeed goes lower than the typical 2-way top!
- a sub doesn't necessarily need to keep up with the tops either: even adding just a little bit of output helps the entire system's performance.
- and no, they don't get blown away and don't need to get replaced under warranty either


here's a pic of a small rig, consisting of a cheap pair of 12" ev subs, used to augment a pair of turbosound milan tops; i haven't kept the smaart measurements but - as was to be expected - both the frequency response and the spl were clearly better with the subs. oh, and subs have been lasting for a few years now without any issues...

Why are there two subs but only one rake? Enquiring minds want to know!

the other one was (successfully) used to keep the rioting mob at bay...

I have been doing events that size goin on 10yrs now for both live musicians and DJs and the majority of those events utilize 2 tops and 1 sub at FOH. I'm a 1 man operation so portability is a priority but I don't own anything but 18" subs. There are several reason for that, in any particular product line the 18 is going to produce the most output for the $$ spent so ROI comes into it, and I want packages that can get a job done to the customers satisfaction with the least amount of equipment, so I'm not bringing 4 boxes if I can get away with 3. And also want some scalability so I don't want a bunch of different sized subs, I want to be able to stack up multiples of the same box where required. The customers expectations of what sounds right is a factor, popular recorded music is very bass heavy these days so for balanced sound the sub part of the system has to be capable of maybe 6dB more output than the tops. As a result my smallest package pairs an upmarket sub with entry level tops, if more SPL is needed I use better tops and add another sub.
For different markets and different music types the system requirements can and do vary, a live wedding band may not need as much subage as a DJ would but they really should have more capable tops than what a DJ can get away with because vocal clarity is a bigger priority, if you are trying to cover both of those uses then you will want to buy better cabs overall.
I get to try out a lot of speakers doing this and have come to a few conclusions, one of those is that I don't like anything smaller than a 15" sub. This is a bit puzzling to me because I own a 12" home theater sub that sounds great, and the 18" and 15" pro subs I have heard sound much the same.. the 15 just doesn't produce as much punch or SPL as its bigger sister. But the trend doesn't continue down to 12's, those just sound lacking even in the double 12 configuration.
As for the OPs requirements I have a couple opinions.
I think a balanced sounding rig based around 10" mains will require starting with one good 15" sub, and I think it would be a mistake not to buy the latest product from whatever brand you like. The original QSC K series is long in the tooth now and the K.2 is a significant upgrade, but Yamaha and RCF just to name a couple also make comparable boxes that are just as reliable and in some cases offer higher performance.

The KSub sucks. The _ONLY_ reason to get a PRX 18" sub is it's possible for one person to carry it up a flight of stairs. If there can be a second person guaranteed for loading in and out I can name a dozen better subs for half the price. Hell you could throw a dart blindfolded and probably hit a better sounding subwoofer.

Yes using more subs does make them go lower. They couple and act as a single radiating source when they are within a quarter wavelength of each other. That is why you get a whole extra octave when you use 4 times as many cabinets. You are really missing out here. Please educate yourself. This is basic subwoofer engineering logic and why manufacturers use smaller cabinets and expect you to buy more than one cabinet to get the intended results. One subwoofer doesn't give you enough bass to keep up with the tops so now you have to turn them down to not make the bass sound wimpy. If your idea of tops is what you used there, then I guess that isn't a problem though. You have basically a nice home theater setup there. Not gonna keep up with 100 drunk people yelling in any way.

you are posting bs in terms of subwoower arrays!

arraying of subs is about pattern control, lf distribution, spl capacity and aligning to mains; the cutoff remains the same, regardless of the array and got exactly nothing to do with the cabinets' frequency response (except that getting any kinda directivity gets harder the lower in frequency one goes and the spacing depends on the frequency one is aiming to control)!

what can get achieved (depending on the array design) is that the coupling of the lowest frequency is optimised and you can stack/array dozens of them in whatever configuration you want but this still does not make the cabinets or the array go any lower!

___


and you also missed out on the principle of summing: any additional sub, regardless of its spl capacity, adds to the overall output of a system: there is zero need to trim down the tops to the level of the sub...

If you don't put the subs all in one place, they interfere and cancel each other out in many places. So of course I am assuming that you put your subs all in one place. People who put subs right under the mains and separate them instead of putting them in a mono array in between the mains always sound worse. Cardioid setups are to help cancel bass from going somewhere unwanted. Helpful when you would get noise complaints otherwise. When you couple subwoofer cabinets, the tuning frequency drops. Meaning now you can run the HPF lower on your DSP. If you don't have a DSP to adjust then I guess you don't know that. But it is true. If you add subs that can't keep up with your tops, then take those frequencies out of the tops, now you will lose lots of punch unless you run the low pass filter really low on the subs and only give them up to 60 Hz or so. And with one cabinet you only get to go down to about 40 Hz. Definitely not gonna rock the dance floor there still. You need enough bass to punch harder than the tops up to 80hz or so for subs to give you a dance club experience. 2 12s will give you more 80hz punch than 1 18 will, even separated across the room. It would be nice to send all the low bass to the subs to relieve the 12s.. but single 18 bins aren't designed to go down into the 30Hz range. You need 4 of them in one place to do that. So make sure you adjust your HPF accordingly. Someone sending 30 Hz sweeps to your 40Hz single sub is a bad thing. Having subs that are permanently HPFd at a frequency so that when you add extra cabs it still won't go lower sounds like a HPF configuration issue to me. The physics still remain the same. Thiele Small parameters.

your misinterpretation of basic principles is baffling...

i'll invite you to present measurements of real-world sub arrays to underlign your claims and not just to post what you think how they will behave based on whatever theory you've been reading.

no amount of dsp can bend laws of physics either...

___


sorry to the op for going slightly off topic - if you get to buy more than one sub and think about arraying them in specific ways, i recommend reading the old but still excellent paper by electro voice on arraying of subwoofers or then most any articles published by (meyersound's) bob mccarthy and (clair's) howard page, for both of whom i've been working on dozens of occasions in the last four decades.

First,

I mostly agree with deedeeyeah on this one.

While it is true that putting a pair of 1x18 subs together does give you some SPL due to coupling effect, you get exponentially less coupling to the 3rd sub you put next to the pair. So in general, you may get 3db increase in SPL by having 2 or more subs together.

Now, I will have to disagree with Chip's assertion that using a pair of subs 1 per side with tops over subs sounds worse .... in fact, it has some pleasing side effects. First, if you look at the heat map for subs when you do this, it creates a very strong SPL node between the two subs located some distance out in front of the subs (warning, also in back if there is no wall). This has the benefit of having the pumping hard hitting bass in the middle of the dance floor while having much less bass further back in the room and to the sides making it easier for people to talk.

The tops do the same thing, but since the frequencies are much higher, the wave pattern they make is spread into many nodes across the room. It is best to set the 90 deg tops far enough apart that they don't cross over too much before the back of the room. Really, you usually don't have any control over this and have to deal with how the system sounds in that room .



An entire line of subs isn't used to increase the output, it is used to increase the coverage.

If you have ever seen a heat map of the SPL output of subs (many design software packages can do this .... MEYER has a version you can download for their speakers, etc), you can actually see how this works.

I have never heard of summing subs to get lower frequency response.

Well, we agree on the KSub .

I'll bite on the PRX's though. Name 2 subs that you can get for $1200ea that sound as good.

... and while I agree that an 18" sub is the best bang for the buck, if you are driving a Honda Civic, good luck hauling it. I always tell people "You have to play the hand with the cards you're dealt"

There is a tiny bit of extension made possible by coupling subs, and that's only because of the increased acoustic load on the drivers, so there's more output relative to driver excursion. This could be "spent" by reaching a little lower or driving the same range a little harder assuming the voice coils are up for it. It does not change the tuning of the cabinets or drivers in any way.

And $1200 subs that beat PRX's? RCF Sub 708-AS's are $1150, and one of those would absolutely murder any pair of PRX 18's. The Turbosound M18B kicks a PRX's butt for only $700. But they're both in the 100lb range. Hell my ancient Yorkville LS808's lay waste to PRX's and you can find them for $350 (unpowered). If you think PRX's have good output you've been deprived of access to good subs. They are only good for their weight, not price or size.

I have heard the Yorkville LS801p and can verify that they get very loud; however, they are also woofy and unfocused IMO. The other subs you list I haven't heard so I can't comment.

I can say that a pair of PRX XLF subs absolutely sound very good and can handle a decent sized indoor venue (120ft by 160ft) where a good portion of the club is the dance floor (~30%).

If you have different experiences, then our ears are simply not tuned the same. I have had the same discussions with a few people here who believe that the Yamaha DSR112's sound awful or don't have great SPL.

I can also say that if you do a forum search on the PRX subs, you will find nothing but people saying they are a very good sounding sub with good output. They are generally considered equal or slightly better than the KW181 and maybe a bit below the SRX 818 subs.

Have you done a direct comparison? If so, under what conditions?

It matters more where you put your subs than how many you have. When you space them apart over a 1/4 wavelength, now they no longer act as a single source so they now interfere with each other instead. I remember when I would work at clubs like Nation in DC that when they decided to move all the subs around to "make it look good", I got more volume out of the system by unplugging a bunch of the subs that were cancelling out bass on the floor. That is why having subs under the mains on both sides and none in between actually has a name for how bad it sounds called "power alley". You don't automatically get more volume from adding cabinets. With subs, it can be quite the opposite if you don't put them in the right place.

True! However, if you use the "power alley" to your advantage, it can actually be a good thing. Look at how nice this particular power profile would be if the dance floor is directly between and in front of the speakers: https://www.sounddesignlive.com/turn...t-power-alley/

Note, I think you can move the alley out onto the dance floor more if you start moving the speakers together in this arrangement (with a wall behind you). It also lets the rest of the audience be free of the bottom end which can disrupt conversations.

Of course, if you are simply trying to get as even of coverage as you can over as big an area as you can, then center clustering subs is always the best way to go.... assuming you have room to do such a thing.

Additionally, if you take out the back wall, it doesn't look so good either.

I guess if you can put the bar there where it sounds awful and some toilets on the other side where it is bad too that will work. If people want to speculate why you can send lower frequencies to subwoofer arrays than you can to single uncoupled cabinets that is their call. They still need to recognize that the low cutoff did go down and the spl meter went up. All because you stacked the subs up instead of putting them all over the place. The main problem putting subs all over the place is now instead of a solid thump from a single source you get a boom boom boom boom mess from all over the place now.

If you talk to bar tenders they will tell you they don't want dancefloor SPLs in their work area because it makes doing the job more difficult.

They don't need to speculate because this does not happen and repeating such does not make it reality, a subs lowend response is determined by the box tuning and nothing changes that.
But.. stacks of subs do produce more output below box tuning because lowend response rolls off at a slope it's not a brick wall, so more output overall means more out of band sub bass too.

Yes, it's a tradeoff as are most things in audio. Multiple subs spread around the room is a common technique in home audio to even out the response.

now we're getting somewhere...

the thing is though that small productions which do not carry their own rig depend on the club's pa in every way or then the venue simply doesn't allow the sub array to get positioned in the place you want it...

in the venue where i get to mix frequently, the room acoustics for once are pretty decent as well as (some of) the gear; however, there is no other place to put the j-subs left and right of the stage, positioned further apart than the flown q1's unless i'm ordering crash barriers but loose about 100 tickets, something that hardly any promotor accepts...

also, the prediction software mostly gets you just an approximation of what might be happening under ideal conditions/outdoors or then one spends way too much time drawing the venue with all boundaries but still the results will be very different...

anyway, regarding the power alley, this doesn't need to be an issue - here are three pics with show the expected pattern/spl distribution at 60hz of my small line array rig (for use on small to medium festivals), the tops alone, a centrally stacked csa and then everything (except frontfills) together: no power alley to be expected anywhere...

175 cap room, house PA has PRX 618XLF's under PRX 515's. The PA hits its limiters for every rock band all night. Same room, KLA12's over KW181's rented while PRX's were being fixed, much better headroom, clarity, and dispersion.

Outdoors I've compared KW181's with my LS808's, which have lots more headroom. The key to using horn subs is to make the most of their punch, and transient modifiers are key there. Once you get used to having as much punch as you want, going back to adequate direct radiating subs is just weak liquor.

250 cap room, M600's over LS808's, never ran out of headroom, had to put weatherstripping on glass bar shelves all the way down the ~40' bar or the bottles would fall off. When they "upgraded" to SRX 815's over 828's (got good deal from rental stock) the tops had less output and dispersion, and the subs are not much louder if any, but you have to brown out the lights to get them there, needed 2400W each compared to only 800W for LS808's.

RCF Sub 708-AS's are comparable in output to LS808's, and probably more stable from room to room. Horn subs can get a little hairy in resonant rooms, but I've learned to manage. In a 1200 cap room with high ceilings I had tons of headroom running 4x dual 18" Sub 7008-AS's (basically 4x 708-AS a side) mixing a very loud rock band at about 106dB at FOH. No way any PRX comes anywhere close to a 708-AS. JBL drivers have been consistently low sensitivity, like 94-96dB. RCF sub drivers tend to be 98-99dB sensitive and tougher than nails.

@ AC2SPL

Not sure what is going on with the PRX618XLF's you are working with, but mine will run rooms like the one you are describing all night long without hitting the clip limiters (In a club that size, I wouldn't be able to get the volume up as loud as the system would go before the owner told me to lower the volume).

I have also actually done an A/B of my rig (DSR112's over PRX618XLF's) to a neighbors (QSC KW153's over KW118's) to verify that the PRX subs hang just fine with the KW118's all the way to limit. FWIW, the DSR112's hold together better than the much bigger KW's do at high SPL which was surprising.

Either those PRX subs have something wrong with them (unlikely since there isn't much to go wrong with them that doesn't result in just plain BAD sound or no sound), or the room is configured poorly and/or the system is configured poorly.

I used to have a pair of CV folded horns. Yea, their overall output was huge, but they sounded muddy and unfocused. The PRX subs in comparison were much better sounding.

I can't comment on the Yorkies though. I have only heard the 801p's which were much louder than the PRX, but more muddy too.