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Hey folks,


The QSC K12 speakers sure seem to do a lot of things right. They run about $800 street ea. 75 degree horn on top matched to a relatively low crossover point (for a p.a. speak) see here: http://www.qscaudio.com/products/spe...re=directivity


in order to match directivity of the woofer to the horn for a smooth power reponse. Then they throw in active power (1000w class d, 500 woof x 500 tweet) and DSP that I'm sure corrects some frequency response issues and time aligns the drives. Additionally, the high sensitivity drivers make that 500 watts per drive really add up in spl.


These K12's seem to do a lot right for the money and I was wondering if anyone had experience with them and what opinions were.

http://www.qscaudio.com/products/spe...series_K12.php


Too bad we can't find the money to buy a set for a "listen around" thing where each person chips in some cash to hear them and then forward the speaks to another guy. If we could by some miracle get QSC to kick in a set, would there be any interest in paying the "shipping only" to audition a set then forwarding to the next guy? On this paragraph, just thinking out loud. Main questions are up above.


QSC's site kind sucks for navigation, so you have to scroll way down on the right to link to some of the features. Just a heads up.


for example, here is a whitepaper on the dsp correction:
http://www.qscaudio.com/products/dsp...paper_2007.pdf


I'm not sure how I found it...just kept clicking around...


Here is the frequency response before and after DSP. With a linear power response, on axis dsp changes will affect total sound power, so this linear frequency response should be preserved off axis as well.


The net response appears to be +/- 1 db from 80 hz to 20 khz, which is pretty good. I suppose that we could get into phase and ask about that, but doesn't phase response change with distance, so if you are far enough back it shouldn't matter?




I will cross list this in the speaker and the DIY fora I don't think that would be considered out of bounds.
 

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My sound company has been using K series speakers for PA purposes for several years. We like them a lot. The combination of light weight, high power and flexible controls makes them very useful. We are in particular, big fans of the K8 speakers. They are sort of in a class by themselves...very small & light, wide dispersion and amazing bass when the "Deep" setting is activated. They get used a lot...from PA and small folk concerts right up to use as center fills in a 500 seat theater.

The K12 are very good too, although there seems to be more choice in the the 12" active speaker market (eg. JBL PRX612M & EV Tour light are excellent value as well).


I don't have any experience about how they would perform in a home theater situation (pretty well. I'd guess) Perhaps you could find a pro audio store in your area and rent a pair of K12 for the weekend. They are popular rental items.
 

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Me thinks since they use the HF/MF section in their SC2150, it may be a better route to go than the K12, but I have absolutely no evidence to back up my claims. I'm a sucker for sales though and if the 153i and K12 are the same price, I'm going to feel like I'm getting more for my money with the 153i.
 

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Quote:
Originally Posted by Looneybomber
Me thinks since they use the HF/MF section in their SC2150, it may be a better route to go than the K12, but I have absolutely no evidence to back up my claims. I'm a sucker for sales though and if the 153i and K12 are the same price, I'm going to feel like I'm getting more for my money with the 153i.
I was thinking the same thing since the horns are made for small cinema's, the K12's are more PA based. I do like the lighter weight of the K12's though since my HT will be upstairs
 

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I'm currently comparing my JTR quintuple 8's to some JBL prx 635's. The JBL's are very similiar to the QSC 153's. In fact I almost went with those instead of the JBL's. Interesting speakers.
 

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Quote:
Originally Posted by fatsow /forum/post/20968807


I'm currently comparing my JTR quintuple 8's to some JBL prx 635's. The JBL's are very similiar to the QSC 153's. In fact I almost went with those instead of the JBL's. Interesting speakers.

Damn! You have them in your house?


I do live sound in a 450 seat theater with 2 PRX635 & 2 618XLF subs and it gets loud with headroom to spare!
 

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Quote:
Originally Posted by mjaudio /forum/post/20969653


So how does the JBL compare to the JTR's so far?

It's hard to say so far, I have only had a few days to compare, and I'm not sure the best way to do it exactly right. The JBl's are very clean before any EQing, but the JTR's seem better after running audyssey. I have not compared them directly before EQ yet. It is very close and probably a matter of personal preference at this point, but I need more testing. I am not sure I love audyssey 100%.
 

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Quote:
Originally Posted by mackiefan /forum/post/20971427


Damn! You have them in your house?


I do live sound in a 450 seat theater with 2 PRX635 & 2 618XLF subs and it gets loud with headroom to spare!

I know. The headroom is what I want. They should be cruising along is my idea. I wonder how low a pair of 618XLF's would go in room?
 

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It seems that most compact PA subs don't go as low as some of the best consumer models (ie: under 25 Hz). The 618 XLF are rated for 30 Hz at -10dB and 39Hz at +3dB. What they do offer is 133 dB peak SPL output. I suspect this because they are designed for music reproduction rather than LFE prowess. Heck, with the usual exception of the bass & kick drum, we usually have 100 Hz low cut filters on all our channels. If you want to be truly impressed with big PA subs, check out the McAuley 421 bins (quad 21" drivers). Monsterous, they are...sonically, physically and financially.
 

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Quote:
Originally Posted by fatsow /forum/post/20971644


I know. The headroom is what I want. They should be cruising along is my idea. I wonder how low a pair of 618XLF's would go in room?

As stated above, for most music they'd be fantastic, wicked good. Low distortion, high tech motor, high linearity/high output...run you out of the room at full tilt
But for LFE duty, they just aren't even in the ballpark. You need massive amounts of excursion for LFE. Each additional octave of extension, requires a 4x multiplication of excursion to maintain same SPL. Both the driver, which is superb by the way, and the electronics, would limit the response to the intended range of 40hz on up.


Good luck
 

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This makes sense, but I already have 2 pb13 ultras. So what if I ran the 618xlf's for the left and right channel and crossed them over to the ultras at 45 or 50? I would essentially have a 4 way left and right channel crosse to the subs. I bet that would sound pretty good for music and movies.
 

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Why don't you run the 618s as a multi sub/flanking sub solution (or main speaker bass bins) from 30Hz to 150Hz??


Send your main channel ouptuts to something like the MiniDSP or DCX2496 and then connected the 618 and your main speaker up to it. Run your main speaker full range (double bass solution). Place your 618s near your main speakers and with some EQing/delay settings you can have a much smoother response from 150Hz on down. You will have full range mains to match up with nice PB13 subwoofers.
 

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Quote:
Originally Posted by penngray /forum/post/20977008


Why don't you run the 618s as a multi sub/flanking sub solution (or main speaker bass bins) from 30Hz to 150Hz??


Send your main channel ouptuts to something like the MiniDSP or DCX2496 and then connected the 618 and your main speaker up to it. Run your main speaker full range (double bass solution). Place your 618s near your main speakers and with some EQing/delay settings you can have a much smoother response from 150Hz on down. You will have full range mains to match up with nice PB13 subwoofers.

I like this idea. I was reading up and the 618's have a xlr out with a high pass of 90hz. I think that would match well, but as I've discovered since I got my omnimic, EQ and delays will probably be needed to get things right. After running audyssey32, I always need to change the sub distance to keep from getting a big dip at the crossover to the mains. Would have never known this with out he omnimic. I just always assumed it would be set right.
 

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Quote:
Originally Posted by fatsow /forum/post/20971630


It's hard to say so far, I have only had a few days to compare, and I'm not sure the best way to do it exactly right. The JBl's are very clean before any EQing, but the JTR's seem better after running audyssey. I have not compared them directly before EQ yet. It is very close and probably a matter of personal preference at this point, but I need more testing. I am not sure I love audyssey 100%.

fatsow,


Do you have any further observations on how these compare?


Thanks,


David
 

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Quote:
Originally Posted by bukiwhitey /forum/post/0



fatsow,


Do you have any further observations on how these compare?


Thanks,


David

I'm traveling this week, but I will be doing some more listening this weekend. I'm really enjoying the JBLs so far. I think it will be a matter of what type of sound you prefer and the listening room.
 
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