Feedback on sctive 18" sub + 3-way top combos. RCF v QSC v JBL v EV v Yamaha

Nathan Townsend

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Hi Everyone, I'm new to this forum and have been searching the internet recently for reviews on active 18"subs + 3-way tops combination. I'm just a weekend warrior and I live in the middle east where our crew puts on underground free parties in hidden desert locations (see pics for example). These events are often located in canyons or an abandoned quarry and can be up to 100-200 people. But even if the crowd is only 50 people, are goal is to have NICE quality sound because we're all music lovers and DJs who mostly play genres spanning techno, house, minimal, DnB, leftfield tech, funk, neo-soul, afrobeat, psytrance and hip-hop.

We're raising some funds to purchase new gear and top of my list currently is the following 18" sub/ 3-way full range pairs...
-JBL SRX series
-QSC kw series (with the newer 118 high power sub, not the 181)
-Yamaha DZR + DXS
-RCF 8004 + NX985
-EV ETX series
Where i live I know that QSC, Yamaha have local dealer we can go through instead of having to arrange expensive shipping, and we can go through a friend's company that brings in EVs.
We WILL be using the 3-way on its own without the sub for smaller parties, which is why this is of interest over a 2-way option. Besides, 3-ways generally sound very nice in the mids with the additional driver.

I've seen many great reviews of the yamaha DZR 315, but one question here is whether the DXS18 can really match this speaker with only 1600W peak power? How can they achieve 136spl at that power compared to others in the same class that generally are listed at 2000w or even a little more peak power? or is this just marketing BS? I know these are all great options but any feedback would be much appreciated because we are not able to go somewhere and actually listen to them in a shop of whatever.
 

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Art Welter

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Jan 11, 2011
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Hi Everyone, I'm new to this forum and have been searching the internet recently for reviews on active 18"subs + 3-way tops combination.

I've seen many great reviews of the yamaha DZR 315, but one question here is whether the DXS18 can really match this speaker with only 1600W peak power? How can they achieve 136spl at that power compared to others in the same class that generally are listed at 2000w or even a little more peak power? or is this just marketing BS?
Hi Nathan,

Asking questions about products, rather than providing "Product Reviews" means you posted in the wrong forum.

That said: The difference between 1600 and 2000 watts is very little, a doubling of power is only 3dB.

A good answer to the marketing questions was given years ago on this forum in the "Junior Varsity" section, by David Gunness, who's company also happens to make some of the best speaker systems possible. See his answer in post #18 to my question in post #11:



"OK, here we go. Once more into the breach. The reason I hate this is that in the process of explaining how our industry does specs, it appears that I am justifying practices that I actually don't agree with.

One of the reasons I don't like peak SPL specs is that "SPL", at least in textbooks, is defined as the RMS sound pressure (referenced to 2x10-5 pascals). So theoretically, there is no such thing as "peak SPL". OK, maybe that's too pedantic: we could interpret it as "peak sound pressure, expressed in units of SPL". Let's go with that.

The point is that "Peak SPL" as it is treated in the professional loudspeaker industry, is peak pressure, not "highest reading of an SPL meter" (SPL meters only measure RMS; even if there is a peak hold function, it is the "highest rms reading observed", and that includes the selected averaging time). Anyway, peak pressure is calculated using the peak voltage of the amplifier. With non-powered systems, the assumption is that a user will supply an amplifier with twice the power rating of the loudspeaker, and that the peak voltage of the amplifier is 3 dB higher than that, because amplifiers are rated with sine waves. Hence, the peak pressure should be 6 dB higher than the maximum continuous SPL.

Keep in mind that maximum continuous SPL is a survival rating, not a useability rating. Of course what would be more useful is "maximum useable SPL", but that would be signal dependent and would have to be subjectively determined. So we're stuck with a calculated value that serves only as a point of comparison: "This one's red line is 2 dB higher than this one's red line." "


Since that time, Meyers Sound introduced M-Noise, a signal that promotes standardized measurement of a loudspeaker system's maximum linear output.
Unfortunately, until all manufacturers start using the same test procedures, you have to either compare products yourself, or rely on the opinions of those who have used the products you are considering that have made comparisons between them.

And there are still some difficulties with M-Noise, Ivan Beaver of DSL (another company that also happens to make some of the best speaker systems possible..) outlines them in posts # 6 &10:


Cheers,

Art
 
Oct 25, 2018
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Whatever setup you choose for the 'big' system, be sure to filter out any bass reaching the top cabs - this should be solely the domain of the subs. 100Hz or so crossover works well and takes much load off the top cabs' bass drivers lowering power requirements/increasing headroom, considerably reducing driver excursion and hence intermodulation distortion. In my view and experience, a sub is not a simple 'add-on' to extend and reinforce existing speakers, but should be fully integrated through a suitable LMS.
PS. Simply stunning locations and lighting!
 

Nathan Townsend

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May 25, 2022
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Hi Nathan,

Asking questions about products, rather than providing "Product Reviews" means you posted in the wrong forum.

...snip...

Cheers,

Art
Ah sorry my bad!! Rookie mistake :rolleyes:
Thanks so much for the detailed feedback though. Very helpful :)

ps: I'm a scientist (physiologist) by profession so even though acoustics is not my field, I enjoy the nerd talk. For example RMS is intuitive to me because we use this in statistical analysis, and in my field we use it to describe heart rate variability, the electrical activity of nerves and muscle, and other biological signals
 
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Roy Andrews

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Just wanted to mention as a general comment for your future reference (none of the products you mentioned fall in this category):

Be VERY suspicious of ANY powered speaker advertising "Class D" power in the 800w to 1500W range built from about 2010 onwards including everything on the market today. Most of these speakers that I have had a chance to personally examine / repair are based on the TDA8953 / TDA8954 power amp on a chip. The chip is rated at 210watts per channel x2 @ 10% distortion, and on an amp dyno it can make about 160 watts x2 without notable distortion. It is usually run in bridge mono mode, so you are looking at around 320watts max. However, this isn't the worst part of the problem... after all, the "Bucket of Power" (BoP) used in QSC KW and original K series dynos at about 300 watts x2, and KW152's and KW153's can make your ears bleed and still sound clean. No, the real problem is that the TDA895x chips are dissipating 320 watts into an area less than the size of an American 10 cent coin. ANY break-down of the silicone heatsink grease, decoupling of the chip from the heatsink (happens a lot in EV ZLX series) or failure of (or in some cases, the complete lack of active cooling) can bring your show to a quick & unexpected end.

If I can buy a car stereo amp for a couple hundred bucks that dynos at 2000 watts or more, and is built using banks of discrete MOSFETs with more than sufficient cooling, then there is utterly no excuse for this level of chintz from famous sound reinforcement brands.

BTW, while QSC KW series & original K series are rated at this 1000w mark, I can confirm they use a discrete MOSFET design, as do the new, more powerful K.2 series. Unfortunately, I have yet to get a chance to disassemble or repair any of the other top tier products that you listed (live in a poor, 3rd world country, people don't buy quality here), but generally, once you get past the most exaggerated power ratings a company can invent for the TDA895x series of chips, then they are forced to use discrete MOSFET designs.

Good luck, and those pics look AWESOME. Have fun, be safe.
 
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