HK audio PA measurement

[Arbr4]

I've posted this thread on the pro-audio, but I think it's better of here because it's a bit more technical
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Hi all,

I'm the sound guy of a 7 piece rock and pop (cover)band, and I tow my system from gig to gig.
I have several sets for smal gigs and bigger gigs.
For smaller stages I use active RCF and HK Audio stuff alongside a digital Soundcraft UI mixer.
The main (FOH-ish) portable system for the smaller gigs consists of two RCF AS8003MK3 subs (18") and two HK Audio Linear 5 MK2 112FA.
The RCF's do a fine job delivering the rock punch and the HK's have a nice long throw (60x40) and have a fine DSP that's fully controllable.
With some tuning this is a good sounding combo!

However:
On the so called HK audio pro users forum I had some discussion on how to setup the system and how the speakers are factory tuned.
For every gig I measure the phase en frequency response (sometimes with ARTA, sometimes REW) and tune it "flat" to make the signal more predictable and more feedback proof.
With most speakers I've used, the standard frequency response is more ore less "flat"... I've used most common active speakers for the smaller gigs: Yamaha DZR, Electrovoice ETX / EKX, Martin, Adamson, Nexo, RCF NX /TT, FBT, JBL etc... If I measure nearfield (1m on axis) the frequency response is mostly flat(ish) with al these speakers.

Only the HK audio boxes (in this case the Linear 5 MK2 112FA) are different; the factory preset they call flat has a very strong " smiley curve".
There is a strong boost towards 10-12khz (+ 8dB) and towards the 100hz region: +8dB. (see attached files). The measurements on the spinorama site give about the same image.

The HK audio representative says that HK tunes the speakers towards the Fletcher-munson curves... They tune their factory presets on "how our hearing works" he says.
The strange thing that occurs is that if I tune the speakers "flat" with the HK DSP control, and compare them to other comparable speakers, high and low seem to be "off" comparing to the nearest competitors; It's like the FIR filter isn't done correctly and delay between high and mid/low isn't correct (high seems to be to far behind the low/mid) and they have tried to compensate by boosting frequencies to get some decent sound image compared to their competitors.
By asking the HK audio guy, he says that my measurements aren't good and that the (HK) have enough experience tuning and measuring speakers.

My questions:
1.How should a factory preset called "flat" should look / sound like? (what should be a good starting point for a P/A speaker out of the box?).
2. Does it seem to you that HK audio has made a design error?

just asking

 

[Multicore]

1.How should a factory preset called "flat" should look / sound like? (what should be a good starting point for a P/A speaker out of the box?).

That's 3 questions already.

Flat means flat. It's such a well understood word in everyday contexts as well as in audio and specifically referring to EQ and FR curves that it's just misleading to use the word flat for anything else. A smile curve is not flat. So what it should look like is clear.

What flat should sound like is hard since it sounds different in every installation and to every person.

What's a good default FR curve for a PA speaker ootb? Idk. It seems common in many audio engineering tasks to start from flat (in the conventional sense, not a smile) and adjust from there. Goes with old advice like "Don't get in an EQ mess. Use only as much as you need."

2. Does it seem to you that HK audio has made a design error?

Perhaps HK has found that they can sell more speakers with a smile default and call it flat. If so, would that be an error?

 

[Arbr4]

@Multicore,

Thanks for your reply, we're on the same page regarding the "flat" discussion (for me it's not really a discussion).
Offcourse a brighter sound is, on first impression, directly next to competitors a commercial decision.... to get more buyers...
For long terms I think it's not the best decision however.

but I think there's more:
Other speakers are flatter tuned but seem to have the same level of highs and lows... so that's something with delay and alignment.
HK might use a little boosting tot make-up that error.

So...for my second question (or 3e? ) the design error would be a not correct alignment of HF en LF drivers in time domain.
HK uses a longer horn and so far as I can see, FIR is only applied on the HF driver (like most every other manufacturer do).
The active boxes use a standard Pascal amp/DSP.
It might be the non-ability of the FIR filter/DSP to delay the LF driver enough or it might be the measurements HK audio does to create the presets and tune the sound (were do you place your reference mics and how do you determine near field and farfield measurements) why they don't translate well with a flat response...

bottom line: if I tune the FR to flat, it looks/hears like there is something not correctly aligned...