Otop 112's Melded Array 2512 Downunder

[Grant Bunter]

Well done TH!

I'll just point out that the melded arrays are quite a bit something and more than most other commercial cabs mids and HF, so you may be hearing stuff you just never heard before! It could be quality of recording as well.

EQing doesn't have to be a dark art, but the more you play with it the easier it becomes.
I'm not as familiar with XTI series, so I looked around a bit, and if I say something incorrect, I'm sure some kind soul who knows better will correct me haha.

You probably have it already, in order to set up your subs, but if not, you need to download System architect from Harmon and use that to set up.

Say you use channel 1 for subs. Set that all up with HP and LP and your limiter and crossover.
Then go to channel 2 and set that for your tops. HP at your crossover point and then go to the EQ section, which, if i have it right, is a 8 or 10 band parametric EQ.
When I did this I printed off the SPL chart for my cab, drew a line roughly in the middle of the response and called that "0".
Looking at the OT12 SPL chart in the SPL section, I reckon that line is around 103dB.

You will see certain frequencies have response above the line you've drawn and others below. eg 375Hz looks to be +3db (compared to "0").
So that's your first selection in the EQ section. Select the first slider, type in 375Hz and then reduce it from 0 to -3dB. Being parametric it should pull down a curve rather than a single frequency.
There's a bit of a trough around 1.2K, -3dB, so select that frequency on the next slider and set it to +3dB.
And so on until you've covered all the peaks and troughs.
This is what is referred to as mirror imaging and should get you into the ballpark. If nothing else, your tops are now "flat" in response.

Save it, have a listen. After this, you should listen by ear (outside is better for this, with more than 15m of free space around you if possible), and see if anything still needs changing.

See if this sorts out your offending frequencies and you're off and running...

Sorry about the essay

[Gregory East]

BandManager has all the necessary functions for live band PA and is a much smaller programme than System Architect.

You can tweak the Q of each parametric and it graphs the resultant as you go.

[Titanium Hand]

Bill, Grant & Mr East thanks very much for all of your advice to reach my goals.

I already Downloaded System Architect upon completion of the Titans and am reasonably familiar with the basic controls.

Grant your explanation of how to EQ is excellent.

Where may I find a response chart of the OTOP112 with twelve tweeter melded array and 2512 driver? Certainly somewhere here perhaps?

Thanks again guys

[Gregory East]

In your plans I expect.

Feck it, I am your search bitch:

http://billfitzmaurice.info/forum/viewt ... =12&t=2550

[Titanium Hand]

Thanks Mr East, I've got a Kiwi offsider at work now too! Bloody hard working lad from Wanaka, makes my life a whole lot easier

I'm supposed to be doing wedding stuff atm so I'm logging out now. Will work on the EQ tomorrow.

Thanks Again

[Grant Bunter]

All good TH, get to it when you can.
You gotta do what you gotta do.

Hope the EQing works out and it's all easy now...

[Titanium Hand]

I've drawn an imaginary line in the chart and made 6 changes. Not more than + / - 6dB. I had it hooked up as intended earlier this evening -outside with room to breathe....

OMG Crazy Loud & Crystal Clear. This was sstill prior to any EQ (sorry Bill) I Played mean songs too;

Express Yourself, Diplo ft. Nicky Da B
Bonfire, Knife Party
Jah No Partial, Major Lazer
212, Azelia Banks
Turbulence, Steve Aoki ft Afrojack
Language, Porter Robinson
and even
Reptile, Skrillex

Clear as the azure sea and bloody loud. To be fair, ok there are a few frequencies that appear a wee bit harsh - yet still clear, they kind of shriek however ZERO DISTORTION or CRACKLING. Very Very happy. No doubt in my mind that a bit of basic eq will have them like nothing on this planet attainable without the U.S. Defence Budget at ones disposal

In relation to EQ.... Can anybody enlighten me as to what Q. means? I encountered it on the EQ part of System Architect. For Those unfamiliar, options are; Slider for + or - dB. Arrow operable up or down Q.(default setting is 4). The last thing is the Hz and kHz allocator.

I'm all over the top and bottom bits like magpies on chip, its the Q. option in the middle where I'm at a loss

Thanks all, special thanks to Bill, your designs are weaponry

[Grant Bunter]

As far as I can work out, Q describes the slope.
So the higher the Q the sharper the slope.

In my example earlier, say you wanted to drag down a curve with the peak (or centre frequency) at 125dB. You would use a lower Q to pull down the whole curve. You keep on adjusting the Q until you have the curve pulling down as you want to.
If you wanted to just pull down 125Hz, you would use higher Q, so the frequencies either side are less affected...

[Gregory East]

Q is the spread of each filter. We're agreed on that.

It's been awhile since I was messing about with bandmanager but iirc "Q" is expressed as a fraction of a whole octave. So 1.0 is a whole octave, something like that anyway. Bigger number smooth correction, smaller number makes it a notch filter.

Either way you'll figure it out. Go forth and conquer.

[Grant Bunter]

Gregory is right, the semantics don't matter, so get into it lol.

Ideally, you would have an RTA and you could see the results of what you do, ie you can see your altered response curve.

Without that, you need to rely on your ears.

Don't know what it is you're listening for?

No probs, start training your ears:

http://www.audiocheck.net/engineertrain ... ficult.php

There's easier pages if that's too much straight up, click "full octaves"...

[biggerrigger]

I tried the test that Grant posted but could not hear all of the tones on my laptop. The little laptop speakers would not play anything under 400hz or over 10khz. Time to BFM my laptop

[Grant Bunter]

I tried the test that Grant posted but could not hear all of the tones on my laptop. The little laptop speakers would not play anything under 400hz or over 10khz. Time to BFM my laptop

lol, good one!

Did you try it with headphones?

My old laptop used to play down to 30Hz and up to 16K through the speakers, but not my current one.
I'm planning to get a USB sound card (eg Creative X-Fi) to up the quality, hopefully that will fix it.

[biggerrigger]

I could hear all of the tones with the headphones and scored a 6/10. Much better than the Dell laptop speakers.

[Gregory East]

Bandmanager refreshes the EQ graphic with each tweak of frequency, Q and +/-dB. Presumably System Architect does same.

[Titanium Hand]

Excellent, thanks very much gents. I feel I've learnt and am learning a whole lot throughout the whole Otop build.

I'm very grateful for the ongoing assistance from Grant & Gregory