Helix P-SIX - EQ Linking Help

[swrocket]

So I've been tuning my front stage (Still waiting on the Sub to arrive) and got it pretty good on each side.
To do each side, I linked the left TW/MR/MB and applied EQ and then did the same for the right and level matched them.
The over all front (both sides together) though, needs a bit more EQ. I have the bands, but I wasn't sure what would happen if I linked the entire front stage (all speakers) together and then applied the 4 eq bands...or should I just apply the same to each side separately?


Any tips would be greatly appreciated.
Here is the REW response graph. (I'm using a Half of Whitledge curve)



and here are the EQ adjustments needed in REW

[Jdunk54nl]

What frequencies are you crossing your speakers?

Ideally you would tune each speaker indvidually, level match them to each other at that time, but get the crossover's right (this really helps get phase issues fixed). Looks like you are having some issues at the 300hz region (Is this where you crossed your midbass to mid range?) and then from 700-2,000hz when summed. This is most likely a phase issue in some way to have that issue. Eq isn't going to solve a phase issue. It might "fix" the graph and make it look pretty, but that isn't how you want to fix that.

[dumdum]

If you get dips while summed it’s likely phase related, so if you get a dip it’s better to apply an all pass to the good side to match the bad side rather than trying to correct the response with eq, as it’s phase related adding more eq won’t help and will have a negative effect on the response as any extra power/level you put in will likely be heard, but not actually do anything to your summed graph

Remember if you don’t get 4+db of summation (to the top end of mids, 5-6db in midbass) it’s due to phase being out due to reflections and standing waves, if you have a phase related narrow dip you don’t pile eq into it... so why would or should you when it’s between left and right sides?

your timing looks good from those three traces

don’t stress over phase related differences, add a little correction with a high q all pass perhaps, but otherwise that’s a pretty good overall response

try maybe a 2nd order all pass on your left side at 310hz to see if you can get better summation of the two drivers, your right side has an obvious dip caused likely by phase, so you deliberately mess the phase on the opposite side so the phase then matches better and you get better summation, it takes a bit of messing because we don’t have phase information but it doesn’t hurt to try

1.4k also looks like it has something phase related going on...

uneqd 1/48th octave graphs of the above drivers would reveal a fair bit more also

[swrocket]

Thanks dumdum.
My x-overs (electric) are at 327Hz (MB to MR) and 2788Hz (MR to TW) all LR24.
I do seem to have some issue on the right mb to mr but not sure why...I did get ~4db summation for MR and TW and ~5db on the MB just summed with eq only on each side.
I have un-EQ measurements for all drivers individually, as pairs and each side, but only at 1/6th Octave. I'll retake at 1/48 and post.

[swrocket]

Ok, here are the measurements at 1/48 no smoothing

Electric X-Overs at 80, 327, 2788.
I wasn't shooting for any particular acoustic x-overs, because I was trying out Andy's method of just eqing each side.

[swrocket]

And here are the full range individual drivers (well, TW is HP at 1800LR4 and MR HP at 200LR4 for protection)

[swrocket]

So I tried the individual driver method (vs each side) and I am really at my wits end. I cannot understand what the issue is in this car...
Here are my measurements after 3 rounds of EQ (measured at 1.48 smoothed to 1/6) all using UMIK-1 moving mic method at half volume on the HU
Acoustic X-Overs at 90-330-2900

I really need some help here.

Here is left


and right


something is weird with the mid range...
Here are drivers and driver pairs

[jtrosky]

It's obvious that you have same phase issues with both L+R are playing (both in the midbass and midrange). You can probably fix those with a few well-placed allpass filters. You also don't seem to be getting very good summing at the crossovers. Usually, this is a timing-related issue. Absolute worst case, you could use an allpass fitler to get better summing at the crossover as well.

I had similar issues with dips in the combined L+R response - and a few allpass filters solved those dips completely.

You just have to experiment a little. For the L+R midrange dips, try a 2nd order allpass fitler at ~1100hz with a Q of 3 or so. Without being able to measure phase, you just kind of have to mess around with the values. I usually start with frequency and Q values that are similar to what I would use to correct the problem with parametric EQ. Most of the time, those values work pretty well for allpass fitlers.

[swrocket]

Thanks James. Would I put the all-pass on both drivers then?

[jtrosky]

No - just on one (left OR right). It may work better on one than the other. I usually try it on the left side first and then if I'm not getting any results, I'll try it on the right side. If you put in on both sides, it will do absolutely nothing (ask me how I know!). :-)