Pre or Post PEQ

rschultz

Hi,

DR 260. Renkus Heinz TRX82's for LR powered by a QSC RMX2450, Yorkville LS700P for mono sub.
Why would I want to use the Post PEQ instead of the Pre PEQ? Besides the Pre has 9 bands of any type (hi, low, bell, etc) and the Post only has 4 bands of limited type. Are the situations or advantages to doing certain types of PEQ post X-over?

Thanks.
Ryan

Gadget

Using PEQ's is NOT intuitive...I would however be remiss if I didn't say here that any \"audio professional\" would agree that PEQ is FAR more preferable to GEQ...The thing here is we have a tool that allows us to get pretty close to \"flat\" system eq...That ...IS important! and to get this using ONLY an RTA based process that uses 28 bands (GEQ) as it's setup is ...well unusual. Take the product of the Auto EQ... set to flat response and implement it using the POST xover PEQ's (since you CANNOT Auto Eq using the 9 and PEQ on the front end...Try to get as close to 'FLAT' AS POSSIBLE USING only THE post xover PEQ's...

SO, yes, PEQ IS superior to GEQ, BUT... what are you basing your EQ curve on ...? With the PRE xover PEQ you cannot get an AUTO Eq sequence...? If your good enough to tune it by ear.. you need no help from me...or anyone here.
Gadget

rschultz

Yes, PEQ is superior to GEQ. But I've never had good luck with the auto-EQ, so I do it manually... generally in the Pre-X-over-PEQ. Manually using a combination of the RTA and my ear with full range music.

So back to my original question... what's the advantages of the pre vs post PEQ?

Thanks.
Ryan

Gadget

More bands..I use em both...

Dennis

Ryan

Generally, people do their initial sound system adjustments in a location other than a gig venue like their shop, garage, driveway, front yard, or friend's farm. The less surrounding walls or structures, the better. The initial adjustments do not deal with room acoustics. They deal only with the characteristics of your specific speaker box(s). Lots of folks are doing ground plane measurements at around 10 - 12 feet which will eliminate reflections from that one surface. The initial adjustments will include setting your xo points, time aligning, and dealing with some basic EQing per pass-band. Any EQing you do will affect the phase response of the pass band you are working on and you will have to compensate by re-adjusting the delay. All of this is easier when doing one band at a time...hence, the need for post xo PEQ. You would be shooting for the flattest response your speakers can deliver minus any room reflections, and with the smoothest phase response. And these settings are generally not done by ear.

Now you have completed your initial adjustments and you have an unused, flat, Pre XO, PEQ or GEQ to tune your system to the venue you are working in. You might do it by ear or with auto EQ. All of the settings in your initial adjustments will never change and the Pre XO PEQ/GEQ will change every venue.

My explanation here may or may not be more advanced than your current setup procedure but I needed to go there to explain PRE vs POST EQ and why you use both. Hope this helps.

Dennis

Gadget

Thanks Dennis...I ran out of time this morning...and left only the blurb...
G

rschultz

Dennis,

Thanks for the response, yes that makes sense.

Ryan