The journey begins.. 16 T60's and 12 DR280's!!

[hifibob]

there is a pre and post xover eq section.

the pre xover eq can be toggled between peq, and geq. post xover there is a peq.

Ahh you da man! That's makes sense now. Thanks bud.

[sine143]

no worries man, I dont own a Driverack, but I've read through the manuals 20 or so times for the PA and the 260.

there used to be a *training* section on the DBX site but I cant find the 260 over there anymore.

If you are planning on using the auto eq, then you should do it outside before you get the venue. Raise an array of 280s off the ground (some scaffolding works nicely for this, put the measurement mic at ear level on axis and let her rip (try to be kinda far from boundaries). doing the auto eq inside is really going to only flatten it out at measurement position.

[Tom Smit]

i'd probably use the PEQ to tame speaker response, and then the GEQ to get it in line in the room.

Hmm I was under the impression you had to use one or the other. It did say the auto EQ only works with the GEQ but I believe still allows 4 bands of PEQ in this mode. Thats what confuses the heck out of me..

I've read recently, that one can auto-EQ, and then use the PEQ to bring it where the GEQ was set to. Re-run auto-EQ to see if there is any more need for EQ, and tweak the PEQ. This, then, leaves you with the GEQ to use as needed for the room.

[Mark Coward]

Excellent work, I'm a little late to the party. One minor tip that I discovered by accident - the foam fillers can be rather fragile. For some of the older jack/omnitop designs where they could show a bit I tried painting them with black spray paint, which unfortunately tended to melt some of the foam. On a whim I slapped some Duratex on them, and it not only covered well but makes them much stronger and bump resistant.

I've had a couple break loose after using hot glue only, after using them for a few gigs. Per the old plans, I carefully ran in a couple of wood screws with large washers "just in case".

[DaveK]

I make my fillers out of wood now and PL them in place. No more fillers coming loose during a gig!

[hifibob]

no worries man, I dont own a Driverack, but I've read through the manuals 20 or so times for the PA and the 260.

there used to be a *training* section on the DBX site but I cant find the 260 over there anymore.

If you are planning on using the auto eq, then you should do it outside before you get the venue. Raise an array of 280s off the ground (some scaffolding works nicely for this, put the measurement mic at ear level on axis and let her rip (try to be kinda far from boundaries). doing the auto eq inside is really going to only flatten it out at measurement position.

Hmmm thats interesting. Do I need to EQ the whole system as it sits in the club outside? The first dance floor that I'm going to fire up will have 6 DR280's (3 per side) and 8 T60's. Just thinking about how I would go about doing that, more for the current needed to drive the 5 MacroTechs slated for this setup..

I've read recently, that one can auto-EQ, and then use the PEQ to bring it where the GEQ was set to. Re-run auto-EQ to see if there is any more need for EQ, and tweak the PEQ. This, then, leaves you with the GEQ to use as needed for the room.

I think I'll give that a shot. I was just playing around with it I got pretty good sound with the GEQ. Thanks!

Excellent work, I'm a little late to the party. One minor tip that I discovered by accident - the foam fillers can be rather fragile. For some of the older jack/omnitop designs where they could show a bit I tried painting them with black spray paint, which unfortunately tended to melt some of the foam. On a whim I slapped some Duratex on them, and it not only covered well but makes them much stronger and bump resistant.

I've had a couple break loose after using hot glue only, after using them for a few gigs. Per the old plans, I carefully ran in a couple of wood screws with large washers "just in case".

I make my fillers out of wood now and PL them in place. No more fillers coming loose during a gig!

Great tips guys! I had wondered if the the hot glue would hold up over time.. I thinks I'll pull em apart and install a screw and washer at a minimum just so I sleep better. Interesting, making them out of wood, I thought they had to be foam for sound purposes but apparently not lol.

[sine143]

The only thing you really need to autoeq is a stack of 3 dr280s (since this is the size of your stacks). as you stack them it smooths response a little so thats why its important to do it as it will be deployed. once the 2 stacks are deployed you will have to start adjusting to taste (make sure everything is in phase and xovers sre wired as per plans)

Dont bother auto eqing t60s, just make sure they are all in phase and leak free. their response will be greatly determined by the placement inside, so you wont start getting them dialed in till they are installed. your main tuning points will basically just be choosing a lopass frequency, slope and filter type to get the sound you want, and to integrate them well with the mains. i doubt you will need to go over 80 here with the 280s. after nailing your xover slope you can start to implement light peq to taste.

[hifibob]

The only thing you really need to autoeq is a stack of 3 dr280s (since this is the size of your stacks). as you stack them it smooths response a little so thats why its important to do it as it will be deployed. once the 2 stacks are deployed you will have to start adjusting to taste (make sure everything is in phase and xovers sre wired as per plans)

Dont bother auto eqing t60s, just make sure they are all in phase and leak free. their response will be greatly determined by the placement inside, so you wont start getting them dialed in till they are installed. your main tuning points will basically just be choosing a lopass frequency, slope and filter type to get the sound you want, and to integrate them well with the mains. i doubt you will need to go over 80 here with the 280s. after nailing your xover slope you can start to implement light peq to taste.

Thanks sine for the tips.. I'm gonna drag them out to the parking lot tmrw and give this a try.. On another note I'm currently setting the xovers to 80 hp for DR's and 80LP for the tubas with a 25 hp.. At extreme high levels of use I noticed the DR's are not really belting out a shit load of mid bass or that tight bass that I'm sure 6 of them can do. Should I drop the xover point done to maybe 60-70 hz since it seems like the DRs can easily produce it?

[sine143]

With an 80hz hipass on the drs, they shouldnt be lacking in "midbass", or at the very least the t60s should be slamming at 80hz. what do you mean exactly by "midbass"?

[hifibob]

With an 80hz hipass on the drs, they shouldnt be lacking in "midbass", or at the very least the t60s should be slamming at 80hz. what do you mean exactly by "midbass"?

Maybe I'm using the wrong words.. Basically that tight bass that a snear drum would make? I can get the sound I want by dropping the xover points down to 60-70hz range and the DR's do it nicely but I don't want to hurt them either.. Am I better off trying to EQ that into the tubas instead? In case Bill is reading this don't think I'm saying these speakers are missing anything cus they are NOT! This system is by far most intense system I've heard to date and I've been in some pretty crazy venues from Miami to LV.. I'm sure I haven't even un-tapped the true potential since I'm adding4 additional tubas and 3 more amps once installed into the club

[sine143]

The punch one experiences in a snare drum hit is in between 180 and 250. if dropping the xover seems to give you more "midbass" at very high output levels it may acually be because you are adding distortion to th system (70hz tone will add 140hz for 2nd order distortion, and 210 for 3rd order) this will add more perceived midbass, but overall is a less accurate representation of the production.




I know this graph is the nsd version but it is the only one that is ported, so we'll focus on less than 1khz. as you can see there is a bit of a dip between 175 and 275 (the snare punch region). rather than boost this range, id start with a wide q cut (1.5-2q) cut by 3-4db centered around 500 hz. you may also have to make some significant cuts in the hf range, as those piezo arrays SCREAM!

You can also experiment with plugging your ports, as you can see that the blue graph (unported), has a bit flatter response, at expense of sub 100hz output.

Final thoughts, make sure your speakers are in phase! test this with either the 9v battery test with acess panels removed, or a phone app plus impulse file. out of phase speakers will def kill the midbass lol

[Bill Fitzmaurice]

I can get the sound I want by dropping the xover points down to 60-70hz range and the DR's do it nicely but I don't want to hurt them either.. Am I better off trying to EQ that into the tubas instead?

Yes, because the capacity of the subs in that frequency range is greater than that of the mains.

[Mark Coward]

Are you running the T60 and DR while listening, have you done any RTA? I've done a good bit of studio work, and a typical snare drum's "low end" is well over 100hz. I run aux fed subs when possible live, and never send the snare to sub even when crossing over @100hz.

If you're used to direct radiator subs, they impart a good bit of 2nd & 3rd order harmonic distortion which is above the crossover range - an 80hz tone will have some 160hz and 320hz content from the sub alone, increasing as the subs are pushed. So many are used to this sound that a good horn loaded sub, little or no distortion, can be perceived as lacking.

I also recommend setting up a stack outside, dial it in reasonably flat. I prefer to manually RTA for this instead of AutoEQ. For an install, you will have time to dial in for the room but there are a lot of factors involved - where you stand in the room, the number of bodies, etc. A traditional method is to use RTA and measure from different points in the room, averaging the measurements for an overall EQ. Dial in a bit more high end which will be soaked up when full of bodies.

[sine143]

you jacked my post Mark.

Using your example of 80hz, 160 is 2nd order, and 320 is actually *4th order). 240 is 3rd order harmonics.

lowering the hipass on the DRs likely imparts this harmonic distortion into the tops, as they are working below their pass band (a 70hz tone will produce 140, 210, and 280 in harmonics, right in the mid range of the snare punch).

My guess is you are testing this with house or techno music right bob? kick every beat, snares on 2 and 4 (as well as kicks?) in this case, the kick will add punch to the snare in the form of distortion.

here's a link to a track that immediatly comes to mind when I think "puncy" or "midbass" snare drum. not exactly my cup o tea, but it has the punch

[hifibob]

Hey guys thanks for all the help, this site is great! Mark no I haven't RTA the DR's yet Ive just tweaked them by ear so far. They sound pretty dam good though. I'm probably explaining this all wrong but I compare this system to the the one in my truck, same ipod and same music.. Granted my truck has 3 sealed 10's but the bass has a tight snap to it on certain songs. I can duplicate this sound with my BFM set up easily but its the DR's are doing it not the Tubas. I started screwing around with the GEQ today and The Tubas were handling that tight snap pretty well and with authority but I think I'll quit right there.. Its probably time to get the master on board and hire Bill for his services.. As it sits playing in my garage its nuts, but I have a lot of people anxious to hear this system, some probably are quietly not believers so I want to come out with a bang!

Sine that link didn't show up?

This is me playing in my garage hehe..