Metropoulos Forum

Hey guys. I just bought a pair of Cerwin Vega EL-36B folded horn subs...the infamous "Earthquake" model. I'll get to test fire them Thursday.

My question is, does anybody know anything about proper setup of folded horns? I understand they have to be time/phase aligned by adding alignment delay to my top speakers to account for the horn length.

If anyone here can explain to me how to properly time align my system to run these bad boyz, please post whatever info ya got.

Jon

Did they come with any documentation to help you set them up? A metre adds a latency of about 3 ms. I'm not sure if there are other factors that have to be accounted for in a horn.

OK...well I figured out how to properly time align the mains to the subs in a folded horn setup. If you flip the polarity of the mains, then play a test tone of your crossover frequency (in my case a 100Hz tone) through the system, you start adding delay until you hear the tone cancel. To be most accurate, I used my Phonic PAA-2 handheld RTA and added delay until I saw a drop at 100Hz, then when the level of the 100Hz tone started rising again, I backed off the delay a bit until it went back down to the lowest level I could get it. Then I flipped the polarity of the mains back to normal. They only required about 1.4mS of delay anyway.

But compared to my ported EV Force i subs...the whole entire mix was MUCH flatter. Before with the old subs I had a large hump in the lower frequencies and also heard a bass resonance problem. However with the new folded horns, with the RTA my overall mix was MUCH MUCH flatter.

Folded horns are DA SHIT and are THE way to go IMHO.

Jon

If you flip the polarity of the mains, then play a test tone of your crossover frequency (in my case a 100Hz tone) through the system, you start adding delay until you hear the tone cancel. To be most accurate, I used my Phonic PAA-2 handheld RTA and added delay until I saw a drop at 100Hz, then when the level of the 100Hz tone started rising again, I backed off the delay a bit until it went back down to the lowest level I could get it. Then I flipped the polarity of the mains back to normal.

You are da man!!!!!

Has anybody here heard any LAB SUBS folded horns (have heard these rock, although have never heard any in person)????

I haven't heard any in person, but my buddy, Gary Perrett in Minnesota has built two of them and he swears by them apparently.

Jon

TABARNAC

my buddy, Gary Perrett in Minnesota has built two of them and he swears by them apparently

The specs on them are fantastic!!!! 2 12" Eminence speakers per cab, 1800W program per cab (do need some parametric besides the alignment delay as they are made to work in clusters of four)....

.......and the biggest kicker......

ya need 2 tops just to keep up with one of these monsters!!!

flemingmras wrote:To be most accurate, I used my Phonic PAA-2 handheld RTA and added delay until I saw a drop at 100Hz, then when the level of the 100Hz tone started rising again, I backed off the delay a bit until it went back down to the lowest level I could get it.

Where did you put the RTA for this? I'm a bit curious as to what point of reference you're generally supposed to use for time alignment.

OK where in the hell did you come up with a figure of 1800 watts program power from 2 12" speakers that are rated at 400WRMS a piece!? Interesting.

As far as where I placed the RTA, it really doesn't fuckin' matter. It's gonna cancel either way. It may cancel less in one point in the room than another, but it's only gonna cancel so much either way you look at it, and that's what you're looking for. You're looking for the point where it's gonna cancel as much as it's going to. Remember, you're not time aligning to the room, you're merely time aligning to be in phase at the crossover frequency, so room acoustics hold no relevance here. But pretty much, I do it at the mix position. You can actually hear it cancel, but it's so subtle I decided to watch it on the RTA, find the point where it cancels the most it's going to, and set the delay to that.

Jon

tonejones wrote:

my buddy, Gary Perrett in Minnesota has built two of them and he swears by them apparently

The specs on them are fantastic!!!! 2 12" Eminence speakers per cab, 1800W program per cab (do need some parametric besides the alignment delay as they are made to work in clusters of four)....

.......and the biggest kicker......

ya need 2 tops just to keep up with one of these monsters!!!

Yeah, the only problem is is that they're 44"x28"x44"! It's bad enough the CVs are 36"x24"x36, why do I need BIGGER cabs when the CVs do the job just fine? My buddy who swears by these always tells me "Yeah, but these things go WAY lower etc etc" and he swears up and down that the frequencies below 40Hz actually do matter blah blah blah. I'm like "Look, I don't need THE BEST, I just need something to get the job done right and the CVs do a MAGNIFICENT job at that."

Now if I was doing large venues, then you can bet your ass I'll invest in the LAB Subs. But until that happens, the CVs work great.

Jon

OK where in the hell did you come up with a figure of 1800 watts program power from 2 12" speakers that are rated at 400WRMS a piece!? Interesting.

From the guys on the LAB SUB board over at prosoundweb.com....

Not real unusual though....as I've seen many other enclosures where the program rating is twice the WRMS rating (and peak at twice the program).

It has been awhile since I've been over there, so that might have changed since then..........

Peak is always at twice the program and program is always twice the continuous. Sometimes they use RMS as "continuous" rating...why the fuck they do that I have no idea.

Jon

Yep,

This is the first time I've seen program higher than 2xWRMS myself, but I've been seeing specs on alot of cheaper cabs here lately where the program and peak aren't going the whole 2x (cheap bastards)!!!!

Well, this last Friday...

I went to go and put our break music on right before the show. Forgetting that my sound guy had a hip hop CD in the player for the break music, with the PA at concert volume I pressed play.

At the first beat of the song, HOLY FUCKIN' SHIT!!! Those folded horns were so loud that the bass literally stunned me for a brief second.

Felt like I literally got picked up and thrown against the back wall of the venue.

Cerwin Vega's ROCK!!!

Jon