T39 - OT12 Driveway Review

[Bruce Weldy]

Well, I toted 'em out to the front yard and fired 'em up with the driverack. Used the AutoEQ function and the adjustments were all over the place. Didn't like the look of that at all. There was a big cut at 125hz, so I moved the Sub xover point to 118 and left the Tops at 125. That may be a no-no, but there seemed to be enough material getting through. Re-ran the Auto EQ with the mic moved up closer (started at about 40 ft - moved to 20 ft). EQ looked better, but there were still some goofy looking adjustments....Up 8db at 1.6 and down 8db at the next one up. So, I evened all that stuff out and let my ears do some decidin'.

Just had one each of the Subs and Tops......I was a little afraid to actually turn 'em up - I didn't want to find out that I'd done all this work for nothing. Started moving the level until I was afraid the neighbors would come out to see who to shoot. Clarity was amazing, bottom end was pumping....that was at 10 volts hitting the sub. I cranked it up to where I thought I was certainly getting close to blowing something up - voltage was up to 28. Folks, I've got the limiter set at 55volts - can it really go all the way up there without the box blowing up?

Called my drummer to come hear it.....he said, "Wow". Then walked about 70 feet away and said it was amazing. I may be able to fill up the outside gig that's coming up after all. I never got the level on the board past -20.

There will be more after we actually get the band running through it and play a gig with it. But for now, I'm ecstatic.

[sine143]

hahaha. Are you using buttersworth or LR xovers? a buttersworth curve will add 3 db at the xover frequency.

[Bruce Weldy]

Butterworth on the high pass for the sub and LR on the low pass for the sub and high pass for the tops.

I only did that because I seem to remember someone saying that's the ones to use. I don't know enought about the differences to make that decision on my own. (uh oh.....I think Syd's about to suggest a book to read )

[sine143]

hahaha, I'm sure. I've been redigging into Mccarthy's book... it really is great.

[WB]

EQ looked better, but there were still some goofy looking adjustments....Up 8db at 1.6 and down 8db at the next one up.

I had something similar. It's doing what it's supposed to be doing.

[DJPhatman]

#1 measurement mic is WAY too far away.

#2 measure in a more open area, at least 60 feet away from anything standing upright, to avoid reflections.

#3 measure with the speakers silent, then raise the volume up until the mic only "hears" what's coming out of the cabs, and not background noise.

#4 Make EQ adjustments manually. This trains your ear, and helps you to learn what to adjust when

#5 Most importantly, TRUST YOUR EARS!!! If it sounds good to your ears, it is good.

[Bill Fitzmaurice]

#1 measurement mic is WAY too far away.

20 feet is the minimum to allow wavefront integration at the measurement position. 10 meters/33 feet is a defacto industry standard.

[Bruce Weldy]

Fired 'em up at practice last night. Set it up about 20 feet in front of us and used the system as a giant monitor to see just what is coming out. WOW. Bass player and drummer were impressed. When the kick and bass hit the downbeat together it was exactly what I had been hoping for.

Wasn't as pleased with the vocal clarity, but it was in a big tin building.

When it was really rompin' pretty hard, I checked the subs and the tops with a voltmeter and the subs never got past 20 and the tops were only registering 10. Any other speakers that loud, I would have been concerned. Can I really push these things to their respective max voltages? Or, even close? I set the limiters to kick in at -0- on the board. I never got it past -20. I don't want to blow anything up, but I'd like to get 'em up to 80-90% if possible. I'm just scared to push it that hard.

Has anyone else gone through this? Are these really THAT much louder than what I'm used to?

[sine143]

They really are LOUD.

The first live gig I did (out of a total of 2... hehe) I had some difficulty dialing in a nice clear vocal. thats when I noticed that the 12 band eq was totally whacked out. Just play around with your eq and levels and I have no doubt you will be able to get a nice clear vocal channel in the mix.

[Benj Ross]

Fired 'em up at practice last night. Set it up about 20 feet in front of us and used the system as a giant monitor to see just what is coming out. WOW. Bass player and drummer were impressed. When the kick and bass hit the downbeat together it was exactly what I had been hoping for.

Wasn't as pleased with the vocal clarity, but it was in a big tin building.

When it was really rompin' pretty hard, I checked the subs and the tops with a voltmeter and the subs never got past 20 and the tops were only registering 10. Any other speakers that loud, I would have been concerned. Can I really push these things to their respective max voltages? Or, even close? I set the limiters to kick in at -0- on the board. I never got it past -20. I don't want to blow anything up, but I'd like to get 'em up to 80-90% if possible. I'm just scared to push it that hard.

Has anyone else gone through this? Are these really THAT much louder than what I'm used to?

I was just going through this exact thing. I was running a pair of T39s with a J112 as a top just trying it out and OMG! I thought I was pushing it way hard and found out that I was putting about 25V into the subs and 10V into the jack. I wasn't willing to turn it up anymore without proper ear protection. I have been second guessing all of my measurements now. I changed the battery in my voltmeter and everything.

I am simply astounded by the efficiency of Bill's cabs.

Cheers,

Coffee