BillFitzmaurice.info

commander_dan wrote:

Bruce Weldy wrote:

commander_dan wrote: In terms of amplification, I'm leaning towards Crowns Xti 4002, which should be good for both my 2 subs and tops. What is the general consensus on this amp? I might go look in the amps section..

Great amp.....2ohm capable on each channel....you can run double that number of speakers on this amp.

Bruce, I ended up buying the XTi 2002 for now. I can run my 2 subs off that and have a separate amp for the tops. Would the 2002 be good for 4 or 6 subs? Just wondering. My brother will have another amp for his 4, but it'd be nice to run 'em all off 1 amp if we couple our systems.

Cheers mate

It will run one per side ok.. at two per side, you don't have a lot of headroom left. At three per side, you'd have to limit 'em pretty low to keep from maxing out the amp.

The 4002 would have given you the ability to run 4-6 with pretty good headroom.

If you limit to 50 volts, two a side will work, but with very little headroom. I like to have more amp available so it will run cool and not have to work hard. I assume that you are running recorded music, not live sound - so the amps won't be getting any breathing room.

the 4002 hates going below 4 ohms, my experience at least.

sine143 wrote:the 4002 hates going below 4 ohms, my experience at least.

What happens? Heat?

I guess it really matters what levels you are trying to achieve, at what impedance load, and whether it's continuous or the amp gets a breather once in a while.

Yep, I had a think about things, and the reason I decided to go with the 2002 was because I plan to run my pair of T30's on that, 1 on each channel, for now. My brother will have his own amp for his 4 for the time being (he has been looking at the Inuke 3000, any thoughts on that?). Once I build my pair of Otops, I would relegate the 2002 to powering them, and get a 4002 for the subs. In the meantime, I don't see us using all 6 often enough to justify buying the 4002. I hope my logic isn't flawed

And yes Bruce, we are running recorded music. That being said, we have a gig in January where we may have a combination of (mostly) recorded content, but with a live band as well. Multiple T30's will be ok with that won't they?

commander_dan wrote:he has been looking at the Inuke 3000, any thoughts on that?

I have a pair of the NU3000DSPs. They do the job, however I did have one go pop within a month of getting it The replacement amp was here within a few days thanks to Berry's 3 year warranty. Whether that amp was one that was produced with some sort of defect or whether it is a defect in the overall design, I am yet to discover and only time will tell. For the price they are unbeatable. I often run them off a genny, so they are not being run in 'ideal' conditions. Did a gig at the weekend, 14 hours straight with no issues. Overall I'm happy with them, although I'd be lying if I said I wasn't slightly concerned about that early failure.

commander_dan wrote:And yes Bruce, we are running recorded music. That being said, we have a gig in January where we may have a combination of (mostly) recorded content, but with a live band as well. Multiple T30's will be ok with that won't they?

Sure, that'll work. Amps get a little breather and can dissipate some heat with live bands between songs. DJs keep it hammering for hours on end.

And that's a good upgrade plan on the amps.

Bruce Weldy wrote:

sine143 wrote:the 4002 hates going below 4 ohms, my experience at least.

What happens? Heat?

I guess it really matters what levels you are trying to achieve, at what impedance load, and whether it's continuous or the amp gets a breather once in a while.

I've run XTi4000s at 2ohms for hours with no issues.

Bruce Weldy wrote:

sine143 wrote:the 4002 hates going below 4 ohms, my experience at least.

What happens? Heat?

I guess it really matters what levels you are trying to achieve, at what impedance load, and whether it's continuous or the amp gets a breather once in a while.

Yes, Heat.

obviously, impedence varies based on frequency, so from track to track, results will be different based on song content/duty cycle.

This track in pariticular brought the issue to light. 4 subs, amp hooked up to sys architect, bass at about -3db consistent ally throughout (-2db is 55v), and the amp reaches 50 degrees C from idle (about 33 degrees C)

.

wait for amp to cool down, try again with 3 subs per side, and watch the amp skyrocket up to thermal within the first 2 minutes (75 degrees C is thermal "limit" for the xti 4002).

is the fan working?

Sorry to interrupt the discussion (it's great, keep it it going!) but my brother did some fine work with the router today in preparation for our next construction marathon next week.. couple of quick pics..

rotebass wrote:

Bruce Weldy wrote:

sine143 wrote:the 4002 hates going below 4 ohms, my experience at least.

What happens? Heat?

I guess it really matters what levels you are trying to achieve, at what impedance load, and whether it's continuous or the amp gets a breather once in a while.

I've run XTi4000s at 2ohms for hours with no issues.

You're lucky. Voice of experience crown xti's don't like 2 ohm loads. Russian roulette.

Bruce Weldy wrote:is the fan working?

Yes full speed all the time. interior is pretty clean as well.

sine143 wrote:

Bruce Weldy wrote:is the fan working?

Yes full speed all the time. interior is pretty clean as well.

While this probably isn't your issue at all....

This might be a good time to remind those reading to be sure that all of their amps are pulling and pushing air the same direction. Some amps' air flow is reversed from others - this will cause hot air to keep looping through the amps if they are next to each other.

Crown goes one way, QSC and Behringer go another.......so don't put Crowns with those others in the same case.

Day 7:

Pretty successful day today! Cab 1 got a double coat of duratex throughout the day, we decided to do the entire cab including horn mouth and it worked out very nicely! Used less than half a gallon of duratex which was less than anticipated. We installed castor wheel blocks on the back of the cab for the screws to have some extra meat. All that remains to do for cab 1 now is install the corners and the castors which will be done tomorrow.

We got the access panels cut out of the sides for the remaining 5 cabs, and then proceeded to cut and install panel 1 on cab 2, then cut panel 1 for cabs 3, 4, 5, and 6 while still setup for it. This is how we intend to continue with the build, so that after cab 2 is done, it should be a lot faster for the last 4 cabs. We got panel 2 installed, and the remaining panel 2's cut. Then we cut the panel 3's to finished length and called it a day. We also broke in the first pair of my brothers 3012LF's over the day. Back at it first thing in the morning!