Having enough headroom for 4-280's

[mdiehl]

Hey everyone! I've already got 2-XTI2000's running my Titan 48's, and while there's enough power to cover, it doesn't leave a lot of headroom, but we should be OK.

I'm looking to place another order for an amp for a set of 4-280's with the Deltalite 2512, 2 flat array and 2 melded. The plan is to group all amps in one rack, which will sit by the subs, so I'd like to cut costs of multiple long speakon cables, and loop each pair of 280's together.

From anyone that has used similar speaker/amp combination setups, would an XTI1000 provide enough headroom, or should i just bite the bullet and get a 2000?

Thanks everyone!

Matt

[DJPhatman]

How many T48s are you running off the XTi2000s? It might be a wiser decision to power the DR280s with the XTi2000, and get a XTi4000 for the T48s.

[mdiehl]

I actually have 2-XTI2000's dedicated for the T48's, 2 cabs per amp. (I got a heck of a deal on the 2000's which is why I purchased them instead of a single 4000.)

[DJPhatman]

I actually have 2-XTI2000's dedicated for the T48's, 2 cabs per amp.

Let me quess.... you are bridging the XTi2000s?

You are better off, financially, to power 4 T48s from 1 XTi4000, 4 DR280s from one XTi2000, and selling or re-purposing the other XTi2000. This setup runs off a single 120V outlet, makes a lot of noise, is very modular, and does not stress the amps, meaning less likelihood of thermal failure. A financial mishap is when a bridged amp thermally fails prematurely, especially during a gig. When bridged, you will most likely damage both amps, as they are connected, and the show stops. If you are running separate mono, you are less likely to lose both channels, so the show could continue. There are many more reasons not to run bridged. I'm just too lazy to type them all.

[Bruce Weldy]

DJP,

Why are you assuming that he's running bridged? The XTI 2000 runs 475 at 8 ohms per channel - sufficient for a T48 with a 3015lf.

And anyway, the XTI series is good to 2 ohms per channel - running it bridged at 4 isn't a big deal. Especially with the horn-loaded cabs only running at 10 ohms apiece.

Bridging an amp is NOT a problem if you run the proper ohm load and don't run it to capacity for long periods. The XTI 2000 runs bridged at 4 ohms 2000 watts - way more than 2 - T48s can handle. With the T48s being limited to a total of 900 watts, the amp wouldn't even breathe hard.

[mdiehl]

Just for clarification, I'm not planning on bridging at all. According to crown specs, I can run 1 tian from each channel, with the only fear that I do have the capability of driving them right to the edge of overloading. Its my goal to make this as simple as possible, which is why bridging hadn't even crossed my mind.

[Dave Non-Zero]

Just for clarification, I'm not planning on bridging at all. According to crown specs, I can run 1 tian from each channel, with the only fear that I do have the capability of driving them right to the edge of overloading. Its my goal to make this as simple as possible, which is why bridging hadn't even crossed my mind.

???? ????? Xti2000 is 475W into 8ohms per channel or 800w into 4 ohm. There is no problem spec wise of running 4 titans off one xti2000. but i would say they are slightly underpowered.
the xti 2000 would be a perfect match for 4dr280 though. I have run mine from a yamaha p5000 which is 700w at 4 ohms for years with great results.
i would try your titans off one amp and the dr280 off the other and see how you go. if you have been happy with one t48 per channel then i doubt you would notice the difference with 2 per channel.

DJP,

Why are you assuming that he's running bridged? The XTI 2000 runs 475 at 8 ohms per channel - sufficient for a T48 with a 3015lf.

because the OP says he is using 2 amps to run 4 t48.

DJP,
the XTI series is good to 2 ohms per channel - running it bridged at 4 isn't a big deal.

bridging at 4 ohms is running it at its minimum ohmage tho, so DJPhatman is just being the voice of caution.

[Bruce Weldy]

Why are you assuming that he's running bridged? The XTI 2000 runs 475 at 8 ohms per channel - sufficient for a T48 with a 3015lf.

because the OP says he is using 2 amps to run 4 t48.

[/quote]

2 amps = 4 channels = 1 Titan per channel......so why assume bridging?

Certainly, in a perfect world we'd all have tons of cash (or a wife who can't wait for you to buy bigger amps) to buy more amp than we need for a huge safety factor - but as this is DIY and most people do have some budget involved with their systems, bridging is certainly one way (if understood and done correctly) to get more bang for the buck. The new amplifiers can handle the load and have built-in protection.

I'm not advocating bridging as the best or only option, but there seems to be a knee-jerk reaction from some that bridging an amp is evil. It's not....it works, it's cheaper and while there may be a few folks that have flogged an amp for hours on end with the maximum load and have it meltdown - I've yet to hear anyone produce any such anecdotal evidence on this forum. Although, I've seen a lot of anytime bridging comes up.

It's just disingenuous to rule out a perfectly good option for most users by parroting something they heard, but with which they have no real-world experience.

For full disclosure, I've run my T-39s for the last year on a bridged XLS1000 without a hiccup. I recently had an opportunity to get another amp cheap that allowed me to move the subs up to a bridged XLS1500. I will continue to bridge my subs as it allows me to get the full potential from a cheaper amp.

We all offer opinions about what we like best, and that's fine. But, let's make sure that we don't turn opinions into facts .... and add more confusion to an already myth-filled avocation. This forum is a great teaching tool for all of us, but let's not rule out viable options.

[Tom Smit]

Hey Bruce, from what I've read on this site, it's better to not run bridged in order to keep the amp from overheat. An amp can run bridged for a while, even for a few years. But if it were to run un-bridged it could last for three to four times longer than that. For those who are very attentive to the voltage output of their amp, this probably doesn't apply.
But there are others who don't watch carefully....just hook up the amp and let it run....to the bleeding edge.
I prefer to have enough amp to satisfy the situation...and then choke it back a little so that no hurt occurs to it. Same goes for drivers.

[Dave Non-Zero]

2 amps = 4 channels = 1 Titan per channel......so why assume bridging?

because you lose nothing running two cabs per channel and I've never seen someone use two amps for 4 cabs.

As for bridging, I have nothing against it. I've done it. I would do it again.
And Bill says it exactly the same way you are - The reason to bridge is when you amp is too small to give a large enough voltage swing on one channel.
So if you have a small amp that can handle the load, then by all means bridge it if you know what you are doing.