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Sorry if this is a dup. of my last post, but question is more focused around the subject now. I am questioning if I have enough headroom with the new XLS 1000 I just bought. 450W to each 3015LF, and 1100W 4 Ohm bridge for XLS 1000. I am actuallly running at 5 Ohms with the 2 T48s, so that's even less headroom. Is there reason enough to step up to more powerful model and would there be a noticeable difference? Thanks as always, and Happy New Year

An XTi 1000 delivers 1400w into 4 ohms, bridged. So, if you're running your T48s in parallel (5 ohms) with the amp bridged, each driver is getting around 650w. That's plenty of headroom, but you're really pushing that amp hard!

Mikey wrote:An XTi 1000 delivers 1400w into 4 ohms, bridged

It's only 1100w 4 ohms bridged. So really working the amp hard, possibly at the expense of sound quality? This is what I am trying to find answers to.

XLS and XTi are two different amps.....you're both right.

As far as I can see there is no margin in choosing an amp with a large amount of excess over the rated power of the horns. If you're hard limiting like you're supposed to then amp "headroom" never gets used. Or else I don't understand headroom.

Gregory East wrote:As far as I can see there is no margin in choosing an amp with a large amount of excess over the rated power of the horns. If you're hard limiting like you're supposed to then amp "headroom" never gets used. Or else I don't understand headroom.

That's why I decided to get rid of my really big (only) amp and replace it with something smaller and closer to the maximum power I would need. I would have had a ton of headroom on the old one, but it was capable of WAY more than I needed. So far I'm very happy with the decision.

Bruce Weldy wrote:XLS and XTi are two different amps.....you're both right.

I tried to be clear on my amp in my post

doncolga wrote:Gregory East wrote:
As far as I can see there is no margin in choosing an amp with a large amount of excess over the rated power of the horns. If you're hard limiting like you're supposed to then amp "headroom" never gets used. Or else I don't understand headroom.

Headroom in terms of the amp not working at 90-95% of its max power, not in terms of having the extra power for the purpose of exceeding max power of driver. I understand amps even less than drivers, so I'm wondering if the amp-at-hand is working too close to its max, or if it even cares if I demand 5% or 95% of its power. The ideal I've seen on here is to have the amp "purr along." If the XLS 1000 will do this while working at 90-something % then all the better - less money to spend. I will spend to do it properly though.

The RMS of music is traditionally a lot less than a sine wave. Even if your bass is BOOMF, BOOMF, BOOMF, BOOMF, that's a lot of resting in between working.

Newfangled sustained high volume synth tones raise the bar. I'm nowhere to be found continuous synth bass is played but somehow I doubt you'd be in business playing sinewaves at high volume for too long before reverting to BOOMF, BOOMF, BOOMF, badabadaBOOMF, BOOMF, BOOMF, badabadaBOO...

Gregory East wrote:but somehow I doubt you'd be in business playing sinewaves at high volume for too long before reverting to BOOMF, BOOMF, BOOMF, badabada BOOMF, BOOMF, BOOMF, badabada...

thank god!
Bring the beat back!

My bad ... sorry about the amp mix-up on my part.

Running an amp, bridged, into a 5 ohm load, will heavily stress the amp. The harder you push it under those conditions, the more you stress it. That "1 ohm" of "breathing room" is virtually non-existent because we're dealing with nominal impedence values and because impedence is in a constant state of fluctuation. If you're not going to set your limiter higher than 30v, the amp should be fairly reliable. If you plan to run it at 40-45v, to coax everything possible from your drivers, then your reliability expectancy factor will be greatly reduced. Even if the amp WERE to run reliably with this configuration, the longevity factor of your amp will be greatly reduced. HEAT is what affects and determines reliability and longevity.

Hope that answers your question.

Just wondering: do the Drivecore amps run on anything between 100-240V (like the Xti's), or are they built with different power supplies for different countries? This is not entirely clear to me from the Crown website and documentation.

I do not need another power amp at this time, but that may change once the bands get going again here. We are on 240V. But the US has way more to offer than Europe, even with postage, VAT and customs added. So I'd like to know if I can keep an eye on international sources as well for these amps (or order one from Leland when the need for an additional amp arises).

AntonZ wrote:Just wondering: do the Drivecore amps run on anything between 100-240V (like the Xti's), or are they built with different power supplies for different countries? This is not entirely clear to me from the Crown website and documentation.

I do not need another power amp at this time, but that may change once the bands get going again here. We are on 240V. But the US has way more to offer than Europe, even with postage, VAT and customs added. So I'd like to know if I can keep an eye on international sources as well for these amps (or order one from Leland when the need for an additional amp arises).

I'm looking at the manual right now....yes, they will run from 100 to 240.

Does it say so on the back as well?
On the Crown site it is worded slightly different between the two series. So I was kind of suspecting the drivecores being different in this respect from the Xti's.

AntonZ wrote:Just wondering: do the Drivecore amps run on anything between 100-240V (like the Xti's), or are they built with different power supplies for different countries? This is not entirely clear to me from the Crown website and documentation.

I do not need another power amp at this time, but that may change once the bands get going again here. We are on 240V. But the US has way more to offer than Europe, even with postage, VAT and customs added. So I'd like to know if I can keep an eye on international sources as well for these amps (or order one from Leland when the need for an additional amp arises).

Anton I'd pose your question at the Crown forums. On the back of the units they show the multiple Voltages and frequencies and there's no selection switch or process noted anywhere, but in the manual it states "configurations available".

My guess is the power supply is able to adapt to the listed configurations without any manual manipulation by the user but without having one to play with I wouldn't put money on that statement.

It's a good question and I'd pose it at the Crown forums if you want a definitive answer. Perhaps they will amend their manual to state specifically what can be done regarding mains supply voltages and frequencies.

Thanks for the suggestion, Ron. Will do and report back here. Too much of a risk to order one and find out it will only be good as a smoke machine, momentarily