full rated handling or half?

Is this amp OK?
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Reticuli
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full rated handling or half?

#1 Post by Reticuli » Fri Dec 29, 2017 4:21 pm

3200W peak rating into 8 ohm subwoofer cabs. One amp for each sub that is each rated at 3200W peak in 4 ohms when bridged. When bridged are these amps going to put out the maximum of the subs' rated handling or one half of the subs handing?

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BrentEvans
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Re: full rated handling or half?

#2 Post by BrentEvans » Fri Dec 29, 2017 4:28 pm

42.
99% of the time, things that aren't already being done aren't being done because they don't work. The other 1% is split evenly between fools and geniuses.

Bruce Weldy
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Re: full rated handling or half?

#3 Post by Bruce Weldy » Fri Dec 29, 2017 4:45 pm

Forget the peak ratings. What is the RMS rating of the subs and the amps?

6 - T39 4-25" 2-22" 3012LF
4 - OT12 2512 Melded/NSD2005
1 - T24
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

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Bill Fitzmaurice
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Re: full rated handling or half?

#4 Post by Bill Fitzmaurice » Fri Dec 29, 2017 4:46 pm

We don't really concern ourselves with watts, because voltage swing is what matters. That's why we tell you the amp voltage output that your limiters should be set at to realize.

Reticuli
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Re: full rated handling or half?

#5 Post by Reticuli » Fri Dec 29, 2017 4:58 pm

Worry not. I'm not holding you guys responsible or anything for your recommendations. Don't worry about the safety of my cabs. These are class D amps rated like this with hard digital limiters. I had read on multiple spots on the net that when an amp is bridged it "sees" half the impedance of the sub or something. Now, I was confused if that was just why such an amp when bridged shouldn't be paired with cabs lower than 4 ohms (because each half of the amp sees 2 ohms and any lower would be bad) or if you end up getting twice the power total than you would think even from the bridge specs. So is each amp going to be peaking at 1600W @8ohm? Worse case, I'm sending the max rated peak handling into them accidentally occasionally (power supply limiting the continuous/RMS output and thus effectively thermal limiting with the class D amps) or the safer situation that I'm actually only sending half their rated peaks into them. I realize that RMS and thermal damage with crest factor concerns is the bigger risk to the drivers. Thanks.

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Re: full rated handling or half?

#6 Post by Reticuli » Fri Dec 29, 2017 5:22 pm

http://cdn-docs.av-iq.com/dataSheet//TR ... asheet.pdf

2X, and with Behringer inuke DSP 3000

If I"m running right up to the edge on this with two bridged inukes, then I'll probably usually only ever use one in stereo mode. I have three of these amps. I also have a pair of Labhorns, which I only use one of the inukes in stereo mode since their excursion limits are only like 72Vp anyway.

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Re: full rated handling or half?

#7 Post by Bruce Weldy » Fri Dec 29, 2017 5:25 pm

Don't mean to argumentative, but peak watts means absolutely nothing. That's advertising crap to make their amps look more powerful. RMS rating at the specified impedance is even suspect sometimes - that's why voltage is all that matters. Running even at RMS numbers can be distorted on some amps. The more important issue is making sure that the cabs get only what they can take by utilizing limiters - but that requires knowing just how much voltage the driver can take...and that's not the thermal rating - it must calculated based on Xmax.

Thermal limiting in the amp will do nothing to protect your speakers. Only very high-end amps have true brick wall limiting, the others have limiting that protects the amp, but not the drivers.

Tell us which speakers and which amps you have.

6 - T39 4-25" 2-22" 3012LF
4 - OT12 2512 Melded/NSD2005
1 - T24
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

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Re: full rated handling or half?

#8 Post by Bruce Weldy » Fri Dec 29, 2017 5:33 pm

Your post hit while I was typing.

The Behringer is probably fine in bridged mode for that sub. Since it's a direct radiator, you can hear it farting out and turn it down.

But beware that Behringer's ratings are a bit overzealous.... I have one of the iNuke 3000-4 amps for monitors. I put a volt meter on it and to get it to put out its rated power, I had to drive the front end into clipping..... So, measure - don't trust.

6 - T39 4-25" 2-22" 3012LF
4 - OT12 2512 Melded/NSD2005
1 - T24
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

Reticuli
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Joined: Sun Dec 01, 2013 3:24 pm

Re: full rated handling or half?

#9 Post by Reticuli » Fri Dec 29, 2017 5:36 pm

Bruce Weldy wrote:
Fri Dec 29, 2017 5:25 pm
Don't mean to argumentative, but peak watts means absolutely nothing. That's advertising crap to make their amps look more powerful. RMS rating at the specified impedance is even suspect sometimes - that's why voltage is all that matters. Running even at RMS numbers can be distorted on some amps. The more important issue is making sure that the cabs get only what they can take by utilizing limiters - but that requires knowing just how much voltage the driver can take...and that's not the thermal rating - it must calculated based on Xmax.

Thermal limiting in the amp will do nothing to protect your speakers. Only very high-end amps have true brick wall limiting, the others have limiting that protects the amp, but not the drivers.

Tell us which speakers and which amps you have.
I didn't mean to say the amp has a real thermal limiter exactly. But class D amps' power supplies effectively give you a kind of thermal limiting for your drivers' voice coils since their switching supplies can't put out massive continuous low frequency tones.

The limiting on class D amps is absolutely brick wall limiting. They all use hard look ahead limiters. The DSP version of the inuke series also makes these limiters adjustable. The dynamic EQ on the DSP version does allow you to fudge a kind of further, user adjustable thermal limiter of sorts by using the EQ and threshold and hold system if you want to do some wizardry, but I haven't messed with that much. I'm more interested in just knowing when my amp (or what its set at) is hypothetically even capable of getting to those limits. Then if I have crazy people (read that, future bass producer kids who don't know how to manage their levels, RMS, or know what redlining is) on my systems, I either adjust the settings, use less amplifiers, or babysit them the entire time.
Last edited by Reticuli on Fri Dec 29, 2017 5:57 pm, edited 1 time in total.

Reticuli
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Re: full rated handling or half?

#10 Post by Reticuli » Fri Dec 29, 2017 5:38 pm

Bruce Weldy wrote:
Fri Dec 29, 2017 5:33 pm
Your post hit while I was typing.

The Behringer is probably fine in bridged mode for that sub. Since it's a direct radiator, you can hear it farting out and turn it down.

But beware that Behringer's ratings are a bit overzealous.... I have one of the iNuke 3000-4 amps for monitors. I put a volt meter on it and to get it to put out its rated power, I had to drive the front end into clipping..... So, measure - don't trust.
Lets say hypothetically the Behringer is spec'ed accurately, would this mean I'd be right up against the subs' implied excursion capabilities (peak handling) or at only half when driven to max when bridged? My thinking is that if I'm right at the peak handling edge, then I'm potentially dancing around the thermal limits and I don't want to send the drivers to an early grave if some dope producer starts sending sine waves into it while compressing the hell out of things.

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Re: full rated handling or half?

#11 Post by Bruce Weldy » Fri Dec 29, 2017 5:59 pm

Well, the Berry claims to be 1500 watts at 8ohms bridged. The peak of the Cab is 1600 watts. Based on each companies ads, the match is pretty good. But, that really means nothing. If you are protecting your subs, they will never see that much wattage.

The cab is 800 watts continuous....that's 80 volts. Put a volt meter on the (bridge) outputs of the amp with no speaker attached and run a 60hz tone through it with the volume knob all the way up. Use the limiter to adjust the output down until it reaches 80 volts (I'd build in a fudge factor and stop at 75). Don't run it any hotter that that and you just might not blow a driver.

Could you possibly be leaving a little volume on the table? Yeah, but that's the smart thing to do. If you need to run on the bleeding edge - get more cabs and amps.

6 - T39 4-25" 2-22" 3012LF
4 - OT12 2512 Melded/NSD2005
1 - T24
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

Reticuli
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Joined: Sun Dec 01, 2013 3:24 pm

Re: full rated handling or half?

#12 Post by Reticuli » Fri Dec 29, 2017 8:09 pm

Bruce Weldy wrote:
Fri Dec 29, 2017 5:59 pm
The peak of the Cab is 1600 watts.
Where are you getting that?

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Tom Smit
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Re: full rated handling or half?

#13 Post by Tom Smit » Fri Dec 29, 2017 10:57 pm

Bruce got that from the link that you gave. http://cdn-docs.av-iq.com/dataSheet//TR ... asheet.pdf ...800 watts continuous.

iNuke 3000 https://www.parts-express.com/behringer ... --248-6706 400 watts RMS/channel at 8 ohm
TomS

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Re: full rated handling or half?

#14 Post by Grant Bunter » Sat Dec 30, 2017 3:09 am

BrentEvans wrote:
Fri Dec 29, 2017 4:28 pm
42.
Thanks Brent, this answer made my day...
Built:
DR 250: x 2 (melded array) with March 2012 plans.
T39's: 4 x 20" BP102 , 2 x 28" 3012lf.
WH8: x 3 with melded array.
Bunter's Audio and Lighting "like"s would be most appreciated...

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Re: full rated handling or half?

#15 Post by jimbo7 » Sat Dec 30, 2017 1:24 pm

BrentEvans wrote:
Fri Dec 29, 2017 4:28 pm
42.
Ah, the answer to the ultimate question of life, the universe, and everything else
BFM builds:
XF212
T24 BP102 24"
2x SLA's 6-5" mids, 9-gt-302's
2x AT 14" MCM 55-2421
TrT 5" MCM 55-2421
AT 18" JBL GTO804
2x OT12 flat array

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