Now you've just got thermal compression to deal with 😉
I've been meaning to read up on the power handling tests but don't be surprised if it's not quite as simple as it seems ... you just can't dissipate that much heat from the voice coil once it's inside a sealed box.
You're right though, the best way to have a system is to have the weakest link as the final stage. The first sign of reaching a limit should be the speaker, not clipping in an electrical stage.
The sealed sub box options I looked at earlier i.e. sealed / 2 x PR are now off the table. I will now be looking at a BR with a big port, or a TH in about 500 liters.
I don't know of any studies on it, but I don't believe a vented alignment (ported/horn) will significantly impact thermal compression or thermal modulation. Getting heat from the voice coil in practical/real world conditions will still be a more real limitation than the datasheet specification suggests on face value.
You would be inclined to think that a driver with voice coil/s exposed closely to a big opening would have to have a far better chance of cooling than many other options.
Ideally the mouth would be at the top of the cabinet to best vent the hot air.
Ideally the mouth would be at the top of the cabinet to best vent the hot air.
Fairly well sorted with driver and amp with both now purchased, I just need to build the box. I also know what sort of enclosure I want to build, so I just need to get the design sorted.
The I-Tech 9000 HD can put 1500 per channel into 8 Ohms, that tells me it must have higher rail voltage than XTI6002 (that has same output topology, but can only put out 1200 per channel). So far so good. More expensive amp - higher rail voltage (I guess it is around 2 x 175Vdc, if the questionable "2 x 3500W into 4 Ohms" is actually correct - but then - it should be 2 x >=1750W into 8 Ohms... !?)
Now consider that: On 4 Ohms bridged, they state higher output for XTI6002 (6000 vs. 5600 W "Minimum Guaranteed Power") - and that is exactly your application. The argument with the weaker power supply on XTI is therefore actually not true - at least not in this 4Ohms bridge application (On 8 Ohms bridged, IT9000 would win big time, but that is not the game here). So the cheaper one could have maybe done your job as well, since on 4 Ohms bridged you do not see a big benefit from the higher rail voltage, that can push 8 Ohms better.
Now consider that: On 4 Ohms bridged, they state higher output for XTI6002 (6000 vs. 5600 W "Minimum Guaranteed Power") - and that is exactly your application. The argument with the weaker power supply on XTI is therefore actually not true - at least not in this 4Ohms bridge application (On 8 Ohms bridged, IT9000 would win big time, but that is not the game here). So the cheaper one could have maybe done your job as well, since on 4 Ohms bridged you do not see a big benefit from the higher rail voltage, that can push 8 Ohms better.
Agree on a theoretical on paper power shoot out they might be head to head but here was the big clincher for me... "Guaranteed minimum power in watts at 20 Hz-20 kHz with 0.35% THD", anytime you got near the max on the 6002 that figure went to a full 1%.
There were several other reasons for going with the 9000. It is capable of doing 2 ohm bridge where the 6002 only 4 ohm and taking the advice given earlier about allowing some head room for the sake of the amp.
Also the DSP side of things is much more advanced, and considering I am trying to squeeze the most out of the driver safely, the more options the better.
I wouldn't right off the idea of using the 6002 if I decided to put my 2 Pro 5100s into sub boxes, as that is a whole different configuration.
There were several other reasons for going with the 9000. It is capable of doing 2 ohm bridge where the 6002 only 4 ohm and taking the advice given earlier about allowing some head room for the sake of the amp.
Also the DSP side of things is much more advanced, and considering I am trying to squeeze the most out of the driver safely, the more options the better.
I wouldn't right off the idea of using the 6002 if I decided to put my 2 Pro 5100s into sub boxes, as that is a whole different configuration.
In my experience the Crown IT HD series are very good at delivering long term power and meeting their ratings. You wont regret spending a bit more and knowing you did not leave any of the 5400 driver's prodigious performance unmet. The 12000HD did very well in my testing. Comparative Performance - SpeakerPower
Efficiency could be higher, but in your application it may not be important. All these super power amplifiers are best driven from 208-240VAC.
Efficiency could be higher, but in your application it may not be important. All these super power amplifiers are best driven from 208-240VAC.
That seems like a somewhat biased test (not to mention the 12000 isn't a class D amp it is class I) with the only positive comment being made about the SpeakerPower amp.
I don't tend to put much stock in a specific manufactures own test, but having said that I did think about buying the SpeakerPower plate amp.
We originally ran on 240v, but was officially regulated back to 230v about a decade ago to fit in with Europe, but we are still normally at > 230v.
I don't tend to put much stock in a specific manufactures own test, but having said that I did think about buying the SpeakerPower plate amp.
We originally ran on 240v, but was officially regulated back to 230v about a decade ago to fit in with Europe, but we are still normally at > 230v.
Last edited:
"It is capable of doing 2 ohm bridge where the 6002 only 4 ohm and taking the advice given earlier about allowing some head room for the sake of the amp."
2 Ohm bridge equals 2 x 1 Ohm stereo (with one channel inverted). I couldn' t find info about this mode.
2 Ohm bridge equals 2 x 1 Ohm stereo (with one channel inverted). I couldn' t find info about this mode.
since both the amp and driver are already purchased, there's no point in further discussing about the amp choices, no?
- Status
- Not open for further replies.