I recently acquired a pair of evo2 gen II amplifiers that I running in mono mode to drive a pair of Energy VERITAS 2.4I speakers. Warmed up amps for two days, using rca interconnects from my Denon 4520ci pre-amp section to each amp, and made sure speaker connections are correct. Amps work up until the volume is raised and there is a drama sequence in the music that cause the amps (both amps) to go in protection mode briefly. The amps will go in and out of protection mode unless I turn the volume down. Now, the volume levels are not all that loud and I can drive these speakers a lot harder with my Denon rated 150 watts into 8 ohms. Do you know of any problems with your amps driving the Energy VERITAS 2.4I speakers? I know mono mode of the evo2 is rated for 400watts which is higher than the manufacture specs for these speakers (250 watts), but I thought it would give the speakers more head room to play with. My problem is I don’t know if there is a problem with the speakers (suspect crossovers) or the amps. I will however note I did attach a pair of Klipsch RF5 speakers to the amps and they seemed to not put the amps in protection mode, however they are really, really efficient speaker ( Sensitivity of 99dB) and I can’t tell if the speakers are really calling on the amp power source like the Energy speakers ( sensitivity 90db) might be doing. What causes amps to go into protection mode intermittently? Is there any reason the crossovers would make the amps think power is going to ground and enabling the protection circuit? I see nothing in the crossover diagrams that would suggest an over load protection for the woofers or tweats. All the woofers seem to be in good shape and work fine with 150 watt applied to them, although they are seriously lacking and I feel it is because they are under power by a 150 watt Denon. Any thoughts?
The evo2 is a Class-D (or similar) amp. They sometimes don't like complex loads such as your speakers.
Really, so Class-D amps don't work well with complex loads Hmmmm. What makes the Energy 2.4I so complex? I am a newbie in the Audiophile world and got such a great deal on these speakers (750$) and really want to find an amp to drive them correctly. Thought I hit a home run with the Bel Canto amps since I am not a big fan of all the cons of running a class A amp (heat, recapping, high price, exspensive to run and long warm ups). Seems I am on the path to figuring out what is going on (thanks to 6L6), after the holiday I hope to get a hold of the tech support at Bel Canto to maybe shed a little light on this problem. Energy tech support is totally useless since Klipsch took over, basically read me the spec sheet over the phone, lol.
Any other theories out there? Tough problem with not much info on the net. It is too bad so many HIFI companies are tanking because was one goes down, so does all the customer service and knowledge.
What about bi-amping those speakers. Try the class D amps for just the woofers, and something else for the mid-tweets.
jeff
jeff
Great idea Vinykid58! Ok, so I hook the amps mono blocked to just the low freq. post on the speaker and still same problem, bummer. (Sounded absolutely horrible btw) These speakers must hate class D amplification or there is something wrong all together. Is anyone out there running Energy's Veritas speakers with class D amps?
Despite the amp being rated for four ohms in mono mode, the Energy's look like they are a pretty low impedance load over quite a wide range. That might be enough to trigger the protection circuitry.
An externally hosted image should be here but it was not working when we last tested it.
Have you tried running one amp in stereo mode just to see if that works? If it does, try running the amps as a 'passive biamp', one amp per speaker, one channel for the woofer and one for the tweeter, using a splitter to drive each channel of the amp with the same signal.
Try running one amp for left and right not bridged. I don't know what type of filtering the amps use but it may be interacting and in mono mode my double it. Class D amp have to filter out high freq. content of it's operation.
I'd have thought this very obvious. The low impedance of the speakers is triggering the protection of the amp, which only reaches a suitable threshold when the levels are raised. If you can run bi-amped then stop running as monoblocks, it may help. If not it's a case of xo mod time
Using the one Bel Canto evo2 to drive the both speakers I have no issues. Seems to not trigger the protection circuit in the amp. However, that cuts the wattage down to 120w to each speaker. I will give Bel Canto tech support towmorrow to see if all is good on run the amps in "passive Bi-amp" and to see if anyone else has this problem with certain speakers with their amps. BTW you all have been really great in helping a newbie out with this HIFI confusion, I can't thank you enough. Even though this has been a little of a bummer but it has inspired me to maybe dig deeper in the mod world of speaker tweaking, LOL.
Contacted the Bel Canto tech and we both agree that the low impedance of the Energy 2.4I speakers is triggering the protection circuit of the amp. Can run in passive bi-amped, so I am able to make these amps work, however I would like to mod the xo to fix this problem and improve the xo resistors and caps. If anyone, has done this with positive results, I would greatly appreciate any advise you may have to offer.
Changing the crossover components will not do much to the impedance curve. To keep the crossover at the same operating point the values will need to be the same, and the sustained low impedance will be unchanged. Changing values will result in the crossover points changing wildly for the worse, with similar effects to the sound.
It seems you have a choice to make - which piece of the system to keep and which to replace? The Speakers or the Amp?
It seems you have a choice to make - which piece of the system to keep and which to replace? The Speakers or the Amp?
Why would you need any more than 200W at 4Ω (which is what these speakers are about)? The mono mode of the evo2's is (almost certainly) bridged mode, but that doesn't bring you any more current capability. Obviously the amps are well protected by a kind of smart circuit that monitors current output related to voltage output.
The only thing that would make sense is to run both end stages in parallel mode with these speakers, but that's not a standard option on the amp I suspect. So sell one amp or connect the end stages in parallel manually (but that could require some tweaking on the amp's circuit).
The only thing that would make sense is to run both end stages in parallel mode with these speakers, but that's not a standard option on the amp I suspect. So sell one amp or connect the end stages in parallel manually (but that could require some tweaking on the amp's circuit).
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