Amplifier Suggestions for Dual Ultimax 15 Build Feb 5, 2019 23:31:39 GMT -5
Post by Afford-HiFi on Feb 5, 2019 23:31:39 GMT -5
The Crown was delivered yesterday and I was able to get it hooked up today. Out of the box I was very impressed with it cosmetically. I was shocked at how light it is compared to any other amplifier I have ever used.
I am hoping that I can continue with questions on this thread, if not please let me know and I will start a new thread. I am having trouble with the settings on the amplifier. I currently have it hooked up to my Marantz SR5011 via RCA to XLR cables. I have the amplifier set to stereo with each channel to one UM15. I have the input set to .75 and each channel is also set with a LPF at 80hz. Immediately after hooking the amp up I could see and hear it was powering the subs but it was highly underwhelming. So I then did a calibration with the amp set as described above and the gain at 50%. During the calibration, and in comparison to the other channels the subs gave out little sound. So much so that after the calibration I checked the levels and it showed the subs were sitting 8’ further than the LCR when in reality it’s the same distance.
I then set the amplifier gain for each channel up to 75% which obviously improved the power output but the amp continually showed clipping. I scaled that back and adjusted the sub level on the marantz and again it improved output but would show clipping during any bass heavy scene. At that point I switched the input to 1.5 and the output was cut in half.
This is as you know my first time playing with a pro amp, let alone playing with a pro amp for HT so I am guessing I am doing something wrong. I simply cannot believe that this amplifier would be so easily shown up by my old Dayton SA1000.
Any thoughts or input would be greatly appreciated!
Hello again Everyone!
It’s been a while since I posted so I wanted to give you an update. Shortly after my last post (quoted above) I ended up exchanging the Crown 2502 for two 1002. I know I had some work to do to get the 2502 where it should have been but the store I purchased it from put the 1002s on sale and I could get two of them for the same price as one used 2502. So, I figured I would go ahead and swap for the new amps along with the additional power bridging each to one Ultimax. I know that THD can go up in bridged mode but since it’s for a sub I don’t think this will be an issue.
The 1002s are now here and while I am getting more power I still think there is an issue with my set up. My amplifiers seem to clip relatively easily and after some reading I am thinking it could be related to the voltage it’s seeing from my Marantz. Despite the selectable .75 / 1.5 v option I am thinking of getting a Art CLEANBoxPro to ensure I’m matching the correct input voltage. Additionally, I am currently getting some hum through the drivers and I am hoping this will clear that up as well.
Do you guys think this would resolve the issue or do you think I should look at something else?
As always, the input is greatly appreciated.