When Marineland revamped their line a few years back - I noticed the change in quality of the filters produced. Since I had older ones at the time (about 2006) I didn't think anything of it, mine were quiet and working fine. I sold my tanks and 'quit' the hobby for awhile due to family issues. I sold my last tank to a friend actually, and she still has it running without any issues with the two old Emperor 400 filters. I was first sold on the Emperor 400 filters by a LFS (now closed) back in early 1999.
When I got back into fish again, I bought Emperor 400 filters again, this was early 2010. I couldn't get them quiet like the old filters had been. The adjustment pull for the flow in the middle back was no longer there, it was solid plastic now at full flow. In the past if there was ever a noise I would just give the lever a little tug and it would straighten out, so I thought maybe I had some bad filters by accident. I found that bumping them did quiet them for a minute, and if I put a brick on the top they ran fine again - but having a brick up there was scary too. I complained to Marineland, they sent replacements, but I still had the noise. This continued for awhile actually, customer service was at least nice, but the quality started showing itself. In total, I had received and tested 4 Emperor 400, 1 Magnum 350 Pro (couldn't even set it up, the impeller was broken inside it when it arrived), and finally I settled on 2 Penguin 350 filters. All the HOB made more noise then any of their older designs. I modded the Penguin 350 by cutting the plastic on the impeller housing and taping the lid on, and then modded the 400s too. I have since sold all of the filters. I started running the Aqueon 75s on the tanks, but now after about a year, they have become noisy as well. In the past few months I was able to pick up an old Emperor 400, beat up like heck too, and after a good cleaning, it runs like new again - and quiet.
This issue doesn't only affect these filters in the company either. I bought a 10 gallon Marineland kit (it was on sale) for a QT tank. It came with a Penguin 100. After setting it up we noticed right away the noise again. A trip to a LFS that sells used equipment and another old Penguin 170 later, and the tank was quiet again.
Since this happened I have been searching for some HOB filters for my two 75g tanks that aren't in a place to run canisters since they have the (now) noisy Aqueon filters on them. I have been looking at the AC 110 for a long time, but until the sale recently (plus a bit of tax return money), I haven't been able to afford them until now.
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