Hello, new guy here. Thanks to anyone who takes the time to read this and post a reply, it is much appreciated as I'm racking my mind for the last 2 days. To make a long story short, i recently bought a budget system. This system includes a Rockford Fosgate R250X1 Prime 1-Channel Mono Block Amplifier, 2 Rockford Fosgate Prime R1S410 R1 10-Inch 150 Watt Subwoofer - 4 Ohm, a ported Bassworx box and a Kenwood KDC-MP345U HU. (found out later the subs are not recommended for a ported box) This setup ran very well for the first week. The subs had very natural sound and didn't take much to make them hit well. The punch EQ knob on the sub wasn't used, just the remote knob at the helm. Gain just about half way. Hz on head unit set at 85 (turned all the way up on the amp so to bypass it). Ok, so decided because the amp is stable at 2 ohms i'd give a try wiring the subs in parallel and get a lil more power to them. The way i ran it was amp+ to SP1+ to SP2+ then amp- to SP1- to SP2-. Once everything was hooked up i turned it on and played the typical music i play such as BassNectar or DeadMau5, you know tech stuff. Instantly i noticed there was a significant loss in sound quality, the subs sounded like they were hitting a brick wall. I backed the gain down a lil and no matter what i couldn't get them to sound very good, i was prepared for small loss in sound quality as i had read this prior, but this was ridiculous. I went and rewired the subs back to 4 ohm or a typical dual sub box wiring. Hooked back up and ready to thump aaanndd notta. The subs and amp had power, the subs made bass but nothing like it was previous to my rewiring. So thinking i wired out of phase, i took it all back apart and rewired again taking special care in everything i did, same. This morning, thinking i may have damaged the amp, i returned and replaced with a brand new one, no luck same sound. So to put it in to perspective if before my 2 ohm wiring i could turn the HU to say level 18, it pounded! Clear crisp bass that rattled my mirrors all over the place. To now when i put the same level on i get maybe half the bass. I've checked and rechecked my ground, power cable, rca's all of it. I spoke to a Rockford tech and his idea might be that for whatever reason giving them that extra power in a ported box may have caused them to go into over excursion. Well that's the story if anybody could give an idea that'd be great as of now i'm thinking i may need to just buy new subs. Better ones obviously.