I was just wanting to share my latest setup and maybe help someone else looking at some of these pieces. I have been trying a few different things to see what my ears liked and also, just to try. I had a Soundigital SD400.4 bridged to 2 AD Designs CX621's and another SD pushing 2 MMAT PA601.4's. I had an inline 100Hz filter going to the MMATs ( I know a DSP would have helped). The AD's loved the SD amp. They flat screamed and had a great sound. With the SD fixed 80Hz crossover, it did fine. The MMAT's, however, never really sounded great with the SD amp, even with the inline filters, I just couldn't get them to sound like I thought they should. I also tried SD amp with the ADs paralleled and the MMATs paralleled and ran them 2 ohm. ADs to channels 1 and MMATs to channel 3. This actually didn't sound too bad but not as loud as with both amps. On to now. I changed the SD amps out for an MMATs MD4100. I started with all four one to each channel, MMATs started waking up but now the 4100 just didn't seem to push the ADs like the SD had. So now, I have the 4100 with 2 channels going to the MMATs and ran the ADs in series and then bridged channels 1 and 2. This setup is loud. My goal was to setup all 4 on one amp and have it clean and crisp. It's starting to sound like I wanted it to. I'm going to ride this tomorrow and see how it does at speed. Next step may be the MMATs on the 4100 and the ADs on the SD. I am very surprised at this little MMATs amp as well as the Soundigital. Both great amps and fairly priced.
I want to thank Gann for all of his help with this. He has been a patient man and no way could I have done this without his help. I did go out on my own with this last setup so if someone has any input or advice on the setup, I would greatly appreciate it.

 

Hey Stric, sounds like your on the right track...another post that seems to prove some amps and speaker combinations just sound better when used together! Keep us updated with your progress!

 

Thanks Moto Mike. Overall, the MMATs amp did great. I could hear everything clear at 80 with volume at 10 and a full face on. The wife said it sounded great on back as well. If I decide to put the SD amp back on the ADs, I'll report back.and let you all know.