chgokid61

Just had istalled a Kenwood Excelon 715 headunit, Xtant 403a amp, Xtant 5 ¼ components in the front and Xtant 6 ½ in the rear deck. I asked the installer to wire up the amp for a future sub because I wasn’t sure if I needed it or not. Well, I need it. I can’t believe how the mids and highs come through, but da bass blows. I decided to get an Image Dynamics 10 inch IDQ. Here is my problem: I’m getting conflicting stories on how many ohms I can/should run the sub at. My installers tell me get a 4ohm DVC, which would run the sub at 2 ohms and double the power from the 1 channel rating of 100 @ 4ohms to 200@ 2ohms. I was concerned about running this amp too hot on five speakers, but the installer tells me the Xtant should take it fine, its “2ohm stable” (not sure what that means). Yet I call Xtant, and the techy guy tells me the running at 2ohms would be too hot for the amp. Anyone out there have any thoughtful answers.

Thanks<p>98 2.8QM Pearl White A4, Sachs Sporting Kit, Bosch Eurolights, Wett chip, K&N, Friction Tech Brake Pads

siberian

Hey,

I got your voice mail this morning.... sorry I didn't get a chance to call you back yet.

Anyway, I was thinking about your question on the amp. I whipped out the trusty old Xtant catalog showing the ratings. Yes the amp is 2-ohm stable.... which more or less in layman's terms means, it won't blow up on ya if it see's 2-ohms. If you're going to run the whole system off that amp it might work, but I'm not sure that you can run the rear speakers and the sub off the same two channels. You might... and I emphasize, MIGHT, have to switch the rear speakers to the front channels #1 and #2... so basically you would be running the fronts and rears off two channels... and I believe they would be in 2-ohm stereo. (well within the capability of the amp) If you do that, you should end up with 100 watts each, but you'll lose fader control. If you normally keep the fade control centered, then this might not be an issue. Now the rear channels (3 and 4) are free to power the sub. There's a couple of options there for you.... of course, one being a 4-ohm DVC at 2-ohms mono- for a total of 200 watts.

Somebody correct me if my math is wrong!

Now, as for the heat.... well, it's probably gonna get hot- especially if you crank it. I know the Xtant's are pretty durable and beefy, but that is the "M" series, which does not have a built in fan... unlike the X series. It's a tuff call. I don't know that I'd risk it. Plus, you probably wouldn't have much head room... meaning... if you are listening to something that has a lot of transients in the music, a particularly loud part might really stress the amp.... and it'll sound thin and weak.... not good!

Honestly, here's what I'd do... shell out another $250 bucks and get another amp... the 121M. (yea, I know it's easy to spend someone else's money!... but that's really the best way to do it)It's a one-channel mono amp- rated at 250watts at 2-ohm.... plenty of punch for a good efficient sub. Then you won't be "pushing" the 404M to it's limit, and you'll have plenty of head room. Get a DVC sub and you're set!

Hopefully they ran 4-gage cable and an extra RCA for the sub output when they installed the 404M. If so, then it sould be an easy drop-in. If not, well, still not a big deal, they'll just have to re-run another cable.

I'll try to call you.

siberian

Andy, forget my last post... I thought you bought the 404M. (next time I'll learn to read!) I noticed that right after I posted last night and tried to correct it right away but my network went down and so I gave up.

Anyway, the 403A was made for just that. It's stable at 2-ohms so I don't know why the Xtant guy thought it would be too hot. I believe that amp has a built in fan too. I know the X series does for sure. That seems strange.

Talk to Foo. He has an Xtant setup in similar fashion.. and I was planning on running mine the same way (In fact I might get the 403A as well).

siberian

just curious.... what did you pay $$$ for the 403A??

Thanks...

BTW, those rims we talked about Ronal R-28. size 17" by 7-1/2"
The tires are Sumittomo HTRZ II
size 235-45R17. Slightly oversize o.d.

chgokid61

Paid $629 at ABT, 70 bucks off of full retail. Whoopee. What a deal. I'm sure if I found an e-tailer selling it, I would have saved several hundred. On the plus size though, I get a 4 year warranty instead of 1 for buying it and having it installed by an authorized Xtant dealer.<p>98 2.8QM Pearl White A4, Sachs Sporting Kit, Bosch Eurolights, Wett chip, K&N, Friction Tech Brake Pads