Bridged the 400/4 puts out more juice. Sound quality and warmth is also superior. It also cost more and is bigger but I think worth it. The Xd line is awesome.

 

500/4 = cheaper, more power, weather rating designed for sleds and ATVs.

Negligible difference in SQ rolling down the road.

T.

 

T we're a JL dealer I use both lines on customer bikes. Really depends on budget and bike. On a RG the 500/4 fits in the fairing...the XD not so much. Now on my personal bike it's all XD line. We've tested both amps and bridged the 400/4 puts out more power and better sound.....its a more efficient amp and will put more out with less voltage required. There's plenty of amps out there that on paper have higher numbers than the XD line. The Diamond micro series is one that comes to mind but a 400/4 bridged spanks it because of its efficiency. Also if weather rating is a concern I'd recommend the Marine rated XD version.

 

Interesting. What test equipment do you use?

T.

 

I can vouch for these XD's. I have a pair of the 200/2v2's and love them. I even got one to fit in the front fairing.

 

my reason for going to the mx micro instead of xd. space

 

Amen brotha!!! This is a MASSIVE determining factor.
At the end of the day JL makes damn solid amps!!! I run the marine 400/4, 600/6 and 600/1 in my floating recreational vehicle and they are killer amps, but space is not an issue.
The 500/4 is reliable as hell and really is designed for the dudes that ride their sleds. Put the damn think in, tune it, put the tuning cover on it and get on down the road.
Also think it's a perfect fit for the AWs. U can run 185-195 all day long with very good head room bridged 250/2 at 14v.
To each their own but JL just makes great shix so the OP just needs to define his parameters and go from there knowing he will be making a solid purchase with the 400/4 or 500/4

T.

 

👍👍👍 i bet i could get 3 of those 500/4 under the hood if i took my time
one of these days im gonna build custom inner fairing uprights, that will open a whole new "fairing amp" scenario

 

T -- the advantage of having an award winning shop is that manufacturers will send guys to you. We've had techs from both JL and PRV to our shop. The thing with the XD line is that it does more than rated with less input voltage which is awesome for bikes. We used a volt meter to measure both tone and musical, loaded an unloaded. We also drained the batteries below 11v and the XD didn't skip a beat while the MX began to clip. We like the MX amps a lot and they are top in their class, but if you walked up to me walking down the street and asked me which one is better without hesitating I'd say XD line --- it's a tier up in the JL line. For a two speaker set up on a SG I wouldn't think twice about it. After spending 20k + on a new bike, and another who knows how much on the audio, pipes, bars, etc. might as well spend an extra 80 bucks and get the best JL has to offer. Size on the XD does suck though for the guys on the Rushmore RG's and for those guys we use the MX. So yeah I agree, they are both very good at what they do and if price or size constraints are a concern the MX is a good 2nd option. In that size and price range I like them over most other ones I've tried. The MMats sounded good, but build quality on the MX is better. The D4 is good too...very warm and cheaper, but it's a tad bigger and doesn't play as loud.

Yoop you asked me the other day over PM and I told you the same. Don't use the MX line for what you were trying to do. I think if it came down to needing to put three MX inside the fairing we could probably find you a better solution brother! Now, if you are going to mod the outer fairing I've seen a bike with two XD 800/8's stacked on each other inside the fairing!!!

 

I too have been pm'ing you lately about the JL amps. Since this is a JL amp thread I will ask you here. Does the XD 400/4 come in a marine version? I could only find the XD600/6 in a marine version.
Just to see if I have this right, you would also rather run the XD 400/4 over the MX 500/4 in a street glide 2 speaker set up? Is there enough headroom? I will be buying 2 JL amps soon from you but I want to do my homework first.
Has the XD400/4 been discontinued?