I did not realize it at the time, but when I had the J&M ROKKER StreetGlide at IMS show in Cleveland OH, one of the attendees made this you-tube video http://www.youtube.com/watch?v=Z-JmrkFM-A8 ,,,

 

John,

I just ordered the 250 watt amp and speakers (reordering the Rockers-just found out about them) from the good Dr. What are the differences between the different batches of Amps? Is there a Rocker Amp?

 

snowman ,,,,

funny you should ask this ,,, I just wrote this response below for another thread here on hdforums ,,,,

we appreciate very much your business ,,,,

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I am not going to try and blow any smoke here ,,,, so here is the REAL skinny on the J&M amps, and 7.25" speakers ,,,,, both standard and ROKKER series ,,

the J&M amplifiers have the HIGHEST ""per channel"" RMS output of ANY amplifier available for your Harley ,,,, 125w RMS continuous into a 2-ohm load ,,,,, and they will produce better sound, at higher volume levels, from your Harley fairing than most riders have ever heard before ,,,,

does not matter if it is our 2-channel amp or our new 4-channel amp ,,,,, the power output ""per channel"" is the same ,,,,, 125w RMS,,

"I" am personally involved in setting the gain controls on all of the amplifiers we sell, and also monitor the installation and gain control settings at most all of J&M's trade shows across the USA ,,,,,

two weeks ago during Bike Week in Daytona the J&M crew installed speakers and/or amps into over 94 Harley Baggers in 8 days ,,,,, and I supervised the gain settings on the 48 total amplifiers that were installed ,,,, this way I get a "feel" for what works well and what does not ,,,,,

one of the reasons we error on the LOW side when we set these gain controls at our factory in Tucson, is that riders don't realize that DISTORTION is what damages a speaker, not output power ,,,, and I can PREACH till I am blue in the face about the Harley HK radio's AVC control, but most riders just let it go into one ear and out the other ,,,,,

this AVC control must be turned OFF ,,,, otherwise, the rider will crank up the volume nice and loud while first taking off on a ride, then the AVC control in the Harley system will drive the volume up very high at say 75-80mph, way up into significant distortion levels for sometimes hours on end, and the rider cannot HEAR that this distortion is happening at high speeds ,, because of all the other background noise ,,,

do this often enough, and long enough and speaker damage WILL result ,,,,,

the J&M ROKKER series speakers will put up with these high distortion levels for a longer period, but even the ROKKERS can be damaged if high power & high-distortion levels persist for a long enough period of time ,,,,,

so in summary ,,,, what is the best way to set these gain controls ? ,,,, there is no ONE setting, as there is an amount of gain control variance from one LOT or BATCH of J&M amplifiers to another ,,,,

so at the risk of confusing the user more than we already have ,,,,,

1 ,,,,, start by turning both gain controls to MINIMUM (fully counterclockwise) with the fairing clamshell off the fairing of course ,,,,

2 ,,,, grab a real good pre-recorded commercial CD with some high intensity rock-n-roll from the likes of AC/DC, Metallica or Nickelback to name just a few ,,,, ((stay away from the bunga-bunga-rap for setting the gain controls)) ,,,,,

3 ,,,,, now crank up the volume on your Harley HK radio system to around 2-3 little blocks BELOW maximum on the display ,,, then slowly increase both the left and right gain adjustments on the amplifier until you start to hear significant distortion, then back off just a smidgen ,,,

4 ,,,,, do NOT pay any attention to the bass response at this point, because the fairing clamshell is off, and without it, your open-fairing acoustics are very poor ,,,,, just pay attention to gain control adjustments at this time ,,,,

5 ,,,, then reassemble and go for a ride to enjoy ,,,, making sure that the AVC is set to OFF ,,, and cranking the volume to maximum BEFORE distortion while sitting still, noting the actual volume level in the display ,,,

then just don't crank the volume any higher on the LCD radio display while you are moving, that way it will never be driven into distortion ,,,,,

more questions ?? ,,, send email to me at john@jmcorp.com ,,,,

 

On the screws stripping issue, I had the same problem. The screws supplied with my kit were too long - period. I had to go the hardware store and get some that were an 1/8 or 3/16" shorter - can't recall for sure. The vendor I bought them from, Custom Dynamics, was willing to assist in finding the right screws. They even followed up with me which I appreciated, but the bottom line was that the screws were not the right length as they came in my kit. It was just a lot easier to get shorter ones from the local Ace and be done with it.

 

Indy Road ,,,,

which screws are you refering to ?,, the ones that hold the speaker adapters to the fairing or the ones that attached the speaker to the adapter ? ,,,,

 

Thanks! You have mail too..

 

so ,i have the older style 7 1/4 in my fairing, i wanted to put the 500 watt amp in with the lower fairing kit,can this be done or do i have to use the rokker speakers to use the 4 channel amp? will the lower fairing kit have the rokker speakers? is it ok to have the rokkers on the bottom and the standard on top with the 500 watt amp? i have been waiting all winter to buy this lower fairing upgrade. Bill

 

solowrider ,,,,,,

yes, yes and yes ,,,,,,

the new ROKKER series LOWERS speakers with housings will be available with the ROKKER series speakers only installed ,,,,,, but you can use the standard 7.25's up top in the fairing, with the ROKKERs down below without problems ,,,,

I am also going to offer a trade-in program shortly, for those riders who want to just trade their standard 7.25" J&M speakers, for the ROKKER series, including the new J&M ROKKER grills ,,,

should have that $$$ for trade-in put together by the end of the week ,,,,

 

I have ran a few sets of speakers in my Harley, MB Quart, Polk, Hertz and J&M.. I have been involved in Car Audio for over 20 years and own some very nice home audio gear as well. I know what good audio is supposed to sound like.

I believe the J&M 7.25" speakers are mid-fi at best. They offer a slight uptick in sound quality to the factory speakers, a better bass response but kind of a muddied mid-range. The three way driver is the likely culprit here.. I have three way components in my '73 Challenger, AVI Tri-Star BSM's, they are driven by a 500x2 Arc Audio Amp.. Lemme tell you, you want audio Nirvana, this is it, too bad this setup will not fit in our fairings and it'd be a total waste in the open air environment of a motorcycle.. Anyway.. The 'mid' in the J&M 7.25" is not physically big enough to produce the sonic impact of the frequency range it is crossed over at. That's why the mid sounds flat to me at least. Pay attention to how a snare drum cracks on the J&M's and a nice set of 6.5" components. Night and day I tell you.

I have an Arc Audio mini amp in my bike and when I use it to drive the Hertz 6.5" speakers it sounds MUCH better than the J&M's... The midrange is much more detailed, yeah I lose a little bottom end but the fact remains that the overall Sound Quality is MUCH better and LOUDER than the J&M's. Anybody wanna buy some J&M 7.25" speakers? I am going to be looking at some Morel components next.

 

sublime ac ,,,,,,

I appreciate your comments on the J&M 7.25" speakers ,,,,, and you are right-on about the somewhat poor acoustical environment for speakers in general, inside the Harley Fairings ,,,,

the new J&M ROKKER series 7.25's address that specific midrange issue, with a more accurate passive crossover network and higher output midrange and tweeter drivers, mounted on the ROKKER series grills ,,,,,,

These new ROKKER 7.25’s will stand up very well in a comparison with Hertz's best 6.5's ,,,, and the J&M's provide better weather proofing for the motorcycle environment at the same time ,,,,,,,

The J&M ROKKER series speaker kit also includes the acoustic foam pads for inside the fairing to help improve those acoustics, SS mounting hardware, etc ,,, all in a specific lightweight design for your Harley fairing ,,,, WITHOUT the extra heavy weight of the Hertz 6.5’s ,,,,,

When you look at the complete speaker PACKAGE from J&M, I think you will find it superior to anything else currently offered in the marketplace for your Harley ,,,