Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[JMJOHN]

The audio system listening environment on your Harley Bagger is quite different from your auto or home system.

When listening to music inside your home, apartment or automobile, you might crank the music up quite loud at times to enjoy your favorite sound tracks, but usually not too high, to a point that the music distorts, because unless you have had a “few too many”, the music just plain sounds BAD when turned up to high distortion levels.

Distortion is what damages a speaker, not necessarily high power levels. You can connect a speaker with a 50w max power rating to a 250w per channel amplifier, and if you don’t crank it up to high distortion levels, it will play just fine for many years.

Conversely, you can take a speaker rated at 250w max power and connect it to a 100w per channel amplifier, and if you crank it up to high distortion levels for hours on end, the speaker will be damaged or blown in a short amount of time.

On your Harley, when listening to music on the highway, especially at high speeds, it is impossible for most riders to be able to actually hear when the volume is cranked up too high, to a point where the music is distorting,,,, we just ride down the road happily listening to very loud distorted music, hour after hour and then wonder why in the hell our speakers and/or amplifier are damaged in a short amount of time.

This distorted listening scenario on your Harley would be equivalent to sitting down in your living room, turning on your 1000w Macintosh powered 5.1 Dolby digital surround sound system, with twin JBL towers, powered separate subwoofer, and cranking the volume to maximum on the dial, pushing all speakers way up to high distortion levels ,,,, then walking out of your house for a couple of hours, only to come back and see what is left of your audio system and speakers.

This is exactly what many of us are doing to our Harley Bagger audio systems.

THEN you have to go thru the hassle of taking your fairing off, diagnosing what is blown-up or damaged, getting replacement parts from the various manufacturers, (some under warranty, some not) reinstalling everything, only to go out and do the same thing all over again!

Now I think I am just like all of you ,,,, I want THE BEST possible performance out of my Harley Bagger audio system, period. I thoroughly enjoy my favorite music while I ride and if I want it loud, I want it loud, regardless of how fast or slow I am going.

To accomplish this without burning the system down every time you ride at high speeds, it is absolutely essential that the amplifier gain adjustments, on your high powered audio amplifier are properly set.

Use the guidelines below for the J&M Corporation brand high-powered amplifiers for the Harley Bagger audio systems. ((these guidelines may also apply to other brands of audio amplifiers used on your Harley))

You want to first adjust the amplifier gain controls to minimum, bass boost (if equipped) set to minimum, crossover switch to the FULL position.

Then slide a good commercially recorded CD into your radio, (Harley HK or automotive type replacement) and crank up the volume to maximum ,,,,, as far as it will go.

“IF” you get distortion on the song track BEFORE you are able to crank the handlebar volume to maximum, you will need obtain the correct HK-Radio-to-RCA jack, isolated input signal adapter from J&M before you can continue, so that you will have a useable range of control on the gain adjustments of the amplifier.

If you are using an automotive type replacement radio in your Harley, make sure that you are connected to the amplifier, using a direct RCA-to-RCA jack cable harness.

Then, with the handlebar volume adjusted to maximum, without hearing distortion, carefully adjust & increase the amplifier gain controls for each channel, to a point “right-before” distortion is heard, but not any further.

This way you will be able to crank the music volume all the way up to maximum on the highway if you want to, without worrying about damage to your speakers or amplifier.

With the amplifier gain controls adjusted in this manner, you will also be able to fully utilize the AVC control on the Harley HK radio.

I am available most days of the week, at John@Jmcorp.com  if you need assistance/recommendations when building or tuning the audio system on your Harley Bagger.

[TIF2]

^^

Nice write-up .... thanks. 


I'll only clarify a bit and state that distortion can come from setting amp gains too high (as you pointed out) as well as over-driving speakers. In the first case, you are feeding the speakers a distorted signal. In the second case, the speakers are the source of the distortion (even if the signal from the amp is pristine) by feeding them too much power (over-driving them). Each case needs to be accounted for when dialing in a new system.  Another reason to set gains as John describes above is to account for various recording levels of different source tracks.

One more helpful tip - when adjusting gains on a new system, use a track that you are VERY familiar with. A track that you have heard many times on a good quality home or mobile system. This will give you a reference point to try and get as close as possible to that quality on your new system. Additionally - there actually IS a break-in period for new speakers so if your new speakers aren't providing as much bass (or warmth) as you hoped, give them a while to break in. If they ARE impressing you from day one then they will only improve over time   .

Either way ... the main goal is to maximize the output SPL (Sound Pressure Level) while never sacrificing SQ (Sound Quality), and maintaining a useful range of volume adjustment on the head unit.

[Hawg]

good info thanks

[ruiner73]

Quick question without searching around too much on the internet, called & ordered one of these, $79.99? That seems a little steep or no? I see Crutchfield has adapters for around $30, I guess I should have questioned the salesman, real polite gentleman by the way, but I just bit the bullet. I've got/had both Rockford & J&M amps and was satisfied with quality, so just knowing J&M stuff is built with our bikes in mind I didn't bother, just told him to get it on it's way.
More of an FYI for anyone interested, but if anyone knows if there is something special built into these, please feel free to enlighten me.

Thanks

and thanks John for posting up some good info for those of us trying to set our amps ourselves...