This is like asking why aren’t you prettier or handsome? Or bigger. Or taller? Why is there air? There could be a lot of reasons, and this is a VERY complicated question. But let’s assume that for this conversation that you bought an amplifier that’s theoretically equal in power to the speaker power handling. So, for example. You bought a 100-Watt amplifier. And 100 Watt-rated speakers. This is a pretty good assumption and typical. Matched? Right?? You’ve had it installed by an HD customizer/audio retailer/installer you trust. But…for whatever reason, it JUST doesn’t “Get it”. It plays well, BUT it SHOULD be louder. Hey, you’ve matched everything what else could you have done! RIGHT?? Not quite that easy. Nice try though. A LOT of things come into play. What is the sensitivity of your speakers? What is the power handling of the speakers? Really? Not the advertised. How much power is the amplifier? REALLY? No BS!! So here is the deal…higher sensitivity speakers play louder. More power (to a point) plays louder. Matching? Not really a thing. Especially under “Music conditions”. Sinewave, YES. But…do YOU listen to sinewaves for music?? Really??? Don’t think so.
This is an age-old question/comment. Not easily answered. Except ..there are some rules (Physics).
- Once your speaker, ANY speaker, reaches “Xmax” (Maximum, Mechanical Excursion) there is NO more output. Meaning it won’t play any louder. No matter what!!
- Then there is the issue of HOW big is the voice coil. The bigger the voice coil the higher the power “handling”. THIS IS SUPER IMPORTANT! No matter what the BS power rating is on a speaker or the gift box or internet, the voice coil REALLY determines the power handling. Not what the marketing guy writes for specs!!! A 6 X9 with a 1 inch (or even 1.5 inch) voice coil will NOT be 250 W RMS!!! No way Jose!!!!
- High pass ALL speakers on your HD bike. PERIOD!! This will help both increase output (volume) and lower distortion. Midbass drivers should be High Passed at 80 -120Hz @ 12dB per octave or FASTER (meaning steeping slopes) Subwoofers (that’s pretty funny on an HD!!) should be High passed AS WELL as low passed (meaning a bandpass) just really low. Like 40-50 Hz for the high pass and 80-120Hz for the low pass. This creates a Bandpass of 40-120Hz and PROTECTS your sub (from you!!) and increase output level.
WE need an example here to show what is REALLY happening:
Let’s say your speakers have a sensitivity of 92 dB 1W/1M. That is good and typical of coax speakers with dome tweeters. But CoAx Horns (like our CH series) are well over 97 dB 1W/1M sensitivity (and at higher frequencies over 107dB) So that is roughly 7-10 dB louder than your 92 dB 1W/1m sensitivity speakers. QUITE a bit louder. Roughly 10 times louder. This means you would need 10 times the power you already have to get even close to the CoAx horn speakers’ levels (loudness) 10 times! So, let’s continue with that logic. Let’s say you had our CX125.4 amplifier connected. Which is about 100 watts RMS per channel X 4. So, to get YOUR system with this amp and your speakers, to play as loud as our CoAx horns speakers play (with the same CX125.4 amplifier) you would need roughly 4,000 watts RMS to do that!! This also means you need roughly 10 times the current to drive this much power or 466 amps of continuous current!! On a Harley Davidson motorcycle? Wow, whatever you are smoking …I want some!!!! Now, are you seeing the issue with how to get louder on your bike? It is a combination of things, power, SENSITIVITY, current draw. This all comes into play. Speaker sensitivity is basically FREE energy. Power from an amplifier is NOT Free. It takes current to make power. Current that you DON’T have on a stock HD bike!!.