Let's start a tuning thread. How about the basics for tuning a dsp if you will.

Crossovers - this is the sandbox you want your speakers to play in. You're going to have slopes (6 dB, 12 dB, 18 dB, 24 dB, etc). A crossover doesn't mean your speaker will NOT play frequencies above or below what you set. The slope determines that. Lower slope, more gradual the crossover line is.

HP (high pass) - this is the frequency at which your speaker will play above.
LP (low pass) - this is the frequency your speaker will play below.
BP - (bandpass) - this is using a HP and a LP to limit the frequency range your speaker plays in.

Back to slopes - most people will find that using a 12-24 dB slope on a HP will work for their applications. This will provide the speaker with a gradual to fast approach to your crossover setpoint. Again, say you set a fairing 6.5 to play at 100 hz on the Hp. This does not mean it will not play anything lower. Depending on the slope you use, the frequencies below 100 are attenuated at a faster or slower depending on slope. My opinion, start at 24 and be safe. Then work your way down to 18 or 12. Again, my opinion only.

EQ - in a parametric EQ you have a set number of frequencies which you can either cut or boost. Basically an advanced sliding equalizer. You can choose the frequencies by typing them in. This is especially helpful when tuning bandpassed speakers which are in a limited frequency range.

Next you have Q. What is Q. Think of it as a spike or a rolling hill. The higher the Q, the narrower the boost or cut of the frequency you're on. The lower Q causes a more gradual boost but will affect a wider range of frequencies. What is the right Q? Well, it all depends. I can't answer that. What I can say is that I've found success with anywhere between 1 and 2 as a starting point.

Next you have dB boost or cut. This is your ears turn to answer what you need. But keep in mind that boosting can cause a speaker to overdo it. Too much bass in a speaker not designed to handle it may turn in to magic smoke city.

I can't stress enough how important it is to have a plan going into your tuning. Lay out your diagram on paper. Write down your frequencies, make a map, do what you need to do to plan it all out. It'll be best in the end for you.

I certainly don't know all the ins and outs of tuning, but at the very least this is a start of a dialogue that may get some new dudes on the right track to setting up their dsp's.

Chime in at will and keep the dialogue going.

AD

 

Great topic and general guidelines Andy. Thank you for sharing. I'm still learning the dsp so I can't offer any tips but i will be following this closely.

 

Thanks for this thread AD. A great idea for folks to get a starting point.

It leads me to my first question. Almost every fairing 6.5 speaker I have tried, I pay attention to the freq range that the speaker is spec'd to play. Most, if not all state 80 or so hz at the low end. I have yet to find one that I can actually HP at 80 and still get it to play undistorted or not muddy. Now for the question.... would this be a Q issue, an EQ issue , a slope issue, or a speaker with aggressive advertising?

 

One thing I do is balance my boost and cuts. If you look at the highs and lows of the eq as rolling hills, I try to keep 0DB as the center line. So some are above and some below 0. If everything is boosting you can end up clipping freqs.
When I start fresh with new speakers the first thing I do is find the freqs that need to be cut, then gradually work up the others.
When you adjust one freq it will often affect another.

 

Honestly it's probably a speaker spec issue. For your case, I'd HP the fairing and lowers at 115-125 and let those margarita bowls in the lids make up for the rest.

 

Are you tuning while running? If so it’s mostly a factory hu issue since the boom hu boosts hard at 96hz.

 

I think one thing we need to remember when reading frequencies on a speaker and trying to obtain those cutoffs, these speakers were never intended to be 2 feet in front of your face, nor were the majority of them intended for motorcycle use and all of the associated noise that a bike comes with. IMO trying to set a speaker at what it's spec'd to play at just isn't going to happen in the sled audio world.

 

Was just talking about this in another thread. Can't add much if anything, too new and still learning.

Thanks for starting this will be reading it all.

 

Slope can have a massive impact as can the boost of the far left EQ setting. A low slope and a high first EQ band setting can drag that speaker thru shix it wants nothing to do with.

T

 

I'll be the a-hole here. 6.5" speakers don't want to and in most cases absolutely cannot reproduce clean and accurate sound with any measure of real volume at 80Hz. Stop chasing what isn't there. We aren't tuning 8s down to 22Hz, why are we thinking 6.5s can effectively play 80Hz. Do we even know what 80 sounds like or is it just a number that we've seen and heard all over these threads? I'd like to suggest letting speakers play where they are happy and capable playing. Stop asking more from them than they are physically capable of reproducing and let them play their role in an entire system. It doesn't matter what the marketing material on the packaging of a speaker says, physics are physics, and for those of you who have met Adenton, expecting a 6.5 to play well at 80Hz is like expecting Andy to dunk a basketball...aint gonna happen. Consider the chart below and consider shifting your expectations about 20Hz to the right and you'll be pleasantly surprised. Shift 40Hz to the right and figure out what you're gaining and what you're losing.. If you don't know what sounds are playing from 80 to 100Hz then figure it out. What plays between 100 and 120? I think the very basic instructions of tuning start with knowing what sounds we actually hear at these frequencies we are blindly boosting.