My first "Active" "SQ'ish" build attempt.

[ItsHammer]

What DSP are you using?

No dsp yet. Probably not for a few months. Just using my head unit. Don't even have a microphone to hook up to the HU for measurement so I'm going to use the old trusty rusty tape measure

 

[ThxOne Premium Member]

No dsp yet. Probably not for a few months. Just using my head unit. Don't even have a microphone to hook up to the HU for measurement so I'm going to use the old trusty rusty tape measure

Whatever gets you there. Some head units have some pretty nice DSP options. I think this RF 3Sixty.3 is a bit over complicated but I love the twin knob remote. I will miss it if I go another route or on the build I will be doing in the Cherokee when I bring it home. I have it set up as a bass knob and overall system volume. My head unit has the ability to go full active and has all the time alignment stuff I could want but I really like the twin knob lol.

 

[SkizeR 10+ year member]

You know when you do stuff with your stereo and you think "wow, I am getting good at this tuning thing." Then one day (today) you drop your brother off at his job then head off to your own job an hour and a half early. I decided to take the laptop with me and mess with the crossovers for the sub, the midbass and the mids and highs. I had the sub crossed at 110hz and the midbass at 110 - 1Khz both at 24db per octave. I was looking in the 3Sixty GUI at both crossover areas and decided to split them up. Sub down to 100hz and Midbass to 150hz and changed to 12db slopes. Then I changed the upper bandpass of the midbass and the midrange crossovers to spread them out as well and switched them to 12db slopes.

I moved on to the EQ. This is where everything got weird and good at the same time. I set the amplifiers with the O-scope using -5db tones so I decided to start adjusting the eq's for the midbass and mids/tweets. Instead of lowering each band I adjusted, I boosted them... up to +5db but not lower than 0db. Remember how I said it sounded good but just needed some more output... Well, it is there now!! But while that is good news I noticed the sound shifted left. Confused by this I decided to pull out my tape measurereerererr thing after listening to track 17 on my IASCA disc to confirm my brain wasn't going nucking futs. Imaging was way off.

Leaving the sub at a distance of zero (70" actual) I began measuring each speaker....................... this is how stupid I am. I discovered that every time I measured the right speakers I would be looking at the tape measure upside down. So dyslexically I subtracted that number from the 70 inches for the sub then input it into the DSP (like instead of 52" [70-52=18"] I subtracted 25" [70-25=45"). See how far out it was pushing my right channel speakers? While technically still left and right, the distances for the delay was way off. Once I caught my mental phuck up, I input the correct numbers... yes, I triple checked them this time and then I played track 17 again. These are 7 snare drums panned from far left and transitioning evenly spaced to far right. For the first actual time... they were spaced so perfectly even from left to right. My eyes got friggin HUGE.

While driving on the interstate at 74mph with the windows down, I heard my music. All of the music. I smiled all the way home.

I really think you need to re-evaluate how your going about tuning. Start here

https://testgear.audiofrog.com/wp-content/uploads/2018/03/A-Straightforward-Stereo-Tuning-Process-and-Some-Notes-About-Why-it-Works.pdf

 

[ThxOne Premium Member]

I really think you need to re-evaluate how your going about tuning. Start here

https://testgear.audiofrog.com/wp-content/uploads/2018/03/A-Straightforward-Stereo-Tuning-Process-and-Some-Notes-About-Why-it-Works.pdf

I am already familiar with that particular piece of literature.

 

[SkizeR 10+ year member]

I am already familiar with that particular piece of literature.

read it, and follow it to a T. I can promise you that the outcome will be much better than anything you have posted in this thread. Its a process that's quick, that works, and he even explains why it works in that article. Thats written by Andy Wehmeyer, owner of Audiofrog

 

[ThxOne Premium Member]

Nothing against Audiofrog, I am sure they make a fine product however I still have issues with people who say that a speakers sound comes from the voicecoil. If they or anyone are so willing to put this misleading information out there, what else are they getting wrong. Like I said, I am familiar with that article and have actually read it in the past a few times. It is informative and can help.

 

[SkizeR 10+ year member]

Nothing against Audiofrog, I am sure they make a fine product however I still have issues with people who say that a speakers sound comes from the voicecoil. If they or anyone are so willing to put this misleading information out there, what else are they getting wrong. Like I said, I am familiar with that article and have actually read it in the past a few times. It is informative and can help.

can you quote exactly what you are referring to? that said, i can promise you that the person that wrote that article has more knowledge on car audio than this entire forum combined.

 

[ThxOne Premium Member]

can you quote exactly what you are referring to? that said, i can promise you that the person that wrote that article has more knowledge on car audio than this entire forum combined.

Please understand that I am not saying the author of that article is in any way stupid. I agree that there is a massive amount of knowledge there.

The quote:

"measure from the tip of the microphone to the center of the speaker grille. The actual origin of the sound for this purpose is the voice coil. You can estimate that distance using the speaker or a side view drawing of the speaker. If those aren’t available to you, don’t worry. Just measure to the grille. This won’t affect the center image at all. "

This is incorrect. The voice coil is an electrical a/c motor used to move a cone or diaphragm. The cone or diaphragm is what moves the air in front of it.... The moving air is how sound is made and it is coming from the movement of the cone or diaphragm. Without either of those items (cone or diaphragm) the air would not move enough to make sound. You would literally have a voice coil moving in and out of a magnetic field... in near silence. One could argue that without the voice coil there would be no movement to make the sound but this also is not true... you don't even need a "voice coil."

 

[ItsHammer]

I think what he meant was when measuring, take into account how far into the door the speaker sits. For example if your measurements are 30" to the grill, then add a couple inches to reach the inner part of the speaker. Ie the voice coil. Don't think he literally meant that the sound comes from the coil rather that the sound comes from inside the door, not from the grill area.

 

[ThxOne Premium Member]

I have heard other people say measure to the voice coil as well. Ultimately we are all going to do what we do.

 

[SkizeR 10+ year member]

Please understand that I am not saying the author of that article is in any way stupid. I agree that there is a massive amount of knowledge there.

The quote:

"measure from the tip of the microphone to the center of the speaker grille. The actual origin of the sound for this purpose is the voice coil. You can estimate that distance using the speaker or a side view drawing of the speaker. If those aren’t available to you, don’t worry. Just measure to the grille. This won’t affect the center image at all. "

This is incorrect. The voice coil is an electrical a/c motor used to move a cone or diaphragm. The cone or diaphragm is what moves the air in front of it.... The moving air is how sound is made and it is coming from the movement of the cone or diaphragm. Without either of those items (cone or diaphragm) the air would not move enough to make sound. You would literally have a voice coil moving in and out of a magnetic field... in near silence. One could argue that without the voice coil there would be no movement to make the sound but this also is not true... you don't even need a "voice coil."

ahhh i see what you are saying. I think you are misunderstanding. Hes not saying sound originates at the voice coil. BUT... In the speaker/driver designing industry, the general rule of thumb is to line up voice coils, not cones. Same reason why its not a "point source" driver if the voice coils arent lined up.. Its just a rule of thumb in the speaker design industry.

 

[ThxOne Premium Member]

ahhh i see what you are saying. I think you are misunderstanding. Hes not saying sound originates at the voice coil. BUT... In the speaker/driver designing industry, the general rule of thumb is to line up voice coils, not cones. Same reason why its not a "point source" driver if the voice coils arent lined up.. Its just a rule of thumb in the speaker design industry.

See, now that makes sense.

 

[ThxOne Premium Member]

I really think you need to re-evaluate how your going about tuning. Start here

https://testgear.audiofrog.com/wp-content/uploads/2018/03/A-Straightforward-Stereo-Tuning-Process-and-Some-Notes-About-Why-it-Works.pdf

Ok Big Apple... I went into the DSP yet one more time because ya never know. 24db at the octaves. I remeasured my distances to the speakers to the estimated plane of the voice coils. Here is what I did. I know AF said set the crossovers at the half octave but for some reason I did them at the octave. Looking at the DSP's graph, they don't look like they are crossing over badly... no gaps to speak of but something tells me that wasn't the point of AF being specific about half octave with the 24db Link Riley. I will re-do them after dinner....

Left Tweeter/Mid (These are in the same door panel but are split off of a passive crossover. Their distances are split in the middle then estimated to the VC plane) 35.5" from left ear, normal relaxed seating position. 70" - 35.5" = 34.5" in the DSP

Left Midbass measured from left ear to the grill plus 1". Left Midbass 42". 70" - 42" = 28" in the DSP

Right Tweeter/Mid (Same as left door) Right Tweeter/Mid 52". 70" - 52" = 18" in the DSP

Right Midbass (Same as left door) Right Midbass 55.5". 70" - 55.5" = 14.5" in the DSP

Sub crossover 24db Link Riley 100hz
Midbass crossover 24db Link Riley 200hz to 1Khz (What is the half octave? 150hz on the bottom?)
Mid/Twt crossover 24db Link Riley 2Khz (Is the half octave 1500hz?)

 

[ThxOne Premium Member]

Crossovers adjusted to the half octaves.

Sub - 100hz
Midbass - 150hz to 1Khz
Mids and highs - 1.5Khz and up

 

[SkizeR 10+ year member]

1) why are your crossover points so high? unecessary. do sub up to 65hz. midbass from 80 to 350, midrange/tweeter 350 on up. you also shouldnt be using generic passive crossovers while mixing/matching drivers, but thats not a huge issue right now if nothing is blowing

2) he means half octave, but this is for a more common crossover, like around 80hz.midbass at 80hz, sub at 65. this helps keep them in phase at the actual intended crossover point while allowing the sub to play at a higher amplitude. This is also ONLY for the sub to midbass crossover. NOT all of them. Set

3) i would probably set signal delay based on the midrange drivers location, not an average of them and the tweeters. Phase isnt as important at high frequencies but will greatly effect the midrange placement if the differences in distance between mid and tweeter arent subtle