r/SoundSystem • u/Droopyweiners420 • 2d ago
Need help
Hey yall some people I know own this system and quite frankly don’t know what they are doing with it. I am also a novice and am building my own system but would like to help them tune this. I wish I had more info on the cabinets and driver so identifying them would be great. I think it’s some sort of W bin design on the sub and a cubo kick 18 mid with a MT121 on the tops but I’m not sure.
My follow up question to what are these cabs is what would the ideal crossover points be? 20-80 subs? 80-200 kicks? 200-20k tops?
Thank you for any help!
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u/djscsi (( (O) )) 2d ago
I think you have a good general starting point but you'll want to high-pass the subs at something like 30-35Hz, at least until you see what the system can do. If the system owner really does not have an external DSP unit(??) they should 100% get one as it will make tuning much more enjoyable. Even a DriveRack or DCX2496 or something inexpensive will be fine, so you can plug in a measurement mic and get a good baseline.
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u/Droopyweiners420 2d ago
Yes I agree I told them to get one they literally have no experience or clue what they are doing.
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u/Realistic-Health-502 1d ago
DBX PA2 can do basic DSP and be had in good condition for <$200 USD online. I just built my first system and it has helped me immensely. Though I'm not sure what that mixer is? That screen looks like a high pass filter so maybe that thing already has crossover ability?
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u/secondgensoundsystem 2d ago
I doubt those subs can do 20 safely
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u/Zativa_ 2d ago
Buy a cheap measurement mic, get REW (free), then send pink noise at low level on your sub, kick and med without filtering, and same on the comp with a hpf roughly around 1000hz if it’s a 1’.
Just with that you know the FR of everything and you can work on the proper xover.
I recommend don’t assume the xover especially for your tops, you’ll have broken component at your first high spl test or the first party you’ll launch with them if it’s not correct.
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u/Droopyweiners420 1d ago
Dope thank you for the helpful info!
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u/Zativa_ 1d ago
You’ll see that you really don’t need a lot of level to have a useable curve on REW, when I say low level I really mean it unless you’ll damage your driver, especially your compression driver even with a hpf, and for your sub it’s gonna sound like you have very little noise out of it with the pink noise, you don’t care, focus on what you’ll have on your screen with the right scaling.
Just watch a quick tutorial on how to measure speakers with REW.
This is the easy job.
After that I just recommend bw24db/oct hpf to protect your sub on the frequency just before your level is falling, or a few hz higher if you want peace of mind, the rest of your xover just use LR24db/oct if you don’t know what you’re doing, as this curve and type of filter provide perfect frequency and phase summation.
And just learn the rest of the fine tuning and voicing by yourself as it’s pretty subjective to you and your audio material !
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u/Realistic-Health-502 1d ago
I'm barely more experiened that you are but this is how I did a ghetto tune on my 3 way system:
- get a cheap decibel meter (I already had one)
- run a laptop into the input, and find an online tone generator
- run varying test tones through each set of speakers *at a comfortable, reasonable volume* and measure the output level with the db meter. Absolute numbers are not important, what you're trying to do is find peaks/valleys in the response and the top and bottom of the range where the speaker responds predictably. That will give you a general understanding of the response curve for each speaker set.
- set your HP at 30hz, maybe higher if the subs drop off above that, which you will know from the previous step. Playing below a subs' tuning frequency can damage it, but that's why you did the previous test at low volume.
- cross the sub and kick around 80hz, this is pretty standard I think?
- cross the kick and midhighs around 250hz and see how they play together. This crossover point will probably have a more pronounced effect on the sound than the sub/kick crossover point. When you're experimenting with this, be sure to leave the subs off. I cross mine at about 190hz because above that the kick gets kind of honky, but I have some very unique enclosures.
- apply EQ cuts based on any weird response peaks you found in step 3. As you get those tuned in you'll be able to play louder without distortion, honkiness, screechyness, etc
- I have a pair of good studio monitors, so I would listen to a track on those, and then on the threeway system, to find the right balance of power to send each of teh three speaker sets to get a balanced sound.
- once you have all the speaker sets playing together decently, you can repeat the test tone scan
- you can also hook up a mic, find an online spectrograph, run pink noise through the system, and visualize the frequency response curve that way. It's not as precise as a measurement mic, but its better than nothing. Take the measurement from roughly where the center mass of your crowd will be.
Take your time. Ear fatigue is 100% a real thing, especially when tuning low frequencies. And don't worry about perfection - with patience and a decent ear you can get a good enough tune on most systems to please the vast majority of people that will ever hear it.
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u/PsychoTea 1d ago
Great advice. But also don’t forget about phase alignment! It’s quite easy to do in REW with “Measure with acoustic timing reference” combined with the “Alignment Tool”
REW’s EQ wizard can also help you find the correct EQ points to meet your target curve
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u/Realistic-Health-502 11h ago
yeah I didn't bother with phase alignment on my setup since it's a small single stack, but eventually I'll have to cross that bridge
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u/Adventurous_Donut480 2d ago
The tops are very small and so are their horn flare. If they are 8", 200 Hz will probably be fine but if they are 6", you need to cross them at 400-500 Hz.
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u/Realistic-Health-502 1d ago
Respectfully, I'm not sure crossing that high is necessary. I'm running a two way midhigh with a dirt cheap 5.25" woofer and its f3 is about 140hz if the spec sheet is to be believed. I shopped both woofers and midwoofers around 4-6 inches on parts express, and from what I recall all of them will play down under 200hz. IDK of the horn geometry affects that though.
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u/Adventurous_Donut480 1d ago
Technically, you can cross it at 200 Hz but the horn doesn't load at that frequency. That means in that range it behaves like a direct radiating driver, it's the weakest point in the system and can't keep up with the horn loaded rest of the system.
If you see the driver info, that's for direct radiation. That's not the same in your top. You can EQ it but with +6 dB you already are at 4x the power. The driver doesn't have cooling, the back doesn't have air ventilation. Heating up causes power compression. The driver will have a very short lifespan, order replacements in advance.
Anyway, good luck with the system.
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u/garbbeat 2d ago
Sa dépend de beaucoup de choses quel type de haut parleur etc un réglage via un micro serait préférable...
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u/JakeJdubdub 2d ago
Tops are mt121, should go cross from kicks 150-180hz depending on the driver. High crossover to the compression driver will depend on the compression driver+horn spec more than anything else
Kicks are Cubo kick 15s with curved bracing to make them look nice 80-200hz ish. No issue integrating these with the tops
No idea about the subs but the look like some kinda of ported horn which is unusual.
When you set everything up make sure you set channel delays up to time align the system.
Have a look at John Whites guide to setting up DiY soundsytems
https://drive.google.com/file/d/1EmEZg5tXgzQuuGSHvtXHijGM8mjZCVFY/view?usp=drivesdk
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u/Droopyweiners420 1d ago
Amazing thank you for the info. The kick cabs are 18” tho. Would that change your crossover or no?
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u/JakeJdubdub 1d ago
You'll need them to go up to about 200 to meet the tops, and you probably wont (depending on the subs) need them going below 80 to meet the subs.
The boxes will go lower than that, but it's likely you won't need them to, and not running them below 80 will give better max spl before cone excursion limits the output
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u/Droopyweiners420 22h ago
Thank you for all the info that read was incredibly informative and helpful. I am going to run measurements on all the cabinets and attempt to time align the system tomorrow. Really looking forward to trying my hand. Can't thank you enough!
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u/JakeJdubdub 18h ago
Happy tuning!
First time I did it I set the delays fully in reverse. Take your time, double check everything, and be prepared to re-do things a couple of times before you nail it :)
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u/Droopyweiners420 1h ago
Can I just measure 1 of each box type (mid/high, kick, sub) and apply the corrections to each box of the same type?
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u/Kind_Ability3218 2d ago
why don't you try hiring someone if you are so far out of your depth?
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u/Droopyweiners420 2d ago
not my system I am literally just trying to get hands on experience and learn more before I have my system finished
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u/DubbingScoop 20h ago
Bro beautiful system, but I wonder how your friends bought it if they don't know how to make it work.. How to buy a Ferrari and not know how to drive😅😂
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u/Realistic-Health-502 2h ago
I mean, if I didn't know how to drive, but someone offered me a Ferrari for $10,000, I would still buy it. I bet it was one of those situations where they stumbled into a deal that was too good to pass up and figured they would figure out the rest later.
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u/Upper-Practice9240 2d ago edited 2d ago
I assume you bought them used? Easiest way is to ask the seller. Did they come with amps and DSPs? If you don't have any additional information, you may want to invest in a measurement mic and USB Interface + Open Sound Meter. This way you can figure everything out on your own.
Also show us the back of the speakers, the connector panel.
The subs are no W bins tough. They look like a horn/ Bass reflex hybrid to me.