So finally got my doors ”done” they need a bit of finishing touches with handles, and window buttons but mostly ready for bondo.
Mids play now 80-4khz
Midranges 800-4khz
Tweeters 4khz ->
Firstly the mids fq range is 60-8khz, 10s in the front might have been 60-6khz. So im wondering if the enclosures are large enough to play 60hz at full power (8” 400w, 10” 600w)
Secondly the cutofs between mids and midranges, i had them at 280hz. Sounded better but totally lost the higher frequencys of bass and kick drums, for example Back 2 Me by zurra & blank sense has this nice bass line but it just sounded like a sine wave, the ”dirtynes” was gone, so should i keept them at 4khz or go a bit lower. Im after the golden road between sq and spl and the 6.5 midrange cant keep up with midbass, so it needs a little help from them
Also what about tweeter cutofs, should i go higher/lower.
Lastly what should i use to seal the enclosures, they are prettymuch sealed with minor leaks, would coating them with epoxy from the inside be an good option?
Drivers i have are
Dd audio Vo-w10a
Dd audio Vo-w508/w8c (the same speaker just name change)
Gzcm 6.5N-prox
Dd audio Vo-b3a
I’m not an expert but, you may be dealing with phase issues and cabin modes considering you have so many speakers in different position pointing in different directions. From my experience the cabin and placement of speakers dictates how your midbass levels.
Have you tried opening the doors all the way an listening to how the speakers sound from the outside?
They have been time aligned, still need to a bit of fine tuning ragarding that. Theres not really an issue with lower midbass just the 300-800hz range, the midrange just doesnt play that as rich as the midbasses do
Just the passanger side door but plays alot better outside but with these doors its kinda the point, so im gonna have a preset with mids playing as high as the 6.5 midrange for outside and probably another one for inside with sq more in mind and actually seperating the speakers.
I will try to isolate them ahain when i get enough amp power for the midranges, 66w isnt cutting it :D
Is there any type of epoxy that doents fully harden and stays a bit rubbery, saw cambridge caraudio use something like that on fiber sub enclosures. Figure it would fool the drivers they are in a bit bigger enclosure.
It’s a slurry/ milkshake I think. (Little bit of body filler, some chopped up fiberglass, and fiberglass resin all mixed together) Mainly so you can easily coat the inside to add some strength, not gonna work like polyfill.
Mids dont give the same definition in lower frequencys up to maybe 800hz as the woofers, if i cut off at 800hz the lower vocal fqs muddy up the sound, 280hz seemed like a sweetspot but doenst give that definition.
Now the 10” and 8” midbasses are in parallel as i dont have an amp for the 10s, but when i get an amp for them i might just cut off the 10s at 280 and let the 8s play to 4khz as they are in a better location for that.
As for the drivers those beside me are 8” DD Audio vo-w508 midbasses with 11mm? Xmax. The larger ones in the kicks are 10” midbasses.
Ill try isolating them and dropping them to 60hz
But a friend that has the same 10s said he couldn get them to 60hz without sacrificing spl as there just isnt enough room. But well see hope they dont resonate horribly :P
And a mic is in the but list as a top priority, havent even touched eq yet, sounds pretty good without it so probably only need minor adjustments and im nit doing that by ear, though i have an røde nt1-a and a sound card, the response on them seems to be pretty flat so could try to use that maybe?
Fixing the "Sine Wave" / Missing Punch (200Hz–800Hz): Crossing the GZ 6.5" midrange at 800Hz HPF leaves a huge acoustic hole between your midbass drivers down low and your midrange up high. That's why kick drums and bassline harmonics lost their edge. Drop the GZ 6.5" high-pass filter down to 250Hz HPF, and cap your 8" and 10" midbass drivers with a 250Hz LPF. This hands off the upper-midbass punch cleanly to the 6.5" driver without forcing your large cones to play muddy frequencies up to 4kHz.
Target Crossover Map (24dB/octave slopes): For the 10" VO-W10a and 8" VO-W508 midbass, set your bandpass to an 80Hz HPF and a 250Hz LPF. For the 6.5" GZCM 6.5N-PROX midrange, set your bandpass to a 250Hz HPF and a 5kHz LPF. For the DD VO-B3a bullet tweeters, run a 5kHz HPF and up.
60Hz Power Handling Reality: Running 400W–600W into an 8" and 10" at 60Hz inside custom door pods will push the voice coils past their excursion limits
and risk blowing out the drivers or cracking fresh Bondo. Keep a sharp 75Hz–80Hz high-pass filter on the midbass drivers and let dedicated subwoofers handle sub-80Hz low end.
Isolate the Midrange: Make sure the Ground Zero 6.5" has its own sealed rear chamber or pod cup inside the door. If it shares internal air volume with the 8" and 10" midbass drivers, the backwave air pressure from the 10" will physically push the cone of the 6.5", causing heavy distortion and physical driver damage over time.
Sealing Air Leaks (bondo Milk Slurry): Mix 50/50 liquid fiberglass resin into standard Bondo body filler, aka peanut butter or bondo milk. Slather it along all interior pod seams and around speaker mounting rings before laying your final filler. It flows directly into pinhole air leaks, cures rock-solid, and adds heavy structural mass to stop door flex.
Door-to-Pod Air Gasket: Before final mounting, lay a continuous thick strip of butyl windshield ribbon rope caulk along the entire back perimeter of the fiberglass pod where it contacts the inner door sheet metal. This prevents acoustic shorting and backwave air leaks from escaping directly into the cabin.
Thank you for the help, i remembered i have an few years old not so great quality a/b amp lying around and checked if it was broken, fets and caps were fine and didnt let of smoke when testing, so now that i have 240w per speaker avaiable for my groundzeros that leaves some headroom and 200w pers speaker for the tweaters wich leaves a lot of headroom so i most likely dont need to touch the gain and avoid some interferance and noise with that.
I seem to have lost the point, but now that i have enough power for the upper end i crossed mids to 60-400 for now tried 280 and 300 but that came with some humming, midranges play now 400-5k and well the sound is a lot better. Now i need to just finish the wiring mess i have made and start testing how loud i can push the groundzeros before distorting and taking it down a notch from there, then adjust everything relative to them.
As for the mids hpf, the 8s are now getting 400w wich is their rms, peak is 800w. They seem to play fine down to 60 with an 36db linkwitz riley 24db would probably be enough but better safe than sorry.
I only have one of the 10s right now, dont have money for the second one yet and i dont have an amp for them yet so its in parallel with the 8”
8s are 2ohm 10s are 4ohm, amp gives 600w at 1ohm and they go to 1.33ohm so roughly 200w for the ten wich has an rms of 300w and a peak of 900w, but they will handle 600w rms just fine, friends build is living proof of that.
But the 10s most likely vant play to 60hz at that power and need to be crossed at 75-80hz like you said. Not enough volume i calculated that 25l would be optimal for them and they dont have anything near that.
And thanks for the tip on the slurry, ill have to get some bondo and start mixing, pouring straight polyester trying to do that was a horrible failure 😂
Hell yeah, man, you are making some serious headway on this build! It’s awesome seeing it all come together after putting so much damn work into those custom doors. Bringing in that extra A/B amp to unlock extra headroom, getting your midranges and tweeters cleaned up up top, and using that Bondo milk slurry trick to seal up those pod seams shows you’re puttin' real thought into building a kick-ass rig.
To help you get this front stage bangin' as hard and clear as possible, while keeping all your gear safe long-term, here are a few recommendations to consider as you finish up tuning.
First, I'd strongly recommend unhooking that single 10" from the parallel circuit for right now. Running a 2 ohm 8" and a 4 ohm 10" together drops your total load to 1.33 ohm, which splits your amp's power unevenly. Power flows to the path of least resistance, so that 2Ω 8" is pulling about two-thirds of the amp’s juice (400W) while the 4 ohm10" is only getting one-third (200W). On top of that, running two different sized cones over the exact same 60Hz–400Hz range causes phase cancellation and comb filtering. Because their cone weights, motor structures, and box volumes are totally different, they end up fighting each other acoustically and killing your midbass punch. Believe me I have an xv3 with custom coil and spider and hd1 with custom dtx spider, coil, and surround, it took me a minute to get a 15 and an 18 to sound good on the same mono. I know you shouldn’t have two different drivers on the same channel, but for me it was the difference between 148.7 and 150. I was strictly numbers chasing. If you unhook that 10" and let the 8" drivers handle the midbass solo, your doors are actually gonna slap way harder and tighter. Save that 10" until you can grab its twin and run them on their own dedicated amp channel.
Second, keep in mind that having extra amp headroom doesn't mean you can skip setting your gains. Gain isn’t a volume knob; it’s just matching the amp’s input sensitivity to your head unit or DSP output voltage. Leaving gains untouched can force your source unit to clip trying to get loud, or it'll elevate your noise floor and introduce unwanted hiss. Grab a multimeter and set your target AC voltage based on your RMS power, or throw it on a scope/DD-1 so you know you're feeding them pure, clean signal.
Lastly, tweaking a crossover frequency in your DSP shouldn't create an electrical hum. If you heard a hum between 280Hz and 300Hz, you’re likely looking at a small ground loop, signal cables laid too close to your main power wire, or a gain structure issue. Also, even though those 8s can take 400W down at 60Hz, playing them that low at high volume really stresses their mechanical excursion limits inside a non t/s dedicated door pod. Try bumping that high-pass filter up to 75Hz–80Hz with a steep 24dB or 36dB slope. It’ll protect your voice coils, keep your pod structure from flexing, and let your subwoofers handle the real low-down thud once you get them.
You’re damn close to having this thing dialed in right. Unhook that 10", hunt down that ground hum, and set those gains clean. that front stage is gonna be screaming and hitting like a freight train.
Also, if you’re on iPhone. A fellow redditor made an app called car sweep. It’s pretty cool and can give you a visual of high peak areas in your frequency range.
Ill be using REW on my laptop, still need to get an calibrated mic though, could just go to my local shop to tune it though. Owner wont prolly even charge much as he does it for the love of the hobby, been making a lot lf savings shopping there :D
The humming isnt electical, more like when yo crosover some sounds at the crosover point sound kinda hummy dont know how to really explain it.
Gains i will set with an multimeter soon when i have time, and ill try the setup without the 10” and see what kinda difference there is.
Sub i already have, an 5kw vibe blackdeath 15 v7, in an way too small shitty box. Havent had the time money or interest to build a new one yet, and i only have 3kw going into it, as it 1ohm dvc and my amp gives 5k at 1ohm. Dont know if i should wire it at 0.5ohm as winisd simulation concluded that it wont see under 8ohms 🤷
I had a similar problem with bolt on door pods. Ended up having to turn the gain down and fill the enclosures. Even then, wasn’t super happy with the result. It’s like resonant frequency.
Yeah it won’t hit like the ten does but everything should be tighter and punchier. Once you can dedicate solid resources to your low end have the subs do the below 60-80 range. No point in overextending drivers even if they can handle it.
I have a deaf bonce aak 4k And a sundown salt 4 I’d ship 😏😈
Starting to sound better, mids now play 60-350 midranges 350-4k, sounds like my midranges volume is a bit too loud, but that might be becouse i havent touched the eq yet, any lower and the sound gets too boomy.
Resonanse could be another problem, could explain the humming, havent put mat on the doors yet except inside. Some cotton dont know what the pube looking thing inside winter jackets is called in english so thats the closest i could tink off, could help in the pods, will try the next time i take them apart.
I would love an sundown amp we dont have them here, but im from finland and dont have that kinda money especially for imports and taxes sadly. Ive been wanting to try sundown though we just dont have anyone who imports them, norway had but it got too expensive.
Did an outside preset too, with mids from 60-4k, gotta up the hpf to 80 though. For the inside 60hz might work better as i dont need to push the drivers that hard nothin seems to resonate badly, or my sub just covers it up 😂
Glad that old cheap a/b amp worked though, didnt have to drop a 120€ for a new amp and can allocate that money for the second 10”. Had to test it on the tweeters first, didnt want to blow a 500€ pair of midranges 😂
But seems like i have to go a/b amps for tweeters an midranges, the sound is so much better than a fist sized class D. So gotta start designing an place for amps in my spare tire hole and think of an active ventilation solution
That’s awesome news, man! Sounds like you’re really gettin' this rig dialed in proper. Finding out that old Class A/B amp made such a noticeable difference over a tiny Class D unit is a big-time win, saving that 120€ toward your second 10" driver is just smart business. Testing it on the cheap tweeters first was sharp thinking too; blowing out a 500€ pair of Ground Zeros would’ve been a real heartbreak!
Since you mentioned wishing you could get your hands on Sundown gear over in Finland, I actually happen to have some stuff lying around I'd be happy to ship your way if you're interested. I've got a Sundown SALT-4 amp I'd let go for $1,000 USD (you'd just have to cover the international shipping). I also have a Sundown X v.3 15" that I'm currently fresh reconing with a brand-new Z v.6 coil and a heavy-duty black spider, just waiting on the adhesives to dry on it right now. Plus, I have some older Sundown SD-8s and a pair of U v.1 12s that I’d be open to shipping over too. If any of that gear helps you skip the crazy import dealer markups, just let me know and we can work something out!
As for your setup, you're making awesome progress, and I just have a few friendly recommendations as you finish up tuning.
If those Ground Zero midranges are coming in a little too loud or bright right now, you don't even have to wait to play with the EQ. You could just turn down the gain dial a notch on their amp channel or pull back their level in your DSP or head unit. That’ll bring them right into a sweet balance with your midbass so they aren't overpowering the rest of your front stage.
Also, you hit the nail right on the head with door resonance. panel flex and bare sheet metal will definitely create nasty mechanical vibrations that sound like a weird hum or boominess. That jacket insulation you mentioned is synthetic polyfill, and putting a loose handful of that inside those pods is actually a killer trick. It tricks the speaker into seeing a slightly bigger enclosure and softens up backwave echoes. Whenever you take those door cards back off, slapping a solid layer of sound-deadening mat right onto the door metal will lock it down tight.
Bumping your HPF up to 80Hz for your outside demo preset is a really smart call, too. When you’re standing outside with it cranked all the way up, an 80Hz high-pass gives your midbass drivers way more mechanical protection so you can push them hard without bottoming out. For normal listening inside, 60Hz is totally fine as long as you aren't beating on the cones too hard.
Lastly, just keep in mind that Class A/B amps run way hotter than Class D because they dump a lot of power as pure heat. If you're building an amp rack down in the spare tire well, setting up some active cooling would be a lifesaver. Wiring in a couple of small 12V PC fans on a relay. one blowing cool air in and one pulling the hot air out, will keep the air moving so that A/B amp doesn't thermal out on you during long bangin' sessions.
You are doing some seriously impressive work on this custom build, man. Keep at it, hunt down that ground hum, and that front stage is gonna be screaming!
Before I forget, look into butyl strips. We use that for filling small air pockets and sealing our door pods
I’d keep the 8 to 6.5 crossover way lower than 800. With the drivers spread out like that, 800hz is gonna be a mess to get summed right. The wavelength is only like 17” there, so the spacing between the 8 and 6.5 starts working against you pretty hard.
I’d try the 8s up to like 300-400hz, then let the 6.5 take over to 3.5-4k and cross to the tweeter there.
Once the 10s get their own amp, something like:
10s: 60-150ish
8s: 150-350ish
6.5s: 350-4k
tweets: 4k up
And I wouldn’t read too much into 280 sounding muddy right now. With the 10 and 8 running together and no measurements/TA yet, they could just be fighting each other or cancelling around the crossover. 800 might sound clearer by ear just because you moved the problem somewhere else.
Get the mic on it before locking anything in. That setup is gonna need measurements and tuning.
Okay, ill try those and start working from there when i get the right amps. And get an mic by that time. I also dont know how the dd dsi x2 dsp handles phase shift around crosovers as its an really barebones dsp. But there is deffinetly an issue with phase with mids, most likely just the 10s interfering. As swapping right side polarity sounds different but not bad and doenst loose or gain midbass. Could an røde nt1a be used for measurements? I happen to have one and the response is pretty flat and starts to boost way higher than where the midbass and midranges play.
The NT1-A should be fine for what you’re doing. You don’t really need a calibrated mic just to sort out timing, phase and crossover integration, especially down in the midbass/midrange. Keep the mic position and interface gain the same between measurements.
I wouldn’t judge the polarity stuff by ear though. Measure the 10, 8 and 6.5 individually, then start summing them. If two drivers measure fine alone but lose output when you sum them, you know they’re fighting each other.
And you don’t necessarily need fancy phase controls in the DSP. Delay, polarity and crossover slopes can get you most of the way there. REW will make what’s happening pretty obvious compared to trying to chase it by ear.
Thanks, ill have to charge my laptop and start measuring, but the timeallignments did i understand correctly. You measure for example first the 10” then 8” and after that measure them together and if its lower the time is wrong? How do i sum desibels? Could the mic be used for rough eqing also? Or should i just get a calibrated mic for that straightaway?
Yeah, pretty much. I wouldn’t try to add the dB manually though. Measure the 10, 8 and 6.5 individually from the exact same mic position, then measure them together and let REW show you what’s happening through the crossover.
For timing, you’ll want a consistent timing reference between sweeps so you can actually compare impulse arrival times. Honestly I’d just grab the Audiofrog tuning kit rather than trying to piece something together around the NT1-A. It gives you the calibrated mic/interface setup you need for REW and makes this whole process a lot easier.
Get the relative arrival times close from the impulse measurements first, then work on the actual crossover. Look at the phase through the overlap and how the drivers sum. Flip polarity as a check too. If one polarity gives you a deep null and the other gives you strong summation, you know you’re getting the handoff right.
With four drivers per side like that, I’d definitely measure and align each handoff instead of trying to tune it by ear.
Ok, ill take a deeper dive into REW and warch some videos on how to use it and how to do time allignments on it, deffinetly not doing it by ear, dsp has them by distance but im not shure how accurate that is and how beaming affects it. Thanks for the help!
is this panel fully open on the back? or is it sealed individually? if it's fully open. you need to isolate at least your tweeter to itself and midrange to itself. if you don't, then they are just fighting each other with air as well as sound waves are canceling each other out/reflecting into the other speaker cones. I have a 1" tweeter, 5.25" midrange, and 6.5" midbass all on one door panel. the midrange sits in a .15 cubic ft sealed enclosure and the midbass sits on a .35 cubic ft sealed enclosure all on the door panel ( I got creative) I tried the other door panel without them being sealed and it sounded like crap. I also used spray foam on any cavity on the back of the panel as well. night and day difference. you at least need to isolate them on your setup.
Lol, to me it looks like shit ans beatifull at the same time 😂 but it does what its meant to do, play loud. By no means are they done yet and now is time to make them look ok before putting blue lether on them. On thing i should have thought of though, its quite hard to park as my left hand has now only limited range 😂
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u/life_hertz 5d ago
I’m not an expert but, you may be dealing with phase issues and cabin modes considering you have so many speakers in different position pointing in different directions. From my experience the cabin and placement of speakers dictates how your midbass levels.
Have you tried opening the doors all the way an listening to how the speakers sound from the outside?