How To Fight Box Rise *Tech Time Thursday* at Sundown Audio

[@barevids]

I don't like the title, it gives the wrong impression. You don't want to fight it. It is your friend. You want the maximum amount of impedance rise while being perfectly on the balance point where mechanical limit is reached as the coils thermal limit is reached. Once this is achieved, you can calculate how low you can safely wire your amps down to yield the highest current possible. I run my amps strapped at 0.5ohm (0.25 per amp) daily and they stay cooler than they did at 1ohm on poorer subs.

[@UnofficialAudio]

No doubt I did the title that way on purpose to attract attention.

[@georgethoman82]

I got a fix for box rise i buy a bigger sundown amp 😉 LoL

[@proffessasvids]

Yeah boi the only time you should ever worry about rise is when doing a one note wonder design for dB drag. Choosing a coil configuration to maximize your amp output at your test frequency. In this case, the playing other tones where the inductance is lower can damage your lovely sundown amp. I always say, if you're playing music.. rise is what it is xx

[@bigvell02]

Glad to see someone else running at 0.5 strapped for 0.25 each amp. Ive had tons of people tell me I'm going to blow my amps. I have 2 DD m2b's and they run like horse with new shoes. Keep up the great stuff as well Peace and Bass :) :) :)

[@spoom937]

This dude stays with the clickbait titles lol! Love the videos though!

[@Supercharged1976]

Simple for me. I always buy an amp that does double what my subs are rated for at the amps minimum safe impedance. 600 rms sub...1200 watt amp. 2500 rms sub, 5k amp. I would rather have the better efficiency of the bigger amp over wiring a smaller amp into the dirt.

[@bigvell02]

LMAO Story of my life right now. My set up is wired to the dirt, great electrical. I'm just like barevids 0.5 strapped each amp seeing 0.25

[@timothyhinton5665]

@@Supercharged1976 it's the opposite of a dead short. It's almost an open circuit.

[@ert-wert]

Hey so what's your opinion on running sfb 3k to a u18 rated @ 1.5k. It would be double the rms.. I'm being told to do it by a friend that's helping me get a pounding system foing and I'm unsure if he is blowing smoke up my *** or if what he is telling me is legit.

[@Supercharged1976]

@@ert-wert Absolutely. It's different for every build but 9/10 you will be seeing 2000 watts or less most of the time out of a 3k wired at rated.

[@dabeardsmen3621]

I was gonna say the same thing but a bigger amp

[@KinqK00pa]

It's simple. Buy an amp that puts out the kind of power you are looking for at 2 Ohms. That way when wired to .5 or 1 ohm, if you rise to around 2 Ohms, it won't really matter because you will still be getting the proper power you need

[@masterdebater8757]

and then you run across a track thats got a signal in the hertz range where your setup flushes out at .5ohm and you dont have a .5ohm stable amp to handle it. dunno bout you but i dont see alot of half ohm stable amps floating around and for sure it isnt the norm. Was thinking out loud that if you know where that .5ohm comes into play and set the lowpass to chop it you might could get by with 1ohm stable amp running a .5ohm sub setup but is just a theory. Im a bit old school, maybe some these fancy DSP's can do that job to save a build from destroying itself.

[@JasonWW2000]

@@masterdebater8757 Your never going to see it dip to 0.5 ohm. It will always be higher than what you measure on DC. You can do a frequency sweep at lower power to confirm.

[@kennysimms5217]

Well I don't want to sound dumb because I'm just wondering but if you have two dual 1 ohm subs in parallel that will be .25 ohms before impedance rise would it be safe to say that once you get impedance rise it would be safe to be in that 1 ohm area that amps can run in? Or no?

[@JasonWW2000]

@@kennysimms5217 The amount of impedance rise will vary based on the sub, enclosure, vehicle and frequency you play. It may only rise to 0.5 ohm and if your amp can't handle that it might go into protect or might damage itself. I would not assume a 4x rise. If I were wiring to 0.25 ohm I'd assume a 2x minimum rise and use a 0.5 ohm stable amp. Or maybe wire it to 1 ohm and use an amp thats 2 ohm stable. Those constant power amps are good for this. I would never wire a 0.25 ohm load unless it was a competition vehicle.

[@KinqK00pa]

@@kennysimms5217 that really depends. Every build is different. One build might rise 1 or 2 ohms while playing songs while other builds may only rise .6-.8 ohms. Wiring an amp down to .25 is pretty risky. I know some that do it but you better hope your electrical is on point (plenty of agm or Lithium power, after market alternators, make sure you are grounded very well, have plenty of fuses, big 3 upgrade, etc). Otherwise you will end up burning everything up running at .25 ohms

[@BURNETTWEALTHGROUP]

4yrs after the video was made I’m seeing this and so damn glad I found it. Very informative

[@dcole808]

Still a great vid after all these years...thx bro

[@markwentz8332]

so . . . . resistance is futile? 🤔 😜

[@vincentrobinette1507]

Resistance is actually a good thing to know, when it comes to power handling capability. The current times itself, times the resistance, tells how much heat is being dissipated in the coil. Voltage is largely meaningless, because any voltage beyond the voltage drop of the coil, is actually motion of the speaker. That energy is the sound you hear. That doesn't contribute to heat.

[@hippo-potamus]

Assimilate into the Borg.

[@Grommet2007]

A few things: 1. A DIY impedance measuring jig and a free software tool like REW will graphically show how impedance varies with frequency, and how that variation can also vary at different power levels. That really could be of benefit here. 2. The subwoofer is actually MORE efficient at higher impedances in its impedance curve, all else being equal. That's because the power it absorbs is related to Voltage*Current, and the Current delivered into the subwoofer is less when the impedance is higher. And less power draw = less draw on the car's power supply = less voltage drop at the amp's power terminals. 3. Unless you're designing a system to have a big peak at one frequency for SPL competition purposes, all you've really got to worry about is if the amp is capable of swinging enough voltage into the subwoofer to get the output that you're looking for at the sub's MINIMUM impedance in the passband (usually 80 Hz and below, and because that's where the subwoofer's maximum power draw will occur), without exceeding the subwoofer's thermal or mechanical excursion ratings. As you suggested in the video, any impedance rise above that in the subwoofer's passband is not something to really worry about.

[@colewoodruff5214]

I'm glad you didn't tell a bunch of people to wire there amps low, cuz I got 1 ohm or .25 ohm and I'm not about to wire down that low, but there is a way to beat the rise, and thats get more 1ohm power, having head room helps, need 5k get 10k.

[@Tekjive]

This was a huge deal for me when I first found out when digging into the what’s what of car audio, great vid

[@seancarraher]

Box design can help fight rise at certain frequencies but most likely there will be a trade off at other frequencies. For obvious reasons he wouldn’t come out and say this but Jl and Fosgate Amps have current sensing ability to somewhat even out the power across the frequency range. Amp technology is like the carburetor vs fuel injection argument. Peaky and Dynamic vs Flat and predictable.

[@thorlancaster5641]

Subwoofer impedance rise causes power to go down, but it also causes efficiency to go up by the same amount. With a properly designed (voltage source) amplifier, box rise will not affect SPL output or sound quality whatsoever. If an amplifier were to "even out the power across the frequency range", it would be supplying more power when the impedance was higher. This would put a big hump in the upper bass response and make the low bass (where the impedance is lower) roll off a lot quicker. A current-based amplifier would also have a horrible damping factor. Sure, it would be great for some SPL applications but it would sound like garbage. Sundown wants their stuff to sound good, so they don't do it.

[@joebelton2146]

I’m glad I watched this video. I just bought 2/15” hurricane cat.2 subs and came into a stetsom 8000 watt mono amp.The subs are rated at 2000rms and 4000 max.So I do have a use for that amp now.lol.I only bought it cause I got it for a steal. I’m glad I did now.

[@jamest.5001]

I did not have box rise until I watched this! Ha-ha!

[@JohnG1000]

How I fight impedance rise..... get a stronger amp that does higher rms at higher ohm loads . Problem solved . Your welcome .

[@unix696]

Right or just wire half ohm knowing it will be over 1 ohm most the time anyways lol

[@ryancapps1254]

Or get something like a smart 3 where all loads give u same watts

[@davidlewis8124]

Or get a Rockford Fosgate T2500-1bdCP Power Series amplifiers actively monitor their speakers' performance using Rockford Fosgate's Constant Power technology. A speaker's impedance naturally fluctuates as it performs. So, just like your cruise control increases the engine's RPM to maintain your car's speed uphill, Constant Power maintains this amp's output by increasing its internal voltage and current when the speaker's impedance rises. This results in up to a 25% increase in the amp's total power output, especially in the crucial range below 50 Hz where a sub amp really has to shine.

[@KillaSquant420]

Exactly what I was going to comment lol

[@212Tan]

Ya I thinking bigger amp, smart 3 or Smart 5 lol he said don't worry bout it 🤣 FOH trying to send these coils to the moon and MF impendence rise killing the vibe over here. 🤷

[@lowhertzhighspl]

10:00 I thought the best thing we can do to fight impedance rise is to buy a stronger amp?

[@billbrush4114]

Great video! I really like when the answer is just forget about it! Can u do a video on subs that are in a box that is too big and one that is too small?

[@slojoegtstang5775]

Great video? What video were you watching? He explained the rise in resistance properly but he didnt tell you how to actually combat it which you can do in Box tuning. He didnt even show you the difference between free air and Box based resistance. They are very different because of Cone area resistance.

[@Bassotronics]

I will select each frequency. Then verify which frequency has the less ohm reading, then tune my enclosure to that particular frequency and since the ohms is very low, I will get the most power out of the amplifier and there I go!...I get a big score!

[@paren8239]

Bassotronics literally a legend

[@brianlee677]

My D2 sub reads 1.4 ohms on each coil good to know great video.

[@iamthemaninde]

Funny .. I tell guys this all the time... You have guys crying about this daily in those Facebook groups asking other MISinformed people and they come up with the most RIDICULOUS answers ..... Thank you once again... Hopefully people pay attention and learn something .... GREAT VIDEO once again....👍👍

[@bigvell02]

I use to love to fight and I was pretty good at it too. Impedance Rise I will be looking for that guy when I see him we will fight! I'm being silly - Great video bro! Look forward to hanging out with everyone in 2019 :) :). Sundown and EMF its almost like Bass University and learning from Bass teachers with PhD's. Seriously I use to go back and forth trying to explain that the impedance rises with different frequencies with out a box.

[@maxfmfdm]

In at least some cases when impedance goes up efficiency also goes up so you are actually getting the same output for less power thus reducing the strain on your coils amp and power system. It's not always a bad thing.

[@ericremple6395]

????????????????

[@maxfmfdm]

@@ericremple6395 I'll put it in words you might understand. Moar powa not alwasy needin mora powa to be moar!!!!..11111

[@ericremple6395]

​@@maxfmfdm Not how it works idiot go to science class

[@Gr8rome407]

It will never be more power or even the same power with impedance rise its the same as if you wire your suns to 4 ohms your amp with give you whatever its rating @4ohm never will be the same as power @1ohm

[@maxfmfdm]

@@Gr8rome407 i seriously have to re-explain a 3rd time for you... there is sound pressure level power and there is electrical power. if you get impedance rise but also gain efficiency then you can still have good output in terms of sound pressure level. this is not just wishful thinking this is a literally reality for all subs. you have an impedance curve and also an efficiency curve. what matters is the sound output and if you can get that output for less power then its better not worse.

[@08magnumsrt]

Many years ago, stinger had an item called the acu match, which would keep the impedance at a steady level if I'm not mistaken. I wonder why that never stuck or became something gonna use today.

[@diciple909]

Thank you for the simplified explanation. It helps a lot!

[@peterb7399]

Can you please fix your audio level on your videos .they are always very low .thanks for all your cool videos.

[@jr1001jr]

Basically @ 9:55 = "... Just, Send-It"!! 😎 🤔🤷‍♂️ .... 🤣🤣

[@phillipvill]

Good video . i allways thought something was wrong with the people that try to fight box rise. Accourding to ur study. The surround being thick foam along with stiff spiders, i could see how it gives it big bigger rise on low frequencys

[@bk3720]

Been working with speakers for 20 years. Never heard of “box rise” before. I only knew of impedance rising at cone resonance or box resonances or from coil inductance. My favorite myth is that underpowered subs blow. If this were true, I would have destroyed many a speaker with an iPod (they don’t even put out a watt of power). Driving an amp into square wave clipping can over heat a sub though and fry it. Adding a low pass passive filter to a sub can be an insurance if the amp overdrives as it will reduce the higher order harmonic distortion and lessen the power and not hold the coil still with power running through it. Myths in audio probably get started from uneducated people and spread to other uneducated people. FYI, the video failed to adequately address why the impedance was changing. In the demonstration of the sub being tapped, the sub was converting the mechanical energy into electricity which would throw off an ohmmeter. In the demonstration of playing different frequencies, the impedance was changing due to the speaker’s mechanical cone resonance. Voice coil inductance was not mentioned either which raises the impedance as frequency goes higher and the inductance roll off the speakers response (this is generally not an issue with car subs as they are crossed over before coil inductance becomes an issue).

[@official_iziah_key]

Whats name of this software you are using on your pc?

[@tammyforbes2101]

I don’t even check mine I just wire it to 1ohm and Rock it. When it sounds distorted I turn it down. I run everything at about half to 3/4 gain and that’s always been about right! I set my amps so no one can twist the volume nob and blow anything. They can turn it to wide open and it want matter cause I got the gains down!

[@girthquake9655]

Aaaaawwwwww yussssss.... Why am I just now seeing this!

[@floydwilliams3321]

Nicely explained

[@lowhertzhighspl]

9:20 What To Do? Simple, upgrade your amp to one that puts out at least 200% - 500% of what your subs total RMS ratings are. It's what I have found to be successful for my setup. 😁👍🏻

[@akuma4u]

Or build a bigger box

[@primalgeek]

Fantastic video Derrick

[@got2getit204]

Well I bought the taramp Smart Bass 8 and it fight rise so you get the most out your amp I rose to 2 ohms most stayed 1.8 and you still get close to 8k at 2 ohms so as long as I stay within .5 to 2 ohms I’m good and the smart technology helps you stay in that range I mean hell I’m sold!

[@holdDeez1993]

So how would i set the gain voltage cuz at 2500 watts it should be 50 volts but since box rise thats means id have to set it lower?

[@JohnNolteAudio]

Once you install that sub into a enclosure you'll have different readings, this is called box rise and yes you can adjust it within the design parameters of the enclosure.

[@FinancePro203]

Absolutely correct. Can’t defeat it altogether, but with proper planning, you can take some control back.

[@akolngto9314]

So what is the best hz for our box sir regading wasting of power? Is it 32hz? Or 40hz?

[@JasonWW2000]

@@akolngto9314 Every sub, every box and every vehicle will be different. If you really want to know, get a Dayton audio DATS3 and it can show you the impedance curve for your specific sub, box and vehicle combination.

[@gfunk702]

The way i understood to deal with impedance rise was to make or pick a box that gets the most exscursion withing the woofers safe max limits but yet have the correct size port and tunning frequency that pulls the max power within safe thermal limits the coil can handle. Impedance rise is a function of the woofer, theres nothing wrong with it but can sort of be controlled or in a sense tuned to get the max power efficiency of the amp and woofer by what box its in along with other things like the way its wired and the general ranges of frequency the woofer will be playing. Id imagine that the manufacture box building recomendations for their woofers incoporate the use of impedance rise to achieve a general decent amp power consumption and woofer performance effieciency. But impedance rise is very variable and not something that can really be completly controlled because how various the ranges the frequecy signals being sent into the woofer, unless you are only playing 1 frequency signal through that woofer then the box can be made to optimum size have a port tuned to get max power out of the amp into the woofer for that 1 frequency its playing since now pretty much ur whole setup your a tunning for is now a satic non variable situation. Im still learning about this subject so hopefully im not unintentionally giving bad info. But never the less that how i understand it at the moment. Very cool video though. The title did grab my attention since you used the word fight in refrence to fighting impedance rise or box rise..lol.

[@jkrollin5180]

Good vid man i wonder if companies should start putting specs for that independence rise but as u stated its if you really that worried about still good shit appreciate the info.

[@UnofficialAudio]

Impedance rise will be different in every setup so its impossible for companies to have a "spec" or "rating" for it.

[@u9Nails]

Can we talk about box parameters in the future? What makes a ported box more or less ideal for a specific sub? How does the box tuning frequency work, and is that specific to the woofer or to my taste in music? How does the box volume effect the speaker?

[@californiajack1244]

Which amplifier fights box rise more? Full bridge vs half bridge?

[@dead6last]

.. taramps smart series

[@JasonWW2000]

Full bridge and half bridge are amplifier topologies. It has nothing to do with what the speaker load is. Certain amps are designed to deliver their rated power over a range of impedances. Those are great. Taramps smart series as said earlier. Jl audio slash series, Rockford CP series, etc...

[@DeathLikeWebz]

Impedance rise is a given, what I think people think with box rise is the additional resistance added to the coils with the subwoofer being in a box. Especially when the box is not designed properly (smaller air space/ port area)

[@Demobrosofficial]

The answer is get a scv7500 to fight the power loss. End of story

[@riveralley]

Simple

[@Lifted_King]

🤘🤘🤘🤘🤘🤘🤘🤘

[@jamesbondcaraudio4247]

_1_ stfu already dude. YOU DONT SOUND SMART. YOU ACTUALLY SOUND LIKE AN ASS.

[@jamesbondcaraudio4247]

Daniel King what happens when the impedence is at its lowest point while playing. Won’t it be sending a lot more power then the sub can handle?

[@Demobrosofficial]

James Bond it don’t stay down long... it’s more high than low

[@bassbuildscarlmeadors6650]

ok questions. if a amp is one ohm stable and sub ohms always rise why cant we wire below 1 ohm and get away with it

[@MazdaBass971]

Well explained Derrick.

[@3RDERA]

Nice video, some people would say buy an amplifier that does the same power ratings 1.5- 4ohms. Like a jl audio or fosgate amp. But I agree with what @barevids said, use impedance rise to maximize and utilize your system properly.

[@AndrewB23]

Or like you said at the top buy an amp that can do the work for you, and have a clean signal.

[@slojoegtstang5775]

What video were you watching. This video was crap! He explained how it functions basically but didnt tell you the most important part and that is you have some control over it with your box tuning.

[@martinmi5]

Impedance rise makes a lot more sense.

[@2025944]

I’ve got 4 vd-12s and I’m doing 140s in a 6.5cube box with a 10 inch aero but I checked it with the amm1 and they’re getting like 500w rms to all of them and they’re on a rp2000 I knew I should’ve gone with the 4500 but dam I’ve spent enough on everything. I would love to float the towel bigass ports sends with they’re ports and I think I could with 2k rms to them but I will never know because I have stock electrical and bigger amp a lil sketchy cause of that 😂

[@michaelk2378]

This doesn't explain thermal rise. Please leave your meter on ohms across a voice coil and place the voice coil above a heat source to bring it up to full operating temp. Then let us see how much the impedance rises. We can't control frequency-based impedance rise but we may be able to design for thermal rise if we knew what it is. Thanks!!!

[@Zack-dk3pt]

it seems to me that if you do manage to minimize impedance rise you will in turn lower the effectiveness of the sub. i can tell you one thing you can do that will actually help though and that is to get a box or design a box to amplify your target frequency. resonance is your friend. lower frequencies are supposed to consume more power than higher but for me that is not the case. my setup makes a anything around 20-30hz ish consume less power than anything above that at least according to my voltage. i'll be honest i never actually clamped it to see the difference in amperage but that shouldn't matter when i can see my voltage dropping to 12.6 at 35hz but remain above 14 at 25hz.

[@pierregervais1567]

Great video! What's the Software on your laptop?

[@UnofficialAudio]

TermLab Magnum

[@pierregervais1567]

awesome!...thanks for replying!

[@smokeythomas4407]

Perfect explanation

[@Demobrosofficial]

That will change in a box . Because there will be resistance on the sub. Right?

[@dbjunior1238]

Yes. Different volume boxes and different tuning will change the impedence curve and spike size. What he didnt explain is when the impedence is at its highest is also the most efficient. The subs resonant frequency will be its highest impedence. When put into a box that will shift depending on box size and tuning. A sub unloads so easy below tuning because there is less box resistance and more power being delivered to the sub. At tuning box pressure is at its highest and power at its lowest. If you are competing you fight this with bigger amps. Daily and demo setups wont be able to push the power limits because of the lower impedence frequencies sending much more power to the sub during music.

[@jamesbondcaraudio4247]

Dbjunior 123 nice explanation 👍🏼

[@johnviera3884]

Why does the cone excursion go down as resistance goes down? At 50Hz there’s higher current and more watts but the cone moves less

[@clydesharman2053]

So it sets me back a bit I saw a video of a guy use a DD 1 set his gains correct on a 500w alpine amp Then when he played music he used another SMD tool like the DD 1. His impedence changed as you said it would but he clipped at 135w not at 500w How does this happen? Should we set gains according to impedence rise of a certain frequency or Set gains at the resting impedence? How did the guys amp clip when I just watch him set his gains correctly using a DD 1 then next thing on music it clipped at 135w ??

[@JasonWW2000]

He should have set it so it does not clip at all. Anyway, its certainly possible to clip at lower power as the amps power falls off based on the load. 135w is probably max at the higher ohm load the amp was seeing.

[@cristovalmontoya5222]

Can you just get another dual 2 and run amp amp at .5 and will rise to 1 ohm.

[@JasonWW2000]

Yes, usually. It may never go below 1 ohm or it might dip a little below. If the amp can handle that, it should be fine.

[@southsidemikevlogs]

whats a good way for fine tunning so your not bottoming out your voice coil because i play all kinds of music like from bass bosted and on just trying to find out some better way of tunning i was 40hz 0db test tone

[@b1782w]

Derrick would the resistance be at its highest around fs or fb ? Also maybe i missed it but does volume affect it or does it not change ..have an amm1 ill try today just incase u dont respond lol

[@b1782w]

Okay replying to myself after doing some testing for anyone who wants to know volume did change impedance but inversely was not what I was expecting at super low volume impedance was slightly higher does not change much but turning the volume up actually lowered the impedance by a couple tenths but in response to the other part of the question yes FS or box tuning frequency impedance will be highest at that point okay thank you Brian... You're welcome

[@RyanBassForLife]

Nice I learned someting.

[@long-dongvonbraun501]

One thing I tell people is ambient temperature can affect impedance. I live where it's 10° in winter and 100°+ in summer.

[@303nitzubishi4]

Great demo this is good info for folks who are not yet familiar with the science of reactive subwoofer loads. You didn't mention the fs of the sub, that is a crucial piece of info to add to a benchtop demo like this. I do completely disagree with your theory that box rise is not a big deal and can be dismissed without much consequence. Port and enclosure tuning is crucial in ANY system, big or small, regardless of the cost or quality of the equipment you are using

[@303nitzubishi4]

Ronnie Smith didn't hit 150db on two 6 1/2s by ignoring box rise

[@the_slow_sti]

How to "fight" box rise? Well you shouldn't fight it, you should embrace it. How do you alter your impediance rise and take advantage of it? Box design. The efficiency of your speaker enclosure directly relates to your impediance rise.

[@kingskingsmanship]

Fight box rise with a box tuned properly. Free air is the worst impedance and sealed is more stable. Box demention and port will significantly improve how loud a note gets. If it's still not enough then up the wattage.

[@RobHTech]

Does Sundown use actual dual VCs, or is it just once VC with 2 windings? For example, a B (no name) subwoofer has 2 Ohm DVC and the same B sub is available as 4 Ohm SVC, which is just both coils connected in series on the coil itself. So, does Sundown sub use DVCs that are ran the entire wining height? Also, if you wire the input to coil 1 then 8 gauge over to VC 2 in parallel, does the sound change because it takes just every split second longer for the power to get over to VC 2? What are you using to make the impedance measurements while also playing and showing V and A?

[@JasonWW2000]

Almost all dvc subs have their voice coils running the full length, top to bottom. The voic coils are one on top of the other, though. They share the magnetic gap. They allow 2 different ways to wire them, either series or parallel. There is no noticeable time delay.

[@larrywright7090]

Great video.👍

[@Life_and_Love]

To fight mine I just wired my sub to a lower ohm on the amp. You would need to run your system and watch the ohms so that you don’t hurt your amplifier.

[@Had22s]

Or get a SMD IM-SG and use it to see what your impedance is at all frequencies.

[@Life_and_Love]

Had22s I don’t need that to see what my ohms are at all frequencies. You can just use a good voltmeter.

[@donjaun540]

OMG box rise. Will more power help??

[@ceciljones1248]

That's why you can wire 2 one ohm subwoofers together and it will never see a half ohm load when the impedance rises?

[@riveralley]

With the 9 Nsv4 15s van can you show thing getting flexed around the sundown audio factory?

[@fasterthanaturtle]

Customer service is half the quality of a company. I respect SA. EXO had custom coils made at I think .75 ohm in series to help combat this issue

[@legendsofcaraudiobradnewso8424]

Great video bro! well explained

[@bassmansl9596]

Good information

[@1-Six-dee]

I consider box rise when u put a few subs n a box and have two dual one ohm subs and ur final load not being what it should be it rises higher than the math formula to

[@eldergoose4075]

The Rockford bdcp series is an attempt to fight this immense rise correct?

[@sbeezynukka]

kyle gray to a degree, but jl audios amplifiers are more geared towards trying to make maximum power from 1ohm to 4ohm where it falls on its face is once you get to 5ohm to 60ohm which happens while in play.

[@teeone10]

which one will fuck your amp up, wiring 2 subs with different ohm loads but not under 1ohm, or wiring below 1ohm say to 0.5 to combat the box rise?

[@bobbybland9497]

but cant the box design change the ohm rise?

[@u.s.dirtneck6777]

🇺🇸🌱SO WHEN YOU PUSHED ON THE CONE, IT PRODUCED ELECTRICITY LIKE A GENERATOR? OR IT'S RESISTANCE WHENT UP?🍃

[@JasonWW2000]

It produces electricity. As the sub plays the mechanical parts of it pull the cone back towards center and this feeds an electrical signal back into the amp. This is part of the box rise and amps are designed for this.

[@ArnoldGaming]

800-1000w rms sub on a 2.4k (less cuz was rated at 1khz), but wired at 8 ohms bridged ouch.

[@zoominnboomin]

What I did to combat impedance rise is add one sub wired to 8ohms to a pair of subs wired to 1ohm. I rolled the dice and turned my amp on. Turned it up and it's been fine. Never getting hot. I check the impedance and it's at 1.4 ohms. Before, it'd was at 2.5 ohms. Now I have more power but going through 3 12s. Sounds great though, and louder.

[@JasonWW2000]

This is definitely not recommended as the power is not evenly spread across the subs. Your probably hearing the 2 louder subs and the 3rd is tagging along at a lower level.

[@LottoDub720]

I want to get six ct sounds ozone 10's(would be 4800 rms total and 9600 peak total). they will be dual 4 wired in series parallel to 1.3 ohms total impedance, powered by a sundown salt 8k. would the rise be too much to get the 9600 watts peak with a salt 8k? or would it be better to get 2 or 3 amps for those 6 10's?

[@LottoDub720]

2 or 3 smaller amps*

[@LottoDub720]

because I have seen your video salt 8k dynoing at 6k watts at 2 ohms but forgot to take into account impedance rise

[@LottoDub720]

also with have at least 9 cubes for those 6 subs

[@RockfordF150Bass]

Well said Derrick!!

[@MikhailFelton]

Great video.... I would say to beat rise just get a slightly bigger amp.

[@Catholic1391]

What if I do half a ohm will it be ok for the subwoofers?

[@johnstarks5323]

power compression or thermal compression is a loss of efficiency observed as the voice coil heats up under operation, increasing the DC resistance of the voice coil and decreasing the effective available power of the audio amplifier.

[@lowhertzhighspl]

I purchased 2 DVC 4-ohm subs which I have wired down to 1-ohm but when I carefully measure them together they settle down at 1.6 ohms. This pisses me off that there's nothing I can do about it other than now needing to upgrade my amp from the 3,750 RMS up to a 5K. Right or wrong?

[@dcole808]

I checked the final ohm load when wired up too. Then, went up 2x-3x(per DD Audio) the final ohm load then I decided on the amp RMS need. Worked for me.

[@chrisgriffin3374]

Awesome explanation

[@Butrdtostngravy]

In other words... "shh... Just let it happen"

[@slojoegtstang5775]

Wrong. You can make it work in your favor he just didnt tell you how.

[@jr1001jr]

@Michael J ... just "Send It"!!! Lol 🤣

[@Thatloudfit]

To manage my raise I wired down low to 0.5 ohms goes to 1.1 ohms on really cold days I’ll stay 1 ohm flat

[@joshholden8561]

How to fight it wire low and have a superb electrical.

[@teamloudsavagez868]

So my question is with this is it better to have dual 2 ohm or dual 4 ohm subwoofers

[@brandonreeves6391]

Ones not better then the other, it just depends on the final ohm load you want... If you don't understand i can go into further detail..

[@teamloudsavagez868]

Okay thanks I meant to put this question in there too so with the impedance rise so when I find out when my subs hold 1 ohm at a certain tone do I need to build my box to that tone

[@Thezuule1]

I have a JL 250/1 slash series with the regulated power supply in it. Does this amp adjust output based on box rise or only based on the base impedance of the subwoofer? Something I've always wondered.

[@JasonWW2000]

A regulated power supply simply means that it can output the same amount of power over a variety of input voltages. In other words it can probably deliver rated power if you feed the amp anywhere between 10 to 15 volts. It really has no effect at all on the output power.

[@JasonWW2000]

Some of jl audios other slash series amplifiers do have a type of constant output from 1.5 ohm to 4 ohm. Not the 250/1 from what I can see.

[@Thezuule1]

@@JasonWW2000 the OG slash series 250/1 has a regulated power supply. Still have mine. You say it has no effect on the output power but that's entirely the point. If I give it a 1.5 ohm load or a 4 ohm load it makes sure the output power remains the same. My question was if it compensates for fluctuations in resistance caused by box rise. If my 1.5 ohm subwoofer rises to 4 ohm during operation a typical amp would be putting out around 1/3 the wattage but one would think a regulated power supply could adjust for that. I just don't know anyone that can answer the technical end of that.

[@JasonWW2000]

@@Thezuule1 I think there's some confusion. The ability to output similar power from different ohm loads happens in the output section, not the power supply or input section. The power supply is what takes 10v-15v or so DC from the battery and steps up the voltage that the output section uses. So a regulated power supply is able to maintain the same high voltage AC that the output section needs across a range of DC input voltages, like 10v to 15v. So when there's a big draw of current and your battery voltage dips low, the amp can still maintain rated power. The part where the amp outputs similar power from 1.5 ohm to 4 ohm is a separate output section design.

[@JasonWW2000]

@@Thezuule1 To answer your question, just look at the specs of your amp. It should clearly say the power output at different ohm loads. The basic way these output sections work to deliver the same power at different ohm loads (at least for Taramps Smart series) is they design the amp to make full power at 2 to 4 ohm and as the impedance goes lower they kinda clamp the high voltage rails to prevent it from trying to output more power. The way they do that is quite complicated. Different companies use different techniques. I just looked up a JL amp, as I'm not familiar with them, and I see they use some confusing terminology. They say "The regulated power supply allows this amp to deliver its rated power to a wide range of impedances (1.5 to 4 ohms), even when voltage levels drop during heavy use." So apparently they are using their own design which does utilize the power supply section in some way. They don't get in to details, though. Thats interesting. So traditionally an amp with a regulated power supply like from the 80's, 90's, 2000's, usually class AB, is just to help the amp do rated power regardless of your battery voltage. JL is using a more complicated setup that uses a regulated power supply to help the output section do rated power across different ohm loads. I hope that makes sense. So as far as your model amp, what do they rate the output power as? Does is say the same power from 1.5 to 4 ohm?

[@lowhertzhighspl]

? The enclosure has nothing to do with Box Rise? But DD Audio says, "Now, If you play a sine sweep through a free air woofer the Fs, or free air resonance frequency, will become apparent as the woofer will move the least at this frequency. This happens because the impedance peaks at the Fs so your amplifier will have the lowest output. Now, if you put the same woofer in a ported enclosure and play the same sine sweep something different happens. Instead of peaking at the Fs of the woofer the impedance will begin to rise after the tuning frequency of the enclosure and will peak anywhere from a quarter to a half octave above said tuning frequency. Due to this phenomenon the average impedance the amplifier will see while the woofer is being played rises from what is measured at in a resting or reactive free air state. This impedance shift is highly dependent upon the enclosure and how the enclosure interacts with the vehicle it’s in, so there’s no way to calculate what level of rise you will before the system is installed." What's correct? Source: ddaudio.com/5183-2/

[@Pittsburgh-412]

You can get a Rockford fosgate that has constant power at all ohms. And I think it's important to know that if you check impedance while the sub is on its side, that will effect it and not always read right. Good video dude

[@RyanBassForLife]

Is it better to wire under ohms to fix this problem. I got 2 Hifonics Brutus amps wired to 2ohms bridged should I wire it to .50 bridged .25 ohms per amp to get more out put seem how after rise its seeing way over anyway?

[@UniCrafter]

there is one way to fight impedance rise, with a smaller box, though you sacrifice efficiency so yeah

[@jr1001jr]

👍👍 I've heard that before. The larger an enclosure is [to a certain point] the more efficient it will be... the more efficient an enclosure is, the more "rise" you will see... thus, a larger enclosure = more rise. Moreover, the smaller an enclosure is [to a certain point] the less efficient it will be. In the end, a [smaller] less efficient enclosure = less rise. I believe that I read that theory/school-of-thought some years ago. 🤷‍♂️

[@sethgt1234]

I have never once checked or been worried about impedance rise. I guess I was born and raised around family members that taught me everything about electronics. My grandfather was an electronical engineer and invented the first push button radio for GM way back in the day. He had the Paton for the wonderbar.

[@wreckless_-jl6uu]

Where did you those braces you have in the demo van???

[@UnofficialAudio]

Scott Bowman Customs. Look him up on facebook.

[@teeone10]

i think i get it now, we always hear amp stable at 1 ohm or 2 ohms etc. so if you wire at 0.5 or where your amp is unstable you will have opposite of box rise you will have box fall, and thats when your amp cooks. the unstable part means your amp will drop all resistance at any given point ,then you get the smell , then its too late

[@JasonWW2000]

No, no. Thats all wrong. There is no such think as box fall. It always rises. Playing music it will never get down to its measured DC resistance. Wiring speakers to 0.5 ohm on a 1 ohm stable amp should be fine because it will never get down to 0.5 ohm when playing music. It will probably be between 1 and 2 ohms at its lowest. Amps don't usually cook due to too low impedance. Most have protective circuits that turn them off. All subs can only dissipate a certain amount of heat. If you overheat them the subs will fail. Even at low power it is possible to feed them a clipped signal and that causes s tremendous amount of heat. You never want to send them a clipped signal. Anytime they start to get warm to the point that you smell them you need to back off the volume and let them cool down.

[@jonpatterson6479]

#SundownAudio if an amplifier is rated at 1 ohm, most class D amps are, why couldn't you wire your system lower than the 1 ohm. It's seems that at nearly every frequency the impedance rise is always higher than the 1ohm. So even if you're wired to ½ ohm, the amp should never actually see anything that low? Hope my question makes sense.

[@JasonWW2000]

Yes, this typically works. Some combinations of sub and box might see a load of 0.9 or 0.8. As long as the amp can handle that it should work. You can also test the impedance with a Dayton Audio DATS.

[@alanchatfield4271]

In my world this is why we have program power and rms, basically double rate your amplifiers, as they will always half,,

[@stevejr4185]

So this means it's okay for me to wire two svc 4ohm sub with 2ohm wiring in parallel to a 2ohm load amp even if the sub is not rated for 2ohm?

[@stevejr4185]

@whatinthefuck shitniggadawg oh ok thanks bro 👍👍

[@JasonWW2000]

Yes, its fine. Subs are not rated to 2 ohm, they are rated AT 2 ohm. Your 4 ohm subs are not exactly 4 ohms dc, they are close to it. With music they should not dip below 4 ohms. So wire them into a 2 ohm load as long as your amp can handle a 2 ohm load.

[@Mistabigge]

Don't fight it. Embrace it. 😎😎