Kicker WARHORSE - How tf does it work?! Subwoofer amplifier

Please excuse the bracelet, my girl made it for me and imma wear that shit with pride! Anyway I couldn't pass up on this opportunity to show you guys first hand a couple of things about this very unique amplifier from back when 10,000wrms was pretty ridiculous from a single amplifier. I hope you enjoy!

[@wal]

These came out in 2008 and at the time only the Rockford Fosgate T15kW and JBL Crown A6000GTi were in this class of power. All of these amps were hella expensive, the Warhorse was $9999 USD, while the JBL was $7999. Rockford said "hold my beer" with the T15kW's $24,999 MSRP and the most limited production with only 20 units. KICKER planned on 1000 Warhorses, but the economy tanked in 2008 and they ended up producing "only" 750 Warhorses. I've been unable to obtain JBL A6000 numbers, but would suspect somewhere in the 500-1000 produced. Sam, as always your videos rock. Thanks for taking the time to make this, I may need to borrow a short clip or two for my full video on the Warhorse upcoming 👌

[@chrisvinicombe9947]

Thanks for the vieo today looking forward to seeing it dyno'd. Gonna be some dummy loads getting a nice cooking 😀

[@southjerseysound7340]

Jams 20 min or more worth of info into a 8 min video, love the no BS approach.

[@firebirdude2]

YES! So hard to find that anymore. Ugh.

[@tmmtmm]

This is called tri-state pulse width modulation. The output can be either 'high' (positive voltage), 'low' (negative voltage) or 'high-Z' (high impedance, disconnected). The implementation with requiring dual voice coils and only putting the 'high' output on one coil and 'low' output on the other coil is probably because they are implementing boost conversion (like a DC-DC boost converter) as well to get 200V on the output instead of just 12V. Combining the two boosted outputs back together would probably require an enormous transformer, and since dual coils combine the signal back together mechanically anyway it's easier to just do that. Tri-state amps with a regular split-rail powersupply, no boosting and single output are far more common. The benefit of tri-state is that it is more efficient as it does not have the quiescent power draw of having the output state constantly switching even when there is no signal present. If nothing is playing there is zero power draw from the output stage. The disadvantage is that they produce more distortion because in order to produce smaller signals they have to produce very short pulses, where as a 'regular' bi-state Class-D amplifiers are only required to produce very short pulses when the output signal is very large and almost clipping. If the required pulse becomes shorter/faster than the time it takes to turn the transistor on and then off again, distortion occurs. You'll find tri-state Class-D where audio quality is not important, but efficiency and size are, such as for the internal speaker in your smartphone.

[@ebarbie5016]

Wrong. No such thing as tri state pwm. It could be a three level pwm with zero voltage mid state not high impedence as it will not allow inductors to discharge..

[@travishoel3755]

Wow that was a really cool explanation on how the Warhorse works. I always wanted know how it works

[@FelixBank]

The cross-over distortion on this thing is hilarious!

[@eurekaakerue4649]

❌✅ A/B amps have this too if the feedback is not correct// but you can’t feedback on this type because it’d be a short and probably kill some FETs I use to build low power amps just like this before kicker as a hobby but I thought no one would buy a amp that you have to wire like dual VC like that 👋😉 I was wrong 😝 it is superior and efficient in its design 👍 I expected a return of this type when components catch up to the design it is superior 👋😉 most don’t know it yet‼️remember you heard it here first //// this design will come back as the best soon P.S. ; for Subs🤔‼️‼️‼️‼️‼️‼️‼️‼️

[@vincentrobinette1507]

Besides the zero crossing distortion, I don't like driving each coil half wave. The reason: by cutting the duty cycle 50%, you can only increase the coil current by the square root of 2.(1.4142135). That's because the heat dissipated in a conductor goes up on the square of current. Therefore, you cannot double the current, just because you apply it for 1/2 the time. With both coils, that means you can only operate the sub at the square root of .5.(.7071067) Running both coils, full wave, really does give the woofer its maximum power handling capability. That's why this is such a rare amplifier. It's a fascinating concept, but, it's NOT the amplifier I would choose.

[@karl6823]

Vincent Robinette wow your knowledge is impeccable much respect brother, I know I would not choose that amp I definitely would hear that in the signal

[@vincentrobinette1507]

@@karl6823 Although this amp would sound OK cranked up, the zero crossing would be painfully obvious at low listening levels.(He DID mention that in this video)

[@cekpi7]

Agreed, this is one of those amps you put on wall because it's amazing but you wouldn't put it in your car and listen to it :)

[@tmmtmm]

Correct me if i'm wrong, but although running half-waves through each speaker coil will make them run hotter at the same overall power, the actual efficiency of turning battery power into acoustic noise isn't reduced because the amp still runs at higher efficiency than a regular Class-D and the same overall flux is generated by the speaker coil assembly. So it's still a winner if you're electrically limited and not coil power handling limited. Edit: Actually that's wrong, this amp topology is a system efficiency failure. The overall current is the same as before (to produce the same magnetic flux), but the voltage is higher because the amp sees a higher impedance with only 1 coil at a time. Power = current^2*impedance so the power needs to be higher if the impedance has increased but the current has remained constant. e.g. If you had a dual 4ohm setup in parallel on a regular amp with 10Arms coming from the amplifier, each coil recieves 5Arms. 5A*4ohm = 20Vrms. 20Vrms into 2ohm = 20*20/2 = 200watts. If you use this topology you need to push 10Arms through a single coil to produce the same magnetic flux as before since magnetic flux is proportional to the current in each turn multiplied by the number of turns. Half the number of turns, twice the current in each turn to achieve the same magnetic flux. 10Arms*4ohm = 40Vrms. 40*40/4 = 400Watts. So before even factoring the potential efficiency benefit of the electronics, you have to make twice the output power to produce the same acoustic noise. The power handling of the speaker coils is actually half not 0.7 because they need twice the power put in to make the same noise. It's basically the same as if you removed one of the coils from a dual coil woofer - you're going to suffer a drop in sensitivity and have to drive the remaining coil really hard to make as much noise as before.

[@cekpi7]

@@tmmtmm Coils wouldn't run hotter since there is only half wave at each coil (not full wave like it would normally be) however with more power than they can handle ofcourse they are gonna heat a lot. You are correct, some say warhorse can get as much as 99% efficiency you can get about 2kW more with same current draw (class D 8kW vs 10kW warhorse).

[@lifewithmarleyandjon4616]

Love your quick to the point technical explanations. Your pretty much a car audio genius

[@josephmuniz9959]

Dude you really really know your shit. I enjoy the videos a lot. I feel like I learn something every time I watch one of your videos

[@H3adcrash]

Hahaha wow! That crossover distortion is hilarious. It's like they decided to audio modulate a stick welder or something.

[@orangejjay]

I can't believe this thing was $10000 and had such ridiculous distortion. Garbage from Kicker, once again!

[@ze_german2921]

This is such an underrated Chanel!

[@TS_sound]

Great Video ! Crossover point was terrible...like a purely bad designed fully class B amplifier... I actually enjoy a lot these quick 10-15minutes videos !

[@anthonyvolkman2338]

Truly amazing how a T-path amp works. Ive rebuilt many amps but never got my hands on one of these yet.

[@Everett-xe3eg]

i loved this video. That amp seems very powerful but damnit if that sine wave didnt get my jimmies rustled. cheers mate always appreciated

[@seanperdue232]

Wow, what a great video. Your knowledge of this stuff is very impressive. Keep doing what you do.

[@jdrissel]

Awesome video. I wonder if they ever made a DVC woofer with the windings split so that one was suitable extending and the other for retracting. It would likely gain 3 to 6db of sensitivity. The next idea is to do more of the same with feedback of cone location. The then only drive the part of the coil that is in the gap at the instant... This might be good for 10 to maybe 20 db of increased sensitivity, depending on how many segments are used.

[@bkrgls]

Very informative video. I remember when these 1st came out. My buddy wanted one so bad, but neither one of us could afford it at the time. Just to upgrade the electrical that was needed to power it was too much for me. I've never seen one in person...so it was always a unicorn to me. 😂😂 It seems like it was a fusion between new tech at the time with some old school class A/B tech with some serious crossover distortion. But I would still like to see this thing perform. 👍✌

[@joshhanson6777]

these things are supposed to be some of the most efficient amplifiers ever produced.

[@thenotoriousrvh6091]

Dang thats crazy helluva built amp. Would love to have one of those on 2 Solo X 18's. Interesting design, Why do you suppose they went that route rather than a traditional design ?

[@barevids]

I have a guess that this may have been the easiest way to get 10K back in those days when mosfet tech wasnt quite as good... supposedly efficiency was also close to the 90%s with this thing. It would need testing to be certain!

[@vincentrobinette1507]

I have to admit: I love those output inductors!!! (I don't like the topology)

[@lmadden6236]

Unusual design.. Glad you made this video because I almost bought a new unused one. My woofers wouldn't work even though I can wire them @ 2 ohm. I would need dual 4 ohm woofers and I have dual 2 ohm.

[@ChrisProvazek]

excellent video bro! Did you know the topology of this amplifier or any type of general workings of it prior to getting it?

[@kennedywong9854]

Best car amplifier and gonna buy one.

[@crunkwun]

Seen 1 of these in my local car audio shop back in 2008ish.. they had this amp and the JBL crown amp that was still in a crate..

[@travis4798]

Yep, purely a spl amp. Interesting design no doubt. I'm not a fan of kicker but I respect the Warhorse.

[@markhatcher4325]

I'm learning a lot from his vids thxs Sam 👍🏁🏁👍

[@2011joser]

Great information. Thanks for the video.

[@Nissanalltheway]

I hope you get to open up the new warhorse

[@vwsculler]

Nice explaind mate!

[@llegacy1870]

Great info and what a super amp. Would love to have one.

[@fromsdtoep8511]

Always a pleasure brother!

[@randomtube8226]

This was Kickers attempt at a servo controlled system for your car. This technology is found in Rhythmic and Reveal home powered subwoofers.

[@ruikazane5123]

I wonder if Barevids can get a glimpse on the huge amp that Rockford Fosgate made...probably not because they won't really break?

[@yaghiyahbrenner8902]

1) 6:19 The crossover point of the sine wave has the short dead-band of ~ 10us or so because the class-d output switching mosfets requires a dead-band where both switches are off at the same time to prevent shot through, now the amount is targeted for low THD (total harmonic distortion which makes the amp runs hotter) VS high THD cooler amplifier. 2) A dummy load a must? this looks like an older generation class-d technology 10 years, where the modulator technique required a load to work.

[@fabriziobrutti1205]

Wow very interesting!! 😃

[@jamesrobinson9176]

Does it have a damping factor of 0?

[@Bassotronics]

Is there a way to have a ‘buffer’ to quench the “off” section of the sine wave?

[@josephrabant7432]

I wonder how these new(2023) kicker 3,600 watt warhorse amps are built?? Completely guessing they are built extremely different than these...not that I really care just curious to see.

[@numlockkilla]

Thankyou for showing a different breed of amp. Please more. Maybe a tube amp. Like a butler

[@AntDaddy1977]

I have a kicker Ix 1000.1 class D mono amp. A friend of mine gave it to me cause he bought a bigger one. I hooked it up and wasnt getting much output at all and noticed I had too ground the rca output before the amp started pushing. There is one capacitor I think im not sure but it appeared to have exploded. Its close to the power connections. Im sure that may b3 the problem but I dont know what the hell to get to replace it with. Any help or a schematic would be great. I love car audio and been tinkering with electronics on my free time. Im no expert

[@kinklesstetrode]

Interesting. Not seen one of these before. And, probably dont want to! Does it run headphones?!

[@davebarr1930]

I have a question,I have an amplifier that had a maxi fuse attached to the board and now it no longer does and its MIA. I got the amp from a friend cause I figured "hey, I can easily just solder on a new one and POW, Bob's your uncle" and voila, I have an amp that cost next to nothing out of the deal. So here's my question; where in the hell do you even find these "on board" fuse holders and what's the proper name for them? I've looked everywhere and tried everything with no luck of finding any such thing

[@wadehensley5005]

this amp was specifically made to work with kicker's Solo-X 18'' square spl woofer.

[@shonuff7317]

Wade Hensley all kicker subs have junk soft parts I used to love solo X's I just got tired of the soft parts failing because they are junk

[@johnpaice8481]

Very intresting thank you .....

[@RichardSablan]

I have a kicker warhorse it powers up but there is no output to subwoofers. Any guidance to know what i need to check on this amp to find the fault?

[@T2D.SteveArcs]

your bare funny blud lol what frequency do those large ferite transformers run at fella

[@kswis]

Great video! Kind of dissapointing way to make that much power. Like you said, seems it would make alot of coil heat

[@joshholden8561]

How efficient can that be and does it take a ton of caps and batterys to get loud sound?

[@MrHipwell1989]

Brill. Sam, could you do a video on the difference between class D and class AB?

[@barevids]

can do - but put simply class AB uses a pair of matched NPN + PNP transistors which generate a sine wave together, one doing top half one doing bottom half but there is a smooth crossover transition defined by Bias level class D builds a sine wave in little steps of DC by alternating a switchwave deadtime on the output between high and low side

[@MrHipwell1989]

Cheers dude. I've got an amp which seems to loose output on one channel (goes crackly) but if I turn the gain up and down a few times while playing both channels come back and work fine. Where would you start with this?

[@barevids]

contact cleaner or isopropyl alcohol on aaallll the switches and knobs. Soak them in the liquid and twist/switch them many times back and forth to clean the connections inside.

[@INCC74656I]

ive installed a few of these, they are fucking huge back in the day. we would wire bunches of l7 15's and the occasional solo X to this guy...

[@dannystrickland1447]

best way to hook up my d2 crossfires in my id pick, my crossfires are 2 of 20 built and only 2 left in the USA, i just bought a warhorse from a friend on payments, ik ill be wired ar 4ohm due to the wireing but should i go to direct leads or just wire normaly with 8ga wire ? thanks

[@NVMDSTEvil]

i've always wondered if you could take two of these amps and wire them both to the same dual-coil subwoofer. I'm sure it might take a bit of work but driving both coils 100% of the time might be an interesting outcome. Would also like to modify mine to be powered by AC input so I can just plug it into the wall. haha.. ;)

[@barevids]

Haha. Yeah you can't mod these work on mains power. Completely wrong circuitry.

[@justinkelsey9218]

And if running multiple subwoofers can u only run up to 2 dual 4 ohm subwoofers because it's only 2 ohm stable it's very confusing

[@mase7207]

With all your experience fixing amps what brand do you think is best in quality for high power 10000 and up? I see you like DD. Are they the best?

[@barevids]

the Banda Viking 10,000 and 15,000 are the best designed extreme high output boards that i have seen so far. Bulletproof and insanely powerful, and able to cope with 0.5ohm reactive. Just remember to upgrade the fuses inside of them if you intend on running SPL.

[@mase7207]

@@barevids why do you need to upgrade the fuses?

[@mase7207]

arent the viking the same as sound digital?

[@barevids]

@@mase7207 the fuses used from factory are for general daily use in brazil where impedance rise is high, music doesnt contail long low sine bass notes, and they usually play at 12v. You should ideally jump over all the fuse locations in the amp with copper bar and then obviously fuse externally as required. No, Banda Viking are very different to sound digital.

[@20hztremor]

Even though a little different from typical class d design. I wonder why many prefer class A/B over D in terms of sound quality? Even though more people today especially the younger generation say class D is just as good.

[@barevids]

It sounds better to them because they "believe" it sounds better. You can only audibly hear the difference when using extremely high end audiophile loudspeakers in a proper listening room. Anything in a car, again unless perhaps extreme high end SQ, will sound no different. If you put a sub on a switch with two amps, one class D one class AB, and set them up identical signal, no one would be able to tell which amp they were listening to.

[@vincentrobinette1507]

With class "D", the slew rate, or the high frequency response, is limited by the low pass filter on the output, which filters out the high frequency square wave produced by the switching transistors. Class "D'" is the only way to go for bass and woofers, it works quite well for midrange, but for the highs, a class "A/B" is a much better choice, because it can produce full amplitude at the top of your hearing range. Because analog amplifiers use continuous bias current, they can respond almost instantaneously to high frequency input signals. That makes them much cleaner, and less "grainy" to treble. for full range, I like class "A/B", but for bass, you don't need that resolving power, you need horsepower. Class "D" does that well.

[@jamesamalfi9303]

Hey so couldn't you bridge the outputs to a single driver using + of chanel 1 and the - of channel 2? To get a full sine wave on one coil?

[@barevids]

good thinking, but this amp requires the load to be connected to common ground to complete feedback loop. It goes nuts otherwise.

[@jamest.5001]

That's how I thought it worked, it looks like this would be be easier on the subs when pushed hard, allowing the coil halves a short time to cool, would that make a diff , who knows!

[@agnesmerlos5977]

Sorry it's 2 channels or monoblock, it works at 1 ohm and how do I connect 4 subwoofers sundown double coil of 1 ohm thank you very much for answering

[@barevids]

It's not 2 channels, it's a split wave mono, take it to someone who knows how to wire it or you'll kill it very easy...

[@Martin1519]

So if each half of the amp is operating dual voice coils individually, will the warhorse work on single voice coil subwoofers?

[@barevids]

No, it will not.

[@justinkelsey9218]

I just got one of these yesterday and I'm wondering if since it's a push pull Amp does that mean subwoofwers have to be wired parallel only?

[@barevids]

That's right.

[@bassonbudget1]

Always wondered how these worked!

[@Conservator.]

Hi, Very interesting video! Tx! Anyone: Doesn’t this separate coil setup reduce the efficiency of the speaker to 50% of its maximum? Tia.

[@boominS10]

The design was done by linear power years ago but they decided against going through with it and kicker ended up getting the copy rights and produced the warhorse

[@PoXFreak]

Probably because Linear Power were more into building powerful SQ amplifiers rated well below their actual capabilities. Think white Phoenix Gold and Coustic uA series from the early 90s.

[@Blandy929]

Seems like an over priced noise maker. That is some crazy cross over distortion! Why split the wave?? Im no expert but Id have figured using a center tapped transformer secondary would mean you can use the same transformer to drive both coils in a similar manner possibly.. and eliminate the cross over by using a push pull setup with a biasing network. Or a center tapped primary transformer with single secondary in which case it can be designed like a switching powersupply but with an audio drive wave and drive each coil with a full wave from the transformer. Could be class d if filters were added.

[@davidfuller581]

Fascinating design, for sure... Now here's a thought: why do we never seen any class AB amplifiers for car audio? Everything seems to be Class D.

[@PoXFreak]

Everything, and I mean everything before the advent of class D was class AB or some variation of A/B/C design.

[@davidfuller581]

@@PoXFreak Well, of course - it's an older topology. I figure it's because of higher power requirements (Class D is essentially a switch-mode power supply so it's much more efficient).

[@barevids]

hey buddy, 90% of car audio amplifiers that are for full range audio, and/or under 500Wrms, are class AB still to this day. It is only the subwoofer mono amplifiers that tend to always be class D, since the lower frequencies are less sensitive to sound quality degradation through class D topology and once its passed through a slow spongy transducer that being a car sub any impurities are smoothed out anyway, so class AB vs a good class D sounds the same on bass, and you get much more power and efficiency.

[@davidfuller581]

@@barevids thanks for the answer dude! I come from the land of hi fi and guitar amps, almost none of which are class D.

[@promo130]

Hey sam, are those hifonics vxi series amps any good? or a wast of money

[@promo130]

its called the vulcan series: vxi, newer amps i think

[@adisonpennings5886]

There’s an audible switch distortion and that’s how it’s designed? Kicker man what the hell

[@krystaldelacruz2010]

Great info my friend.

[@jaydee2620]

I think it was pure spl, So they didn’t care if the sound was a little off

[@ashneilroy]

Really interesting

[@christopherperdue977]

I've always wanted one till now. What a strange design.

[@dannystrickland1447]

i just picked up my warhorse this past saturday, the size of it is crazy, looks small in videos and picks

[@rob22849]

How do they sound have you heard any crosstalk or noise?

[@dannystrickland1447]

Robert Woodard i havnt hooked mine up yet, working on the electrical, will be running 3 alts and a 45ah proto bank on mine

[@rob22849]

@@dannystrickland1447 right on Danny if u ever decide to get rid of it let me know it's funny he says these have quite a bit of noise but no has said anything that I know like he said though u have to put your ear to the sub at low low volume which is minute cuz if u gotta go out your way to hear it. It cant be that bad just imho

[@dannystrickland1447]

Robert Woodard im hoping to have it all hooked up sunday

[@ratykat]

Wow I've never seen anything like that!

[@mikec4585]

How many batteries do you need to run it

[@mr.18s73]

Have you worked on a jbl gti6000? I wonder wich one does more power? Gti6000 vs warhorse..?

[@barevids]

I have one in the workshop at the moment.

[@wessleymarshall1748]

Hello buddy! How do I get in touch with you bro, I have several old school car amps that need attention, I would be very grateful if you able to take a look at them? Many thanks! 🙏🏼

[@jaideshjainarine5114]

Informative as always

[@syncmob2871]

Did you ever repaired a T15kw from rockford ?

[@barevids]

noppeee. Not even sure there is one in my country.

[@syncmob2871]

@@barevids i cannot found on the web a recone kit for my 9515 could u help me?

[@Zack-dk3pt]

@@syncmob2871 if all else fails check out psi's site they can send you a recone kit for anything

[@iinstallrva]

Finally..the classic BEAST KICKER AMP 👏👏👏

[@TheVickersDoorter]

That's a lot of low end just to listen to a Miss Marple audio book in your Vauxhall Corsa...

[@red666A]

I want Kicker warhorse.

[@hiteshdhaigude]

nice brother

[@eijigolzinho]

Never seen this amp before!!

[@slojoegtstang5775]

I used to have one of these epic monsters.

[@rob22849]

How did it sound I've never heard anyone complain about crosstalk/noise did yours having any noticeable noise when playing music?

[@chrisvinicombe9947]

That's a strange amp. Like they didn't finish it's design.

[@tammyforbes2101]

chris vinicombe have you heard one of these it’s done and then some believe me. Some ridiculous setups with this amp.

[@chrisvinicombe9947]

@@tammyforbes2101 no I've not heard one or ever seen an amp of that design before. I'm into sound quality I assume this amp is aimed at the spl crowd?

[@danielbeavers8701]

@@chrisvinicombe9947 how have you not heard of kicker???? But yea I don't think to many people who are only concerned with SQ. Obviously it's aiming towards SPL. For sound quality you can achieve that with very low watts.

[@danielbeavers8701]

For sound quality i would use "A" or AB class Amp

[@chrisvinicombe9947]

Of course I've heard of kicker 😉 just haven't seen a amplifier with that type of topography before.

[@BarrySchanz]

4:30 is that zero-crossing distortion?

[@anthonycruz8011]

Can you help me sir I used 4 gauge wire on an amp that needed 0 gauge wire and apparently that can break it so can you tell me what is broken and how to fix it

[@anthonycruz8011]

It's a machete ma2000.1d btw

[@generalkickass6385]

I had a chance to buy one of these for a 1000 bucks I passed up the chance and went with sundown

[@charliefrancis6438]

So it’s like two amps bridged out of phase ?

[@barevids]

nah not really

[@stephenborst3535]

Awesome, there's more than one way to skin a cat!

[@mazda2284]

cool amp but i hate that design lol , it seems like it would be a old design before they found a better way to do it. is unique though

[@vincentrobinette1507]

The good thing about this amp is it's ability to adapt to differences in impedance, and still produce its full rated power. This amp is just as happy to drive 100 volts @ 100 amps into 1 Ohm, as it is to apply 200 volts @ 50 amps into 4 Ohms. that means, in an SPL competition, this amp will be louder than any conventional amplifier with the same power rating, unless the impedance on the conventional amplifier is a perfect match at test tone frequency. This is a competition amplifier, more than it is a Hi Fi amplifier. If you play it loud, it sounds great. at lower levels, you will hear that 0 crossing distortion, and it may even give the impression that something is wrong.

[@danielmoraes9637]

amazing! thanks

[@arlanfalk856]

question to group. where do you find gain pots, i want to fix my soundstream amp and need new gain pots and crossover switches., thanks

[@barevids]

Mouser has the biggest selection. Takes a while to find the right one though.

[@COMPASBASSCHICALI]

@@barevids Can this amp be wire to 1 ohm ? Or will it turn on at least?

[@ze_german2921]

There is one for sale right now on eBay USA $1750

[@ubza1234]

You probably only notice cross over clicking if your forget to HPF@40hz, cause, you know... 😉

[@barevids]

The noise is induced after crossover filter, on the output stage. So crossover settings do not impact it.

[@ubza1234]

@@barevidsyou never saw this video, did you 😂 kzbin.info/www/bejne/bZmUfpx8ZpqphdE

[@TRX450RVlogger]

So in other words it's just a old school Mono Block D?

[@PoXFreak]

I'm still trying to grasp how they get a common ground for both coils separate from each other, and why they feel it's more efficient to only use 1/2 of each wave for each coil as opposed to bridging the output across a single coil as a full wave. In normal 2 phase topology, each coil has a center tap for both coils, one coil out of phase with the other. Think 2 phase home wiring in America, where one tap plus neutral equals one half of the voltage than what you'd get from both phase 1 and 2 together. Both are a complete 60hz sine wave, but tap 2 is out of phase with tap 1. The phrase "does not compute" keeps running through my head.

[@tmmtmm]

The entire amplifier is effectively just the powersupply section of a regular amp but with one important change: the supply rails are constantly variable! A regular powersupply might make a +200V DC rail and a -200V DC rail, with a common ground. Here, the positive rail can be instantaneously adjusted from 0 up to 200V, and the negative rail from 0 down to -200V. One speaker coil is connected between the positive rail and ground and the other speaker coil is connected between negative and ground - and they must be connected with opposite polarity so one can push and the other can pull. The reason you can't bridge this setup is because the positive rail can only ever produce positive voltages and the negative rail can only ever produce negative voltages. They can't both go positive or negative like when bridging a regular amp or 2 phase mains supply. If you connected a coil between both outputs of this amp, it would either push on both half-cycles or pull on both half-cycles of the sine wave: -200 bridged with +200 just makes +400V, so you can now only produce a voltage between 0v and 400V, never negative. Reversing the polarity of the connections you can produce between 0 and -400V, but never positive. Effectively that is what the half-bridge or full-bridge output stage of a Class-D amplifier is there for - it allows the speaker connection(s) to be switched so that it the polarity can be reconfigured to be positive or negative and by pulse width modulation the voltage can be varied. The 'amplifier' section is completely absent in this amp so that can't happen. They have added the ability to change the voltage by implementing variable PWM in the powersupply stage, but don't have the ability to switch the output polarity like a normal amp does. You could use a transformer with two primary windings and connect the speaker to the secondary which would accomplish an output that can go positive and negative, however the transformer would be HUGE (like the size of a woofer) because it has to operate at audio frequencies (down to 20Hz) and handle full output power. The coils you see inside Class D amps are comparatively tiny because they only handle switching signals somewhere in the region of 20kHz to 500kHz. The higher the switching frequency the smaller they can be for the same power handling. Using a dual coil woofer allows the polarity of one coil to be wired such that it can pull and the other coil push so you don't need to use a huge, expensive and heavy audio frequency transformer and they avoid the need to have a conventional output stage in the amp.

[@vincentrobinette1507]

Have you seen how the output transformer is wired in a tube amplifier? Each output can only go positive from the positive rail which is common, not negative. when one tube pulls to ground, it pulls the speaker cone in. When that tube lets go, and the other tube comes on, the coil in the transformer connected to it, is in the opposite polarity, the cone is forced out. This is called "Push-Pull". This amp uses a similar theory. the halves of the output stage can only swing positive, so they take turns. The reason you need 2 voice coils, is because one coils negative is connected to common, and the other coil has its positive connected to common. That way, when the opposite output swings positive, it's connected to that coils negative, and pulls the cone in. That creates a "Push-Pull" effect on the speaker, just like a tube amplifier. This thing even produces similar voltages, but backed with 100 times more current! The main advantage of this amplifier, is that since it uses a flyback topology, (similar to how an ignition coil works in a car) it can trade in amperage for voltage. This amplifier can produce its full rated power, into any impedance. It makes no difference weather it's producing 100 volts @ 100 amps to drive a 1 Ohm load, or weather it's putting out 200 volts @ 50 amps to drive a 4 Ohm load. That said, the amp optimizes itself to impedance changes common to all speaker systems. This amp is louder than any conventional amplifier with the same wattage rating. This is a purpose specific SPL competition amplifier, never intended for high fidelity use. You're right about the lower efficiency of the voice coil. The current that is normally shared by both coils, is now applied to one voice coil. That increases the heat dissipation of the coil, even though the current is applied for only half the time. At a given wattage, the coil will dissipate 1.414 times more heat, than if the coils were driven full wave, with a conventional amplifier. This is no problem in competition, where the test tone duration is short enough for the thermal mass of the coil to absorb the extra heat. This would NOT be ideal, for sustained fundamentals, like music with a lot of sustained bass. (I hope I haven't raised more questions than I've answered)LOL

[@PoXFreak]

@@vincentrobinette1507 I understand how that works as well as the old school "current" amplifiers made by pyramid and others back in the early 80s. What I gather from this is that the dual voice coils in the sub act in the same way as the push-pull style class A\AB transformer would, but the secondary is actually the cone. Follow?

[@vincentrobinette1507]

@@PoXFreak That's exactly right. That's why it MUST be a dual coil driver. I DO believe that this is a current amplifier, but I don't know for sure. I do believe, that common is on the positive of the battery power, and that the transistors connect to the inductors, are connected to the negative. The transistors come on, pulling the inductors down, building up a magnetic field in the inductors, then, the transistors let go, and the magnetic field collapses, sending a flyback voltage through a diode, across a capacitor, which is ultimately connected to the speaker coil. The transistors turn on and off at switchmode speeds, and by varying the duty cycle, that's how it controls the amplitude applied to the speaker. The longer the transistors stay on, the more current builds up, the more power it applies to the speaker. If the amp is not loaded, that flyback voltage can exceed the rating of the transistors, and cause failure. With that, the primary current that the transistors put on the inductor, is sent to the load. As the voltage is allowed to go higher, the duration of the spike becomes shorter. the transistors just have to come on again, and apply the current. that's all controlled by duty cycle. It is super efficient. about 95% of the power drawn from the battery goes to the speaker, regardless of amplitude, or impedance. That's what makes this a monster for SPL contests. I tried to design an amp like this years ago, but, I couldn't get the damping factor I wanted, nor, could I get rid of the 0 crossing distortion. I could make it better, but never cure it. It just didn't sound good. Besides, I kept running into magnetic core saturation, because I couldn't find inductors that could handle high current. I abandoned it, because I wanted high damping factor like standard amplifiers have. I thought this would be a solution to a problem called "shoot through", which is simultaneous conduction between the high side and low side transistors in a half bridge totem. At the time, field effect transistors didn't exist, and bipolar junction transistors had a habit of being quick to turn on, but slow to turn off. so, by using one transistor per coil, and using a diode, I could get out of that. The diodes I used, were standard recovery, and weren't suited to high speed switching, so I just couldn't get the necessary switching frequency. I gave up.

[@PoXFreak]

@@vincentrobinette1507, the typical TIP-35/36 combo found in most class AB amplifiers from the past can't get that far past 1MHz anyway, so attempting to build a circuit with them that includes a digital waveform (square wave?) buried in the signal to control duty cycle would be fruitless as your output bandwidth is limited by that waveform. Secondly, if there is an output transformer before each coil, that might be the only efficiency leak in the entire signal chain, especially when the source falls below 40-50hz, unless the transformer has been wound as such to accommodate that roll-off. I'd really love to sit down with one of these on a bench and get an understanding on the how and why, as well as the why not, like why can't you use a center tap 2 phase transformer good for the amount of VA this thing is capable of producing and drive a single coil with it? That's where my "center tap" question originates, because I would think that a transformer would at least smooth out, if not eliminate, the audible switching going on at the center of the waveform. Would the inactive secondary winding present a pull-up/pull-down effect while one coil is active? So many questions...

[@liangmarkv]

It was like a class b amplifier because it have gap between since wave

[@mercadiesgrissam2633]

Where can I order a gain pod for kicker amp

[@Theoryofadj]

I've never seen that type of design. This would be great for competition bass tones but for music, that's going to sound terrible. I wonder what class that is.

[@Theoryofadj]

@Tekboy 808 I'm only an Audio Engineer but hey, what do I know about sound. Stupid prick.

[@tmmtmm]

it's sort of tri-state Class-D, but unique in that it has separate outputs for positive and negative portions of the signal and resonant circuits on each output to boost the voltage from 12V to 200V. They could technically recombine the separate outputs back into a common output but that would require more power transistors and effectively just turn it back into a regular tri-state Class-D amplifier, nullifying the novelty of recombining the signals by using a dual voicecoil speaker.

[@Theoryofadj]

@@tmmtmm Yeah that is a pretty cool design. Someone was having some fun at the design desk.

[@1ohmwrecker]

Dope to see one of these!