Hippo's Audio Build Help

[chamilton89]

I've heard that amp to be inconsistent long term and if you plan to hit 1ohm you're definitely stressing the power supply. There's a myriad of reasons NOT to run 1ohm.

I agree but at this point he doesn't have much of a choice, its either 1 ohm or 4. I suppose he could just push 250w.

[Hippo Machine]

dude you recommended the sub, I'm wiring it at 1 ohm.

[I800C0LLECT]

dude you recommended the sub, I'm wiring it at 1 ohm.

Maybe you should pick a different sub too? I could care less what you plan to do. It's how you get to that decision that worries me. You chose a great amp to start with and you're only changing that out to another brand because somebody "thinks" it has more power. I attempted to get you a better built version of the same amp...it didn't work out *shrug* Now you're placating a stereo type of "more power!!" that I was hoping to educate you as well as others moreso to help alleviate potential problems. I just want people to know the risks. Good luck

page 1-10 is a decent read but probably too in depth for most...

http://www.zedaudiocorp.com/pdfs/ZedManual-2010.pdf

The impedance of the speaker also determines the point at which the efficiency is
optimized. Well as was said on a famous TV show “FOREGETABOUTIT”, this is a pipe
dream. Speaker’s impedance curves are all over the map and too many car audio buffs
love to drive their megawatt class D amplifiers into low impedances, like 1 and 2 ohms.
Well now that I mention “1 ohm”, I cannot resist getting into this subject. Scenario: Kid
buys gizzilion watt amplifier with manufacturer’s specifications of x watts into 4 ohm, y
watts into 2 ohm and z watts into 1 ohm. Well let’s take a wild guess and I bet you all that
the vast majority will drive the amplifier into 1 ohm. Why? Easy, he feels that he is getting
his “moneys worth” by doing this. OK let’s see what reality is. Said amplifier is maybe
rated at say 600w into 4 ohm, 1000w into 2 ohm and 1500w into 1 ohm. We will assume
that the speaker impedance is resistive. The difference between the 4 and 2 ohm power is
2.2dB, the difference between the 2 and 1 ohm power is 1.76dB and the difference
between 4 and 1 ohm power is 3.9dB. So what do these numbers tell us. First if the
speaker is 4 ohms vs 2 ohms, no way you can hear any difference. Same issue
comparing 2 as to 1 ohm. I grant you that between 4 and 1 ohm there is almost 4dB
difference BUT at what price. Two issues. Low impedance loads affect the amplifier’s
sound quality adversely and this is quite easy to prove. Load an amplifier with a 4 ohm
woofer and listen. Add parallel resistors to the speaker to make the amplifier “think” that it
is driving a low impedance speaker and listen to the difference in sound quality. You will
be surprised. This test is not 100% valid in fact as the resistive loads added, let the
amplifier off the hook as the reactive components of the load are confined to the 4 ohm
part. The idea of this test is to keep the loudness about constant but load down the
amplifier.
The average person can just perceive a 3dB (doubling of power) difference and to
actually double the sound pressure on your eardrum, you require TEN TIMES the
amplifier power. Yes TEN TIMES no kidding!
The other consequence of driving amplifiers into these ridiculously low impedances is that
the amplifier is stressed substantially more as compared to when driven into more sane
impedances. Efficiency drops as the losses in the output stages increase dramatically
even with “super efficient” class D amplifiers.
It serves ONLY to boost the ego of the owner of the car so he can quote numbers to his
buddies.
We at Zed are absolutely against these silly loads of less than 4 ohm.
Page

[SeanGTP]

All this is fine and good, but my question is... if this is the case, why are 8 and 4 ohm the most common subwoofer impedances? I feel in most cases it makes things much more complicated than needed. If I have 2, 4 ohm subs, and I wire them parallel I now have a 2 ohm load, if I wire them series, 8 ohms, effectively halving the power the amp can give them. Wouldn't less power at a lower load be better than trying to cap the thing out with more resistance?

[KeithGTP03]

Its not about the DB output gains. Its about not underpowering his sub. This is his first stereo, and everybody that has had their first subwoofer installed knows that they drove the shÃ*t out of it. And I doubt he's going to connect a DMM to test for clipping. Of course at 1ohm it will put more strain on the amp than at 4ohm. But the amp specs say its rated for it, so the manufacturer has to stand behind it.

[I800C0LLECT]

Car audio doesn't sell based on EE principles. It's all about what the customer purchases. Customers don't usually research choices and marketing/snake oil take over. Let's break this down for a second...ROOT MEAN SQUARE. Aren't root and square polar opposites? Nowhere on Earth is RMS used to to specify power supply characteristics because it doesn't make sense let alone describe any real world performance. It doesn't exist anywhere except the consumer amplifier world.

The truth behind different ohm/resistance ratings is for the purpose of system design flexibility and it relates directly to speaker's purpose/application.

Who cares if an amplifier can withstand a bullet...you still wouldn't shoot it. 1ohm = sloppy cone. Sloppy cone = mediocre speaker performance. A amplifier power supply has MUCH MORE control over a voice coil and speaker cone at 4ohms vs 1ohm.


So here's an idea....

Anybody who's curious can go wire their sub system for 4ohm or to make it more drastic 8ohm. Do an A/B comparison with 1ohm. The audience will be friends and family. Ask them if they can perceive a difference. Don't tell them anything at all...just ask which one they prefer or which one is noticeably louder. If nobody can tell or even cares then just do whatever floats your boat. If you end up with a personal preference...then that's your ticket.

Its about not underpowering his sub.

under powering subs?...that's a farse.

http://www.diymobileaudio.com/forum/...ering-sub.html

http://community.crutchfield.com/forums/t/23638.aspx

http://www.the12volt.com/installbay/...TID~74226~PN~1

Let's put it another way too...if watts = heat and a coil is rated to handle 2384028 watts; then why would 50 watts overheat the coil and cause it to melt or deform?

Typically, people who "think" their sub is underpowered will push their gain far beyond the signal amplitude and cause clipping as well add lots of distortion. Everybody knows that distortion and clipping kills...what caused it?...gain knob stupidity.


EDIT: I'm sure nobody cares but I had ~15 watts hooked up to something I threw together at 8ohms and I repeatedly had people asking if I had 1000watts running to the sub. Nope. Sure didn't.

[KeithGTP03]

Let's put it another way too...if watts = heat and a coil is rated to handle 2384028 watts; then why would 50 watts overheat the coil and cause it to melt or deform?

Typically, people who "think" their sub is underpowered will push their gain far beyond the signal amplitude and cause clipping as well add lots of distortion. Everybody knows that distortion and clipping kills...what caused it?...gain knob stupidity.

You answered your own question. Also, which would give me better sound: A 600w sub on a 250w amp, or a 250w sub on a 250w amp? (all brands and impedance equal)

[I800C0LLECT]

You answered your own question.

uh...

Also, which would give me better sound: A 600w sub on a 250w amp, or a 250w sub on a 250w amp? (all brands and impedance equal)

All brands and impedance equal? There is no winner. Everything is equal. Do you really think your subwoofer is receiving "600 watts RMS" at 10% volume, 30% volume, 100% volume? You do realize that Steve mantz designed probably most every major manufacturer's amp at some point in time and almost all of the chinese crap are direct reproductions of his designs? You're not disputing me, just industry guru's. Did you notice that there were some major industry players in some of those threads?

ADDED BY MOD: Link to great discussion on this topic from some respected industry experts, including people like Manville Smith of JL Audio, Mark Eldridge of JL Audio and multi IASCA world champion, and Andy Wehmeyer of Harman Kardon. : Clipping: damage from power or cone movement - CARSOUND.COM Forum

I hope this doesn't come off wrong but are you trying to teach me something? I provided sources concerning the ideas I brought forth; I'm not arguing my opinion. Hrmm. I'm throwing my hands up. The purpose of my comments here are for hippo and his audience. If you really think I have no idea what I'm talking about...so be it. Hopefully I've managed to help at least one or two to become curious enough to go look for answers specific to their goals.

[KeithGTP03]

All brands and impedance equal? There is no winner. Everything is equal. Do you really think your subwoofer is receiving "600 watts RMS" at 10% volume NO, 30% volume NO, 100% volume YES?

I hope this doesn't come off wrong but are you trying to teach me something? I provided sources concerning the ideas I brought forth; I'm not arguing my opinion. Hrmm. I'm throwing my hands up. The purpose of my comments here are for hippo and his audience. If you really think I have no idea what I'm talking about...so be it. Hopefully I've managed to help at least one or two to become curious enough to go look for answers specific to their goals.

I have read them and here is a quote from Manville:
"a W1v2 can dissipate 150 watts average power for eight hours or more with signal peaks of 600 watts. So, we rate the speaker for 150W continuous power. This way, when a customer needs to choose an amp for it, they will hopefully choose one that can make about 150 W clean power... Even if they clip the bejeezus out of that amplifier, it is unlikely that the speaker will fail thermally"

I do not know your audio background. I do know that you read alot about it. I agree with you on most things audio. But I have experienced people blowing subs due to lack of power and too much power. And I have also experienced JL audio denying warranties because of it.

[Hippo Machine]

Ok I understand now. I could still get that amp and wire at 4 ohms, get 250w rms. One of m my friends powers his sub with only 100w and it still is extremely loud when he wants it to be. 250w isn't under powering it according to the manufacturer.

[I800C0LLECT]

There's one more variable nobody is accounting for and that's the recording studio volume. That's why you don't typically get "600 watts" with "100%" volume. Some tracks yes, some tracks no, some make it even worse. It's all dependent on the amplitude of the incoming signal and that directly correlates to the gain knob as well. It's typically the poorly recorded tracks that are clipping your signal significantly and the end user still turns up to 100% which is actually a highly distorted and very much clipped signal because the recording amplitude is different than what's expected(whether higher or lower). And an "underpowered" sub is not ruined because it's not getting enough power. It would only ever get ruined with distortion and clipping. The end user who thinks that gain = volume is the culprit...not an amp that puts out a clean 30watts vs. a clean 4.2 jigawatts. Overpowering a sub WILL hurt a voice coil. One more time, the primary culprits, assuming everything works right, are misunderstood gains, poorly recorded tracks, or install.

That's why customer service is such a B. in car audio. The manufacturer knows this but the audience doesn't.

[BillBoost37]

Where the wet leaf suggestion?

[Hippo Machine]

lol Bill.

So I800Collect, you believe I will be happy with wiring it at 4 ohms, 250w?

[I800C0LLECT]

I think so...but what's nice about this whole thing is if you have both options available to you who cares what I think? But 4ohm would definitely lend itself to the amp having a longer life! ANd if you can "hear" the difference...it should sound better too

[KeithGTP03]

There's one more variable nobody is accounting for and that's the recording studio volume. That's why you don't typically get "600 watts" with "100%" volume. Some tracks yes, some tracks no, some make it even worse. It's all dependent on the amplitude of the incoming signal and that directly correlates to the gain knob as well. It's typically the poorly recorded tracks that are clipping your signal significantly and the end user still turns up to 100% which is actually a highly distorted and very much clipped signal because the recording amplitude is different than what's expected(whether higher or lower). And an "underpowered" sub is not ruined because it's not getting enough power. It would only ever get ruined with distortion and clipping. The end user who thinks that gain = volume is the culprit...not an amp that puts out a clean 30watts vs. a clean 4.2 jigawatts. Overpowering a sub WILL hurt a voice coil. One more time, the primary culprits, assuming everything works right, are misunderstood gains, poorly recorded tracks, or install.

That's why customer service is such a B. in car audio. The manufacturer knows this but the audience doesn't.

I have been reading up on this for most of the day. I am now a subscriber to this logic, even though it goes against everything I was taught years ago. Hell, even the manufacturers would send back a "Possible Cause" statement with the repaired/replaced subwoofers claiming "Damaged voice coil possibly due to inadequate wattage". And Reps from the manufacturers would hold seminars and would tell us that the worst thing we could do to a subwoofer, is to connect it to an amp that is not powerful enough to deliver the appropriate RMS. I guess, as with most things, audio has evolved since then (8-12 years ago). Carry on.

[Hippo Machine]

Of course the grill I order for a 12" subwoofer is too small with the sub lip on, suggestions?

[Hippo Machine]

This is the only 2 gauge wiring kit I could find Tsunami AMP02BL 1600 Watt 2 Gauge Amplifier/Amp Installation Kit

[Hippo Machine]

This one would work better because its the fuse size I need, but its out of stock!! db Link CK2Z 2 Gauge Amplifier Wiring Kit with ANL Fuse Holder

[Hippo Machine]

nevermind i need a 120A fuse..........................

[KeithGTP03]

Its not out of stock here

Amazon.com: DB Link CK2Z 2 AWG Competition Series Amplifier Installation Kit (Blue): Car Electronics

Annnnd nevermind.

"Usually ships within 2 to 4 weeks"