JL 500/5 amp

CrBoy · January 2006

cam5860 wrote:

The Alpine v-12 amps will make all those amps yall like sound like ****.

and yet again..................... the Club Polk CLOWN!!! :rolleyes:

MacLeod · January 2006

HiPerf360 wrote:

MacLeod wrote:

I suppose you could make an argument that an amp with better crossovers or more flexible bass boost circuitry could be more "musical" but then we're not talking about the amp anymore but rather its EQ's.
QUOTE]

Ok you just admitted it.... there is a good possibility that amps might sound different.

My definition (although slightly skewed from the scientific definition) is as follows; the amp includes every circuit, resistor, capacitor, potentiometer....hell, anything that has mass inside the case as part of the amp.

Whoa, you really nailed me. Oh wait, thats right I NEVER said all amps sound the same. What I have said and always said is that if compared equally there will be no audible difference between the amps. And I dont consider EQ's in this because nobody is claiming there is no difference between EQ's. All Im talking about is the amps performance. An EQ (bass boost, x-over, etc) changes the output of the amp so its not a fair comparison. Kinda like comparing engine A which is bone stock and engine B which is identical but is equipped with nitros and saying engine B makes more power. It doesnt. The nitros does. Same with an amp. The amp isnt adding any bass, its the bass boost circuitry.

HiPerf460 wrote:

Would this mean that your response to my opinion that one cd player sounds different than another be: Oh, well yeah the output circuitry in that one is different than this one so it sounds different, i was talking about the transport.

I dont know what youre talking about here. But no, the same rule applies to head units. If compared equally, there wont be an audible difference.

1996blackmax · January 2006

neomagus00 wrote:

i can see where an amp could change the imaging or staging of a setup... my stage, for example, is very dependant on my EQ... treble goes up, stage gets higher and narrower... so if they have a twitchy install, the differences between amps could highlight that...

just an idea to explain the differences...

I had read an article or something regarding tuning, and how adjusting certain frequencies were helpful in raising the stage a little.

1996blackmax · January 2006

MacLeod wrote:

Yeah, I remember that issue. It was kinda stupid.

They were big proponents of the warm sounding amps but after the test they determined that there was no tonal difference between the amps but instead there were staging differences! Gimme a break!

That test was also anything but scientific. They just set up a bunch of amps and then let the testers score them in the order they liked best and because a couple more people scored the Tru amp higher than the rest they determined it must have been the winner. The only scientific, unbiased way to test these theories is with a double blind test like Richard Clark's.

To me it was still an interesting test as the differences between the very expensive tube amp were not big compared to the other amps.

PoweredByDodge · January 2006

Solid state amps are not built "all with the same transistors, resistors,and caps".

Not to mention that many of them have small operational amps within the input stage.

Power supply stages vary greatly, but for the sake of your argument, say they're all close enough that its not worth mentioning...

Output stages can be BJT's or Mosfets -- sometimes even J-Fet's although it's more of a **** to build one that way... not to mention there's really no benefit to it. J-fet's make great inputs though... although Op-Amp inputs are more popular.

Moving along...

You can have complimentary N and P channel Fet's or straight up N-channel fets (as MTX has been doing for years).

You can have a single transistor drive a speaker output rail, or multiple transistors do so.

... amplifier designs from company to company are not all that similar at all. a "class" is not a design, it's an architecture. Those are two different things. An architecture is more of a "theory of operation", while a "design" is just that - a specific "this part goes to this other part in this manner" type of thing.

Tear apart a sony Xplod amp and compare it to the inside of a JBL amp ... they look absolutely nothing alike whatsoever. Compare either to an MTX or a Soundstream... again, they look nothing alike.

Although two JBL amps or two Sony amps may look very similar to each other, if not virtually identical, save the fact that one is more robust to fulfill a larger power need than the other.

That being said --- if an amp is properly designed and properly functioning, the outputs even on an oscilloscope are going to look virtually if not completely identical (driven within spec). One may last longer than the other, one may have more features... one may not give off as much heat... one may work with more varying loads...one may put out way more power... one may have better safety protocols built in... one may be more efficient... one may have just straight out better built quality.

But they'll sound the same.

I'm not saying go buy Jensen... I'm just making a point.

Resistors and capacitors and inductors and whatever the hell are not magical things as some might think...

If the tolerance is off on a resistor, then you burn off more of less voltage across its terminals... which results in things like improperly biasing transistors or pulling two much or too little current on a Fet. What that does is make you produce more or less power... if it effects the bias point enough, you'll end up prematurely clipping... but again... that does not change the "True" sound output. I already qualified my statement by saying "so long as it's not clipping and within its specs" or something to that effect.

Class D (I and T as well) SS within its active bandwidth produces the same output sound as class AB and B within their given active bandwidth (prior to clipping) with no enhancements.

Class A is excluded and stipulated as having different tonal characteristics.

MacLeod · January 2006

Yo Vinny, how does the rail voltage thing work?

This relates to home audio but you can buy a receiver rated at say 500 watts RMS but yet it only consumes 200 watts. I emailed that question to Denon once and they said that the rail volatages are higher than input. I take it that means the amp takes that 200 watts incoming and kicks it up in the rails?

neomagus00 · January 2006

i'll hold on an answer to this till pbd chimes in, but i believe that denon is lying... you can't create power, though you can change its form... you can't take in 200 watts and put out 500 watts, that violates energy conservation... you can double the voltage and halve the amperage and still stay at the same wattage (P = I * V), but not double the voltage and keep the current draw the same...

1996blackmax · January 2006

An amp does not make power, it converts it....

MacLeod · January 2006

So the rails take the incoming voltage and convert it to more voltage? Like Neo said, I didnt think you could do this. I know transformers can convert AC to DC and so on but make 200 watts 500 watts?

Of course, the only guy on here that has actually built an amplifier is nowhere to be seen! That bastige was on here too when I first asked the question. Damn Itallians, never around when you need one.

PoweredByDodge · January 2006

*grumble*

I've got some bad ram in my computer... I had started with a stick of PC3200 (400 mhz) Crucial and then went and got another --- well it had the same modelnumber but it is a different revision (like revision D or something as opposed to the other which was A or

... should be the same... well its not -- when I switched over to the 400 mhz FSB Athlon XP 3200 from the 333 Mhz FSB Athlon XP 2500 (overclocked sickly but the same sat at 333 [actually 166]) it all went haywire... I'd burn half a DVD and it would lock up... blue screens of death randomly -- finally got sick of it when it **** the bed while replying to your question... GRRRR ... memtested it (memtest+86 -- great program that runs from a cold boot) and sure as **** - the second stick, while claiming to be PC3200 will not run at PC3200 speeds, I get tons of bad data errors (had over 1,500 in one pass) ... underclocked the processor and ram at 333 and sure enough - zero errors... so it'll sit like this till I get Crucial to send me another stick.

ANYWAY... to answer u're question...

Neo is right, Denon's fulla ****.

Amplifier power supplies will transform your AC line voltage to DC, then split it up into DC rails... for example... 110 AC to 24 VDC, then you have a +12 and -12 rail... +24 VDC is your +12 rail... 12 VDC is your ground (hence the reason why "ground isn't ground... ground just means "common") and 0 VDC is your -12 rail.

however its done doesn't really matter... what matters is that if you output 500 watts, then you're drawing MORE than 500 watts... 500 / (% efficiency) = what you're drawing.

Now, at any given moment, your 500 w amp may only be putting out 100 watts or 150 watts... or whatever... we don't always listen at full power... at that time, ya you're only drawing 100, 150, 200 watts, whatever.

Power has to come from somewhere... the only things that produce power in this world are fusion, fission, alternators/generators driven by anything from a gas motor to a windmill or a water wheel, or solar panels, and hydrogen fueled apparatus (or any chemically fueled engine that drives an alt/generator).

So, unless Denon's amps have nuclear reactors, engines with exhaust pipes, or a decaying star inside of their casings, then whoever told you that is full of ****.

Now... wanna get a little more "plausible".

You can draw 200 w rms and output 400 w peak if and only if you're at 100% efficiency.

Denon may have rated the amplifier output at peak power, and then rated the power supply draw upon the house electrical socket in rms. but still, that assumes a 100% efficiency. Chances are, it's like 70% or so... so if it only has a 200W total rms supply, then you're looking at 400 / 0.7 = 280 w or so peak output.

Maybe they got greedy and said... "lets rate it peak-to-peak and get more people to buy it" - in which case the peak to peak estimate would be 560 watts... so I could then definately see where "200" in would become "500" out. But when you rate an amp like that you're lying.

PoweredByDodge · January 2006

Transformers

You can go AC to DC... or you can "Scale".

By scaling I mean you can take 10 amps of 12 volts and turn it into 5 amps of 24 volts with the proper transformer.

but see power stays constant... its the whole "conservation of energy" deal Neo mentioned... energy has to come from somewhere and it has to go somewhere... when I say an amp is "70% efficient" -- the other 30% of the power is burned off as heat...heat is energy... blah blah, you get the idea...

24 volts * 5 amps = 120 watts (power out)

12 volts * 10 amps = 120 watts (power in)

power in = power out ... law of energy conservation is adhered to, so our math is good.

thats how Tazer Gun's work....

You put like 3 or 4 1.5 volt AA batteries in there... that's at most 6 volts DC @ like 0.25 amps if you put them in parallel... Transform it up to 50,000 volts and only 0.03 milli-amps (0.00003 A) .... that's also why you don't die.... current kills.

Red230SX · January 2006

PBD,

Ya know.... You rock! You remind me of Doctor Phil, only the "electronics guru" version.
Next time someone says something out in left field can you do me a favor and respond
with "ARE YOU NUTS???" (Said with a heavy Texas accent!

P.S. I can "hear" the difference between a 1% Tolerance Capacitor and a 5% Tolerance
Capacitor, But only when I take my tin foil hat off!

PoweredByDodge · February 2006

1996blackmax wrote:

I had read an article or something regarding tuning, and how adjusting certain frequencies were helpful in raising the stage a little.

12 to 15 k Hz... if you've got dash speakers... push up the 12 to 15 k range and voila, all of a sudden you've got a "taller" stage. It's not a perfect fix for actually doing your stage up right... but for most cases it's certainly "good enough".

I'm this close *holds fingers real close together* to being able to say I'm ready to go to comp with my loudness off, expansion off, bass, trebble, and mid all at dead zero.

God I built a good crossover

PoweredByDodge · February 2006

Red230SX wrote:

P.S. I can "hear" the difference between a 1% Tolerance Capacitor and a 5% Tolerance
Capacitor, But only when I take my tin foil hat off!

heh heh... its kind of funny, i mean, the more parts you have that are say 5% tolerance, or 10% tolerance, or 1% or whatever, the more the "law of averages" takes over... one might be 5 high, theother 5 low... but when you've got 15 or 20 of them in there, overall, you're at where you need to be.

what gets sticky is why you're doing something precise like a crossover or any other sort of filter... and you're only using 1 cap. you want a cap that'll cut you out at say 300 hertz, then all of a sudden you buy el-cheapo-ramma and end up with a 10% tolerance and now you're down at something like 250 or up at 350 hertz... imagine if you just did caps as bass blockers in a car with a stock radio or something... so just one cap on the + speaker lead to left and right.... but you're left speaker was out of tolerance at 350 hertz and the right was out at 250... that would freaking suck! I'm all for the higher precision parts in those cases, but just about every other time, unless you're all anal and it'll keep you up nights of its off by even a little (such as myself at times) then the 5% caps are just fine. especially at the cost... you an usually get 3 or 4 for the price of a single 1% cap -- availability sucks too... its harder to get "odd" sizes in 1% caps.

"Are you nuts son? Are you on druuuuggggs?"

1996blackmax · February 2006

PoweredByDodge wrote:

12 to 15 k Hz... if you've got dash speakers... push up the 12 to 15 k range and voila, all of a sudden you've got a "taller" stage. It's not a perfect fix for actually doing your stage up right... but for most cases it's certainly "good enough".

I'm this close *holds fingers real close together* to being able to say I'm ready to go to comp with my loudness off, expansion off, bass, trebble, and mid all at dead zero.

God I built a good crossover

Glad things are working out

. Now go get some trophies

.

PoweredByDodge · February 2006

I'm workin on it... I've got a replacment tweeter coming (sendin me a set, just need one though) and a somethin like 80 square feet of dynamat extreme.

1996blackmax · February 2006

That reminds me. I have quite a bit of Dynamat that my buddy gave me that I want to put to good use

.

MacLeod · February 2006

Definitely keep all the loudness and other crap OFF when competing. These are great for your own personal listening but screw everything up for the extremely picky SQ judges and brutal SQ recordings they use to judge your system.

1996blackmax · February 2006

I do not compete, but I have all those things turned off

. No amp bass boost, no loudness engaged, nothing. The only thing I do is cut peaks in my response with my parametric EQ.

PoweredByDodge · February 2006

Well i'm actually finding that if i try to add bass or add mid or add loudness it makes teh truck sound like ****...

the system is extremely pequiliar and bitchy... the least little deviation and it sounds haywire.

I'm sittin with just about equal power going to the midbass and the mid's and the tweets... there's a 2 db boost at 12.5 k .... everything else is dead on flat.

fronts are now crossed over at 60 hertz.

subs kick in at right around 60 as well.

I was waiting to do this until it cleared about because I modded one of the 81000d to filter the 10's ... had to "un-do" that. 10's and 12's are both running from the low end of the response (20-ish Hz) up on through 60.

It sounds RICH.

It just seems thicker, like you could cut it with a knife, in a good way.

still gotta dick with it some more...

I really need an RTA.

Red230SX · February 2006

My two channel line array's I am working on for my 2 channel home rig don't use the
most exotic parts but I did make sure I went with good stuff.

I am using Solen 1% metalized polypropelene capacitors, Mills 1% resistors and perfect
lay 18awg hand wound inductors. Anal maybe (though I could have spent MUCH more
on Capacitors) but it will all look pretty looking through the jewled crossover boxes

How many people can say they have 24 7" Kevlar Midbass and 24 Kapton Planar Ribbon
Tweeters in thier 2 channel mains

(12 of each per cabinet).

audiobliss · February 2006

Wow, man! Those are some wicked line arrays! 7" midbasses? 12 of 'em?! That's gonna be some low frequencies. And ribbon tweeters? Smoooooooth!

What have you figured the frequency response is going to be? What are you planning on driving them with?

Red230SX · February 2006

audiobliss wrote:

Wow, man! Those are some wicked line arrays! 7" midbasses? 12 of 'em?! That's gonna be some low frequencies. And ribbon tweeters? Smoooooooth!

What have you figured the frequency response is going to be? What are you planning on driving them with?

The prototype set designed by a friend of mine who does this for a living (he
did all the anechoic testing and XO Network design) on his set he went with
vented enclosures and measured down to about 25Hz with solid output (more
than 110Db) from there down they rolled off. I will be going sealed with mine
and F3 was 37Hz if memory serves me.. I have all the acoustic charts on my
hard drive somewhere, along with the XO schematics.

Here is a photo of the prototypes finished in Burled Walnut and Cherry.

PoweredByDodge · February 2006

that's MONSTROUS

holy ever living ****... you guys really do make some wild ****.

I'd love to have something like that in the house, but i think the family would kill me!

very nice looking cabinet too!

metal poly caps are pretty much the way to go to... good job.

Red230SX · February 2006

Oh I forgot to mention what will be powering my pair when I get off my lazy **** and
finish the cabinets!

For the tweeters I will run them off my Antique Sound Labs Wave20DT Monoblocks, that
is 20 Watts RMS per monoblock. For the Midbass I will run them off S.S since tubes do
not do well on the low end (unless you spend TONS of money on big hybrids). I have an
Onkyo M282 which puts out 110 RMS Full Bandwidth @8 Ohm

Nominal load is 8 ohm on the whole array and I am wiring mine so that the XO Boxes
are completely external and can be unplugged for when I decide to go to an Active
Crossover with built in time delay and all that goodness.

Red230SX · February 2006

I realize those power figures don't seem like much, but when you are talking sensitivity
in the 110DB 1W 1 M range.. It don't take truckloads to hit rock concert levels. And the
bonus is that one driver is doing 1/12th the "work" it normally would which leads to
extremely low (almost unmeasureable) distorsion figures.

PBD,

Like I said... I like to "Dabble"

they will stand about 8.5' tall when completed and
will have 2" thick solid marble bases unless I go and make hollow bases and load them
with buckshot for dampening. Marble would be easier...

PoweredByDodge · February 2006

oh... my... god.

you do a little more than dabble dude. jesus christ.

wanna build me a set? lol

Red230SX · February 2006

PBD,

Sure, right after I finish my pair.. sometime in the next decade or so...

Too many "Projects" not enough "Me" to go around! I need a fricken clone of myself!

audiobliss · February 2006

:eek:

That's pretty sensitive!!

Toxis · February 2006

those look awesome! What'd you pay for all the drivers?

JL 500/5 amp

Comments