Quote :

"if you can overdrive his front speakers by twice (maybe more) what is a safe overdrive, what speakers can take it, etc?"

I think I remember reading once where JL did a similar experiment with their lowly w0 sub where it took 10x the amount of power it was supposed to.

12/14/2005 11:04:49 PM

I'll post a larger reply later, but its obvious now that 1CYPHER was dead wrong. Now that he posted his "secret" reason that everyone was supposedly over looking, some others pretending to be an authority should catch why.


I'd also like him to try and flame me some more about how wrong or ambiguous I am with some real reason behind it. This comment is the best though:

Quote :

"It seems to me that tnezami and dannydigital might know whats up, but I am a little skeptical of you and gephelps right now based on the language and terminology you have used in this thread so far."

Before I even begin later on, go ask your pal Google the difference between bridging and bi-amping.

I'm surprised you never jumped down anyone's throat about how a 4x75 amp could output 2x200. One scenario has the amp putting out 300 watts vs 400 watts. Where do you think the extra 100 watts came from?

12/14/2005 11:10:04 PM

When do classes start back? I need something to do with my free time other than this.

Quote :

"but its obvious now that 1CYPHER was dead wrong."

Dead wrong? Did you read the whole thread? I admitted that I haven't played with a new amp in awhile and am actually sorta surprised on the one hand and not surprised on the other that newer amps are smart enough to apparently only take left channels for one bridged pair and right channels for the other bridged pair so that you can use a 4 channel amp bridged to two in a stereo setup. dannydigital apparently had tried this before, I was hoping someone would be a bit more descriptive (I asked for good details). He also mentioned a Y adapter, which is what made me think he might be on to something, but again, he didn't flesh it out so I didn't want to assume too much.

Quote :

"Before I even begin later on, go ask your pal Google the difference between bridging and bi-amping."

In respect to what. Would you like to go into detail about why you are asking this? Specifically, I was going to propose bi-amping as another possible alternative to his setup instead of bridging. I can't say off hand which will sound better. To me, I'd rather run 2 extra wires, use the amps built in active crossover especially if it is adjustable (if he has an old amp this might not be an option though), and have gain control for my tweeters to dial in just the right amount of brightness on then. This way you also avoid having to find a place to install your big passive crossovers (of course some people like displaying them). I say this might be a good option because I don't know how much you get by going from driving the component set with 75w versus 200w in this instance. I'd play with both options and see which sound better.

Quote :

"I'm surprised you never jumped down anyone's throat about how a 4x75 amp could output 2x200. One scenario has the amp putting out 300 watts vs 400 watts. Where do you think the extra 100 watts came from?"

Jumped down anyones throat? What are you talking about? If you want to talk amp theory mister smarty, why don't you tell me where the other 200W went that theoretically should have been acheived by bridging.

At least MaximaDriver was a little levelheaded about this stuff and we are already past that. You on the other hand do like most people on this site, you take offence to every little question someone might have about something you said. Rather than being a bit calm and confident in your abilities, and attempt to have a civil discussion, you fire back with some pretty meager stuff ripe with resentment and hatred. It's just a message board, thankfully for you, it isn't real life.

12/14/2005 11:26:15 PM

Wow, a few posts were added when I was making my last reply. This is classic....

First you post:

Quote :

"Eh, everyone is so adamant on being correct. It seems to be the trend in every thread I have ever viewed. Why are you not confident now in your understanding of the material that you place the burden of proof with me? I want to give you a chance to be the thread hero, to show the whole site you know what you are talking about here."

Then you posted:

Quote :

"I haven't had any new equipment in awhile and my old stuff (probably 5 years old now maybe?) you couldn't do it like this. So for fairness sake to both of us being "right" for different reasons, this bucko has to be sure that his amp will work like this."

Just because technology or your understanding of it advanced in your eyes doesn't make you right. Who is being adamant about being correct now?

----- Whole new topic.

You posted:

Quote :

"Only info I could find around these numbers is 24 mmatts and 12 Cerwin Vega 15s. When you typed that out, did you honestly think to yourself, a sub that can handle 20,000W surely exists, right? Here - "

If the numbers are wrong, then fine. I personally thought the number of subs was 12 to be honest from when I saw the van in their shop, but configurations change over time. I pulled the numbers I got from here: http://www.termpro.com/asp/competitorstats.asp?Competitor_ID=170
Looking at link in more detail it seems some of the info is wrong. I know they used to run strokers before they got factory backed by kenwood and switched to them (although trying to compete in a lower class).

But then you posted this:

Quote :

"I think I remember reading once where JL did a similar experiment with their lowly w0 sub where it took 10x the amount of power it was supposed to. "

Cerwin Vega rates the stroker 15 as 1,200 watts RMS. http://cerwinvega.com/products/mobileaudio/stroker/stroker15.html
So 10x that amount would be 12,000 watts RMS. You admitted the w0 is JL's bottom sub. Compare that to the stroker being Cerwin Vega's top of the line (or used to be). Cerwin Vega also knew this was a competition sub so I wouldn't be surprised if they underrated it. So regardless if the true number of subs they used was 12 or not I could see them trying to push 20,000 Watts per sub. Especially in the db drags where frying equipment is not infrequent and typically they only "burp" the subs. Just because we are talking about ratings being a certain number hardly means the end user is trying to use the max amount of power for a long duration.

12/14/2005 11:58:51 PM

i think you should power all 4 speakers with 75 watts each. How big is your car? Care about your passengers? 75 watts RMS is more than sufficient for components inside a car.

12/15/2005 12:33:35 AM

I'll probably end up trying both methods, I suppose.

12/15/2005 8:30:30 AM

are you going to be entering in competitions? no
do you want clean, crisp sound with the ability to play loud if you want it to? yes
do you really care about soundstaging and imaging? no

use the amp to power all your speakers.

the reason i suggest this is the polks put out very little bass. you will benefit from the extra power going to the 6x9s to give you the low fill in case you dont want to run a sub. plus, with the polk's sensitivity rating, they won't require that much power to sound the best. hell, the tweeters are already ear piercing as is running off a head unit.

12/15/2005 5:43:57 PM

really? well I do have a sub im putting in....considering that, would you still run 75x4? I'll figure out either way saturday...i cant do shit till then, when I actually am not working and its sunny.

12/15/2005 8:55:56 PM

well, you'd have to consider what frequency you'll be cutting your sub off at. i usually cut mine off around 100 hz. i would still run the amp to all speakers so the 6x9s will provide decent midbass. you can always fade more to the front so you'll hear the rears less to give more of a false soundstage but you'll still get the midbass required so you won't have any holes in your frequency range.

12/16/2005 8:37:52 AM

Quote :

"do you really care about soundstaging and imaging? no"

So far, the people in this thread giving advice care. bucko, you have to ask yourself, if you are a "sound from all around" kind of guy, then it's worthwhile to consider driving the 6x9s with the amp, but not for the reasons underpsi is giving.

Quote :

"do you want clean, crisp sound with the ability to play loud if you want it to? yes"

This amp driving the woofers and tweets bi-amp will sound as loud and most certainly better to the driver than if you power the 6x9s with the amp. Rare is the occasion that my passengers are as interested in going as deaf as I am when they are riding with me (usually I have the music down so we can talk anyway), meaning the HU is plenty for driving the rear fill. Besides, this statement in support of your suggestion:

Quote :

"ou will benefit from the extra power going to the 6x9s to give you the low fill in case you dont want to run a sub."

is just dumb. Thats like saying, let me slap a supercharger and nitrous on my ride, just incase I don't want to run the super for some reason I'll still have nitrous.

Quote :

"hell, the tweeters are already ear piercing as is running off a head unit."

Thank you for inadvertently(sp?) supporting my suggestion about running the tweets off their own channel so you have gain control on them.

Quote :

"i usually cut mine off around 100 hz"

This is probably reasonable for these 5.25s, especially considering they aren't enclosed. I have some CDT 6.5s boxed in my ride and I cross them down at 50hz myself. There isn't much that can be done in his situation to really help the midbass situation. Running an amp to the 6x9s is just going to color (muddy) any midbass gain you might get by doing this by trying to get the 6x9s to play sub bass frequencies. And anyway, he has a sub. And if he crosses it this high then he will get all the midbass he cares to have out of them provided the box is designed right.

Quote :

"you can always fade more to the front so you'll hear the rears less to give more of a false soundstage but you'll still get the midbass required so you won't have any holes in your frequency range"

How do you propose to have your cake and eat it too? Midbass frequencies are certainly directional. If he runs it like this it will pull the stage back there for sure.

I still think you should try the biamp scenario first if you have any kind of a discernable ear. If you are a bit of a basshead and just like to make yourself go deaf, then consider amping your 6x9s instead. If you have a strong HU, then you aren't going to gain that much over the amp if you don't box the 6x9s up (basically, you'll be wasting power).

12/16/2005 2:29:45 PM

Awesome replies, thanks a bunch to all of you.

12/16/2005 3:12:11 PM

^^as big as you are into clean, crisp sound, soundstaging and imaging, and thd, i'm surprised you suggested to run speakers off the h/u's internal amp and use the pre-outs. you should know that is a no-no when it comes to keeping thd levels low.

12/16/2005 7:15:21 PM

huh?
I tell you what, you set up that strawman a little bit better and I might be inclined to telling you that you don't know what you are talking about.

12/16/2005 10:12:52 PM

this thread is getting annoying

[Edited on December 16, 2005 at 10:21 PM. Reason : mainly just 1CYPHER]

12/16/2005 10:21:40 PM

^^so are you saying using the head unit's internal amp to power speakers and power a set of pre-outs will not increase THD?

12/16/2005 11:14:41 PM

This is long as shit, and technical as hell... I'm crazy bored and can't sleep

I've got to admit that I was annoyed with 1CYPHER when I first started reading this thread... but then he laid down very correctly how you can damage a speaker by overpowering it.
I say be nice to him he appologized for being a dick in the first few posts...

I'm going to re-itterate and then bring in some technical numbers and how you can damage a speaker...

first how does a speaker move: (joe#### correct me if I'm off on anything)
Amplifier puts out power. power = Voltage*current. A speaker is an electromechanical device that moves by the current through the voice coil inside a magnetic field. A Voice coil is made out of magnetic wire (its what its called its not actually magnetic) that has a very fine coating so the coils create an addidative force (turns) the gauge of this wire determins how much current the speaker can handle, and its resistance is directly related to its length which is directly related to the number of turns and diameter which is directly related to the force it can exert on the total moving mass INCLUDING itself. because of this you can have a poor performing speaker with a extroadinarily high powerhandling (big wire lots of added weight from the wire itself).

The insulation coating is very thin. As the voice coil heats up the coating becomes more suceptible to melting away, which will bridge the pieces of the coil together, Power dissapated in the voice coil comes directly from the DC component (=bad) if the coil gets hot enough its possible for the entire thing to fuse together and become a direct short circuit. interesting enough the motion of the speaker actual provides cooling for the coil at lower frequencies this cooling function doesn't happen AND the speaker is more suceptible to spikes which can overdrive it harmfully out of range (overthrow or bottom out or both).
http://www.powerstream.com/Wire_Size.htm voice coils range from 32 gauge which handle half an amp (p= IV so .5*70 = 35w) on tweeters to 16gauge for subs. (70*22 = 1540w) (70v is a typical voltage rail for a higher power amp... its somewhat of an arbitrary number)

point being you can run too much power to a speaker, the numbers given aren't precise but are for example. The ammount of power a speaker can handle is determined by the gauge that the voice coil is created with.

"clean power" means that there aren't spikes in the signal sent to the speaker that originate from the amp and not the signal. These spikes are very bad b/c they are nonlinear in relation to the music and detract from the sinusoidal nature of the signal and can send the speaker to one side or another where the voice coil can bottom out or the cone can pull too far.

Under powering a speaker hurts a speaker because the amplifier is not capable of sustaining the current needed to drive the speaker each way. Speakers DO NOT HAVE FEEDBACK they are somewhat like a stepper motor, and work under the assumption that they have done what you have told them to do. So if you underpower a speaker the speaker does not have the current to drive to the correct position, it will be out of position when its told to go further the other way. The mechanical suspension on a speaker can contribute to this because it wants to center the speaker. if the speaker isn't under control once again eventually it will track to one side if the signal is not sinusoidal or if there is not enough current (translates to power) to drive the speaker correctly and bottom out the speaker or overthrow which can create a nonlinear instance for the voice coil to come in contact with the side of the magnetic gap and warp. a warped voice coil is what you hear when you press on a speaker and it scratches.

pushing more power to speakers is a good thing because it provides a wider range that the speaker will function under it makes sure that the speaker will always have the proper current to move where its suppose to. TOO much power and you will burn the voice coils, however with properly set gains and if you don't listen to your music cranked full blast all the time you won't run into this problem. I ran 350wRMS (xtr1400 ) to 2 cerwin vega 6.5's for a week with the crossover turned on at 80Hz... they sang like birds... the moment I turned the crossovers off at high volume they fried almost as fast as when I hooked a different pair to a wallsocket(3600wRMS @60Hz until the 15A breaker flips)

75Wrms is a lot of power for any door speaker 200wRMS is excessive. A Lot of power for door speakers is 100w but I too favor a solid front stage so go ahead and feed them 200w

12/17/2005 12:22:54 AM