RMS capabilities

[Slick]

I know alot of us on here have installed sub systems in our Yarii. My question is, does anyone know how much power we can pull from our car before something starts to go? Say, could it stand 2 1100 rms subs? on a 3,500 watt amp? Who has pushed there vehicle to the max? Any help will be appreciated

[The Architect]

I had a zx1500.1 rated for 1799rms @2ohms and I pushed it rather hard....constantly.

come winter time my yellowtop had problems starting...then it wouldnt start. the yellowtop had effectively died.

Im now down to 1200rms for the sub amp and 120rms for the front components amp.

I maintain my yellowtop with a ctek charger if it ever falls below 12.8v for a cold dmm read and I turn off my radio etc a few minutes before i get home to give the alt. a chance and I've had no problems yet.

My current voltage readings are 13.8-14.23

[IllusionX]

Another local member had an Orion 4x100wRMS amp for his speakers, and then a 200wRMS Orion amp for the sub...

the battery alone with the OEM alternator was not enough for it. Not to mention the 4x100w is huge.. took 3/4 of the hatch space. He ran gauge 0 wire for the 2 amps...

i don't know how you guys push thousands watts RMS :(

[talnlnky]

Although you can install tons of amps in a car... realistically, due to the size & voltage of our alternators.... and the stock battery.... you are pretty much limited to about 1000-1300 watts. Anything higher than that and your car won't be able to sustain it for very long.... course... most music doesn't supply constant bass.. and that's where most of the power is eaten up.

to answer IllusionsX's question..... his buddy was running a Class A/B amp which is about 50% efficient... so... his 400 watt speaker amp really was pulling more like 800watts. The 200watt amp may have been Class A/B (50% efficiency) or maybe even a Class D (70-80% efficient).

Now days most people run subs off Class D amps because it saves a lot of power, and means you can get more rms before your electrical system becomes the bottleneck.

Upgrade the Big 3, and that'll help most people squeeze out a few hundred more watts

[sqcomp]

Architect has exemplified what is happening with the charging system rather effectively.

The physics are sound. The alternator can only push SO much out. After it keeps maxing, the amplifiers look for more potential...from the battery.

Now, if you're not leaning on a big Ampere drawing system constantly, supplying power for the short duration shouldn't be a problem. This is given the proper safeguards of course...The big three (which I've proven can be done properly and neatly for under $13), an aftermarket battery, and if you so choose to put another load on the alternator, a cap.

The stock Yaris alternator is what, 80 Amperes? It will provide your entire vehicle 80 Amps...no more. After your amplifiers go beyond what the stock setup can produce, the battery takes it from there. This is why Architect charges his battery (wisely I might add). After my little tour here in Iraq, I'll have four amplifiers in my trunk, one that will be loaded to 1 Ohm and in a perfect world, able to put out at least 1500 Watts. Will I EVER take it to that extreme? Hell no. I'm a little girl when it comes to sound quality...I whine when the car doesn't sound realistic (i.e.-too bass heavy).

The truth is, that we DON'T push thousands of Watts consistently. We do, however, have the potential to push that Wattage given the right ingredients. If you pushed that much Wattage consistently, your stock alternator would die a horrible death rather quickly. I remember such an experience myself. It happened to me using three amplifiers, two of the "older" Kicker ZR360's and one Kicker ZR600. Each 360 was pushing a D series solo 15". I was stranded approximately 50 miles from my home one day after hiking...guess what happened. Those amplifiers ATE my alternator ALIVE over the course of several months.

Take this for what it is, be work your system smarter NOT harder!

[sqcomp]

Hey Taln...nice MPG! That is what I'm getting after my big 3. Where's you get that pretty counter anyway?

[Slick]

Well, I plan to run 2 of these at 4 ohm http://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?ProductID=15441
However, I am questioning the power capabilities of my current amp http://www.sonicelectronix.com/item_10232_Lanzar+MXA282.html

Its true output at 4 ohms is roughly 750 ish, all things taken into consideration.

The amp is 1000 rms at 4 ohms each channel. However, if I'm not mistaken, you cannot wire a single DVC 4 ohm sub to 4 ohm, either 2 or 8. Correct me if i'm wrong. The problem i'm having is that the amp is rated at 1600 rms at 2 ohm. The subs are only rated 900. Even if the amp is capable of only producing even 1000 rms at 2 ohm per channel, wont that severely injure my subs?

Now, I know you can wire 2 4 ohm DVC subs to 4 ohm together in parallel but in order for the amp to see 4 ohm I would have to bridge the + of the left output on the amp with the - or the right output. And again, please correct me if I'm wrong. I only half-ass know what I'm talking about :) If i wire the subs up like that then that means it will be trying to push the full 4000 watts. Obviously not going to be that much but you can sort of see where I'm going with this.

I have been trying to figure this out for about a week now, asking ppl different stuff tying to get a fix on what to do.

Can anyone please give me a REALITY CHECK and explain this stuff to a freakin noob, I will be forever grateful. Thank you in advance.

[IllusionX]

Although you can install tons of amps in a car... realistically, due to the size & voltage of our alternators.... and the stock battery.... you are pretty much limited to about 1000-1300 watts. Anything higher than that and your car won't be able to sustain it for very long.... course... most music doesn't supply constant bass.. and that's where most of the power is eaten up.

to answer IllusionsX's question..... his buddy was running a Class A/B amp which is about 50% efficient... so... his 400 watt speaker amp really was pulling more like 800watts. The 200watt amp may have been Class A/B (50% efficiency) or maybe even a Class D (70-80% efficient).

Now days most people run subs off Class D amps because it saves a lot of power, and means you can get more rms before your electrical system becomes the bottleneck.

Upgrade the Big 3, and that'll help most people squeeze out a few hundred more watts


you are right about the AB class amps... but.. why would anyone sacrifice sound quality for more power? :) I would not go for a class D at any time soon lol

[talnlnky]

you are right about the AB class amps... but.. why would anyone sacrifice sound quality for more power? :) I would not go for a class D at any time soon lol

because they are only used for 250hz and down.... where its really hard to tell the difference between D & A/B.... the lower you go... the harder it is to hear. I personally never run sub amps crossed any higher than 60hz (when I had a decent component setup).

I doubt you could honestly tell the difference consistently between A/B & D in a blindfolded test.

I personally am all about efficient setups... I currently only own 2 A/B amps... but would do a D for my sub stage anyday.... if I planned on having a substage long term (my dream setup won't even use subs.... won't need them, my midbasses play a bigger range and better than a sub could).

[sqcomp]

The only reason I'm using four amplifiers is because I'm going to be running a three way set plus two 15"s on tha one big D class. Gotta have all my component speaker pairs on a four channel of their own...it's called headroom!

400 potential watts to the tweeters is going to be fun to control. I'm thinking that the Bit One is good at attenuation though! :)

[talnlnky]

The only reason I'm using four amplifiers is because I'm going to be running a three way set plus two 15"s on tha one big D class. Gotta have all my component speaker pairs on a four channel of their own...it's called headroom!

400 potential watts to the tweeters is going to be fun to control. I'm thinking that the Bit One is good at attenuation though! :)

yeah... and due to impedence issues those tweets will never see more than 20 watts no matter how high you turn up the volume.... I love headroom... tho I'm going to say you're going over the top since its on a tweet. Love to hear it when its done.

[sqcomp]

I'm still trying to nail down which source I'm going to use. I'd love to be able to comfortable use at least an old 7909...but with them dissapearing and maintenance costs going up...I'll force myself to use a new source.

As for the tweeter impedance (rising over 4 Ohms as the frequency increases), it's going to be interesting to see how those Exile Xi 4 channels, the bit one, and the source itself (with it's Voltage output)...and the car acoustices with all it's variables are going to affect the performance.

I WISH I could use a smaller amplifier on those tweeters too...Exile just doesn't make an amplifier at that level that puts out less power. Although, that's what a gain adjustment and volume pot is for...I suppose I could simply use two channels off the four but...

[IllusionX]

because they are only used for 250hz and down.... where its really hard to tell the difference between D & A/B.... the lower you go... the harder it is to hear. I personally never run sub amps crossed any higher than 60hz (when I had a decent component setup).

I doubt you could honestly tell the difference consistently between A/B & D in a blindfolded test.

I personally am all about efficient setups... I currently only own 2 A/B amps... but would do a D for my sub stage anyday.... if I planned on having a substage long term (my dream setup won't even use subs.... won't need them, my midbasses play a bigger range and better than a sub could).

you are right for the low frequency...but do you SERIOUSLY need 2500wRMS for subs ???

i personally only have a 4 channel AB class 50wRMS for my fronts and two 8" subs on the rear deck.

[talnlnky]

you are right for the low frequency...but do you SERIOUSLY need 2500wRMS for subs ???

i personally only have a 4 channel AB class 50wRMS for my fronts and two 8" subs on the rear deck.

I don't... but every D-bag 16-22yr old male on the streets seems to. I'm a huge proponent for high efficiency setups. I did the SPL comp setups when I was 18-22... I bought custom made alts, $160 bats, and 00awg cable.... Been there done that... its fun, and somewhat challenging, but for a daily ride its not much fun.

I have a very similar setup to yours currently... I run the dual 8's in the 1.2cuft ported @ 28hz box you see in my sig powered by an A/B amp bridged to get around 150rms. Then I run the front stock speakers (no rears) off the stock deck.

My planned system, when I get time, and access to a shop...
custom built 3 way components using an 8" midbass 4.5" mid and 1" tweet. The 8's would get 150rms each, the midrange and tweet would get 80rms per side. No subs.... so a grand total of 450watts of A/B power.

Honestly... most people will think there is a 10" sub and a few hundred watts hooked up.... I did this install in my mazda a few years back it it was amazing. Sounds like there is a sub hidden in the dash instead of in the back.

[RedRide]

Fist off speakers do not actually "pull" power/watts.
They simply utilize what ever the amp is capable to deliver.
It you attempt to drive an amp beyond its capabilities, it will simply begin "clipping" the wave form or go into some form of oscilation. This happens all the time (even with the stock sys) when you turn the volume up louder than the amp is able to reproduce cleanely. This usually does no harm to the amp.

The obvious solution is to match speakers and amp to prevent this. IMO there is no substitue for amp wattage and efficient speakers.

For every increase in 3 decibles, about double the wattage is needed to reproduce it cleanly.

Rember the deal where you take a penny and double it every day? By the end of the month you will be a very rich man.
The same priciple hold true with amp wattage. So, to stat with very efficient speakers to begin with, you are ahead of the game.

To add to this, very high and low frequencys need even more wattage.

Bottom line, I would seriously consider installing a seperate amp for the sub with the proper "crossover" :smile:

[talnlnky]

For every increase in 3 decibles, about double the wattage is needed to reproduce it cleanly.

Rember the deal where you take a penny and double it every day? By the end of the month you will be a very rich man.
The same priciple hold true with amp wattage. So, to stat with very efficient speakers to begin with, you are ahead of the game.

To add to this, very high and low frequencys need even more wattage.

Bottom line, I would seriously consider installing a seperate amp for the sub with the proper "crossover" :smile:

Good post, but the doubling of power = +3dB is very misleading.... 99.9% of speakers produced waste an ever growing percent of power as you give them more power.

Its called power compression, and happens due to two reasons...heat & movement, but basically, if you take a 100rms speaker and put 50rms into it, it's most likely already feeling the effects to a good extent, and if you put 100rms its really feeling it... and if you put 200rms into it it will barely be louder than 100rms.... course its not rms dependent but actually movement dependent, so putting the speaker in a ported box, vs a sealed box makes a huge difference.


so... your point of diminishing returns is even greater than what you posted, but finding a high efficiency speaker on the other hand won't put you that much further ahead of the game if it doesn't have a flat BL curve (keeps cone movement linear). I've got PDF's at home, but no net there... so I can't really post them

[sqcomp]

...Hence the idea to work smarter, not harder.

Hey RR, do you want to continue to tell how and what DOES kill speakers?

Also efficiency is only one of the variables that play into a good system. Even then it depends on the type of speaker, the environment it's in, and the signal it's recieving.

Simply basing the choice of a speaker by the sensitivity will not yield good results. Taln starts to illude to this as well. I can buy a Goldwood speaker that has a "99 dB" sensitivity but...it may not fit into my formula due to many other variables. Most won't figure this out until it's too late. If speakers were judged on sensitivity alone, we'd all be using HLCD's in our rides (of which I am a fan).

The signal amplifier itself is what will determine the life of your speakers. The amplifier's goal is to reproduce signal. Preferrable a high fidelity signal. This is all based on how and how well the amplifier itself is made. We should really stay away from starting a whole other topic here...it will suffice to say that sensitivity of a speaker is by far NOT the only or the most important factor in good sound from said speaker.

We could SO get into a big talk of AC, magnetism, transducer contruction (and purpose), crossovers, plus a heck of a lot more here...

[RedRide]

Well, of course the efficientcy of a given speaker depends on a few factors. This is a given.

For examople:
All things being equal, a "tuned port" speaker sys will be more efficient than a sealed "acustic suspension" sys.

Agreed, efficency should not be the only criteria in chosing a speaker. After all, they have to sound, good etc also.
I only brought this up in the contex of making the most of a low wattage amp.

What will kill a speaker? Feeding it more watts than it can handel .
Also, driving it beyond its accustic (volume) capabilities can some times dislodge the "voice" coil. :smile:

[sqcomp]

To clarify the most important point in RR's last post...

The one of two main culprits of dead speakers is raw Voltage. Both of RR's responses to my question say the same thing essentially. More "Wattage" (Voltage is what he means in this case) CAUSES the speaker to go past its physical limitations. A speaker can only move so much.

In my years of doing this, I have only killed one set of speakers by overpowering them and that was a pair of Diamond Audio Hex Aluminum tweeters. I fed them off of a Kicker ZR600 to the passive for the S600a set. If anyone knows that amplifier, you KNOW it is a bad a$$ piece.

I’d speculate at least 10 to 1 that most speakers are killed by UNDERPOWERING them.

When Johnny Boy Racer cranks up his badly planned system to impress Sally Mae Cameltoe…he’ll more often than not clip the signal by asking the amplifier to produce more of a signal than it can. The voice coil of a speaker moves it back and forth (hence the positive and negative points off the voice coil). Well, when junior turns that volume knob on the stereo (technically referred to as a potentiometer), he increases the signal Voltage going to that amplifier. The signal Voltage is then amplified into the positive and negative (go look for a definition of alternating current) outputs of the amplifier into the speaker’s positive and negative poles of its voice coil.

Keep tracking with me here…

An amplifier can only amplify Voltage to a certain point. When the amplifier is asked by Johnny to get louder than it can…it clips. The positive and negative Voltage signal wave wants to go beyond the amplifier’s limits. Well, the signal does, but the amplifier doesn’t put out anymore (output Voltage). It clips the wave. Unless the moron behind the volume turns the Voltage signal down, every time the CD signals the radio to play that information that clips the amplifier, it will keep clipping on that certain part. ANY part of the signal that goes past the amplifier’s ability to reproduce the output Voltage will stay at the amplifier’s maximum output. Imagine a bass line that keeps repeating on your favorite show-off CD track. The amplifier will keep trying to put out as much as it can. Well guess what people, the speaker will follow suit. The cone will move whatever way that Voltage wave is going and stay there until the Voltage wave comes back to where the amplifier can play into normal limits.

Oh, we’re not finished yet…

That speaker trying to reproduce the output Voltage signal (clipped signal) comes back to the opposite side of the wave. Basically, when you clip your amplifier, you’re heating up the voice coil. Why you ask? The voice coil isn’t moving when it’s stuck at the top and the bottom of the signal wave! You’re burning the hell out of the voice coil. Why am I burning the coil? Because genius, the cone has to move to cool itself! Why do you think speaker manufacturers have made such a selling point on the “cooling technologies” of their products? Does anybody remember the first time they smelled ferrofluid or the metallic burning smell? I certainly do. There are two main ways to work past clipping a signal. The first and smartest way is to turn down your $hit! The second way is to have enough output on the amplifier as to not need all its output Voltage. You do run the risk with the second choice of physically overpowering the speaker though. With this being said, the REAL cure to clipping is level matching your system. It’s also called gain matching. I think I put a little ditty on the board a while back about that.

In my case, my worry for my system is using the Exile Audio Xi 800.4 on a pair of VERY NICE Hybrid Audio L1 Pro tweeters. That translates to a potential output of around 400 Watts per channel bridged given 14.4 Volts. That will be watched VERY closely and mitigated with containing the speaker's signal within certain frequencies and the signal Voltage being controlled by both the processor and the gain on the amplifier itself.

There’s also the part about frequency I didn’t talk about in my rant here. I can cover that if you want but it should be obvious why you use certain speakers for certain frequencies…

If I’ve made a mistake in any of this little rant, PLEASE correct me. It’s LATE here in Baghdad. I’m a little tired from working 7 days a week.

[sqcomp]

Just for our enjoyment...A clipped signal:

http://upload.wikimedia.org/wikipedia/commons/thumb/2/2a/Clipping_1KHz_10V_DIV_clip_A_5ohms-1-.jpg/400px-Clipping_1KHz_10V_DIV_clip_A_5ohms-1-.jpg

Oh what I wouldn't give for that piece right now!

[sqcomp]

…Also, while the vented/ported enclosure is more efficient in terms of sensitivity, you MUST give something to get something. The sealed enclosure helps the woofer play at a more even and stable frequency range AND you take up much less room.

…I’m also biased towards the sealed enclosure. I have never had a vented enclosure (sort of). I do like playing with variovents (aperiodic vents) on my sealed enclosures. I’m a sealed pervert!

We're going to be experimenting with them to see how they affect the sound of the impossibly small sealed enclosure with my two ID 15"s in my Yaris when I get back.

[RedRide]

…Also, while the vented/ported enclosure is more efficient in terms of sensitivity, you MUST give something to get something. The sealed enclosure helps the woofer play at a more even and stable frequency range AND you take up much less room.

…I’m also biased towards the sealed enclosure. I have never had a vented enclosure (sort of). I do like playing with variovents (aperiodic vents) on my sealed enclosures. I’m a sealed pervert!

We're going to be experimenting with them to see how they affect the sound of the impossibly small sealed enclosure with my two ID 15"s in my Yaris when I get back.

Yes, I agree that a sealed encloseure give a tighter, more refined bass response due to due to the increase damping factor of the speaker.

[sqcomp]

You mentioned another characteristic of amplifier performance...Damping factor. Generally that phrase will tell one that an amplifier can "control" it's transducer load. That being said, I'm about to come down like I did on the sensitivity issue...Remember the give something to get something issue? It's the same here as well.

There are SO many variables to "calculate" it'd be a bitch to talk about. Needless to say, in this matter its very much like speaker sensitivity...there's much more to overall sound than just one or two measurements.

Here's a quote from a fellow music enthusiast, "There are an awful lot of people out there spending money on specs they will never be able to hear as differences in the music in a million years. Just don't expect them to ever admit it. I have to really work not to laugh my head off when someone tells me they spent several hundred dollars - or even over a thousand - on speaker cables and they "sound better" than a nice heavy gauge twisted pair of stranded copper wires they could have had for about five bucks..." -B.B. 2001

The same works for my philosophy for the most part. With the equipment I'm using on my Yaris, the amplifiers and the source are upper "midline" (being Exile and JVC) however the specs and construction on the pieces are very solid. I'm not worried about induced noise at all. The processing piece and the speakers are "high end" however. I'm taking into account that the install is the best I can make it (I know it is with all the little installer tricks, experience, and shop support that I have). I have NO reservations about the equipment choices that I've made.

[talnlnky]

Yes, I agree that a sealed encloseure give a tighter, more refined bass response due to due to the increase damping factor of the speaker.

Depending on how you tune a ported box, you can actually get ported boxes to have a better transient response time (aka group delay). Its really easy to do in home theater subs where you aim to tune at 20hz or lower... The group delay spike doesn't really start to kick in until 30hz... thus giving you a slightly better group delay in the 30hz and up region compared to sealed setups. And honestly, once you get below 30hz.... you really can't hear the difference in group delay.

[sqcomp]

Aside from the vented/ported space requirements and powerhandling/sensitivity changes of a speaker in a ported enclosure...the group delay idea is fairly new to me.

I'm wondering...in reality...are we going to hear a difference between a two properly constructed enclosures (ported and sealed), everything being equal, in the realm of response time?

If the amplifiers have good control...wouldn't the added "sensetivity" of the ported enclosure make it inherently more loose when dealing with equal sized woofers?

Then again, we have to wonder to what specifications the ported enclosure is built...I know darnwell I've heard some tight ported enclosures. *sigh* And then on the other hand, that "tightness" may have been from the added output amplitude rather than physical control.

The problem is that you MUST give something to get something. For the quick response of the ported enclosure, what do you have to have? A bigger, more elaborate enclosure (which is a given versus a sealed enclosure), or do we loose power handling and/or frequency response? What do we give up here?

That in itself is enough for me to stick with a sealed enclosure's benefits of space savings. Mind you, that's MY preference. A 15" woofer in one cube with plenty of power sounds just sexy to me...

Let us talk more on this specific subject though, its interesting.

[talnlnky]

Aside from the vented/ported space requirements and powerhandling/sensitivity changes of a speaker in a ported enclosure...the group delay idea is fairly new to me.

I'm wondering...in reality...are we going to hear a difference between a two properly constructed enclosures (ported and sealed), everything being equal, in the realm of response time?

If the amplifiers have good control...wouldn't the added "sensetivity" of the ported enclosure make it inherently more loose when dealing with equal sized woofers? You are close... the "loose/boomy/sloppy" sound is usually due to an over-accented low end, Usually due to a ported or bandpass box being tuned to high which results in a huge 6-10dB spike somewhere in the 40-60hz range. If you make the frequency response flat, slightly rolled off, or even with a small dB bump you will not get that bad "sloppy" sound.... unless the group delay is really slow.

Group delay is basically the time that the coil takes to get saturated and reverse its directions.... so... how long it takes for it to stop, and start. The quicker it can do that, the cleaner the sound. The T/S spec that you can check to guesstimate if the GD will be good or bad is the (Le). Also... tuning a sub low will also help keep GD spikes down.


Then again, we have to wonder to what specifications the ported enclosure is built...I know darnwell I've heard some tight ported enclosures. *sigh* And then on the other hand, that "tightness" may have been from the added output amplitude rather than physical control. It is about the design of the box... a properly designed ported box (for sq) will be indistiguisable from a sealed box in terms of transient response (tightness)... but it will have slightly more low end.... even if you do design the box to roll off and mimic a sealed box (Makes for a darn good sq box in cars). Once again, the naturally dB gain from a ported box doesn't make it sloppy, just louder... an exaggerated bump will make it sound sloppy (mostly due to a high tuning)[/QUOTE]


The problem is that you MUST give something to get something. For the quick response of the ported enclosure, what do you have to have? A bigger, more elaborate enclosure (which is a given versus a sealed enclosure), or do we loose power handling and/or frequency response? What do we give up here? True, there is no perfect enclosure... size, response, efficiency, all kinds of enclosures suck at at least one of the three.... kinda like Hoffman's Iron law for speakers. The main thing for keeping a tight response on a ported box is a tuning at or below 30hz & a sub with a relatively low Le. You can do it with a huge box, or with a very small box.... If you want to mimic the frequency response/ roll off of a sealed box you just make the box undersized. Like the box in my avatar. Its 2 Tangband 8" 740C Drivers... a normal box would be .75-1cuft per driver @ 30-35hz for car use... I changed it to .6cuft @ 28hz for each driver... rolls it off nicely starting at mid 30's due to the small box size, but the tuning is still low so it tries to play low still.... I might have some picks on my laptop of the response somewhere.


That in itself is enough for me to stick with a sealed enclosure's benefits of space savings. Mind you, that's MY preference. A 15" woofer in one cube with plenty of power sounds just sexy to me...

Let us talk more on this specific subject though, its interesting.
I NEED to show you the joys of the software I have for box modeling... Box modeling is where it's at when it comes to designing a good sub stage. You'd shit bricks if you saw what you could do with the right software. I've found that many times, a big sub in a sealed box is no better than a smaller sub in a well designed ported box, and that the smaller sub will actually play louder down low.

I forget exactly what it is... but physics states that a speaker will need an ever increasing box size the bigger the speaker gets.... It has to do with the Surface area (SD) of the speaker & the Vas I believe. If you double the cone area, I think the speaker would require 4 times the box size....all other variables staying the same of course. I might be a bit off on that tho....

Regardless... in the space that you could fit a single 15" sealed woofer... I could probably fit 4-6 similarly spec'd 8" subs.... would have less cone movement, & probably higher efficiency... meaning... louder & less distortion.


Like I said... I really want to spend 30mins to an hour showing you the joys of box modeling and what crazy shit you can do with a driver. I've got a copy of a really nice program.

[sqcomp]

No no man...we need to do this over a beer or seven after hours at the shop in Vancouver. I'm one of the old school types who LOVE big woofers. I'd like to see what could happen with two ID 15"s given the space requirements I'm working with.

...you know...

there's a "cavern" of space under the rear seat of the Yaris sedan...

[talnlnky]

No no man...we need to do this over a beer or seven after hours at the shop in Vancouver. I'm one of the old school types who LOVE big woofers. I'd like to see what could happen with two ID 15"s given the space requirements I'm working with.

...you know...

there's a "cavern" of space under the rear seat of the Yaris sedan...

no problem... you give me the TS specs for each sub, or even just a link that shows the TS specs and I'll make sure the drivers are loaded up into the database before I drive up.... Bring the laptop.

found some pics of the TB8 box... Top pic is a frequency response graph of the box using an older program that was decent, but not quite as good as what I currently use.

http://www.cardomain.com/ride/208374/3

[talnlnky]

ok sqcomp... started its own thread... so we don't jack this one anymore...
http://www.yarisworld.com/forums/showthread.php?p=372567#post372567

[Slick]

I still dont think my last question was ever answered :( Its otay though. I've already redesigned the substage :) Happy to provide a high-jackable thread :)

[talnlnky]

Well, I plan to run 2 of these at 4 ohm http://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?ProductID=15441
However, I am questioning the power capabilities of my current amp http://www.sonicelectronix.com/item_10232_Lanzar+MXA282.html

Its true output at 4 ohms is roughly 750 ish, all things taken into consideration.
Actually... looking at the specs for that amp... it states is uses dual 35amp fuses... meaning a realistic expectation would be for that amp to produce a MAX of 500watts rms (at its lowest ohm rating with both channels hooked up).... so if I had to guess... I'd say the amp was really a 125x2 @ 4ohm, 250x2 @ 2ohm or 500x1 @ 1ohm. Basically, for an A/B amp you take the total fuse rating, times it by .5-.6 and then multiply that by 13 to get a realistic idea of power output. Reason is .5-.6 = 50-60% efficiency of the amp. 13 is the voltage. Total power = voltage times amperage.... but the amp wastes about half that power.

The amp is 1000 rms at 4 ohms each channel. However, if I'm not mistaken, you cannot wire a single DVC 4 ohm sub to 4 ohm, either 2 or 8. Correct me if i'm wrong. The problem i'm having is that the amp is rated at 1600 rms at 2 ohm. The subs are only rated 900. Even if the amp is capable of only producing even 1000 rms at 2 ohm per channel, wont that severely injure my subs?
Correct a single 4ohm DVC sub can do 2 or 8 ohm on a single channel. To get full power from this amp you'd want a sub with DVC 2ohm coils, DVC 8ohm, or SVC 4ohm, or even QUAD 1ohm (yes quad coils do exist). Like I said above... I highly doubt this amp actually puts out more than 500rms, so I think the sub will be fine. even if it did put out 1000rms or more... it would really depend on what box you put the sub in (mechanical movement) and how you beat on your sub (how you play it)... Often times subs can take more power than they are rated for if setup properly.


Now, I know you can wire 2 4 ohm DVC subs to 4 ohm together in parallel but in order for the amp to see 4 ohm I would have to bridge the + of the left output on the amp with the - or the right output. And again, please correct me if I'm wrong. I only half-ass know what I'm talking about :) If i wire the subs up like that then that means it will be trying to push the full 4000 watts. Obviously not going to be that much but you can sort of see where I'm going with this.
take a look at the JL tutorials.. .they are pretty good, and even though JL uses wierd voice coils (3ohm,1.5ohm, 6ohm) you get the idea... If you do parallel you half the ohm load, if you do series, you double the ohm load.

http://mobile.jlaudio.com/support_pages.php?page_id=145

I have been trying to figure this out for about a week now, asking ppl different stuff tying to get a fix on what to do.

Can anyone please give me a REALITY CHECK and explain this stuff to a freakin noob, I will be forever grateful. Thank you in advance.

We be back on topic now... so any other questions you have i'll be able to address now.


On a side note... I generally would try to urge steer people away from audiobahn equipment... and to a lesser extent the lanzar amp. You can usually find products better designed, and more durable for the same price as bahn.

[talnlnky]

Take a look at this... just one idea... there's tons of options out there.. Comes in DVC & SVC 4ohm
http://www.soundsplinter.com/rli10_subwoofer_information.html