Advice on bass system.

I'm thinking of putting 2 rf punch xlc 12" in a vented box with ports extending into the passenger compartment. Each sub will get 200rms. I like it loud and I was wondering what you guys out there with more experience think. What would you do(keep in mind i'm not made of $$$). I already have one of the 12's and have been using it for the past year or so. If I get another one and have them firing at the same time it should be no problem right?

Thanks
Mladen

[Ashman]

Shouldn't be, just get a box made to fit the cubic inch capacity of the woofers so they get maximum sound.

Also you will want the amp to be bridged mono if it is stable mono to hit those suckers nice.

Port into the cabin either by removing the rear speakers, cutting through the rear deck and putting in the ports, or hollowing out the first aid box.

On another note, you might also want to a 1F Capacitor to boost voltage to the amps allowing them to put out a bit more power.

If running from an eq which you havent bought, try finding one with higer output voltage on the pre outs, it will make it louder.

Hope that helps you.

Alon

I'm not a pro, I just know about this because a friend does it all day and I used to install years ago.

Alon, I appreciate the help on both my posts but I have one more question. here are the features of the Power Acoustic 2apc980 amp.

2Ohm Stable
2 Channel x 980W Max.
360W x 2 RMS @2Ohms
200W x 2 RMS @ 4Ohms
980W Max. Bridged
1/2/3 Channels Possible

In order to push two of those svc rf xlc 12's isnt my only option to put 200 watts to each at 4 ohms. If not please explain what else I could do. One more thing, is it really worth it to spend $$ on capacitors, is the difference even audible?? Once again thanks a lot for the help.

Mladen

[Q]

If running from an eq which you havent bought, try finding one with higer output voltage on the pre outs, it will make it louder.

Sorry, that is just not true. You can't get any more power out of an amp than it was designed to deliver. That suggestion would only apply if your head unit was unable to deliver the correct input into the amp in the first place. Although, almost all amps have a gain adjustment that will accomodate even those head units.

My recommendation to you would be to get a pair of Image Dynamics IDQ 12" subs and run it off of an Arc Audio amp. I know you haven't heard these brands before, but that doesn't mean that they suck. The reason you haven't heard of them is because the companies are both pretty new, and only high end dealers carry their stuff. You will NEVER find it at Circuit City or Best Buy.

Before you buy anything, come check out a site that I moderate. You can ask any question you want, and the format is very similar to this one. You will even find people working for those two companies I mentioned on that site.

http://www.elitecaraudio.com

Also, there are a lot of guys selling some of their gear over there. Those guys baby everything they have, and they don't hang on to it long before they are upgrading again. I bought almost my entire system from people there. My amp and front speakers had never even been used.

[Ashman]

Actually you can. Adding a 1F Capacitor and an eq with higher voltage pre outs, lets say 5 volts in stead of 3, the sound will be louder.

The capacitor allows the amp to get a constant of around 13-14 volts, which in turn makes the amps provide more powwer.

Think of it like this. if overclocking a CPU you sometimes have to up the voltage to get the increased speed to stabilize the system.

My brother just put a Amp I bought for him in his car, and then he added a 1F Capacitor and the thing hits much harder than it did before the capacitor, in fact power output in his system on his amp with the capacitor was around a 30-40% increase.

An EQ with higher voltage pre outs - if you do the reasearch you will see some radios come with higher output voltage on their pre outs. this sends a stronger signal to the amp, which in turn is able to amplify the signal higher because its getting it at a higher voltage, thus increasing the sound. and making it cleaner.

As for running amps, if its stable at 2 ohms mono, you basically are almost doubling the output of the amplifier. I personally would run mono because you can set the gain lower and have more sound.

The woofers of course need to be able to handle the extra load.

A Friend has a 93 300Se Benz, 3 12's hooked up to an 800 watt amp, bridged mono, that thing hits so hard you can feel your ear drums being pushed into your skull.

Adding a 1F Capacitor will keep voltage at the amps at more than 12 volts. any good quality amp will love the extra voltage and put out more power.

I have a friend who does installs all day, crazy stuff, GPS Nav Systems, TV Tuners, DVD with surround Sound, playstations, VCR's, you name it he installs it, and I have dealt with the company he works at for 9 years.

I have seen all sorts of crazy installs. In fact I have a friend who put two 18's with 2000 watts on the 18's, and blew the camper shell to pieces on his pickup truck. If you've ever wondered how much bass is too much bass, imagine it being so strong it can bend metal and blow out windows.

Always check with everything at your local stereo shop, but I can guarantee you there is a reason for the Capacitors. they help boost voltage which helps boost power.

And higher voltage pre outs will give you a better signal and a louder system. it may not seem like it would be, but it does get louder, maybe not by much, but a higher quality signal to the amps makes for a higher quality output signal

Q I'm not saying you are wrong, but I have done installing in my day, and I have witnessed the creation of some pretty sick systems. I do know though that a 1 Farad Capacitor will make the amp produce a bit more power. When there is a big load on a car's charging system the voltage can drop below 12 volts, and will reduce the power output. the capacitor helps to keep that voltage constant and above 12 volts, where it should be.

Alon

[Q]

Please don't take this as me wanting to get into a pissing contest, I just want to try to get the facts out there. To back up my position, I went to school for Electrical Engineering. Although, in the last year, I switched to Computer Engineering. I have plenty of electical engineering background. As for car stereo stuff, I have been a moderator over on http://www.elitecaraudio.com for 2 years and have been witness to MANY discussions on the same myths that you have come to accept as fact.

A higher preamp output voltage will not give make your system louder, period. The reason is that for an amplifier to achieve maximum power transfer, the impedance of the input stage of the amplifier needs to be 100% matched to the impedance of the output stage of whatever device it is connected to. What a higher preamp output voltage will get you is a higher signal to noise ratio. That is an excellent advantage, as it helps in reducing induced noise from the car's voltage supply (alternator).

A capacitor does not cause an amp to produce more power. What it does do is supply current to the amp during times when the car's power supply can't keep up. The length of time that the capacitor is capable of delivering its charge is extremely short. That being the case, a capacitor is actually a drain on your system, because once the charge is depleted, it must recharge. If you take a look at any major SPL competitor, they don't use capacitors. If a capcitor gives you a big difference in the punch of your system, you are in need of a higher output alternator, or your amplifier's power wiring is insufficeint. I am not saying that a capacitor should never be used. They do aide in delivering the correct kick to music reproduction.

[Ashman]

Q, I was merely pointing out that when my brother put one on his car it did get louder. The bass before he did it was good but not bumpy like he wanted. After the Capcitor, the bass was much more profound. and louder.

Based on that, and probably based on the quality of the amp, the capacitor does just that it improves the power going to the amplifier by keeping it at more of a constant.

I'm not trying to get into a pissing contest, just relaying what I have seen from actual use of such items.

The higher voltage pre outs do not necessarily make the system louder, but they do send a better signal to the amp, which in turn will assist in the system being cleaner, and possibly a slight bit louder due to the signal being more.

I don't doubt your knowledge, and I welcome you or anyone to correct me and put me in my place. I would rather have someone correct me with accurate info than to let me give someone advise that is not correct.

But like I said from my experience with capacitors, they do improve the sound. probably because of the constant voltage it keeps at the amp.

My brothers cap keeps the voltage to his amp at a constant 13-14 volts, and it rarely drops below 13. before he had it, sound didn't sound as good, after, the sound was much much better.

A Lot of the new high tech amplifiers are power hungry, and like to have more than just a simple 12 volts to produce maximum output. Especially when that 12 volts could become 10 under load.

in anycase, I'll leave this one to you to provide accurate answers.

I always tell people to listen to someone else's car that sounds good and model your system based on how you want it to sound.

If its big pumping bass, there are specific things that are needed to keep the system sounding good, and a capacitor and good EQ are key items for a really good sounding system.

My jeep which had a very nice system, sounded ok. then I put on an old kenwood 6042 EQ which has parametric frequency adjustments. Well I can tell you the sound quality improved ten fold. Everything was adjustable, and I still have that EQ to this day. and it has worked great for 8 years. In fact I put it in my brothers car because he needed something to make the adjustments better, and I wasn't about to let him spend money on an eq whne I had one I wasn't going to use because my car only has a sub amp and not any amps or high quality speakers in it. yet. hehe

Its always good to have more knowledge about things.

If you say the cap doesn't improve power, then I trust that you know, but I have seen it improve it, so I must say that I do know from actualy seeing it in action that it does improve the quality and loudness of the sound.

This is probably due tot he constant voltage it gives without letting it drop.

The cap in my brothers car has a digital voltage readout. The thing looks like he has a bomb wired into his car.

In anycase, please do correct me if I am wrong. And lets not argue over this. All Mladen wants is boomy bass from two 12's. he has 1 12 already. so all he needs is one more, a matched box to the woofers, a good amp, and I think a capacitor will help him achieve his goal. an EQ or sub level control is also someting I believe should be used to really get the sound to sound good.

In anycase, I do apologize if I have given any misinformation. I always give info based on what I know from experience, but of course sometimes I am wrong. if I am tell me. I don't want to see people spending money on things they wont need.

In anycase, Its been fun butting heads with ya Q. hehe perhaps through all the confusion That may or may not have been created here, some good information is in here, that should help with the boomy bass install.

Alon

[Ashman]

Q, I was merely pointing out that when my brother put one on his car it did get louder. The bass before he did it was good but not bumpy like he wanted. After the Capcitor, the bass was much more profound. and louder.

Based on that, and probably based on the quality of the amp, the capacitor does just that it improves the power going to the amplifier by keeping it at more of a constant.

I'm not trying to get into a pissing contest, just relaying what I have seen from actual use of such items.

The higher voltage pre outs do not necessarily make the system louder, but they do send a better signal to the amp, which in turn will assist in the system being cleaner, and possibly a slight bit louder due to the signal being more.

I don't doubt your knowledge, and I welcome you or anyone to correct me and put me in my place. I would rather have someone correct me with accurate info than to let me give someone advise that is not correct.

But like I said from my experience with capacitors, they do improve the sound. probably because of the constant voltage it keeps at the amp.

My brothers cap keeps the voltage to his amp at a constant 13-14 volts, and it rarely drops below 13. before he had it, sound didn't sound as good, after, the sound was much much better.

A Lot of the new high tech amplifiers are power hungry, and like to have more than just a simple 12 volts to produce maximum output. Especially when that 12 volts could become 10 under load.

in anycase, I'll leave this one to you to provide accurate answers.

I always tell people to listen to someone else's car that sounds good and model your system based on how you want it to sound.

If its big pumping bass, there are specific things that are needed to keep the system sounding good, and a capacitor and good EQ are key items for a really good sounding system.

My jeep which had a very nice system, sounded ok. then I put on an old kenwood 6042 EQ which has parametric frequency adjustments. Well I can tell you the sound quality improved ten fold. Everything was adjustable, and I still have that EQ to this day. and it has worked great for 8 years. In fact I put it in my brothers car because he needed something to make the adjustments better, and I wasn't about to let him spend money on an eq whne I had one I wasn't going to use because my car only has a sub amp and not any amps or high quality speakers in it. yet. hehe

Its always good to have more knowledge about things.

If you say the cap doesn't improve power, then I trust that you know, but I have seen it improve it, so I must say that I do know from actualy seeing it in action that it does improve the quality and loudness of the sound.

This is probably due tot he constant voltage it gives without letting it drop.

The cap in my brothers car has a digital voltage readout. The thing looks like he has a bomb wired into his car.

In anycase, please do correct me if I am wrong. And lets not argue over this. All Mladen wants is boomy bass from two 12's. he has 1 12 already. so all he needs is one more, a matched box to the woofers, a good amp, and I think a capacitor will help him achieve his goal. an EQ or sub level control is also someting I believe should be used to really get the sound to sound good.

In anycase, I do apologize if I have given any misinformation. I always give info based on what I know from experience, but of course sometimes I am wrong. if I am tell me. I don't want to see people spending money on things they wont need.

Its been fun butting heads with ya Q. hehe perhaps through all the confusion That may or may not have been created here, some good information is in here, that should help with the boomy bass install.

I gotta get back to work. hehe Catch ya later.

Alon

[Q]

If I weren't planning on building a Cobra kit car, I would be more inclined to put my stereo back together. I just got my Alumapro Alchemy 12" back from the manufacturer the other day. Seems it need a new coil. Hmmmm...couldn't have been me playing Beastie Boys a little too loud, could it? Fortunately, they did it for free.

Ashman,
You should see what I am trying to do with my kickpanels in my 85 SE. It is INSANE! I did the left side in MDF, but didn't like it, so I am going to redo it in fiberglass one day. I have a 6.5", 4", and a 1" tweeter down there. The fronts are run off of an ESX Q1204 delivering 120W per side. The sub was driven by a pair of bridged channels at 400W. I removed the first aide kit and storage box to deliver the bass. Problem is, now I can hear my gas sloshing around. I have an Autotek 31-band stereo EQ, and an Alpine CDA-7940 head unit. I got everything for right at $1400, and that was with me spending $400 on those front speakers.x

[Ashman]

Sounds very nice. hehe well it sounds like it is. I havent heard it so I don't l know what it sounds like. hehehe but I'm sure it is intense.

I plan on just upgrading my speakers in the stock locations. My car came factory with the 6 speaker stereo, so it has the door panel speakers. I will replace them all with good quality speakers, running off a 40x4 or 50x4 amp. I will have a 300W Amp hitting the woofer. in about a month or less.

I will be taking my bass port and extending it into the airbox. this will keep the gas sloshing sound out, and will put all the bass right in the cabin and not in the trunk.

Drop me an E-mail, and the links to those sites you mentioned, I'd love to check out the sites and chat with you more about car stereo stuff. hehe

Alon

[Tolahouse]

Q
In your last post here you mentioned that you had just got your Alumapro Alchemy back from the manufacturer. How does your sub sound. I have one in a bandpass box built by Alumapro and I have a PPI 4400 with 2 channels bridged driving it. Now I got this sub because of it's tightness/smoothness in producing bass notes but I keep on feeling that I need free air subs instead of it. Mainly because the music does not come into the car cabin that well. I'm yet to provide any porting into the car but I just want to know what you feel 'bout this sub. BTW I have it in a '97 E420.

[Ashman]

Well to start, you will want to port into the cabin.

Best bet is to actually extend the port from your box if it has one, through the rear deck. this will make the bass come into the car without entering the trunk much at all.

I will be porting into the cabin of my car by extending the box port through the first aid box.

Doing this will allow the sound to come intot he cabin, with little sound actually filling the trunk.

When I open my trunk bass is decent, when I close it, in the car it adds a little oomf but not enough for my tatstes. but enough for now until I start cutting the hole. hehe

I'm sure the woofer you mentioned is nice. I like woofers that give tight clean bass, and the one you describe sounds like ti does just that.

Alon

hey q - I think what they meant was that adding an equalizer will give the amp a better signal, allowing better, cleaner power. I was running my three amps using one set of rca's from my head unit, with a bunch of y-splitters. The signal was weak to begin with, and was made much weaker by being split to so many amps. As a result, when i added my eq, with one set going in and three pairs going out, the signal was much stronger, so the gains didnt have to be set so high. The amp is just more efficient and the poewr is cleaner with better voltage outputs.

[Q]

The Alumapro Alchemy 12" sounds really good. I love it because it is very accurate for such a loud sub. To get the full effect of the sub, you are going to have to allow the air in the trunk to connect with the air in the cabin. The easiest thing to do is to cut out the rear boxes in the package shelf and also remove the lids. You can create some very slim grilles to go over the holes with some 1/8" masonite and grille cloth. There is a place called http://www.partsexpress.com that sells all different styles and colors. If you are serious about hearing your sub, that is the only way you can do it. You could remove the rear speakers and the fiberous jute that is below them to "port" the rear shelf, but it won't work as well. Also, you can gain a lot just by moving your sub box around in the trunk. Usually, the best location is against the front of the trunk with the sub facing the rear of the trunk.

[Ashman]

Hey Q, I have an update on some info I found out while I was looking at some amps at my local stereo shop, and the power ratings they give, are based on a 14-14.4 volt input into the amp.

Without a farad capacitor, the voltage going to the amp will be below its maximum power output specs, thus making the amp not put out as much power as it should because it is not getting the voltage it is supposed to get to produce its rated power.

By adding the capacitor, you allow the amp to get a constant higher than 12 volt power input, which allows the amp to run at its peak power because it has the correct voltage.

I know you have stated a farad capacitor doesn't boost power, but in actual fact if you don't have one, the amp is not putting out its peak power.

Most high end amps are rated at 14-14.4 volts power going into them to produce their maximum output.

Say I get a 380Wx2 amp. if I check the manual for the amp, it states that the 380W Power rating was achieved at 14-14.4 volts. Now if I just install the amp without the farad capacitor, it will put out significantly less power because it is getting less voltage than it should to get its maximum power output.

I don't want to get into an argument with you about this, but I will suggest that you check out the information I have provided, because it does appear to hold true that a farad capacitor does boost power, but not beyond the amps limits, but it boosts the power so the amp can reach its maximum power output.

Hope that clears up that issue for you and anyone else.

Even if you were to put in a high amperage alternator, with battery isolation system and all, your car still would not be sending 14-14.4 volts to all your electornics, but rather around 12 volts or just a bit more.

With the farad capacitor your amp will get the voltage it needs to put out maximum power output as tested and rated by the amp manufacturer.

I looked at several high end amps, each of which stated maximum power output is only achieved at 14-14.4 volts.

Alon