Using an amp with Boston Acoustics

[camaroshaun]

I have a four channel amp 200W and I would like to use it on the Boson Acoustic Speakers in my Camaro. Will this work or will it be too much? Do you think it is even worth it?

[Tal]

Waste of time, the speakers will be matched to the amp they come with and putting in a different random amp will at best make very little difference while at worst sounding crappier and/or blowing the speakers. If the system isn't good enough you will want to upgrade speakers and amp together.

[alan422]

Hey Shaun,

Actually an amplifier upgrade might not be a bad idea. I haven't seen a factory installed amplifier yet that doesn't distort at higher volume levels. Amplifiers have limits. Many people think the awful sound you begin to hear at higher volume levels is the speakers distorting. It's actually caused by the amplifier not being able to supply the demand placed on it by the speakers, which in turn destroys the speakers. The technical term for it is called "amplifier clipping".

The build sheet on my car says 245 watt, 9 speaker system. A VERY general statement. I'm pretty sure that is 245 watts /9 as to 245 watts x9. If that is the case, you're talking amp output of about 27 watts (not much) per channel. The first thing you need to do is find out what the speaker max power handling capability is. The general rule for a correct amplifier/speaker match is to use an amplifier with rated output 1.5x to 2x the max rated power handling capability of the speaker. THAT DOES NOT MEAN DRIVING THE SPEAKERS WITH THAT KIND OF OUTPUT. It simply allows the amplifier the RESERVE power to safely drive your speakers at higher levels without destroying them. And it sounds sooooooo much better.

Good luck on that!

[Nexus6]

Originally Posted by alan422

Hey Shaun,

Actually an amplifier upgrade might not be a bad idea. I haven't seen a factory installed amplifier yet that doesn't distort at higher volume levels. Amplifiers have limits. Many people think the awful sound you begin to hear at higher volume levels is the speakers distorting. It's actually caused by the amplifier not being able to supply the demand placed on it by the speakers, which in turn destroys the speakers. The technical term for it is called "amplifier clipping".

The build sheet on my car says 245 watt, 9 speaker system. A VERY general statement. I'm pretty sure that is 245 watts /9 as to 245 watts x9. If that is the case, you're talking amp output of about 27 watts (not much) per channel. The first thing you need to do is find out what the speaker max power handling capability is. The general rule for a correct amplifier/speaker match is to use an amplifier with rated output 1.5x to 2x the max rated power handling capability of the speaker. THAT DOES NOT MEAN DRIVING THE SPEAKERS WITH THAT KIND OF OUTPUT. It simply allows the amplifier the RESERVE power to safely drive your speakers at higher levels without destroying them. And it sounds sooooooo much better.

Good luck on that!

It also depends on how all the speakers are wire.They could be using a series parallel combination.Back in the i wired up 16 speakers to a punch 500 that totally rocked.My suggestion would be to take that amp and use it for a set of nice 8's or 10's.

[Rogue Leader]

Originally Posted by alan422

Hey Shaun,

Actually an amplifier upgrade might not be a bad idea. I haven't seen a factory installed amplifier yet that doesn't distort at higher volume levels. Amplifiers have limits. Many people think the awful sound you begin to hear at higher volume levels is the speakers distorting. It's actually caused by the amplifier not being able to supply the demand placed on it by the speakers, which in turn destroys the speakers. The technical term for it is called "amplifier clipping".

The build sheet on my car says 245 watt, 9 speaker system. A VERY general statement. I'm pretty sure that is 245 watts /9 as to 245 watts x9. If that is the case, you're talking amp output of about 27 watts (not much) per channel. The first thing you need to do is find out what the speaker max power handling capability is. The general rule for a correct amplifier/speaker match is to use an amplifier with rated output 1.5x to 2x the max rated power handling capability of the speaker. THAT DOES NOT MEAN DRIVING THE SPEAKERS WITH THAT KIND OF OUTPUT. It simply allows the amplifier the RESERVE power to safely drive your speakers at higher levels without destroying them. And it sounds sooooooo much better.

Good luck on that!

It is a total RMS rating of 245 watts, and definitely not 9 channels at 245 watts each. That said the trend these days (in new vheicle sound systems) is to count separate components as separate speakers. In reality the car has probably 2 components sets, and a small sub, that would be "9" speakers total (4 mids, 4 tweets, and 1 sub). Each component pair is driven off of 1 channel. So the BA amp is likely a 5 channel amp. There is another post somewhere here that has the full tech specs, I don't recall it though.

Also you absolutely do NOT want to match an amp based upon max power, you want to find an amp that RMS's per channel at a similar rating as the speakers you have (+ or - 15%).

In any case replacing the factory amp with some other 200 watt amp is an incredibly poor idea. If you wanted to upgrade the system replacing it with a far higher power amp as well as matching a set of components to it is a much better plan, and can be done though line level inputs.

EDIT: Found it! http://www.camaro5.com/forums/showthread.php?t=8762 Looks like I am wrong on the exact setup of the speakers, but I was close.

[josh1147]

Speaking from years of mobile audio/video experience in GM vehicles....

You do not want to try and "amp" a factory stereo system....all you are doing is throwing away money and sound quality is horrible. The factory systems are impedence/ampage matched components that are designed to work as a system.

If the factory system isn't good enough for you, scrap it, and start with known components from a reputable company like Treo, DynAudio, Alpine, etc...

[MTron]

Originally Posted by alan422

Hey Shaun,

Actually an amplifier upgrade might not be a bad idea. I haven't seen a factory installed amplifier yet that doesn't distort at higher volume levels. Amplifiers have limits. Many people think the awful sound you begin to hear at higher volume levels is the speakers distorting. It's actually caused by the amplifier not being able to supply the demand placed on it by the speakers, which in turn destroys the speakers. The technical term for it is called "amplifier clipping".

The build sheet on my car says 245 watt, 9 speaker system. A VERY general statement. I'm pretty sure that is 245 watts /9 as to 245 watts x9. If that is the case, you're talking amp output of about 27 watts (not much) per channel. The first thing you need to do is find out what the speaker max power handling capability is. The general rule for a correct amplifier/speaker match is to use an amplifier with rated output 1.5x to 2x the max rated power handling capability of the speaker. THAT DOES NOT MEAN DRIVING THE SPEAKERS WITH THAT KIND OF OUTPUT. It simply allows the amplifier the RESERVE power to safely drive your speakers at higher levels without destroying them. And it sounds sooooooo much better.

Good luck on that!

+1

Now all that being said, it all depends on the characteristics of the amp and speakers. A few important characteristics to compare between amps are damping factor, signal to noise ratio, and the power rating at a specific resistance (i have seen some amps labeled 500 watts on the casing, but if you look at the specs, its 500 watts at 2 ohms...typically speakers are rated at 4 ohms).

For the speakers, the power rating and the sensitivity rating are important as well as the impedance. The power rating is rather self explanatory, how much power can they take, average and peak, the sensitivity, usually given in dB/watt or something similar is a measure of how effectively a speaker converts input power to sound. As for the impedance, you want to make sure that the impedance rating of the speakers is within a range that your amp can handle and still makes good power with good signal to noise and damping factor

If that amp you have has a much higher signal to noise, better damping factor, and the speakers are the right impedance (4 ohms for most aftermarket speaks and amps...some amps can handle between 2-8 ohms, consult your manual for details on ur amp) then it might be worthwhile switching it in.

It will be hard to say exactly how you will be able to fit it in without the wiring diagram and exact speaker config. From what we know about the BA system so far, it seems to have some decent speakers and possibly a sub. If your amp has better characteristics then the BA amp, and the BA amp can be re wired, you might be able to have your amp drive the midrange and the highs, where signal to noice and damping factor are important, and leave the BA amp for the subs (and possibly the center, but again, need wiring diagram)

[alan422]

Excellent point Rogue and thanks for that info... I'm really not the guy who knows how car audio systems are wired. And yes you can match an amp with an RMS rating that is close to the rating of the speaker. It is more than likely the way most factory systems are matched. However, Where you can get into trouble is how well the amplifier holds up under a larger load or aka higher volume levels or aka the real world. Most amplifiers are rated with a given wattage at an 8 ohm load. But in real life when the volume goes up a speaker can put a 4 ohm load or more on an amplifier. I would love to see how much power this 245 watt amp puts out under a 4 ohm load.

If you are replacing an amplifier with a similar output of what the speakers are rated for you should look for an amplifier that will give you good specs on power output under 4 ohm load as well as the 8 ohm load rating. That is where I don't see factory installed amps holding up. An amplifier needs to supply more power under heavier load. A good amplifier will do that. Or you can go with a higher powered amp than what the speakers are rated at. It's all good. Bottom line, if your amp can't handle the load the speaker is placing on it at high volume levels, it will clip and more than likely take out your tweeters first.

As for myself, I'm not going to change any of the audio components in my car as I don't get too crazy with volume levels in the car. Only in the house!

[Nexus6]

this thread is starting to make me

[alan422]

Hi MTron..

You also have great points on what to look for in a good amplifier, S/N ratio damping factor, etc, its all good stuff. And as you say impedance matching is important. You don't want to match a speaker nominally rated at 4 ohms with an amp that can't handle a 4 ohm loads well. As far as the power ratings you mentioned you see on the amp label or even spec sheets is power output under a given load. The speaker load in ohms put on an amplifier is variable depending on speaker demand. A speaker which is nominally rated at a 4 ohm load can easily put a 2 ohm load on an amp once the volume is kicked up. Given that, If you have an amp which is rated at 400 watts into a 4 ohm load but can also output 500 watts under a 2 ohm load is basically just telling you its a very good amp. The power to ohm ratings are just to tell you how well it performs under different load situations.

[MTron]

Originally Posted by alan422

As far as the power ratings you mentioned you see on the amp label or even spec sheets is power output under a given load.......If you have an amp which is rated at 400 watts into a 4 ohm load but can also output 500 watts under a 2 ohm load is basically just telling you its a very good amp. The power to ohm ratings are just to tell you how well it performs under different load situations.

Originally Posted by MTron

signal to noise ratio, and the power rating at a specific resistance (i have seen some amps labeled 500 watts on the casing, but if you look at the specs, its 500 watts at 2 ohms...typically speakers are rated at 4 ohms)

I guess i was just a bit misunderstood Alan422, my little blurb on labeled wattage was just to illustrate that some manufacturers can try to mislead you by stating the power output for an impedance rating that is lower then typical to make the amp seem more powerful. I did sate that all power ratings are for a specific load, although i used the word resistance, which is the same as impedance, but i should have been more clear. Since the vast majority of speakers are around 4 ohms, i find it misleading to state the power of the amp on the casing or the box at a different impedance, since you buy your 500watt amp, but its 500 at 2ohms, so you only get 250watts when you use 4 ohm speakers (assuming speaker line voltage stays the same...ohms law)

As for

A speaker which is nominally rated at a 4 ohm load can easily put a 2 ohm load on an amp once the volume is kicked up

Correct me if im wrong here, but the impedance of a speaker should not go down as the volume is turned up, in fact it should increase. As you turn the volume up, the current supplied to the speakers increases, and increased current causes increased heat, and an increase in heat will cause the resistance to increase as well.

[PQ]

I'll wait to see what it sounds like first.

Ok, HEAR what it sounds like first.

But I beleive it would be one of two choices.

1. Leave the system alone and enjoy it how it is.

2. Take the entire system out and replace with compatibley built components.

[Rogue Leader]

Originally Posted by alan422

Excellent point Rogue and thanks for that info... I'm really not the guy who knows how car audio systems are wired. And yes you can match an amp with an RMS rating that is close to the rating of the speaker. It is more than likely the way most factory systems are matched. However, Where you can get into trouble is how well the amplifier holds up under a larger load or aka higher volume levels or aka the real world. Most amplifiers are rated with a given wattage at an 8 ohm load. But in real life when the volume goes up a speaker can put a 4 ohm load or more on an amplifier. I would love to see how much power this 245 watt amp puts out under a 4 ohm load.

If you are replacing an amplifier with a similar output of what the speakers are rated for you should look for an amplifier that will give you good specs on power output under 4 ohm load as well as the 8 ohm load rating. That is where I don't see factory installed amps holding up. An amplifier needs to supply more power under heavier load. A good amplifier will do that. Or you can go with a higher powered amp than what the speakers are rated at. It's all good. Bottom line, if your amp can't handle the load the speaker is placing on it at high volume levels, it will clip and more than likely take out your tweeters first.

As for myself, I'm not going to change any of the audio components in my car as I don't get too crazy with volume levels in the car. Only in the house!

I think you might have mixed some specs up. Most all amplifiers are rated at a 4 ohm load, and in some cases 2 (or even 1) ohm load (especially amps that are designed specifically for subs). You can run them at 8 ohms by wiring some 4 ohm speakers in series, not really sure why you would want to do that. The amp load is all based upon how the amp is configured, the speakers you use, and how you wire them. I won't even start to get into all the possible configurations. Once its all installed then you have to adjust the gain and volume levels to find the highest point you can drive it, you have to listen for distortion, and yes if you are driving it hard it will clip, which means you need to turn down the gain and back off on the volume a bit. BUT even at that sweet spot where it still works, you can overheat the amp, or burn out voice coils in speakers. The main lesson is, you have to pay attention to the sound quality closely at high levels, because damage happens quickly and you may not even realize it.

However... Volme levels have nothing to do with the load placed on the amp. As you crank the volume up the load does nto increase from 8 to 4 to 2. As I mentioned it depends on the speakers, the rating of the channel on the amp, and how you wired it. And once its done its set.

I would bet that BA likely went with a 4 ohm load on all its channels. Most past factory sound systems ran at 4 ohms as well, and as such 4 ohms has become the de-facto "standard" load. However the old Monsoon system actually ran its channels at 2 Ohms! The tweeters however were all powered off the headunit and those ran at 4 ohms.

[Vash]

I doubt it would help to reamp. We need to look at the system and or service manual for the electric first to make DIY's guides.