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While I'm really wanting an excellent SQ system in the Caddy, I'm wondering if I am going to be able to invest in all the components that I dream of or whether I'm going to get plain ole good components.

That being said, will the XD amps be good enough for me or will I really need to step up to HD amps?

All this assuming I step up to an MS8 running off my factory h/u...
 

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I think they're fine. Yeah Eldridge is sponsored, but he wouldnt use them if they weren't good enough. I've heard a difference between cheap amps and boutique stuff, but once you reach a certain point, the speakers, tuning, and especially install make a much bigger more noticeable difference.
 

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I don't mean this to be rude but, even your experienced car audio shops that do installations in commerce generally can't answer your question making the online crowd typically as ignorant to such questions.

If you really want to know the quality of an amp, there are two ways to find out. One is to put it on a true RMS meter, thermometer and an oscilloscope, put a load on it then start hitting it with dB controlled test tones and watch how it responds to the variations in signal, specifically the low end.
These is the low tech approach and obviously, it's costly equipment and not exactly all that low tech in truth of the event. You must be able to competently understand the data and apply it to real life conditions.

The second way is to pull the amps open and look at all specific components. First, the amplifier chips. What is the name brand and model number on them. The name brand on the casing has nothing to do with what is inside of these units. These companies generally build their amp based on a schematic(for laymen a circuit blueprint) provided by the amplifier chip manufacturer. So it says JL Audio, HD, Jensen WHATEVER, doesn't matter. The brand of chip on the inside will often be a Hitachi or Texas Instruments etc and the core design that brand used to build their amplifier was given to them by the chip manufacturer which has been common practice now for close to a century!

So the first thing you do with those chip numbers is look up their data sheet as provided by the manufacturer. It will tell you the chips maximum potential output at a fixed voltage. That voltage is often 16 volts rather than the 12-14.4 99% of the automotive audio crowd is used to. You will also be able to determine what class of amplifier it is. Personally, I still think class D sounds the best aside from it's performance as recorded by data meters proving it to be cleaner and more power efficient. You will generally also see quite clearly that your chips are not capable of the claimed wattage and I don't care who's brand name is placed on the amp!
If those chips put out 340 watts RMS @ 2 ohms, the brands that then build that circuit will tell you 500 watts RMS @ 2 ohms or whatever hopped up ******** RMS wattage they attained using a non standard test tone. Standard is 1 Khz so many will use a higher frequency, overdrive the amp and indeed, get that 500 watts of RMS out of it.

Unfortunately, your question falls under the category of imperial brainwashing. 999,999 answers out of 1 million people asked will be based on brand loyalty which is of course unreliable.

So here's what to look for.

First, and even before the chips, your transformer. Fortunately just about every company loathed or loved uses a round toroid power coil.

Second, how large and how many power caps does it have. Are they name brand? This is an area in life where we can pay credit to brand names!

Third, the amplifier chips. Now that we've had a good look at our power station, lets look at our engines. It's again where we can trust name brand manufacturers. Your amp may say Broblaster 8100XPA on the outside then on the inside, have Toshiba power amp chips. Truth be told, it's unlikely you will get a crap power chip. The issue here is, what is the maximum potential wattage output documented by the manufacturer.

Fourth, how many resistors and non polar caps do you see and what color are they. Burgundy or brownish red polypropylene caps are the highest grade caps. Second would be green, your polyester caps. Third and of course cheapest are your round ceramic disc caps. Ceramic caps produce their own unique distortion and are the cheapest caps that give highs the sharpest, crispest texture. Sometimes this is actually a very good cap to use but bottom line is if the amp has a lot of them, you might want to avoid that brand. You will get 100 ceramic caps for what it costs you to buy 10 polypropylene caps.

Fifth.
Op amps and transistors.
Do you see a lot or just a few. Some amps will have a half dozen op amps and 30 transistors. This is a very good sign because it means your built in preamp/crossover should have a very good dB range and is preamplifying, cleaning and conditioning your signal for further power amplification.
However, it's also not crucial as one may think. A single op amp and a few transistors can make an excellent preamp and filtering circuit.
What is crucial is the name brand and model number on these suckers. For one, a half dozen to a dozen brands can and do legally produce the same model number. You indeed want name brand op amps. Secondly, the most common op amp you see is the TL072 or JRC4558. Even without those letters, if you see those numbers you have one very crisp turd in your bag of chips! Unfortunately, you will always see these op amps in just about everything that uses electricity and makes sound. If you feel competent, replace them immediately with some T.I. NE5532's.

Lastly, your resistors.
Are your resistors super tiny barrels or are they large barrels. Basically a red ant verse a big ass black carpenter ant. Second, what color are they. Are they blue or a tan color. Large tan resistors are generally the most desired. Resistors are hard to scorn because in some if not majority of cases, the type used makes absolutely no difference to the sound but in the few it does..well that's why I included this portion of the post.

So let us recap.
Round power transformer.
Name brand chips like Hitachi, Texas Instruments etc.
Name brand power caps, how large and how many.
Lots and lots of resistors and capacitors.
At least a couple op amps and a half dozen transistors.(generally this is what majority of your caps and resistors are connected to).

I've seen a lot of amps come and go for myself and others. Admittedly I've had more Brand-X gear than name brand but I've also experienced $50 amps with about 20 pieces to the entire circuit take 20 years of abuse in just 2 and survive! Then one minor incident from wire tinkering kills them dead as a doornail where your amps with 200 part counts aren't going to take any level of damage. It's unfortunately a question that isn't open for academic debate because there is no reliable let alone factual answer.
 

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Well, if you just want a "decent" SQ, XD will be good enough... If you want an "execelent" SQ, HDs are not for you, atleast Audison LRX and above.....
That's a very very subjective opinion.. you would need a very special pair of ear to hear a double the price difference:confused:

I think they're fine. Yeah Eldridge is sponsored, but he wouldnt use them if they weren't good enough. I've heard a difference between cheap amps and boutique stuff, but once you reach a certain point, the speakers, tuning, and especially install make a much bigger more noticeable difference.
x2...exactly right......Imo speaker make a lot more difference then amps
 

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Def speakers, but I feel install is much more of a difference. Either one of those lines will work great. I think the hd's are better, but the xd's are more than enough, esp with using the signal from a factory deck. It seems you're still just getting into active setups, so I'd esp save the money from the hd's and be sure to buy an rta solution or spend it on the speaker install.
 

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I don't mean this to be rude but, even your experienced car audio shops that do installations in commerce generally can't answer your question making the online crowd typically as ignorant to such questions.

If you really want to know the quality of an amp, there are two ways to find out. One is to put it on a true RMS meter, thermometer and an oscilloscope, put a load on it then start hitting it with dB controlled test tones and watch how it responds to the variations in signal, specifically the low end.
These is the low tech approach and obviously, it's costly equipment and not exactly all that low tech in truth of the event. You must be able to competently understand the data and apply it to real life conditions.

The second way is to pull the amps open and look at all specific components. First, the amplifier chips. What is the name brand and model number on them. The name brand on the casing has nothing to do with what is inside of these units. These companies generally build their amp based on a schematic(for laymen a circuit blueprint) provided by the amplifier chip manufacturer. So it says JL Audio, HD, Jensen WHATEVER, doesn't matter. The brand of chip on the inside will often be a Hitachi or Texas Instruments etc and the core design that brand used to build their amplifier was given to them by the chip manufacturer which has been common practice now for close to a century!

So the first thing you do with those chip numbers is look up their data sheet as provided by the manufacturer. It will tell you the chips maximum potential output at a fixed voltage. That voltage is often 16 volts rather than the 12-14.4 99% of the automotive audio crowd is used to. You will also be able to determine what class of amplifier it is. Personally, I still think class D sounds the best aside from it's performance as recorded by data meters proving it to be cleaner and more power efficient. You will generally also see quite clearly that your chips are not capable of the claimed wattage and I don't care who's brand name is placed on the amp!
If those chips put out 340 watts RMS @ 2 ohms, the brands that then build that circuit will tell you 500 watts RMS @ 2 ohms or whatever hopped up ******** RMS wattage they attained using a non standard test tone. Standard is 1 Khz so many will use a higher frequency, overdrive the amp and indeed, get that 500 watts of RMS out of it.

Unfortunately, your question falls under the category of imperial brainwashing. 999,999 answers out of 1 million people asked will be based on brand loyalty which is of course unreliable.

So here's what to look for.

First, and even before the chips, your transformer. Fortunately just about every company loathed or loved uses a round toroid power coil.

Second, how large and how many power caps does it have. Are they name brand? This is an area in life where we can pay credit to brand names!

Third, the amplifier chips. Now that we've had a good look at our power station, lets look at our engines. It's again where we can trust name brand manufacturers. Your amp may say Broblaster 8100XPA on the outside then on the inside, have Toshiba power amp chips. Truth be told, it's unlikely you will get a crap power chip. The issue here is, what is the maximum potential wattage output documented by the manufacturer.

Fourth, how many resistors and non polar caps do you see and what color are they. Burgundy or brownish red polypropylene caps are the highest grade caps. Second would be green, your polyester caps. Third and of course cheapest are your round ceramic disc caps. Ceramic caps produce their own unique distortion and are the cheapest caps that give highs the sharpest, crispest texture. Sometimes this is actually a very good cap to use but bottom line is if the amp has a lot of them, you might want to avoid that brand. You will get 100 ceramic caps for what it costs you to buy 10 polypropylene caps.

Fifth.
Op amps and transistors.
Do you see a lot or just a few. Some amps will have a half dozen op amps and 30 transistors. This is a very good sign because it means your built in preamp/crossover should have a very good dB range and is preamplifying, cleaning and conditioning your signal for further power amplification.
However, it's also not crucial as one may think. A single op amp and a few transistors can make an excellent preamp and filtering circuit.
What is crucial is the name brand and model number on these suckers. For one, a half dozen to a dozen brands can and do legally produce the same model number. You indeed want name brand op amps. Secondly, the most common op amp you see is the TL072 or JRC4558. Even without those letters, if you see those numbers you have one very crisp turd in your bag of chips! Unfortunately, you will always see these op amps in just about everything that uses electricity and makes sound. If you feel competent, replace them immediately with some T.I. NE5532's.

Lastly, your resistors.
Are your resistors super tiny barrels or are they large barrels. Basically a red ant verse a big ass black carpenter ant. Second, what color are they. Are they blue or a tan color. Large tan resistors are generally the most desired. Resistors are hard to scorn because in some if not majority of cases, the type used makes absolutely no difference to the sound but in the few it does..well that's why I included this portion of the post.

So let us recap.
Round power transformer.
Name brand chips like Hitachi, Texas Instruments etc.
Name brand power caps, how large and how many.
Lots and lots of resistors and capacitors.
At least a couple op amps and a half dozen transistors.(generally this is what majority of your caps and resistors are connected to).

I've seen a lot of amps come and go for myself and others. Admittedly I've had more Brand-X gear than name brand but I've also experienced $50 amps with about 20 pieces to the entire circuit take 20 years of abuse in just 2 and survive! Then one minor incident from wire tinkering kills them dead as a doornail where your amps with 200 part counts aren't going to take any level of damage. It's unfortunately a question that isn't open for academic debate because there is no reliable let alone factual answer.


easy....You are going to get the OP confused:p
 

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Discussion Starter #13
easy....You are going to get the OP confused:p
Once upon a time I took electronics at a tech school. So most of that I got. Even as familiar as I was with old school audio and passive systems, it's a whole new animal with these active setups and using my factory h/u and class D amps...
 

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There is no question that the HD is the better amp. But only you can decide if the XD is good enough for you. That is about as real of a response that you could hope to get.

Sent from my HTC Sensation 4G using Tapatalk
 

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I'm currently running a XD700/5 from a factory HU. I had run HD previously. I also just recently removed a MS-8 from the signal chain which was used with both setups (XD & HD). As far as perceived SQ goes, I don't believe I detected any difference between XD & HD. The only real difference is the output power. Once I decided to remove the MS-8, the XD made sense because of the X10 switch that allows me to run fully active with tweeters. Now I'm experimenting with wide-banders in place of the tweeters. So my HP crossover has moved from the 2.5kHz range to the 250Hz range. If I settle with this setup, I may replace the XD700/5 with a HD900/5 to gain additional subwoofer output.
 

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The JL XD amps sound wet and almost tube like.


The A/B 4 channel in the HD900/1 sounds awesome, but the D-class sub channel sounds like over-rated garbage @ 2ohms.


The XD has 60% of the detail of the HD series on the highs, but makes up for the detail in clean and clear SPL.

My sister has an XD500/3 on a 10w3 and a pair of components and its loud and clear.


I would not recommend the JL HD series amplifiers, especially not for subwoofer duty. They don't even have adjustable subsonic filters.
 

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The JL XD amps sound wet and almost tube like.


The A/B 4 channel in the HD900/1 sounds awesome, but the D-class sub channel sounds like over-rated garbage @ 2ohms.


The XD has 60% of the detail of the HD series on the highs, but makes up for the detail in clean and clear SPL.

My sister has an XD500/3 on a 10w3 and a pair of components and its loud and clear.


I would not recommend the JL HD series amplifiers, especially not for subwoofer duty. They don't even have adjustable subsonic filters.
Are you saying the HD900/5 is A/B + D? I think you are very mistaken on that.

IMO, the two biggest factors that would swing my opinion in favor of the HD's over the XD's is the power output plus the regulated power supplies.

I have this issue with my car where the volume and tonality changes with what seems to be rising and dropping of my car's operating voltage. Yes, that likely means I have car related issues I need to deal with, but I don't need my car stereo telling me that.

Amplifier power should be strong, consistent, and rock solid. If the regulated power supplies give that, then I'd be in.

That XD700/5 looks mighty tasty for going active though.
 

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I have thought of this aswell since i just need an amp to do a 2 way active setup on my 6.5 clarus. i'm stuck between the hd600/4 and xd400/4.
 

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The A/B 4 channel in the HD900/1 sounds awesome, but the D-class sub channel sounds like over-rated garbage @ 2ohms.
If I told you the 4 channel part of that amp is also class D, would it still sound awesome to you? If not, what does that say about our ability to hear awesomeness?

The XD has 60% of the detail of the HD series on the highs, but makes up for the detail in clean and clear SPL.
Closer to 72.332%, but that's just an approximation.
 
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