What 2 channel amp to run Hertz fronts?

[MillerSHO 10+ year member]

I have an older alpine F450 amp bridged running a pair of Hertz components and it's overheating after about 45min-1hr of playing loud. I already had this issue with this amp running those same front with a 10" sub so I bought a dedicated sub amp.

The amp only runs the fronts now but again it will eventually get too hot and cut out for a few seconds if its running hard for too long just like before.

I want to move away from a 4-channel amp to a 2-channel amp so here are my questions:

1. What are some good recommendations for an amp like I described to run only front components? I would like to run the full RMS to the speakers like I'm currently doing.

2. Do mids-tweets sound better when running at 4ohms vs. 2ohms or does that have no effect on sound quality?

3. My sub amp is a digital D class amp and stays cools and doesn't beat on my electrical as hard as this older AB alpine amp, are AB amps still the way to get the most sound quality out of mids-tweets or are these new digital D class amps have just as much quality of sound as AB amps?

Thanks

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[dragnix 5,000+ posts]

The newer class D amps have been shown to have SQ as good as most class AB amps. How hard are you driving the alpine right now? Maybe just turn the gain down? What's the Hertz rated at anyway?

 

[neo_styles 10+ year member]

PPI Phantom P600.2. 200 bucks shipped from most places and should be more than enough. Also tri-mode compatible so you could run a 4-ohm sub off it at the same time.

 

[zako 10+ year member]

I have an older alpine F450 amp bridged running a pair of Hertz components and it's overheating after about 45min-1hr of playing loud. I already had this issue with this amp running those same front with a 10" sub so I bought a dedicated sub amp.
The amp only runs the fronts now but again it will eventually get too hot and cut out for a few seconds if its running hard for too long just like before.

I want to move away from a 4-channel amp to a 2-channel amp so here are my questions:

1. What are some good recommendations for an amp like I described to run only front components? I would like to run the full RMS to the speakers like I'm currently doing.

I think this depends on how much money you want to spend. More recently, I have been impressed with PPI P900.4 amplifier. At 4 ohms, it gives you 4x140watt RMS channels, which is plenty. I had it bridged for subwoofer duty, and the amplifier was pretty much stuck in between rear seat and subwoofer box, with little airflow around it, and it never got hot during summer months. This was amazing value for $230 I paid. There is also a 2-channel version, the P600.2. Of course, if you want to spend more money, you can buy an Alpine PDX series or JL Audio HDs as these have become very popular in high end installs, and they have very good reviews. I was also going to recommend you Boston Acoustics GT-2125. The GT series are pretty high end amplifiers, and I have heard reviewers claiming that their music does sound better with these. Now that BA is going out of business, you can buy GT-2125 for $110 (they used to cost like $300 two years ago). However, this is a Class A/B amplifier, so it will run hotter. If in your environment, the amps tend to run hot, then perhaps it's more prudent to buy a Class D amplifier.

2. Do mids-tweets sound better when running at 4ohms vs. 2ohms or does that have no effect on sound quality?

It is difficult to answer this question. There are high quality amplifiers that display no change the their performance characteristics as you change the ohm load. However, it is typical of a lot of amplifiers, specially Class A/B to double their THD with lower impedance, but their RMS power output goes up considerably. One school of thinking is to bridge the channels always as the difference between say 0.05 and 0.1% THD should not be audible, while more power gives you more headroom for dynamics. My take on it? If you need a lot of power, get a powerful Class D amplifier. I have often run into heat issues with Class A/B amplifiers with channels bridged.

3. My sub amp is a digital D class amp and stays cools and doesn't beat on my electrical as hard as this older AB alpine amp, are AB amps still the way to get the most sound quality out of mids-tweets or are these new digital D class amps have just as much quality of sound as AB amps?

Thanks

There are a lot of different opinions on the issue of sound quality of Class A/B vs Class D, and the opinions are very different. For example, a lot of people would like to say that Class D is just fine for subwoofers, but Class A/B may make a difference on the mid and tweeter drivers. Well, the other day I saw the former owner of Image Dynamics say completely the opposite on a forum. (his main point was that many cheap Class D amplifiers have damping factor in single digits, which is not good for subwoofers). In my opinion, the difference is so minuscule that if there is any at all, there you will serve you much better to concentrate your energy to the quality of physical installation, sound proofing, good tuning, etc.

 

[MillerSHO 10+ year member]

Thank you everyone for responding, you guys have always been a wealth of information for me.

I want to tell you guys what happened today on my amp search and I'll try to not make it long winded but it all kinda happen fast and I hope I made the right choice.

My buddy knows the owner of a shop who is an authorized Hertz/audison dealer and he sold me an audison LRx 2.4 for $350, it was his last one and it's been replaced with the Voce line.

The catch was that it was used but the customer only had it in his car for 1 week. I didn't get into the details on why the guy didn't want it anymore but I did ask him about the warranty and he said I have the normal warranty on the unit as if it was bought from him brand new. Also it looks brand new, has the box and manual the only thing missing is the mounting template.

I'm really nervous about this purchase in one way, it is a class A amp which means it's going to run hot but I'm only going to run it at 4ohms stereo which is 130x2 so hopefully it will stay cool and have some headroom to work with.

Thanks again for the replies, I'll try to do a follow up to let you guys know how it works out.

If you can can see any holes in my purchase please let me know.

 

[berretta96 10+ year member]

just an FYI

a good friend of mine had a local Hertz dealer install a complete Hertz setup around 8 months ago; hertz components in both doors, Hertz 4 ch, Hertz subs and Hertz sub amp. The sub amp took a dump around 3 months ago so the shop sent it in for him. Hertz called him last week and said it could not be repaired and that they discontinued the model for their new line up. The equivalent model is not 1 ohm stable so they refused to upgrade him to the new model. They gave him prorata off of MSRP for the time left on his existing warranty. HE REALLY GOT SCREWED BY HERTZ IMO. This is a guy who paid top dollar for their products from an authorized vendor and even had them do the install.

I hope you don't get in the same situation buying an old model amp. Despite his problems, his system sounded AWESOME while it was up and running.

 

[ace_800 5,000+ posts]

I've got 350rms to each side of the hertz i'm running. The Eclipse is a beast

 

[MillerSHO 10+ year member]

I've got 350rms to each side of the hertz i'm running. The Eclipse is a beast

350 each side? I know the XL's can handle a bit more power then my HSK 165's.

I thought they were only rated at 125-150rms, are you saying you can run a good amount more than that?

 

[MillerSHO 10+ year member]

just an FYI
a good friend of mine had a local Hertz dealer install a complete Hertz setup around 8 months ago; hertz components in both doors, Hertz 4 ch, Hertz subs and Hertz sub amp. The sub amp took a dump around 3 months ago so the shop sent it in for him. Hertz called him last week and said it could not be repaired and that they discontinued the model for their new line up. The equivalent model is not 1 ohm stable so they refused to upgrade him to the new model. They gave him prorata off of MSRP for the time left on his existing warranty. HE REALLY GOT SCREWED BY HERTZ IMO. This is a guy who paid top dollar for their products from an authorized vendor and even had them do the install.

I hope you don't get in the same situation buying an old model amp. Despite his problems, his system sounded AWESOME while it was up and running.

That's too bad what happened to your friend, I hate hearing people getting screwed like that.

FWIW the owner of the shop implied if there's any issues then I get a Voce model due to them not making the LRx line anymore.

He also said once I get everything installed and tuned to my liking to bring it in and he help me tune it more. He's a really cool guy.

I guess we'll see what happens, again I hope I made the right choice.

 

[ace_800 5,000+ posts]

350 each side? I know the XL's can handle a bit more power then my HSK 165's.I thought they were only rated at 125-150rms, are you saying you can run a good amount more than that?

Yeah, the eclipse is bridged doing 350/side. Though I do only have the gain at barely 1/4, but thats just cause they were so loud with it higher

 

[neo_styles 10+ year member]

At the current price point, I'd say you might as well get something like a Boston GT-2125 for a solid backup. For its size, it puts out a decent amount and it's typical BA quality. I'm sure 100 bucks won't set you out much if you just bought the Audison.

 

[MillerSHO 10+ year member]

I got everything installed and it's working great so far.

The amp runs pretty hot but I've ran it long a few times now and no overheating.

Few things I noticed:

I can run the higher frequencies on the EQ at higher volumes now, with the other amp it was just too hard on the ears.

Also I can now run the HSK 165's crossed over at 60hz instead of the 90hz-100hz I had set on the other amp and they don't sound like they're bottoming out.

Thanks everyone.