Amp suggestions

[mwb]

i am looking at the earthquake amp, the 3 channel unit is around $1500 i think
in this price range , what other amps should i consider.

system is

Polk Rti12

polk csi5
polk fxi5
polk psw505

Denon AVR at the moment. (rated at 80 watts)

Room is 25 ft wide by 18 foot long with vaulted ceilings

 

[mtrycrafts]

i am looking at the earthquake amp, the 3 channel unit is around $1500 i think
in this price range , what other amps should i consider.
system is
Polk Rti12
polk csi5
polk fxi5
polk psw505
Denon AVR at the moment. (rated at 80 watts)
Room is 25 ft wide by 18 foot long with vaulted ceilings

Not sure of that amps power capability but you may want to consider 3 BehringerA500 at $180 each?

 

[mike c]

Not sure of that amps power capability but you may want to consider 3 BehringerA500 at $180 each?

the rti might have a nominal ohm rating of 4 ohms (regardless of the webpage spec of 8ohms) - as per buckeyefan's measurement

so the OP actually needs something with lots of power through a 4 ohm load

IMO, that earthquake amp is hard to beat ... unless the OP can use pro amps with fans

 

[mtrycrafts]

the rti might have a nominal ohm rating of 4 ohms (regardless of the webpage spec of 8ohms) - as per buckeyefan's measurement

so the OP actually needs something with lots of power through a 4 ohm load

IMO, that earthquake amp is hard to beat ... unless the OP can use pro amps with fans

Not this again. Bukeye used a DC resistance measurement of each section, if I remember correctly, but that discussion was some time back and my memory is fleeing
I further think that he combined the two 8 Ohm DC resistance in parallel to come up with 4 ohms. If that is how I remember it, then it is totally not right.
The speaker section is a frequency dependent impedance, hence you cannot use parallel calculation as a DC resistor.
But, as I said, I may be confusing this with something else.

Besides, manufacturers don't make that kind of mistakes misquoting the speaker impedance.

 

[mike c]

Besides, manufacturers don't make that kind of mistakes misquoting the speaker impedance.

couldn't they have conveniently TYPO-ed the impedance so as NOT to scare away potential buyers with the low ohm rating?
or isn't there a possibility that this set of speaker dips 4 ohms more often than others ... considering the number of drivers ...

but anyway, even polk themselves recommend:

Nominal Impedance 8 ohms
Recommended Amplifier Power 50-500 w/channel
Efficiency 90 dB

500w recommendation is ginormous.

 

[eirepaul]

i am looking at the earthquake amp, the 3 channel unit is around $1500 i think
in this price range , what other amps should i consider.

system is

Polk Rti12

polk csi5
polk fxi5
polk psw505

Denon AVR at the moment. (rated at 80 watts)

Room is 25 ft wide by 18 foot long with vaulted ceilings

I'm sure that is a great amplifier - however, I just wanted to point out that you can get great value for your hard-earned money by going the used route for power amplifiers. For example, I picked up a Adcom (200w x 3) amp off Audiogon for $400 a couple of years ago. It was mint and reputable amplifiers are pretty hard to damage - there isn't a whole lot that can go wrong (at least in my experience). Something to consider.

 

[jcPanny]

Emotiva Amp

MWB,
In your price range check out the Emotiva MPS-1 amp. It has 7 monoblock channels with 200/300 Watts into 8/4 Ohms and is only $1700.
It would give you plenty of power and room to grow.

The Behringer A500s are a great budget option if you only need 2-3 channels.

 

[Reorx]

Personally, I am a big fan of Pro amps. The downside is that most of them have fan's, and depending on which manufacture you buy, those fans can be loud.
There are plenty of threads here with lots of amp recommendations.

If I was to buy an amp today, it'd be either a Earthquake, or a Mcintosh.

 

[Haoleb]

im a fan of Odyssey myself, Wouldnt have bought them if i didnt think its bar none the best value out.

Check out the Stratos HT3. I think you will be impressed.

http://www.odysseyaudio.com/products.html

You might not have ever heard of odyssey before, But check out their forum at Audiocircle too if your intersted.

 

[agarwalro]

Outlaw Audio also makes some good amps that you can look into.

 

[PENG]

Polk recommends 50 to 500W because the RTi12 has quite a few bass drivers in them. If Polk spec them as 8 ohm nominal, then they are. Like many other speakers, they all dip lower at certain frequencies, not always at the bass frequencies neither. Likewise, 4 ohm nominal speakers could dip below 4 ohms. Some manufacturers would specify both the nominal and minimum values, e.g. my Energy Veritas is specified as 8 ohm nominal, 4 ohm minimum.

If you can get a new Earthquake 3 channel amp for $1,500, that's a great price. I don't know of any amp with comparable power that goes for less.

 

[Newfiestang50]

Check out NAD, I have two, the C372 & C272, great sound with loads of dynamic headroom and don't be fooled by the rated power of 150 watts, they have a reputation of sounding much more potent. I currently use my C272 bridged to provide 400 watts to my sonosub and it is unbelievable. Just my $.02

http://nadelectronics.com/index

 

[mtrycrafts]

couldn't they have conveniently TYPO-ed the impedance so as NOT to scare away potential buyers with the low ohm rating?
or isn't there a possibility that this set of speaker dips 4 ohms more often than others ... considering the number of drivers ...
but anyway, even polk themselves recommend:
500w recommendation is ginormous.

If, this is the same issue that I remember, I called them, or emailed them to be sure. The nominal impedance is 8 ohms. If it dips below 4 ohms enough then the nominal would not be 8 ohms. The algorithm for the calculation changes and affects the nominal rating. Since the nominal is 8 ohms, I cannot accept the below 4 ohm being more than other 8 ohm speakers, not yet with no evidence anyhow.

Number of drivers don't matter. What matters is nominal impedance, sensitivity. As you can see, they recommend 50 watts and more.
Just because you have a 500 watt amp doesn't mean that your 80dB spl music will sound different, just that is you really crank it up, any really high dynamic passage will not be clipped. And, dynamic passages of that magnitude are few and far between.

But, again, this revolves around what I remember the previous discussion may also have been about this speaker. If not, then it is a different issue.

 

[PENG]

Number of drivers don't matter. What matters is nominal impedance, sensitivity. As you can see, they recommend 50 watts and more.
Just because you have a 500 watt amp doesn't mean that your 80dB spl music will sound different, just that is you really crank it up, any really high dynamic passage will not be clipped. And, dynamic passages of that magnitude are few and far between.

I didn't think it matters but it could be one of the reasons why the speaker could take up to 500W (not continuously). I meant it could take 500W, not that it needs 500W.

 

[mike c]

isn't that like asking a suspected murderer who claims innocence if he killed anyone? (I know I know ... polk is a respected company ... just thinking out loud ... ignore me )

even the B&W 6 series is 8ohms nominal but 3ohms minimum
if that were the case, I'd still be looking at amps that have decent 4 ohm capabilities (even if the speakers really are 8ohms nominal) so you'd have a future proof amp.

 

[xboxweasel]

MWB,
Try Anthem MAC30 3 channel amplifier

continuous RMS 20-20kHz <1% THD
One channel driven 8ohm=225W, 4ohm=375W, 2ohm=550W
All channels driven 8ohm=180w, 4ohm=265w, 2ohm=340W

frequency response 20-20kHz +0, -0.15dB, 5-100kHz +0, -2dB

I paid $1400CND for mine 2 years ago.

 

[mike c]

xboxweasel, once upon a time, I was considering the MCA amps ... but if compared to other amps with the same THD rating ... do you think the 180w ALL channels driven will drop to 140wpc if with .0something THD?

 

[xboxweasel]

I am not sure what you are asking. Also, I am not technically inclined when it comes to electronics. Also, if you are asking what I think you are asking, then won't that happen to all amplifiers as well? I just know I really like the amp. And you can't go wrong with that. I also know for a fact I will eventually buy something else (read: more expensive). It is inevitable in this hobby (addiction). Bryston I think.

 

[mike c]

sorry ... I couldnt get into words what I meant. how about an example:
rotel amp 130wpc 20-20khz .03THD
MCA amp 200wpc 20-20khz <1% (which can be as high as .99THD)
if rated at 20-20khz .03THD would maybe be:
140wpc?

I was thinking that the 1%THD rating is kinda like window dressing the specs of the MCA amp ... anthem should publish .0something THD ratings like everybody else. just my opinion.

note: I am only talking about power ratings and NOT sound quality. I did hear that anthem amps sound good to a lot of people.

 

[xboxweasel]

Mike C,
Okay how about these additional specs....from the same publication:
THD+N:
0.0015% @ 1kHz 100W into 8ohm
0.03% @ 20kHz 100W into 8ohm

That and what I mentioned earlier are all they say about THD.