Recommend a good 5 channel 200+WPC amp?

[Landmonster]

Hi guys. Like the title says, I am looking for a 5 channel amp with at least 200 WPC @ 8 ohms. I would like as little distortion as possible, with the best SQ.

I will be using these to drive 2 Polk LSiM 707s up front, 1 706c center, and 2 surrounds... which I have not decided on the LSiM 703s, or 705s (That's another discussion, unless someone here has good advice) This will be used for both home theater and 5-channel music.


Anyway, I would prefer to look on the used market to keep the cost down.... but I am not opposed to new stuff, if there is a deal. Any ideas? Brands, models, etc to look for?

 

[Pogre]

Monolith 5, built by ATI . I have the 7. It sounds great and is plenty powerful.

 

[Pogre]

Check out TLSguy's comments about the 705 before you buy one..

 

[lovinthehd]

One of the better values would be the Monolith 5 amp (Pogre posted as I typed). Another might be the Emotiva XPA-5. Maybe even a stack of Outlaw 2200s if you don't mind extra boxes but assume you prefer/want a 5 channel amp in a single box? Maybe get three Crown XLS1502s. I'd go new with warranty unless I found something good used but proposing what you might find used would be up to you.

PS Why not just external amp for the front three and let the avr do the rest?

 

[Landmonster]

That might be okay too. I'd like a good 3 channel amp then as an option

 

[Pogre]

That might be okay too. I'd like a good 3 channel amp then as an option

HD's suggestion for a couple of crown amps would probably be the most cost effective. Monolith also has a 3 channel amp for $879 right now (thought they were more, sale price?), but your best value starts with the 5 channel amp when you look at it as only $200 for each additional channel.

 

[Landmonster]

Check out TLSguy's comments about the 705 before you buy one..

That seems like a fishy comment. The Polk 705s have been out for nearly 10 years, and use similar crossovers to the 707s.

Do you think the top Polk engineers would make that horrible of a blunder, if it was known to ruin receivers? Versus some guy's opinion who makes DIY speakers in his basement?

I suppose anything is possible.... the poster in that thread received a defective speaker though.

 

[lovinthehd]

HD's suggestion for a couple of crown amps would probably be the most cost effective. Monolith also has a 3 channel amp for $879 right now (thought they were more, sale price?), but your best value starts with the 5 channel amp when you look at it as only $200 for each additional channel.

Yeah if I did go Monolith I might even go for the 7 like you did, as it is a better value if you don't mind the cost and with enough channels it could well come in handy...thought the 3 was $1k tho. A stack of three Outlaw 2200s is $1039 shipped. Personally I'd get the Crowns (and already have several 1500s)

 

[Pogre]

That seems like a fishy comment. The Polk 705s have been out for nearly 10 years, and use similar crossovers to the 707s.

Do you think the top Polk engineers would make that horrible of a blunder, if it was known to ruin receivers? Versus some guy's opinion who makes DIY speakers in his basement?

I suppose anything is possible.... the poster in that thread received a defective speaker though.

He's a lot more than diy in a basement. Click his sig to get a look at some of his work. Simply stunning.

Yes, defective speakers are a possibility. I've been posting here for a couple of years now tho, and while TLS can be a bit gruff, I trust him. You could always hop over there and ask more questions about those speakers for more details. I can also respect that you would want to go to more than one source for info like that so I'd Google and see if others have reported similar problems with that design (difficult to drive, distortion at volume, etc.).

It's not about beating up on a particular manufacturer so much as nobody here wants to see anyone buy (potentially) bad speakers!

 

[lovinthehd]

Meh TLS guy has his opinions on speakers and subs that aren't shared by everyone and he has been known to jump to conclusions. I once ran across some diy speakers built to TLS guy's spec, the guy was selling them because he didn't particularly care for them (I asked). Researching for known problems is one thing but seems there are plenty of people who like these speakers OTOH. Not that I'm a fan of Polk particularly either, haven't heard any in ages.

 

[Landmonster]

Well.


The monolith amps were on my short list, but so would the Emotiva Gen-3.... or perhaps a used Parasound, or Sunfire, or ATI, Adcom, etc.


People very experienced with the Polk LSiM 707s say they really shine and come alive at around the 250 WPC to 300 WPC mark. Essentially, the more power you can throw at them the better.

 

[Pogre]

Meh TLS guy has his opinions on speakers and subs that aren't shared by everyone and he has been known to jump to conclusions. I once ran across some diy speakers built to TLS guy's spec, the guy was selling them because he didn't particularly care for them (I asked). Researching for known problems is one thing but seems there are plenty of people who like these speakers OTOH. Not that I'm a fan of Polk particularly either, haven't heard any in ages.

I'm not turning up a lot negative myself tbh (ima googling!) . General consensus seems to be that they do present a difficult load and a beefy amp section is recommended, but that's all I could find. Reviews aren't bad. If op gets a 200 wpc amp (as he's considering), from what I'm finding, they shouldn't present any trouble.

 

[Pogre]

Well.


The monolith amps were on my short list, but so would the Emotiva Gen-3.... or perhaps a used Parasound, or Sunfire, or ATI, Adcom, etc.


People very experienced with the Polk LSiM 707s say they really shine and come alive at around the 250 WPC to 300 WPC mark. Essentially, the more power you can throw at them the better.

That's pretty much what I'm finding too. The 707's have been measured dipping down to 2.8 ohms, but a good amp should be able to handle it.

Impedance measurements (also performed with the Clio FW) indicate that these speakers may be a little tough to drive for inexpensive receivers. All have a fairly low measured nominal impedance of 5 ohms. The tower is the toughest load, hitting a minimum impedance of 2.8 ohms at a low frequency of 66 Hz with a fairly reactive phase angle of -32°. That’s enough to cause some inexpensive receivers to shut down if you crank up the volume, but I think a typical mid-to-high-end receiver (say, $1,500+) or any good stereo amp should handle it fine.

 

[Landmonster]

So, it is difficult to find a 5-channel or 7-channel amp with 250+ WPC. I suspect that there is a physical limitation problem in there. Perhaps you can't draw 250x5 watts out of 1 power cord or outlet? I don't know.

What about combing a very strong 2 or 3 channel amp, along with a similar or weaker 2 channel amp for the rears?

IE. XPA-3 for the front stage, and an XPA-2 for the rears? or XPA-3DR + A-300 for the rears?

Are there audio reasons not to do this, where it would cause problems with sound quality, or other system issues?

 

[Pogre]

So, it is difficult to find a 5-channel or 7-channel amp with 250+ WPC. I suspect that there is a physical limitation problem in there. Perhaps you can't draw 250x5 watts out of 1 power cord or outlet? I don't know.

What about combing a very strong 2 or 3 channel amp, along with a similar or weaker 2 channel amp for the rears?

IE. XPA-3 for the front stage, and an XPA-2 for the rears? or XPA-3DR + A-300 for the rears?

Are there audio reasons not to do this, where it would cause problems with sound quality, or other system issues?

I think you'd be okay with 200 watts. If you read that review and measurements he was using 150 watt amp and said he was able to drive them louder than he would normally listen.

As far as a smaller amp for the surrounds a good receiver should be able to handle those if you offload the front 3 to a 3 channel amp.

 

[Landmonster]

Other thoughts....

It seems the XPA-2 is high powered, meant for the front 2 channels. It is 300 WPC for 2, whereas the XPA-3 is only 275 WPC for 3.

Would it be wise to use an XPA-2 for the L/R channel, and connect an XPA-3 for the center, and rear surrounds? That setup would produce the mots power to L/R, but less power to the center channel... so I'm not sure if that would be a big problem or not.

Or would it be smarter to connect an XPA-3 for L/C/R, and XPA-2 for rear surrounds?

 

[Pogre]

Or get the Monolith 5 and call it a wrap. I'm a big proponent of overkill, but I really don't think you need the 300 wpc for those speakers (tho it wouldnt hurt!).


What you propose would certainly work well, but wait for some more replies. Others here are more knowledgeable than I am when it comes to separates. I'm using a SR6012 as my prepro and to power my surrounds. I use my monolith for the front 3 and am super happy with the results.

 

[ryanosaur]

Other thoughts....

It seems the XPA-2 is high powered, meant for the front 2 channels. It is 300 WPC for 2, whereas the XPA-3 is only 275 WPC for 3.

Would it be wise to use an XPA-2 for the L/R channel, and connect an XPA-3 for the center, and rear surrounds? That setup would produce the mots power to L/R, but less power to the center channel... so I'm not sure if that would be a big problem or not.

Or would it be smarter to connect an XPA-3 for L/C/R, and XPA-2 for rear surrounds?

I don't have the know-how to discuss Phase Angle against the Impedance of the speakers, but if those dip that low, you should make certain you are getting the right amp for the job. None of the Amps being discussed, short of the Crown XLS are rated to support 2 Ohm loads.

Aside from that, I agree for the most part that "Budget Friendly" good-quality Amps like the Monoliths, Emotiva XPAs, and the Outlaw Monoblocks would be great options to consider, assuming the speakers aren't going to prove lethal to them.

Here's a link from our good friendly Mod, Steve:
https://www.audioholics.com/loudspeaker-design/understanding-impedance-electrical-phase

Depending on the ratings for your Center, remember that it is the workhorse in HT, and may be better served putting a 3-channel amp up front rather than pairing it with an Amp for the Surrounds. Usually, the surrounds, Rears, and any Atmos speakers will only see a fraction of the power required for the front three, hence why we often recommend running those from the AVR and using the external Amp up front.

 

[Phase 2]

He's a lot more than diy in a basement. Click his sig to get a look at some of his work. Simply stunning.

Yes, defective speakers are a possibility. I've been posting here for a couple of years now tho, and while TLS can be a bit gruff, I trust him. You could always hop over there and ask more questions about those speakers for more details. I can also respect that you would want to go to more than one source for info like that so I'd Google and see if others have reported similar problems with that design (difficult to drive, distortion at volume, etc.).

It's not about beating up on a particular manufacturer so much as nobody here wants to see anyone buy (potentially) bad speakers!

Well said Pogre, yeah ole Doc, TLS Guy, pretty damn good.

 

[Landmonster]

To counter TLS guy.....


The LSiM series speakers use a NEW, patented, crossover design invented by Polk acoustical engineer Scott Orth (Orth crossovers). The 707 and 705 have a separate driver which is dedicated to producing very low bass frequencies. Therefore, for the 707 and 705, the crossover diverts frequencies below 100 Hz to the very low bass driver and frequencies between 300 Hz and 100 Hz to the mid bass driver. Having a separate driver handle the low bass frequencies significantly lowers distortion in the bass range because the same driver is not trying to handle very low bass and mid bass at the same time.

The 703, 706c, 704c, and 702 F/X do not have a dedicated low bass driver, and therefore no such lower bass crossover point is required. Scott Orth holds five US patents on speaker design and has three speaker design patent applications in process:

https://patents.justia.com/inventor/scott-orth

Scott holds a master of science degree in acoustics from Purdue University and he is an adjunct professor of electroacoustics at John Hopkins University.

As for the speakers being "not being safe", The LSiM series has been approved by all the electrical safety authorities in the countries in which the speakers are sold.