Amp Suggestions

The main advantage of adding an external amplifier to the front channels is better sound quality. You really do not need to buy more than one good two-channel power amplifier. the front channels are the main thing.

The small power supply of most receivers can not provide enough peak current to drive multiple speakers adequately. Their power amplifier ratings are unrealistic and badly overstated.

Adding a good-quality amplifier to the front 2 channels will make them sound much better IMO, and that also takes that major load off of the receiver. That allows it to do a much better job of driving the remaining channels. The Crown amplifiers are low-quality public address amplifiers that have no place in a high-quality sound system.

I recommend that you consider either the Vincent SP-331 or the Marantz MM-7025. Those are the two best amplifiers IMO for under $1500.

To connect an external amplifier, you run cables from the two front channel pre-out jacks to the left and right inputs of the power amplifier, and then connect the two front speakers to the power amplifier output terminals.

$500 is not a realistic price to get a major sonic upgrade. The Marantz, at $799, is the cheapest thing that will really deliver what you are looking to get IMO. You might get a lower price on it if you shop a bit.
Edited by commsysman - 8/24/12 at 9:04am

This isn't consistent with either my experience, or much substantial opinion of professionals.

As long as fan noise isn't an issue, pro audio amplification is perfectly suited for high quality playback. What is important and oftentimes mis-understood, is the extraordinary amounts of power required to accurately track signal transients that are associated with demanding and dynamic material, ... be it for music or HT. It's of paramount importance to operate within the linear envelope of an amplifier. As happens all too frequently, very brief clipping is encountered on peaks (without any indication), and this adds subtle distortion components to the playback that can be avoided by the typical power ratings that accompany very powerful, yet very affordable, pro amplifiers.

As was brought to my attention by both Tom Danley, and Bob Carver, what many perceive as audible differences in amplifiers, is merely the non-linearity and distortion artifacts from momentary clipping.

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Once the power level requirements for the application are met with any decent amplifier, there will be no major sonic upgrade regardless of money spent.

Admittedly, the term "major sonic upgrade" possesses a significant subjective element. However, I maintain that a major sonic upgrade is the realm of loudspeakers and even more-so, room acoustics. Without a solid and enjoyable acoustic environment to experience the music and HT material, any upstream upgrades would be difficult to discern. Typically, at the listening position, merely moving one's head around a few inches can elicit 20-30dB swings in frequency response from destructive interference. The room first, it's always the room.


KTM, I'm uncertain of your level of experience, however if you're interested, PM me and I'll hook you up with a few best bang for the buck first moves, .... acoustically.


Best of luck

Can't your onkyo power the speakers? Why do you think you need to add amps?

Unless one has very high sensitivity mains, a nice benefit is achieved from alleviating the load on an AVR's modest amplifiers. All those amp channels pulling from a common power supply just isn't the best scenario and quickly runs out of steam.


I was very much happily surprised by feeding three Klipsch RB75's across the front, with an inexpensive pro amp. Ok, swapping out a 130 wpc AVR, and feeding each Klipsch with one side of an Behringer EP4000 (450w@8ohms, 635w@4ohms), and I only left one pair of surrounds on the receiver. Really, really a nice little change in realism with much material. The big Behringers were merely coasting along feeding a bass managed LCR set of Klipsch mains (RB75 has the real compression tweeter). I also owned the RB35, look identical, same 8" two way design but with the modest tweeter (actually just a dome in the horn). They're great for the money, strong performers, but that's a few speakers ago.

Just wanted to re-iterate, a decent pro amp even just for one's L&R's could easily be a sweet little upgrade. Also, you needn't obsess over speaker power ratings. Most any will absorb huge amounts of peak power. Just listen for compression,....they'll compress prior to damage.



Good luck

Using your Amp's internal LPF, setting it to 120Hz takes a huge load off your Amp and puts the load on your subs Amp. Before spending the money, get into your new home, dial your system in based on setting the LPF at 120Hz and see how your Amp responds to letting your sub carry the load. If you do choose to go with a Crown Amp, go with at minimum, the XLS 1500. Because of the lower noise floor the XLS 1500 has, when compared to the XLS 1000, it's a more neutral amplifier.

To prevent argument, many here are fans of setting the LPF to 80Hz. My understanding, this is done due to issues of the directionality of sound waves >80Hz. I'm using directional subs so I set the LPF at 120Hz so as to not have the sound wave output of the sub conflicting with the sound wave output of the mains. So for me, this is not an issue. What ever setting you choose, setting your LPF in this fashion will take a load off your AVR and put it onto the Amp you have in your powered subwoofer.

Hope the above helps.

Over time, the learning curve settles down. In the meantime, here's a link to help you with bass management.

Some followup on the above material.

Here's where bass management gets dicey.

See "Applications."

"Periodic sounds, even complex ones, are easier to cancel than random sounds due to the repetition in the wave form."

"In sum, the most effective noise reduction in three dimensional space involves low frequency sounds."

Hence the importance of proper bass management and the need for properly placed, on-axis speaker alignment.

Hope the above helps give you insight.

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Edited by BeeMan458 - 8/25/12 at 8:46am

I side with BeeMan on this. If you have set up your system and tried it and it sounded like it was clipping and underpowered than yes adding an external amp should help. Really it takes the most power to drive the low frequency sounds so assuming your sub is internally powered, you have already reduced the demand on the receiver. If you have yet to set it all up, try it with what you have!! Don't assume you have to add an amp. I did that and found in my system that adding an external 200 watt amp made no noticable changes to me at the levels I listen at.

If you go with an amp, I recommend adding a 3 channel to drive your front speakers and let the receiver coast along driving the surrounds. Brands - Wyred4Sound, D-Sonic, Emotiva - all make nice 3 channel amps and I am sure there are many others.

I think what is being confused here is the term LPF...The Low Pass Filter should be at 120 Hz and is the upper limit set for the subwoofer...The other setting is when you don't run your speakers as Full Range and set a crossover for them to send the lower notes to the subwoofer and that is usually set at 80 Hz so your bass isn't directional.

EDIT: BTW this is from the link BeeMan provided:

Low-Pass Filter: A low-pass filter blocks (attenuates) high frequency signals above the cutoff frequency and passes low-frequency signals. It is sometimes called a high-cut filter, or treble cut filter. Low-pass filters are generally used on subwoofers to block high frequency signals that they cannot reproduce. The low pass filters in most high quality receivers have a 24 dB / octave slope.
Edited by Zen Traveler - 8/25/12 at 12:20pm

Which is exactly how I meant the term to be used when I posted: "Using your Amp's internal LPF for the mains is set to 120Hz and doing so takes a huge load off your Amp. There was no confusion in how the term was applied.

A LPF is not a specific term but a generalized term with many applications that applies to both internal AVR LPF filters and a subwoofer's cutoff filter.

"A low-pass filter is an electronic filter that passes low-frequency signals but attenuates (reduces the amplitude of) signals with frequencies higher than the cutoff frequency."

In this case, both the subwoofer's LPF or cutoff filter and the AVR's internal LPF for the mains are set to 120Hz so sub and mains are sonically simpatico.

And FWIW, none of my above has anything to do with the 0.1, LFE channel information as that information is not amplified by the AVR's amplifier, therefore, is not a consideration to the question.

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Edited by BeeMan458 - 8/25/12 at 12:52pm

The 806 is marketed at 130W while the 5007 is rated at 100W, a difference you are not likely to notice unless you are in a very large room and have the AVR maxed out which is unlikely as those Klipsch speakers you are considering will only be drawing 1-2W on average, even for reference level volumes.


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Edited by jdsmoothie - 8/25/12 at 1:17pm

I am sorry BeeMan, but you are new here and if you continue to use the term "LPF" the way you are doing it's going to confuse people and if you look at what both JD and I said it does nothing to relieve the stress on the AVR or amp. This is my last post to you on this thread and I suggest you go back to the link you provided for the OP to gain knowledge and you will see that they don't use that term either when describing the crossover from the speakers to the sub.

My newness to the forum is not consequential as I'm using the term correctly and yes, when used in the fashion I described, stress is unequivocally relieved on the part of the amplifier. Some here need to get over their need to argue every point they disagree with and since some here won't control themselves, my solution is/was to put a boatload of old timers on ignore; about a dozen in total as it's the same ones every time. Even you've made it to the ignore list but the way you couch your comments, I'm compelled to respond. I see that as a good thing.

You'll note I stay away from starting threads and asking questions as I purposefully stay out of any threads started by those who are on ignore. In other words, I do my best to quietly keep to myself. FWIW, for the purpose of maintaining thread context in threads I do choose to post in, I read all posts of those on ignore yet don't respond directly to comments they may have posted or comments posted in my direction as for the most part, they're always rude or argumentative. And because of this behavior, there's no point in antagonizing by responding to comments directed at me or getting involved in defending comments I've made.

Here's to peaceful interactions amongst all forumites.



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Edited by BeeMan458 - 8/25/12 at 8:58pm

alternatively, you could learn from those old timers and realize that you aren't providing "useful" advice...

"directional subs", huh? really...

Yes set it to 120 Hz. And no, that is the Low Pass Filter for the sub and it doesn't relieve any strain on your AVR.

Definitely don't set your crossover from your speakers to the sub in your AVRs Bass Mgmt that high .As mentioned, for most people that should be at 80Hz or what Audyssey comes up with if higher (I don't know how bass mgmt works in the Marantz). EDIT: Any mention of LPF in the AVR should also be set at 120 Hz and that is not a crossover.
Edited by Zen Traveler - 8/26/12 at 7:50am

The "LPF for LFE" setting in the AVR should be set at 120hz while the "dial on your sub" should be set to whatever the maximum setting is (eg. 150hz).

If the question is directed to me, No. Doing so will help the LFE sound track but the two are unrelated and in the way you couch your comment, doing so will have no affect on the AVR . The LFE track is mixed to 120Hz so yes, it allows one to hear all of the LFE soundtrack. Limiting the "dial on my powered sub woofer" will limit the LFE sound track. This is not a good thing. But setting the LFE dial to 120Hz is a good thing.

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Edited by BeeMan458 - 8/26/12 at 10:39am

Fwiw, the upper limit to his sub is 120 Hz http://www.klipsch.com/sw-450-subwoofer