Need advice on amping my HT

[cornfedksboy]

I recently purchased two Marantz MA-500U THX Ultra Certified Monoblocks from an esteemed member of this forum (thanks BluBitRates!), and I liked them so much that I bought two more. Here's my question: Should I bridge my monoblocks to run my front L/R channel, or run my front three on a single monoblock amp per channel?

My system is RF-82 front L/R, RC-3 center, RS-52 II surrounds, RF-25 rear L/R, two front firing RW-12ds. These are currently run with an Onkyo TX-nr708.

Receiver specs: 7 channels @ 110 wpc with two channels driven. THD is 0.08%. Dynamic power is 130 watts with 1 channel driven.

Amp specs: Monoblock, 125 watts continuous and 170 watts dynamic. THD < 0.05%. Two bridged monoblocks (manufacturer authorized) output 360 watts continuous and 500 watts dynamic @ a THD of < 0.1%.

My room is adequately sized that the THX Select II receiver can drive the 7 channels to THX reference levels w/o external amps per George Lucas. The Marantz amps are designed for a room about 50% larger than my current configuration (unbridged) per George Lucas. I use my speakers for about 90-95% HT and 5-10% music (two channel). Would I see more benefit by amping the front three at 125 wpc and running the surrounds at +/- 110 wpc, or running the L/R at 360 wpc and the other five at +/- 110?

Thanks,

Jason

[wuzzzer]

I'd go the monoblock route for the front 3. Bridging amps adds distortion and your speakers aren't that power hungry.

[JasonJCarney]

Monoblocking the front 3 makes one useless (would have to sell I guess). I guess it would take the stress off your onkyo and you would see a full 110 watts at your surrounds and of course the 125 up front. Bridging them would give you a ton of power at your mains but you would have to turn around and boost the db's on your center to keep up and now your onkyo would be running 3 channels and you would not be getting the full 110 watts per channel from it. I would sell 1 amp and monoblock the front 3. The other option seems like your either pushing your onkyo really hard or not pushing your amps at all (depending on your db settings).

[willland]

I recently purchased two Marantz MA-500U THX Ultra Certified Monoblocks from an esteemed member of this forum (thanks BluBitRates!), and I liked them so much that I bought two more. Here's my question: Should I bridge my monoblocks to run my front L/R channel, or run my front three on a single monoblock amp per channel?

Keep this in mind, Blu used two MA-500's to power his RF-7II's and he was more than pleased with the results. Your RF-82's are not as power hungry as the RF-7II's and will benefit greatly with 125 monoblock watts over the 110 receiver watts in 2-channel. Those 110 watts are more than enough for your side surrounds.

I had (2) of the MA-500's and (5) of the MA-700's(200watts) and really could not tell a real noticeable difference in power in 2-channel. I hooked both pairs up to Forte's, Quartet's, Heresy's, RB-5's, and even my RF-63's and there was no discernible difference to my ears. I never used them in HT mode so in that application you may notice the headroom difference.

I say run your front soundstage with (3) and find one more and use in 5.2 and let Onkyo drive the rears or sell one and let Onkyo drive all surrounds and pick up something else you may want with the proceeds.

Here is a MA-700 if you want just one to drive your center.

http://stlouis.craigslist.org/ele/2469112344.html

Here is a killer deal on a pair of MA-700's.

http://portland.craigslist.org/mlt/ele/2511045346.html

Bill

[cornfedksboy]

I won't leave the left over mono-block out. If i do the front three, i will likely add one more in the future and run the rear channels with the Marantz as well. I actually made a modest bid on 4 units and won two and lost two on e-bay.

[elitedemo]

i had 8 ma500s on my system, i went with passive biamping the front 3 and had 1 on each of the 2 back speakers, to tell the truth i could barely tell a difference between that and having only 1 on each tower and letting a receiver run the center and rears

if it were me id put 1 on the front 3, then you can save your 4th one and look for 3 more or sell the 4th one and put it towards something else you want

[JasonJCarney]

tell you the truth I cant hear a difference between my onkyo 3007 and the emotiva xpa-5. Guess I'm not playing my system loud enough.

[cornfedksboy]

i had 8 ma500s on my system, i went with passive biamping the front 3 and had 1 on each of the 2 back speakers, to tell the truth i could barely tell a difference between that and having only 1 on each tower and letting a receiver run the center and rears

if it were me id put 1 on the front 3, then you can save your 4th one and look for 3 more or sell the 4th one and put it towards something else you want

I am considering bridging them, not bi-amping. Those are two totally different things. Thanks for the input though. And thanks to everyone. Still kinda mulling it over while the amps are in transit.

[silentprofecy]

I would say bridge them for the fronts and up the DB's on the center
and you should be rocking. You'll notice a drastically fuller sound than
you had with just the onkyo. At least i noticed it with my mono's
across the fronts (3 Heresy's). The blocks actually bring a welcomed
stage to not only music but HT, so either way you really can't go wrong.
With the onkyo preouts and it's internal settings you should be very
happy with your purchase. However i will say that it might get a bit
tricky with all the triggers running to the mono's from the onkyo.. do you have a clean power block or something along those lines? To me it wasn't a must have but when you come across one at an estate sale for 20 bucks you buy it. It has come in handly with my amping.

With the extra space i think you will more than likely want to initially set it up bridged and then if too much (it could never be too much [Y]) it would be easier to remove then add.

If your fear is that the center will be swallowed don't worry about it, the onkyo will surprise you when you let it breathe.

Let me know if that's helpful!!!

[cornfedksboy]

I'm currently running my two monoblocks on the front L/R while I await the arrival of the next two. I did some critical listening and here are my thoughts:

I put in The Black Keys album "Brothers" for a nice bluesy rock album. The 82's sounded great! I listened in Pure Audio mode (front L/R only) and the 82s had a much greater LFE than I realized was possible. They filled out the bottom end and continued to be very detailed with the highs. The mid-bass was slightly muddied, but the overall sound was rockin! THX music and other decodings offered little to no benefit over the straight 2-channel listening experience.

Next was the Black-Eyed Peas CD, "The End." Again, the highs were quite detailed, but to my suprise the LFE from the 82s actually sounded fantastic on this bass laden album, although they couldn't quite reach the bottom end. The electronic mids were much more present with this offering as well. Changing the Onkyo for to Direct Stereo listening mode (added the dual subs in) REALLY shook the room, but the fast-paced crispness of the soundtrack was lost a little. Another change to THX Music sent the sound swirling throughout the room and brought in a great concert like surround field. The bass tightened up and the music jammed.

My final offering was Vivaldi's Four Seasons. Pure audio, and Direct Stereo did not do the composer proper justice. There are too many mid-bass strings and they were distinctly muted when compared to the cellos and double bass. The high end on the violins was nice, but not airy (this is as expected of a Klipsch Reference speaker). THX Music was better, but the Orchestral decoding was really great! The center speaker brought out the mid-bass detail in a fine way and the side and rear surrounds opened up my tight theater room and filled the air with beautiful strings. My WF-35s still have a more "airy" quality for this type of music, but require a sub to fill out the bottom for all source material.

Being that this is a dedicated HT room, the review wouldn't be complete without a movie review. I watched the 2009 Nick Cage Sci-Fi thriller "Knowing" presented in HD and Dolby Digital 5.1 by my cable provider. I used THX Cinema ES to get all 7.2 channels involved. I hadn't ever seen this before, so I have no frame of reference, but WOW! This is a must see in a good HT room, and not just another over-the-top disaster film. I hadn't heard much about this film, but the visuals were great (a different review) and the sound was incredible! There was a consistent and ominous LFE throughout the film that kept me in suspense. Dark visions of fire roared through my front sound stage and crackled through the surrounds. Plane and train crashes had me shifting in my seat to "avoid getting run-over." The explosions and "whispers" that filled the majority of the soundtrack were 100% immersive. The original orchestral score of the film is also beautiful (and dark) and worth a listen on it's own merit.

[psg]

tell you the truth I cant hear a difference between my onkyo 3007 and the emotiva xpa-5. Guess I'm not playing my system loud enough.

Wow, there's an honest (and rare) opinion! Unless you are driving the amp to clipping and the amp can handle the impedence of the speakers, you probably won't notice. I don't either.

[Dysmae]

Hey cornfed. You know what you should do? You should do me a favor. Haha. I have also been looking at these monoblocks. You should try hooking them up to your WF-35s or the WC-24 and tell me if you hear a huge difference. I have always heard that the W series is extremely efficient and you couldn't hear much difference adding an amp. I want to add an amp so bad, but I wanna make sure that it is worth it with my W series. And I agree. I would run your front stage with the monoblocks.

[cornfedksboy]

Hey cornfed. You know what you should do? You should do me a favor. Haha. I have also been looking at these monoblocks. You should try hooking them up to your WF-35s or the WC-24 and tell me if you hear a huge difference. I have always heard that the W series is extremely efficient and you couldn't hear much difference adding an amp. I want to add an amp so bad, but I wanna make sure that it is worth it with my W series. And I agree. I would run your front stage with the monoblocks.

Will do once I get the new ones in. It will probably be a week or so before I have the opportunity, but will make sure I get back with those. Of note, my WF-35s are currently hooked-up to my 140 watt Yamaha and not in an ideal room, nor with ideal placement. None-the-less, I will give it an honest review to the best of my ability.

[Dysmae]

As always, thanks cornfed.

[Brunt]

tell you the truth I cant hear a difference between my onkyo 3007 and the emotiva xpa-5. Guess I'm not playing my system loud enough.

Wow, there's an honest (and rare) opinion! Unless you are driving the amp to clipping and the amp can handle the impedence of the speakers, you probably won't notice. I don't either.

Interesting...Do you think this is do to some (not all) people "hearing" the amount of money they spent on an amp versus an actual improvement?

[JasonJCarney]

tell you the truth I cant hear a difference between my onkyo 3007 and the emotiva xpa-5. Guess I'm not playing my system loud enough.

Wow, there's an honest (and rare) opinion! Unless you are driving the amp to clipping and the amp can handle the impedence of the speakers, you probably won't notice. I don't either.

Interesting...Do you think this is do to some (not all) people "hearing" the amount of money they spent on an amp versus an actual improvement?

Bingo. Maybe in a large room type a difference would b more evident.

[Youthman]

When I added my Parasound amp, it was not an incredible "Night and Day" difference but it was a substantial improvement in my system.

Here are some thoughts from my build thread...

With 220 watts x 5, the Parasound adds even more bottom end to the
RF-83's, giving them more authority in the bass region. I used to not
enjoy listening to music in 5.1 or 7ch stereo but with the new amp, it
really brings the surround channels to life. With movies, the surrounds
seem more alive and engaged. At high volumes, the amp has no problems
maintaining the integrity of the source material. The sound never gets
harsh or muddy. Crystal clear no matter what volume. Musical has more
separation of instruments than with the Yamaha alone.

I also had a friend over this weekend for some 2ch listening. It was
his first time hearing the Parasound in my system. We both agreed that
the Parasound added tighter bass response as well as more separation of
music instruments. Subtleties were now definitive. I used to have to
crank the RF-83's to a descent volume to get the full sound I like.
With the Parasound, I can now listen to it at moderate levels and you
still get the depth, clarity and separation that makes 2ch listening
worth listening to. I'm definitely very pleased with the purchase.

That's just my 2cents but with deflation and our poor economic state, it's probably worth about 1/4 of a cent. []

[Brunt]

You seem to be a bit more restrained in your description of a separate amp than some. I am running what I would call a budget amp setup, (3 Audiosource 100's bridged @160watts for front stage) and haven't tested this setup for movies yet. I have tested it for two channel music though, wiring the right channel off of the Onkyo and wiring the left off of one of the Audiosource amps. There WAS a difference in some rock music I played at fairly loud volumes, vocals did seem a bit more forward in the mix, so to speak. I would listen directly in front of each speaker for 30 seconds at a time and then bounce over to the other for a comparison. I will follow up with my thoughts after setting everything up for HT, but it's my belief that in my space I might not hear a difference between the amps and AVR due to the constantly changing audio of a movie versus the constant charge of a 4-5min song. (The comparo was with a pair of Rf62's)

Again, this is my experience with my cheap amps, but i will say this. I spent about $200 for all 3, but if I spent $600+ and got similar "improvement", I'd be pissed. That also speakes to my expectations, income level, etc.. For the money I spent, I will take the minor bump in audio quality, but for me the fact that my Onkyo may run cooler/more efficiently is the real benefit..at least for my money.

[cornfedksboy]

For the money I spent, I will take the minor bump in audio quality, but for me the fact that my Onkyo may run cooler/more efficiently is the real benefit..at least for my money.

I'm with you on this one. I can't get over how hot my Onkyo gets.

[Heritage_Head]

tell you the truth I cant hear a difference between my onkyo 3007 and the emotiva xpa-5. Guess I'm not playing my system loud enough.

Wow, there's an honest (and rare) opinion! Unless you are driving the amp to clipping and the amp can handle the impedence of the speakers, you probably won't notice. I don't either.

Interesting...Do you think this is do to some (not all) people "hearing" the amount of money they spent on an amp versus an actual improvement?

Bingo. Maybe in a large room type a difference would b more evident.

Depends on how loud you listen to your system. Personally I crank

it up pretty loud. It’s just easier to watch at reference levels with more

power. A 200x5 amp gives 1,000 watts total. An avr is more like 120x2 which is

240 watts total. I think some avrs are better than others when it comes to

power. So the upgrade will be more with some than others. I think my avr was

bench tested in a review at only about 45x5 watts (it’s a 2k retail avr. Paid

only 1100 though). I did read a denon

avr review that benched close to about 70x5 so it varies a little. But if someone

watches movies at an average of only about 1 -10 watts per channel. Then the

avr would be plenty. But if you like to listen to stuff at about 100 watts or

more average per channel then you would want that extra 100 watts per channel

of head room for the loud parts of movies. In my system I noticed a huge difference

when watching movies. But when just watching tv at normal listening levels I don’t

hear any difference. So an amp isn’t for everyone.