# Upgrade receiver/external amp?



## Interspy24 (Apr 22, 2009)

Just looking for input/advice on powering a set of rockets. I posted a similar thread on av123 about a year ago but was wanting to revisit the topic since the rockets seem to love extra power. 

Listening habits are probably 70% movies and 30% music. It seems that different tracks/sources have a huge impact on high the receiver is turned up. Obviously it varies between receivers and speakers, but for some blu-ray discs the volume at -30 would be louder than a regular dvd at 0 and vice versa. Some music needs to be turned up to the 0 mark and other cd's are fine at -20. Not sure how the variance is this much, but whatever... (Btw, everything is played through a ps3 via hdmi). 

Currently using a Yamaha 663 and it seems to be turned up quite a bit, I'm wondering if it's being pushed pretty hard to power the rockets...

I'm curious about upgrading to a higher end receiver, such as the onkyo sr805 or maybe the newer pioneer sc-05 with the ice amps. I've seen the results from the test bench and with five channels driven, the onkyos seem to put out great power. I know the 805 has a couple issues, but I'm curious about finding a used one and seeing if the power difference would be noticeable..

The other option was since my receiver has pre-outs, using an external amp such as the emotiva lpa-1 or something similar. My only worry is this being overkill, not to mention probably getting a new stand to house to monster that is the lpa-1. 

Just curious how you guys like the higher powered receivers powering your setup and/or other advice you might have. Thanks in advance. :thumbsup:


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## droht (Sep 15, 2008)

I haven't tried the exact components and speakers you are using or considering, but I have run Ref1s with Yammy 659 and Emo LPA-1. The LPA-1, with either the Yammy or the LMC-1 was a pretty signifcant improvement over the AVR by itself. 

I got rid of the Refs and the Emo gear, but then really considered more Refs, with a better AVR instead of separates. Lots of research lead me to believe that better AVRs will be an improvement over the 659, but not the kind of step change I experienced with the LPA-1. I think separates is the way to go, I just don't have the space to do it.


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## Mike_WI (Feb 26, 2009)

*AVS - (un)Official "Should I get an amp" Thread*



Interspy24 said:


> Just looking for input/advice on powering a set of rockets. I posted a similar thread on av123 about a year ago but was wanting to revisit the topic since the rockets seem to love extra power.
> 
> Listening habits are probably 70% movies and 30% music. It seems that different tracks/sources have a huge impact on high the receiver is turned up. Obviously it varies between receivers and speakers, but for some blu-ray discs the volume at -30 would be louder than a regular dvd at 0 and vice versa. Some music needs to be turned up to the 0 mark and other cd's are fine at -20. Not sure how the variance is this much, but whatever... (Btw, everything is played through a ps3 via hdmi).
> 
> ...


Check this AVS thread out...

*(un)Official "Should I get an amp" Thread* 

From that...

"IMHO there are three main questions you need to answer YES to in order to benefit from an external amp

*1) Are your speakers difficult to drive* - Typically this means that they are 4 ohm or lower.

*2) Are your speakers inefficient* - The less efficient your speakers are, the more power they can benefit from

*3) Can your speakers hit very low frequencies* - IE. bass. For now I'll go with a figure of < 40 hz." 


I hope that helps.

Mike


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## Interspy24 (Apr 22, 2009)

droht said:


> I haven't tried the exact components and speakers you are using or considering, but I have run Ref1s with Yammy 659 and Emo LPA-1. The LPA-1, with either the Yammy or the LMC-1 was a pretty signifcant improvement over the AVR by itself.
> 
> I got rid of the Refs and the Emo gear, but then really considered more Refs, with a better AVR instead of separates. Lots of research lead me to believe that better AVRs will be an improvement over the 659, but not the kind of step change I experienced with the LPA-1. I think separates is the way to go, I just don't have the space to do it.


Thanks for your response, I appreciate it. 

Just curious what advantages do I gain from running the LMC-1 versus a receiver? Are their any disadvantages? I believe most don't have the latest hd audio formats like the receivers do...


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## Interspy24 (Apr 22, 2009)

Mike_TX said:


> Check this AVS thread out...
> 
> *(un)Official "Should I get an amp" Thread*
> 
> ...


Mike,

Thanks for the info, I'll read that thread as most others seemed too one-sided. Meaning, an external amp will sovle world hunger or it didn't make a significant difference... Most who suggest the external amps seem to note they make a considerable difference for music. My main concern was volume, I have my receiver at "0" and I'm worried about how hard I'm driving it. Maybe I'm doubting the receiver and could do this for a long time? Or maybe it's peace of mind? Given a choice, I'd rather use a more powerful receiver at 60% of its capacity than mine at say, 95%.


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## droht (Sep 15, 2008)

Interspy24 said:


> Thanks for your response, I appreciate it.
> 
> Just curious what advantages do I gain from running the LMC-1 versus a receiver? Are their any disadvantages? I believe most don't have the latest hd audio formats like the receivers do...


I honestly was not a big fan of the LMC-1. I think the Yammy sounded just as good with the LPA-1.

In terms of what the LPA-1 did with the Refs, for 2 channel music it opened them up. I know that sounds like reviewer **, but it is the best way to describe the change. The improvement on HT was significant as well. With the LPA-1 the Refs did an amazing job on details at low volume. Stuff that you might be straining to hear or missing unless you crank volume up was very audible. Maybe it seems odd that separate amplification made more difference at low volumes? 

From lots of reading at av123 forum I think the Refs are harder to drive than the Rockets. CW seemed to be that Rockets benefit from better amplification, but Refs need it.


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## Interspy24 (Apr 22, 2009)

droht said:


> I honestly was not a big fan of the LMC-1. I think the Yammy sounded just as good with the LPA-1.
> 
> In terms of what the LPA-1 did with the Refs, for 2 channel music it opened them up. I know that sounds like reviewer **, but it is the best way to describe the change. The improvement on HT was significant as well. With the LPA-1 the Refs did an amazing job on details at low volume. Stuff that you might be straining to hear or missing unless you crank volume up was very audible. Maybe it seems odd that separate amplification made more difference at low volumes?
> 
> From lots of reading at av123 forum I think the Refs are harder to drive than the Rockets. CW seemed to be that Rockets benefit from better amplification, but Refs need it.


Thanks again for sharing your experiences with the Yammy receiver and the LMC-1. :thumbsup:

The characteristics you stated are what I've been reading - more detail, fuller sounding, and smoother at high volumes. It would help to hear the smaller things at lower volumes imo. 

I really don't listen at high volumes, but using the volume readout (though a bit silly) it seems the Yammy is being taxed quite a bit. I'd hate to hurt a perfectly good receiver because I'm playing movies too loud.

I will say I echo the thoughts of what others stated in regards to volume with the x-series vs the rockets. At lower levels the x-series seem to have more detail than the rockets. I was first using 4 x-sls classics with a matching x-cs center. I then upgraded to 5 x-cs encores. At lower volumes these speakers seemed to have more detail and/or I could hear more if that makes sense. The x-cs speakers are rated around 90.5 for sensitivity, so their efficieny over the rockets probably plays a major role in this. 

With the rockets, they seem to be at their best when played at higher levels. At lower levels they sound okay, but when turned up they rock (no pun intended).

Btw, a bit off topic but I wonder how speakers such as the jtrs/catalysts/sparks sound at lower levels. They are very efficient speakers that can played at very high levels.


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## Mike_WI (Feb 26, 2009)

Interspy24 said:


> Mike,
> 
> Thanks for the info, I'll read that thread as most others seemed too one-sided. Meaning, an external amp will sovle world hunger or it didn't make a significant difference... Most who suggest the external amps seem to note they make a considerable difference for music. My main concern was volume, I have my receiver at "0" and I'm worried about how hard I'm driving it. Maybe I'm doubting the receiver and could do this for a long time? Or maybe it's peace of mind? Given a choice, I'd rather use a more powerful receiver at 60% of its capacity than mine at say, 95%.


Interspy24 -

I may have missed it, but can you spell out:

- Rocket speakers and impedance in ohms
(realizing that impedance varies across the FR -- see av123 graph on link)
- SPL desired - see link
- music ("pop" music compressed with smaller dynamic range vs. classical, etc. with wider dynamic range)
- listening distance

EG...

If the speakers are av123 Rocket 850 Signatures then...
*Frequency Response:* 36 Hz to 20 KHz (± 3 dB)
*Impedance:* 8 Ohms nominal
*Efficiency: *91.5dB (@ 1 watt / 1 meter)

At 1 meter with 1 watt of power you would get 91.5 dB -- pretty loud.
You can look at the power calculation tables for:
- increasing distance
- increasing SPL
- peak dynamic range 

From AVS link:
"So to hit 110 db, you'd need 19 db or roughly 6 doublings. 

2 - 4 - 8 - 16 - 32 - *64 watts*"

and

"Distance from the speakers - Your SPL drops 6 db every time the distance in meters doubles"

at 2m SPL could be *107 dB for 64 watts*


There is another link/thread on *AVRs with "all channels driven"* which is much less than 1 or 2 channels driven in most cases (eg cheap AVRs). 
This is more critical for HT than 2 channel listening.

Mike


**EDIT**
Oh yeah, and...

2 speakers (vs. one adds 3dB), so in example above for 850Sigs at 2m at 64W = 110 dB (loud)


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## Interspy24 (Apr 22, 2009)

Mike TX - thanks for the response.

Center: Bigfoot classic
89dbs and 6.8ohms (these are the specs for the sig, I assume the classic is close?)

Mains: RS750 classics
88dbs and 6ohm

Surrounds: RS250s
88dbs and 6 ohms

I know it's an important factor, but I can't say the spl for sure. 
I don't listen at very loud levels, it just seems the receiver is cranked to 0 for the entire length of the movie. If this isn't a problem, then I'm good to go. If it is and/or I can gain quite a bit gaining more power, then I'll definitely look into it. As I stated earlier, even using the ps3, some dvds and blu-rays use the volume level at VERY different settings. 

Seating distance is about 8 feet from the center and mains. 

For music, I listen to mostly rock, jazz, classical, and some pop. 
For movies, it's usually the action stuff with fun lfe scenes


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## PhenomeNhan (Mar 4, 2008)

Vik,

Basic question (not sure if it's been mentioned), but have you re-calibrated everything after you changed out to the new Rockets?

I'd go for something like an Emo 3-channel amp and use whatever receiver to power the surrounds. If you need a new pre-pro, then I'd wait for something like the UMC-1 to be thoroughly tested before hopping on board.


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## Mike_WI (Feb 26, 2009)

*Calculator - Amplifier Power Required*



Interspy24 said:


> Mike TX - thanks for the response.
> 
> Center: Bigfoot classic
> 89dbs and 6.8ohms (these are the specs for the sig, I assume the classic is close?)
> ...


I don't know that this is the best amplifier power calculator, but I found it with google...

Link

*Dist:* 2.7 m
*SPL:* 85 dB (reference for HT)
*Sens:* 88 dB/1W/1m
*Amp headroom:* 15 dB (85+15 = 100 dB)
*Req Amp power (W):* 116

*Dist:* 2.7 m
*SPL:* 85 dB (reference for HT)
*Sens:* 88 dB/1W/1m
*Amp headroom:* 20 dB (85+15 = 105 dB)
*Req Amp power (W):* 365

So, trying to hit really high peaks (105 dB) at that distance could require power.

However, if you listen quietly...
*Dist:* 2.7 m
*SPL:* 70 dB 
*Sens:* 88 dB/1W/1m
*Amp headroom:* 15 dB (85+15 = 105 dB)
*Req Amp power (W):* 4


Play around with that a little and see what you think.
If you had an SPL meter and saw the SPL you listen at it might help.
I think given your distance and perception that you need more power -- it might be true.

This doesn't take into account room treatments.
If you have a heavily treated room then you may need more power.
My room _is_ heavily treated (Rives Audio designed) and can use the power.

Good luck,

Mike


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## Mike_WI (Feb 26, 2009)

*Professional Audio Calculators*

Here is another audio / SPL / amp calculator

Link

http://www.doctorproaudio.com/doctor/calculadores_en.htm


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## Interspy24 (Apr 22, 2009)

PhenomeNhan said:


> Vik,
> 
> Basic question (not sure if it's been mentioned), but have you re-calibrated everything after you changed out to the new Rockets?
> 
> I'd go for something like an Emo 3-channel amp and use whatever receiver to power the surrounds. If you need a new pre-pro, then I'd wait for something like the UMC-1 to be thoroughly tested before hopping on board.


Nhan,

Hey what's up? Hope things are well!

I did re-calibrate using YPAO (but not a spl meter). What's funny is it always seem to sound better the 2nd time I do it, so I used those settings. 

At this time I think a pre-pro is probably out of my budget, but my thought was instead of buying a nicer receiver, just save and buy a pre-pro setup down the road.


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## Interspy24 (Apr 22, 2009)

Mike TX - thanks again for the links and some numbers to start working with. I think if I could get ahold of an spl meter, it would help greatly as you stated.

Again, the Yammy 663 almost plays loud enough. My concern is it's running pretty high on the volume dial. I don't know if its silly, but I think having just a bit more power would be peace of mind for me.

Btw, I know the yamaha is quite stressed when 5 channels are driven. I think the power drops to about 60w per channel. 

http://www.ultimateavmag.com/avreceivers/608yam663/index7.html

On the other hand, something like the onkyo 805/875 seems to be underrated in regards to its power levels:

http://www.soundandvisionmag.com/receivers/2463/test-bench-onkyo-tx-sr875-av-receiver.html

Obviously the test results were done at different times and there could be variances among them, but the onkyo seems to have nearly twice the power of the yamaha. Imo I think this would do the trick and provide a little extra headroom over the receiver I'm using now.

Problem is, I know the lpa-1 would provide even more power...


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## Maximum kahuna (Mar 5, 2008)

I use a Yammy 657 (older version of the same AVR) and it powered my Rocket 550's just fine (so I thought.) Like you I was looking for something more. I went to an LPA-1 and it was a big step up in clarity at all sound levels, but it made a bigger difference as the volume went up. From there I went to an XPA-3 to power the fronts and used the Yammy for the rears. This was another step up but not as big a one as going to the LPA-1. Having said that, I'd still recommend the XPA-3 or XPA-5. It's not overkill. They're the same size as the LPA-1 and like it's been said, Rockets just love the power. You might even find yourself listening to more music than before. 

Of course the next step down the rabbit hole is the ninja upgrade to the 750's. I think you'd find another big improvement especially over the classic 750's.


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## droht (Sep 15, 2008)

Nice deal on XPA-3.

I have no affiliation with seller.


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## Mike_WI (Feb 26, 2009)

*Want/Need*



Interspy24 said:


> Mike TX - thanks again for the links and some numbers to start working with. I think if I could get ahold of an spl meter, it would help greatly as you stated.
> 
> Again, the Yammy 663 almost plays loud enough. My concern is it's running pretty high on the volume dial. I don't know if its silly, but I think having just a bit more power would be peace of mind for me.
> 
> ...


Even if you don't "need" more power, you might "want" it.
No harm in that.

A higher (all channels driven) AVR may do the trick.
Then again, a beefy power amp can be combined with whatever AVR or pre-amp you want in the future.
Just so you realize why you are getting it.

I think my Denon 5308CI could well have done the job, but I got an XPA-3 for my LCR. 
I'm not sure it changed anything, but the placebo effect (if that's all it was) was nice!
:rock:

Mike

PS - My 3 year old son thinks "want/need" is one word.


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## imported_edward (Jan 31, 2009)

Interspy24 said:


> Just looking for input/advice on powering a set of rockets. I posted a similar thread on av123 about a year ago but was wanting to revisit the topic since the rockets seem to love extra power.
> 
> Listening habits are probably 70% movies and 30% music. It seems that different tracks/sources have a huge impact on high the receiver is turned up. Obviously it varies between receivers and speakers, but for some blu-ray discs the volume at -30 would be louder than a regular dvd at 0 and vice versa. Some music needs to be turned up to the 0 mark and other cd's are fine at -20. Not sure how the variance is this much, but whatever... (Btw, everything is played through a ps3 via hdmi).
> 
> ...


For what it is worth.
Was running my set up with a Pioneer 9300tsx then i bought a couple of Carver TFM-35x Amps let the reciever handle center channel duties and have not regretted that decision once.
wonderful amplifiers producing great sound plus the meters on those things are pretty cool :thumbsup: :thumbsup:


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