New 770amp and Configuration Settings

Holydoc

I was a bit surprised when I got my new 770amp and then adjusted my calibration. All my speakers had to be adjusted UPWARDS from my receiver inputs instead of what I predicted downwards.

My thoughts was that since I more than doubled the power to my system with the amp, that my calibration adjustments would have less power needed to my speakers. However it was just the opposite.

Is this common? Does anyone know why my thinking was incorrect on my calibration?

WilliamM2

My guess would be that it's the input sensitivity of the amp.

I use a 300 wpc amp on my fronts and the reciever powers the other 3 speakers with 125wpc. Even with this setup, fronts are set at 0db, center is +1.5db, and the rears are both +3db.

If the system seems to have more power than before, I wouldn't worry about it.

cfrizz

I wouldn't worry too much about calibration so long as its done.

The most important question is: HOW DOES IT SOUND?!!!

John K.

Doc, yes what you observed isn't unusual and is no cause for concern. The first point is that you haven't more than doubled the actual power to your system. The maximum power output of the 770 is about 3dB higher(double) than that of the 901, which would mean, for example, that if a brief peak could be played with low distortion at 110dB with the 901, then the 770 could play it slightly louder at 113dB. However, your speakers use the same amount of power for a given output regardless of whether the amp is 10 watts or a thousand watts(when calibrating it's likely that on the order of 1 watt was used), so when calibrating at the same output level no more power was used from the 770 than the 901. Now, for that amount of power it appears that the 770 required a slightly higher amount of voltage from the pre-outs of the 901 than was required for the 901's internal amplifier channels(again, not unusual), so the trim levels on the 901 had to be adjusted slightly higher. The bottom line is that you have about 3dB more headroom with the 770, but unless you were exceeding the output capability of the 901(unlikely)you won't be using it.

Dennis Gardner

The 901 tested for Sound and Vision only produced 50 wpc!!!
S & V Tests

I hope his 2100 watt amp can do better than 3db increase....................... :rolleyes:

Holydoc

Thank you all for your advice. I am visiting a dear friend and will be returning home on Monday. I only had a chance to set it up and calibrate before I had to take off. If she only knew the sacrifice I am making to pull myself away from my new toy. *smile*

I will tell you guys how it sounds when I get home and try it out.

koyaan

I recently upgraded from a Dennon 3800 to a 990/770 combination and saw essetially the same phenomema. not to worry.
I've found the improvement in sound quality to be staggering.

Give us your impressions.

Holydoc

Now for a review of my system with the new 770 7x200watt amp.

Lets start out with what I do not like about the amp. 1) Amp weighs a ton! Be sure you have lots of room and have eaten your wheaties before lugging this thing around. 2) Amp is picking up 60hz hum from cable tv grounding loop. Have ordered a ground loop isolator, so hopefully this will be a non-issue soon. In the meantime, I am running the TV cable through a UPS which has eliminated most of the grounding issue (i.e. hum is so low now you have to press your ear against the speaker to hear it).

Things I like about the amp... Everything else!!

The HT sounds like a whole new system. It has a nice encompassing sound. You feel like you are part of the sound and it is sweeping you up. What I was really surprised about was the surround speakers. All of them opened up and sound extraordinary. I was assuming that the front and center speaker would be where I would hear the most difference. Was I ever surprised when it was actually the 4 other speakers that seemed to be emphasized. All I can think is that the receiver was using all its power to push the front speakers and thus there was no "umph" left for the 4 surround speakers.

Music DVDs sound wonderful. It is as if you are sitting in the middle of a concert. I played the "Blue Man Group Audio DVD" to test just the sound (if you do not own this DVD, it is a must for showing off surround around music and bass). The loudest I could go was -5 from Reference Level, and then only for short times. The sound became quickly overwhelming and chest pounding. What was amazing was when I set the sound at -20 below reference (that is right, negative 20) the sound was still pleasing and spread through-out all the speakers just as if it was at -5 from reference Level. My radio shack SPL Meter was averaging around 83db when the stereo was set at -20 below reference. I just was sitting there listening and smiling.

Music CD play is going to take some getting use to. When I first put in Sade and Eric Clapton to listen to them, the system almost sounded like there was reverb added to it. What I discovered after listening for a bit was that the extra sound I was hearing was not reverb but the ambient sounds (pick strokes on guitars, rubbing of fingers on frets, the breaths between playing notes on the sax, and the vibrato in the voices). The sounds that use to blend into the background were now part of the music. I think this was due to the RTi12's actually coming to their potential and emphasizing all parts of the CD. To tell the truth, this is going to take some getting use to. Never considered myself a music critic, but this new clarity in music may change my listening habits.

Movie DVDs were pleasingly enhanced. What was really noticeable about movies (besides the fact that the surround speakers sound incredible now) was that the dialogue was being emphasized quite a bit. I typically watch movies at around -10 or -9 below reference and with the new amp this did not change. What did change was that I could turn up the subwoofer to 88db instead of 85db (All speakers were calibrated using Avia DVD at 85db) to increase the bass impact without distracting from the rest of the movie. Now with the dialogue being emphasized the bass could be cranked up some without worrying about drowning out the on-screen interaction. This really added to the enjoyment of movie watching. I love the feeling of LFE as the bad guy approaches.

I am loving the amp. I am also very happy with my choice of getting an amp that works for all the speakers. I have zero problems with timbre modification and the added enhancement to the surround speakers would never of come to perdition had I just got a couple mono-blocks. I was a bit worried about investing so much into an Amp, but with each DVD or movie watched, I forget about the pocket drain and enjoy the feeling of being part of the action.

After all why make money if you are not going to enjoy it.

cfrizz

This should be the poster child write up for the benefits of separate amplification!!!

Isn't it amazing???? I can totally relate to hearing things out of your cd's you never heard before! And be warned, that if you have poorly mastered cd's you will NOT want to keep them! You will quickly be looking for a remastered copy of it!

Enjoy your BRANND NEW SYSTEM!!!!

Cathy

mldennison

Holydoc wrote:

I was a bit surprised when I got my new 770amp and then adjusted my calibration. All my speakers had to be adjusted UPWARDS from my receiver inputs instead of what I predicted downwards.

I have a question about this, I was always under the impression that the adjustments that you make when calibrating are only relative adjustments and that the absolute values are not that important since they are controlled by the volume control. it sounds like you (by changing the adjustment contols for all of your speakers) are attempting to hit some reference level when doing your calibration. Is there some sort of level I should be shooting for on my SPL when I am calibrating or are these measurements only relative?

Thanks,
Mike

McLoki

mldennison wrote:

Is there some sort of level I should be shooting for on my SPL when I am calibrating or are these measurements only relative?

Thanks,
Mike

Yes, if you are using the test tones in aviya (I always spell that wrong) you should calibrate to 85db. If you are using video essentials you should calibrate to 75db. If you do this then when you volume control is at 0 you should be playing at reference level reguardless of your speakers or electronics.

That being said, if you have to adjust anything to more than about +3 in your pre-amp to get to those output levels, I would not do it because you could start introducing clipping in your pre-amp signal. (just adjust to 5db less and know that at 0db you are actually -5db from reference.)

Michael

mldennison

McLoki wrote:

If you are using video essentials you should calibrate to 75db.

Great, that is good to know, I guess I will have to pull that out and see how much I was off by.

BTW- that is definately the best of the Wizard's Rules...

Holydoc

Mldennison,

One of the most important things you can do to make your HT better is calibration. Your receiver probably produces speaker test tones that would, with the purchase of a $39 Radio Shack SPL meter, allow you to adjust all your speakers to produce the same volume. The mistake that a lot of people make (I was included in this sweeping statement) is that they presume that by calibrating using the built in receiver test tones, that your system is then calibrated for HT use. This is a very incorrect assumption.

You need to calibrate your HT for the components that make up your HT production. In my case, it is the receiver, speakers, DVD player, amplifier, and Television. Since your sound and picture is being delivered to your receiver via the DVD player, it makes sense to get a DVD that allows you to calibrate your whole system using the DVD player as a basis.

Two of the best calibration DVDs on the market are Video Essentials and Avia. I currently use Avia since it has a bit more tweaking features than VE. Each of these calibration DVDs will instruct you on how to adjust your speakers so that you get the best HT sound and video from your system. Items like reference levels, phases, tint, color, etc will be tested and explained in detail on these DVDs.

What was surprising to me was the vast difference in my "loudness" calibrations between my DVD and my receivers test tones. This could be caused by how your receiver interprets the signal from the DVD player, the cabling between the two components, the quality of your DVD player, etc. Whatever the reason, without calibrating using the DVD player as the source instead of the receiver internal test tones, you will never get the HT sound that the movie producer intended for you to hear.

Hope this helps,

McLoki

mldennison wrote:

BTW- that is definately the best of the Wizard's Rules...

Certainly the most applicable to home audio...

Michael

tdeluce

I ordered three Outlaw M-2200 amps to drive my
front, center, and right speakers ( LSi15s and a LSiC )
and will use my Denon AVR-4802 as a pre-pro and
to drive my surround speakers.

Looking forward to getting them!

tdeluce

Dennis Gardner wrote:

The 901 tested for Sound and Vision only produced 50 wpc!!!
S & V Tests

I hope his 2100 watt amp can do better than 3db increase....................... :rolleyes:

It will be hard for that 2100 watt amp to get more than
the 1800 watts supplying it ( assuming it is an isolated
15 A circuit )...

jdhdiggs

tdeluce wrote:

It will be hard for that 2100 watt amp to get more than
the 1800 watts supplying it ( assuming it is an isolated
15 A circuit )...

This won't really matter since the reseves are so massive that he would need to be listening to a sustained level for several seconds for this limitation to come into play. By that time he would be deaf and it would no longer matter anyway. Still, dedicated 30A circuits are very nice! :cool: