Got my AMC amp today, first impressions

faster100 · September 2003

Well i purchased an amc amp from Sean (ATC) and it arrived today, i built my UPS lady a computer.. so i told her i had a package coming today and she brought it first thing 9:30 or so.. LOL

Well either these Rti150's are really power hungry or, i don't know what.. LOL

I hooked them up to the AMC, they sound about the same, maybe brightened them up a bit from the laidback state they usually are, however after i hit a few clicks above where my Integra gave out(shut down) the right channel shut down.. the green light turned orange and the right channel went south.
That was on large, no sub, bass +2

so i went to small, sub yes, but powered off.. bass +2... a click or 2 higher and shut down,

so then i went to same as above except bass +0 flat.. it worked the best here but right when i started opening these 150's up. kablamm right channel went off and orange light on,

So anyways aside, The amp looks like new,, was shipped very safely.. snug inside with the manual and as described or better.. Sean came through on this one. and this post isnt about the amp works... its about my speakers eating up power like a vulture..

So does this sound like the speakers eating yet more power? or any problems... I am going to try and bridge one speaker and see what it does, if it still does it we have a problem.. and also i may hook up my rti70's and see how they do..

on a side note: I calibrate my system.. and something strange has happend recently.. I used to calibate center channel At 0 flat and i had to turn the volume down to 56 on the master volume, then i would set all the speaks accordingly... ever since we had electrical problems and re-wired our house, the avr lost all the presets.. so i re-set everything up to find now i had to calibrate to 61 for 75db at 0flat on the center and the rest were done accordingly.. Now today with the amp in place i had to crank the master control to 64 to get a reading of 75db at 0 flat on the center and with the mains on the amp i had to take them from +1 each to +4 to get the same 75db.... what is up with that??? please someone help me on all these concerns here...... Thanks

faster100 · September 2003

No thoughts, LOL Bump

Dr. Spec · September 2003

You are learning the hard way what I've been preaching all along.

The RTi150 and it's 3 woofers (per speaker) is one power hungry SOB. Every post I've ever made regarding this speaker has suggested a minimum of 300 watts per channel of high current heavy duty amp.

You got sucked in by the price and manly features/look of the RTi150. And that's fine. But I'm sure you already know that your RTi70's paired with the SVS (and its 320 watt digital amp) present a FAR esier load on your Integra and/or the AMC than a pair of RTi150's running on full range.

I wouldn't buy a set of 150's unless I planned on running them on large - otherwise what's the point? Their claim to fame is the kick **** bass and they have it in spades - with the right amp.

But your SVS has bass in spades too, and your RTi70 is arguably a better performer above 80 Hz than the RTi150 is. Why buy your bass twice?

If you want to keep the RTi150 as a full range unit, get yourself an Adcom 300x2 amp and really let them sing. If you want to do it on the cheap, take a look at the Samson S1000 for $365 B-Stock on the SVS website at 365/channel into 8 ohms. Or look at offerings from QSC along a similar vein. But these are touring amps that "might" compromise SQ as compared to an Adcom or B&K or Crown, etc.

Good luck........I don't envy your position.

Doc

faster100 · September 2003

I hear ya doc, thanks alot for your support and suggestions.. Much much apprciated!!! I took the top banana's off temp. to let the AMC run just the woofers.. and turned the surrounds off which activates the 3 channel stereo option in the DSP.. so i have just for testing of course.. center on small and 150's onlarge only powering the woofs and the AMC is kicking alot better.. did kick off at HIGH volume, but extremely high.. Now could i power the mid and tweet with the front main amp from the Integra? I know this starts compromising SQ, possibly... The AMC just isnt enough current and power for these, Simply... a great amp but not for 150's... i see... be back after lunch for more discussion

Thanks

organ · September 2003

The differece in volume setting you're experiencking after calibration is probably due to a different gain on the AMC.

Maurice

faster100 · September 2003

Yeah i figured as much, however i noticed this before the AMC.. a few weeks ago.. strange.. then with the AMC today it just changed alittle more.. But you explained that.. Thanks

faster100 · September 2003

Ok i am in demo mode today!!

I just removed the 150's and placed the 70's in their spots.. I do now notice the improved mid range.. Really i am happy with both sets, however the wife has to be happy as well, and she thinks the 70's are to bright.. Strange i thought the AMC brightened the 150's, however im getting confused now.. the 70's sound alittle more warm i guess you could say.. let me know guys..

HBombToo · September 2003

Hey faster lets try something if you have some time. On your bass setting turn the gain to its very minimum and then crank it up. I'm beginning to suspect its not the amp but the bass (going to your left and right) preamp causing the problem. Sounds like clipping to me....

Let me know?

HBomb

BTW, The Integra L/R pre... sorry for the confusion here.

faster100 · September 2003

well i already lugged these heavy sob's out in the other room and re-hooked the 70's.. BUt i cranked the 70's with the AMC and no problems, I didn't want to clip it and pop the 70's.. so i kept it nominal.. but very loud with no problems.. My 150's put my Integra into protect mode also.. It seems the speakers are the culprit?? I even disconected the top binding post and only powered the woofs and it seemed to crank right along.. however at over 100 db it did shut down

These are some power hungry speakers to say the least.

seems they may be 2 channel rig bound. Its just not feasable to spend all this amp money to get the 6 woofers pumping when i have a SVS as Doc mentioned.. he's right!! I got tied up in the looks and price. The think the AMC is actually doing the 70's some justice in sound quality and warmth...

Now last question, the amp doesnt have a 12v trigger

can i just leave the amp on all the time idle? otherwise i have to turn it on everytime.. although its nopt far from me to turn on, LOL

HBombToo · September 2003

again it is the preamp messing with you. turn your preamp levels down so your not clipping.

HBomb

faster100 · September 2003

well the thing is, I had the 150's hooked to the Integra before i got the amp today, and it did the same exact thing.. just a few volume notches lower then with the amp.. at 61 on master volume it shut down when set full range.. with the Amc it went to 63 or 64 on master volume before shutting one side off of the amp..

HBombToo · September 2003

Originally posted by faster100
well the thing is, I had the 150's hooked to the Integra before i got the amp today, and it did the same exact thing.. just a few volume notches lower then with the amp.. at 61 on master volume it shut down when set full range.. with the Amc it went to 63 or 64 on master volume before shutting one side off of the amp..

I don't think I'm explaining myself very well here... sorry but give me 1 more chance.

the Integra has seperate gain controls for each channel... correct?

Simply lower the gain of the left and right to the absolute min. This will prevent the preamp in the integra from clipping. When the preamp clips the amp see's what it thinks is dc and goes into protect. The added response of the 150's are loading the preamp IMO. Just try it for **** and grins because your still going to get huge volume even at the min presets.

When you determine that your no longer going into protect then slowly increase the individual channel gains up untill it happens again then you know where the threshold is. Back it down 2dB from there are your up and running.

HBomb

faster100 · September 2003

yeah, I understand what your saying.. I think the speakers are the final cause in the end. I will possibly be leaving the rti70's/SVS combo.... Just not worth all the hassle IMO. shoot i could return these 150's and get a upgrade on my SVS to the pb2-isd for that matter..

I'm still tinkering here, got some stuff to do now so it will be later, thanks for all the help

faster100 · September 2003

Nah sean, It works fine for what it was designed for.. The 70's take it like men, LOL... The 150's are brutes and should be treated as such, amp power included... I am very happy with the amp actually.. it looks nuetral and i like that.. It may some day serve as rear center speaker duty.. ( ie: fxi 30's) as my receiver doesnt power 2 rear centers, only 1... 6.1 powered.. 7.1 with a outboard amp.. this would be perfect for that considering the price.. it can't be beat. Thanks for the fast ship and great pack job

Far as the 150's or the 70's.... I'm so confused right now i have to take a minute to think what i wanna do.. far as the amp// amps are cool to look at and have, i will use it somewhere or just on the 70's.. who knows at this point.

faster100 · September 2003

I know, I don't know maybe one of them is defective? your amp made the right channel shut down.. after i had it cranked.. turned off back on and it was fine, like 3 times.. but on the 70's its fine.

could it be the speakers? or speaker

Frank Z · September 2003

Faster,
I gotta agree with the previous post regarding your 150's and the "New" amp. Based on the amp's spec's and the speakers, I think that your kinda up the creek, power wise. Have you tried running just 1 speaker with the amp in a bridged mono configuration. You might want to give it a shot and see how the speaker handles it, and see if the amp shuts down again. I'm going to go out on a limb and say that your 150's will play quite loud, and the amp won't shut down.

faster100 · September 2003

I also had thought of that. although i didnt do it yet. I would need another amp then eventually that matches this one.. But you mean run one speaker in a bridged setup to make sure that the one speaker has plenty of power and its not the amp or speaker causing the problem but lack of power that i stated a few replies back early on in this thread.. Thanks for the suggestion

tryrrthg · October 2003

I'm a little confused also... what do you have your left and right main speakers volume set at? as in how much do you have them turned up (or down) so they are calibrated for HT? try running them flat on your receiver and turn the bass flat also. I don't see how this amp should be turning off... just wondering...

faster100 · October 2003

regardles if i turn the speaker output levels down or not, its still the same volume at some point.. just takes more on the m,aster volume to get there.. The receiver did the same thing.. with these speakers.. so its obviously the speakers needing more power..

RuSsMaN · October 2003

Faster, sell the AMC, and go buy Cred's pair of m200t's in the flea market. Bridged, that'll do 350w continuous - that ought to work the 150's just fine.

Cheers,
Russ

faster100 · October 2003

Ok Russman tell me this? Its the speakers needing more power right? I know that's what it is but some people seem to think the amp should power these, however a 100 watt receiver couldnt.. and i understand the amp has more power, reserve and all that.. but its still 100 watts.. for a 500 watt max speaker with 10 drivers total...

RuSsMaN · October 2003

Yes, imo they need more power.

Your amp(s) are shutting down at high(er) levels, no? Next question....

Cheers,
Russ

faster100 · October 2003

Thank you!! that's what i have been trying to tell everyone.. IMO is what i thought.. however i'm no expert on the subject of amps and multi driver speakers.. I kinda figured..

Well me and my wife had a talk last night heart to heart about the speakers and what we like/dislike.. possibilty of a 2 channel rig or not.. which to keep/sell... she really is getting into the audio thing and since we listen to music everyday and movies a few times a week min. we decided the 70's are just to bright with our room, gear, what ever.. their to damm bright compared to the 150's.. we arent going to change receivers to try and remedy it, its not feasable.. or cost effective.. people seem to shy away from the 150's... however they work great in stereo without even a sub, for movies they add that extra kick and of course they cant keep up with the SVS bass that is why we got the SVS... to rumble, shake and make movies sound great!! the 150's are just a supplement.. Ok so with that said.. i'm selling the 70's no holds barred.. I/we have decided!! Now we need an amp to power the 150's.. the AMC although nice isnt cutting it.. I don't nessasaraly (sp) want to just grab anything to power them as it will be a part of our HT/music setup for a long while and want it to be good, powerful and dependable.. Its no secret we have to ration our money and its getting low with all the recent purchases.. so i will see what i can do,, to power these...

tryrrthg · October 2003

Originally posted by faster100
regardles if i turn the speaker output levels down or not, its still the same volume at some point.. just takes more on the m,aster volume to get there.. The receiver did the same thing.. with these speakers.. so its obviously the speakers needing more power..

What I was getting at is if your receiver is sending the amp a clipped signal then the amp will be over powered. It's just like setting up your SVS sub. They tell you to start with the receivers sub volume at about -5 so that the receiver doesn't send a clipped signal to the sub. That's what I'm thinking the output trims to your mains are doing... but who knows... yes the 150's do need more power but I think the AMC should do just fine without shutting off... either way I agree you need more power...

Good luck!

RuSsMaN · October 2003

Not arguing, but just curious. Why would the receiver (ever) send a clipped signal via RCA to an outboard amp? I've never seen a volt 'distort'.

Cheers,
Russ

faster100 · October 2003

It was doing this at +1 on the left and right channels.. flat bass.. large or small.. I'm going to tinker this morning.. will get back to yall.. later

HBombToo · October 2003

Originally posted by RuSsMaN
Not arguing, but just curious. Why would the receiver (ever) send a clipped signal via RCA to an outboard amp? I've never seen a volt 'distort'.

Cheers,
Russ

Whether its a preamp or amp the same principles apply. The gain in dB of an amp is in reference to voltage and if the power supply of that amp cannot provide the necessary current then your clipping.

Just remember everything follows V=I*R...

HBomb

I'm in your camp on this 1 tryrrthg. Turn all the individual channel gains to the min and crank away on the volume.

faster100 · October 2003

BUT, it would clip on multiple sources correct? not just on the 150's... it doesnt do it on the 70's... it doesnt do it powering the woofs until extrem volumes.. only powering the full 150 speaker with receiver or AMC amp.. I just don't feel the logic with turning down the gain, BUT i am going now to switch out the 70's again and place the 150's out there and do some testing.. and i shall report back

RuSsMaN · October 2003

I see what you are saying Henry, but if we drop the input voltage, it is only going to require MORE from the amp to get to the same 'reference' SPL? No?

Cheers,
Russ

HBombToo · October 2003

Originally posted by RuSsMaN
I see what you are saying Henry, but if we drop the input voltage, it is only going to require MORE from the amp to get to the same 'reference' SPL? No?

Cheers,
Russ

You got it... the difference is a cleaner signal into the amp. if the input signal does not approach dc then the amp will not go into protect. Also the input and output signals are well within the linear curves of the gain stages for the 2 respective amps.

I'm not sure what the total gain of fasters new amp is but I'd bet it goes into protect somewhere around ~75% of total gain.

HBomb

faster100 · October 2003

Russman,

exactly!!! what i think.. Ok its -12 and it just takes alot more master volume to get to the spl/volume you want..

Ok here is the deal... I hooked one 150.. bridged mono.. on the left side.. no other speakers hooked up or running, speaker level to -12 it was.. only because at max master volume it wasnt as loud as it was when it shut down normally.. It run it up to like -7 and up shut down.. come on... this thing bridged is like 250 with dynamic of 500 or some such.. that is plenty for the 150... It is i am thinking the amp..

any suggestions now???

Got my AMC amp today, first impressions

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