Got my AMC amp today, first impressions

HBombToo · October 2003

Originally posted by faster100

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???

What is the full swing number on the integra and where did it shut down prior to decreasing preamp gain??

HBomb

BTW, what are you playing and what is your source??

faster100 · October 2003

my Integra go's from -12 to +12 which is max speaker volume.. the master volume go;s to i think 78 on relative.. I am listening to FM stereo.. regular radio.. nothing bass intensive .. actually mellow music.. flat bass and treble controls.. no sub.. large..

I started at -12 and around -7 it shut down.. actually also it doesnt shut the left side down but the right.. in normal stereo mode.. it just lowers the left volume.. in bridged mode it lowers the left(which is the speaker im useing) and the protect orange light comes on..

Tour2ma · October 2003

Sorry, but my brain is starting to hurt here. Ignore this mini-jack until faster's helped, but...

Henry, I was with you when I was talking about bass gain, and I agree that pre's can clip, but how does lowering the channel gain help if faster wants to listen at the same level? TO lower the channel gain and the raise the master volume is just a different route to the same pre output... yes?

Faster,

First, I'd swap the mono set up to the other speaker.

faster100 · October 2003

ok will do tour, right now... take the speaker problem out of the equation...

RuSsMaN · October 2003

Agreed Tour, from what I understand that Henry is trying to say, is that clipping is reached through a combo of output (rca) and master (volume pot).

Maybe I'm reading it wrong, but if the RCA output is ran hot +10, then the combo with the volume pot at 50% would clip. Where as if the RCA output was +0, the volume pot will be able to run higher, before clipping.

I still feel like we end up at the same point either way though.

-Russ

HBombToo · October 2003

Originally posted by faster100
my Integra go's from -12 to +12 which is max speaker volume.. the master volume go;s to i think 78 on relative.. I am listening to FM stereo.. regular radio.. nothing bass intensive .. actually mellow music.. flat bass and treble controls.. no sub.. large..

I started at -12 and around -7 it shut down.. actually also it doesnt shut the left side down but the right.. in normal stereo mode.. it just lowers the left volume.. in bridged mode it lowers the left(which is the speaker im useing) and the protect orange light comes on..

Very interesting... what was the master volume control set at when the amp went into protect?

Also you should pop in a mellow type cd which is about the same as what your listening to over the air and we'll make sure the inherent noise of the tuner is not a big part of the issue.

This is cool!

BTW lets use -8 as our reference.

HBomb

faster100 · October 2003

Ok everytime i do this and shut the amp down.. essentially im clipping the amp, and have the potential for damage.. i don't want that to happen... i'm done with this torture test.. I ran the other speaker Mono, still did it.. at -12 now.. and also changed the RCA cable from left to right and back on the pre-outs..

It doesnt have the **** or the amp has problems one or the other.. i dont wanna damage the amp or my new speakers.. its just not working.. However i appreciate more then you guys know all the help set forth here.. you understand though..

bigsexy1 · October 2003

Faster, sorry I got in on this so late. I agree 100% with Dr. Spec in the 2nd post on this thread about this speakers power requirements. I'm driving mine with 200 watts per channel of full bandwidth rated Adcom watts going only to the woofers, and another 125 of full bandwidth rated Adcom watts going to the tweets/mids, and that is enough to make them shine. However, I want even more! I wish I had one of those 300 watt per Adcom amps Edward was talking about just for the woofers alone!

However, I do know that Em was driving 4 of them on a 5 channel 125 watt per Rotel amp. Granted, I know AMC isn't exactly Rotel, but maybe he'll see this and weigh in. Frankly, I am a little surprised that the AMC shuts down just like my 3802 or your Integra did. I thought it would at least be able to drive them! Hell, my 3802 ran them on master volume 00 for like 10 or 12 hours nonstop one day without shutting down! Maybe I've been severly underating Denon's amps after all!

One thing I am a little perplexed about however, is how the 70s seem to be so much brighter, especially when they have the exact same tweeter. You're not the first one I've seen say that.

I do not blame you about abandoning the seperate dedicated 2 channel rig though. Just pick the speaker you feel is the flat out best (which I see for you it's the 150s), and either sell or return the other set. Instead of making 2 different rigs, make the one the absolute best you can.

I can see where you're coming from though about selling the 70s for so much less than you paid for them though. I had a '97 or '98 vintage Yamaha 2092 receiver, then their flagship and second from the top of the line only to the integrated amp DSP A1. Well, after a few short years, it was pretty much obsolete with only DD 5.1 and no really useable pre-ins/outs, and it couldn't be upgraded. As much as I paid for it then though, and no more than I could get by selling it now, I was bound and determined to keep using it in some way, shape, or form no matter what. Finally, I decided to give it up when I realized that you can get a $400 or $500 receiver new today that would literally run rings around it in it's processing ability. So, I guess that's kind of where you're at with the 70s. Sell them and the AMC,and use that cash to help get a really suitable amp for the 150s!

faster100 · October 2003

yeah, that's what my thoughts are.. we could hash this and hash this.. make excuses,,, clip amps and speakers... till something breaks or we could face the facts that for what ever reason the AMC isnt cutting the mustard.. sell the 70's as i already plan now and possibly sell the AMC and get a nice maybe new amp.. I am not in the camp of buying really old gear , amps included but im not totally against it.. i called a local shop here to get a price on new, told him 5-700.00 max and he said he would call back.. that is if i can unload some of this stuff...

bigsexy1 · October 2003

Ya know Faster, Ubid.com always seems to have Audiosource amps cheap. I'm not sure exactly how good they are, but you could get 2 of them bridged in mono, or even 4 bridged in quad/bi-amped configuration on your 150s!

faster100 · October 2003

I cant have a ton of amps in the rack,,, Im looking at Adcom, parasound and Rotel.. if i cant buy it now.. i'm in no rush.. I can wait, they work at pretty high levels with the Integra.. just extremes and it shuts down.. havent tried them in surround mode loud.. well i watched jurrasic park 3 and they did fine.. maybe im just power hungry.. The AMC didnt sound real clean at extreme levels either.. worse in bridged mode.. to me IMO

Dr. Spec · October 2003

I know exactly what Henry was trying to do. If you push the preamp hard enough, it will clip and the AMC will see a square wave incoming and shut down to protect itself from simply amplifying an already clipped signal.

But IMO Integra will not clip that pre-out signal in the -5 to -10 region. A waveform analyzer is the only way to tell for sure, but I'd bet the signal looks fine even at 0.

I honestly think the 150's are simply sucking the life out of the AMC and it flat out doesn't like delivering massive amounts of current to those six woofers at the higher volumes Cliff prefers.

I have a 2 channel h/k 870 that can pass 60 amps of current for brief periods of time. It's a real bruiser with huge caps and transformer and weighs about 40 pounds. I used it as a subwoofer amp for several months and it never even winced and that was powering twin 10" Advents to levels high enough to bottom the woofs. Trust me, that h/k could smoke those six woofs if you got a little crazy with it.

You need something like my h/k, or a touring style amp designed for continuous max power abuse and fairly frequent soft clipping.

There's a reason Polk lists 500 watts as the upper limit for the 150 - that's a lot of VC's to move around. BS1 is running 325 per side and he wants more!

Doc

faster100 · October 2003

Thanks Doc and others for all your time and efforts on this,

Eastern · October 2003

Hi Faster,

I am running Rti70 in parallel with the RTi150 on my rotel 5 channel 120WPC amp and I can crank it up all the way till 75/90 and no clipping. I had to leave the room and turn up the volume using the remote through the window. And I was suprised that the Rotels seems happy with this load. I was wary about cranking up the volume further ... that's the only reason I left stopped at 75/90...It gets REALLY LOUD.

I hooked up the the 70 / 150 in another experiment using the zone feature of the Processor. and the RTi70 on the Main L/R channel of the AMP and RTi150 on the LSurround and RSurround of the amp, so that I can do a proper A/B test with just a click of the remote. And to me and my wife, we seem to prefer the Rti70 setup for music with SUB (Paradigm PS1000) The Rti 150 sound good, but as I crank up the volume I found that the bass was somehow interrupting with the vocals/midrange that distorts the clarity. I suppose I could compensate for this by tweaking with the bass/treble.

The funny thing we noticed while A/B ing 70 vs 150 was that we noticed for CDs like Norah Jones, the 70 will place the singer in front and music in the background. When I switched to the 150, the singer seems to hope to the back. We had loads of fun switching to and fro. The change was really dramatic. 70 was like Norah was 5 feet in fornt of me and the band another 5 behind. Whereas on the 150, Norah was well behind the band.

Anyway, when I hooked 70 in parallel to 150, they seem to balance each other out and sounded to our liking a lot. Now, when I either switch to 70/150 alone, it sounded kind of naked -- don't know how else to describe it.

Dr. Spec · October 2003

Originally posted by Eastern

The funny thing we noticed while A/B ing 70 vs 150 was that we noticed for CDs like Norah Jones, the 70 will place the singer in front and music in the background. When I switched to the 150, the singer seems to hope to the back. We had loads of fun switching to and fro. The change was really dramatic. 70 was like Norah was 5 feet in fornt of me and the band another 5 behind. Whereas on the 150, Norah was well behind the band.

This is not a big surprise. The majority who A/B the 70's and 150's find the midrange on the 70's to be superior, which is expected. Of course the 150's stuff the 70's into a hole in the bass department.

Both have strengths, but the 150's are clearly the more demanding mistress to own and operate. High pass the 70's with a dedicated sub and you have just a cake load for any decent AVR.

Emlyn · October 2003

I ran my four RTi150s and the CSi40 for a couple of weeks with the five channels of my Rotel RMB-1075 and found it adequate. It would hit 104db with music in five channel stereo mode at -10 on the receiver's volume control with no signs of distress, and very little heat coming from the amp.

I switched the RMB-1075 recently to biamp the front RTi150s and noticed much improvement in the speakers. The RTi150s are really like two speakers in one enclosure. Even when bi-wired, the woofers seem to suck the power from an amplifier to the detriment of the midrange and tweeter. It wasn't really noticeable to me until trying the speakers biamped. I now think using the biamp method is the best way to treat these speakers. They will run well with a receiver as I'm using two channels from mine for the second pair, but the speakers crave more power and the receiver gets hot. I'm not sure any more that biwiring and putting 380 watts per channel from an RB-1090 is the best way to hook these speakers up. A better way may be to biamp from an RMB-1095.

Edit: I forgot to mention that I had been running the speakers at +4 on the receiver's bass tone control when running both sets of RTi150s with the RMB-1075. When I biamped, the sound quality changed so much I had to set the bass level back to flat to get the speakers to sound right.

Tour2ma · October 2003

Not too surprising since the Rotel can slug out ~60 amperes per channel. The AMC just over 30... and they don't actually specifiy whether that's per channel...

Did not look at the AMC's specs earlier. Even if it's 30/ ch, it is not really a high current amp...

Terrax · October 2003

Question, would it be possible to bi-amp these 150's using outboard amp's powering the just the woofers alone, and use the receivers internal amp to power the tweets and mids? Rather than using to seperate outboard amps to bi-amp with. Atleast I would think you could, and it would further reduce the drain on the outboard amp, allowing it a bit more breathing room. I wish I could try, but with my reciever I don't have main pre-amp outs. I just got a HCA1000a, I hope to get another one soon so I can run both bridged.

faster100 · October 2003

you can do it, Ive done it before.. run reciever and amp, bi-amped..

how you gonna use that amp if your receiver doesnt have front pre-outs??

Terrax · October 2003

In another two weeks or so, I plan to get a different receiver that will have pre-amp outs for all channels. I'll move my Panny receiver to my computer room, where as my nForce2 M/B has DD 5.1 output through digital coax. As I stated above, I 'wish' I could try bi-amping with my current receiver, but oh well.

Honestly, my SA-HE200k can make my 150's shake the house when ran on large, and at levels I wouldn't want for very long, and I love it loud. Mind you, it does get way freakin hot. But it's only overloaded once, and that was on LotR's. Ran on large that is.

bigsexy1 · October 2003

Eastern

"Anyway, when I hooked 70 in parallel to 150, they seem to balance each other out and sounded to our liking a lot. Now, when I either switch to 70/150 alone, it sounded kind of naked -- don't know how else to describe it."

Sid would be proud! This sounds like it's right up his alley.

==============================================

Dr. Spec quote:

"The majority who A/B the 70's and 150's find the midrange on the 70's to be superior, which is expected. Of course the 150's stuff the 70's into a hole in the bass department."

Blah, blah, blah. Yawn!

Eastern · October 2003

Yeah I'll try stacking them next

(<-- I'm not serious)

Actually, I have returned the Rti150, I am in Canada, those RTi cost me 1300 CAD (1000 USD) and take up too much floor space to hook up in parallel. I'm gonna save the dough for another AMP instead.

bigsexy1 · October 2003

Eastern
"Yeah I'll try stacking them next (<-- I'm not serious)

Actually, I have returned the Rti150, I am in Canada, those RTi cost me 1300 CAD (1000 USD) and take up too much floor space to hook up in parallel. I'm gonna save the dough for another AMP instead. "

Yeah, 70s on top of 150s. That would be like what, 8 feet tall?!

You mean that the absolute cheapest they are available for in Canada is the equivalent to $1000? Man, that sucks!

Eastern · October 2003

Yup 1000 from future shop (equiv to CC) on a customer appreciation night after 15% discount off the clearance price plus 30 min of haggling and bargaining. You got it...it sucks.

Got my AMC amp today, first impressions

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