An Amp for the Monitor70's?

Log1x

Hi friends. I had an incident recently where one of my Monitor70 tweeters blew while watching a movie in 5.1 at THX Reference Level. (0dB on my Onkyo TX-SR608) .. this leads me to believe that I need an amp to better power them. I understand that if I want to get an Amp, I need to upgrade my Receiver which I'm willing to do. I was looking at the Adcom GFA-555 since it's so highly regarded. Would that be a good choice? My budget is around $600 in total to upgrade my receiver after selling my current (probably upgrading to a 708?) and purchasing an Amp, but I've seen 555's go for pretty great prices. I used the forum search feature to find more on this subject but it was mainly people just telling someone asking my same question that they will be fine running it on a Receiver..well me upgrading to an Amp was a long time coming and I'd like to get one that would be great for the Monitor70's and please me when I upgrade my 70's one day (but I really shouldn't need to with my room size. They sound GREAT! I think they just need cleaner power...and a little more juice.) I also listen to quite a bit of music in 2 channel mode (more than I watch movies, really) so I'd like an Amp that is..I guess Musical? This will be my first amp. My dad had a Nakamichi PA-7 when I was younger (he sold it since then :frown:) but...it's a tad out of my price range. :P

Thanks

tonyb

Even with an amp, your still going to blow tweets if you don't turn the volume down a few notches.
The M70's are some of the easiest to drive and most any receiver will kick them up towards their limits. Turn it down my man, or if you like it that loud, get an amp and speakers that will handle the volume.

slk55amg

I ran my 70,s with an EMOTIVA XPA5 before I upgraded to the LSI front sound stage, and they sounded better than ever, in fact come to think of it, they are still being driven by that amp as my side surrounds.

Log1x

I have a hard time believing that Monitor70's can't withstand THX reference level volumes with the right power.....heck, they should have no problem with it on this Receiver. My living room is NOT big. I'm not trying to drive them way past their capacity.....

EndersShadow

tonyb wrote: »

Even with an amp, your still going to blow tweets if you don't turn the volume down a few notches.
The M70's are some of the easiest to drive and most any receiver will kick them up towards their limits. Turn it down my man, or if you like it that loud, get an amp and speakers that will handle the volume.

+1. I ran my Monitor 60's from my Integra DTR 5.9 and never got above 60 before either my ears were going to bleed or my neighbors were at my door.

Now I did add an external amp, more to have the extra overhead, that and I planned on getting some LSi's which are in the works right now.

I am betting if I cranked my current gear I would blow my tweeters really quick above 60. Hell, Audysee set their level's @ between -8 and -10 for all my front 3....

However you may have been sending a clipped signal to your speakers from the Onkyo, and like you said getting an external amp would be one way to not do that.

That adcom is pretty good. I would hop on AVSFORUM and check around there for info as well. They have lots of folks who are running gear similar to yours with recievers & amps that can help you out. Look for the **Calling all Polkies** thread in the Speaker forum

Ron Temple

Running a 608 at reference level is asking for it. Depending on your room, reference is 85db average at the LP with 20db peaks in the main channels. That's asking for 100X the power at any given moment. Frequently dynamic action scenes can easily push an AVR in clipping. It's most likely what happened. Most watch movies at -10 or greater(or lesser). You're pushing it too hard. Adding an amp with an AVR or pre will probably get you to reference safely, but the question is, do you really need reference. If you're going to run at -0, then yes you'll need an amp.

ibewbrother

You are clipping that Onkyo.... I have long since got into external power amps, but I don't know if I would blast my 70s with my 807 strictly 2 channel. I know mine is a toaster only driving my heights. Get a power amp (or two) and enjoy.

thsmith

Ron Temple wrote: »

Running a 608 at reference level is asking for it. Depending on your room, reference is 85db average at the LP with 20db peaks in the main channels. That's asking for 100X the power at any given moment. Frequently dynamic action scenes can easily push an AVR in clipping. It's most likely what happened. Most watch movies at -10 or greater(or lesser). You're pushing it too hard. Adding an amp with an AVR or pre will probably get you to reference safely, but the question is, do you really need reference. If you're going to run at -0, then yes you'll need an amp.

Nice Ron !

Get the Adcom or if you want to play get an Anthem AMP 1 if tubes are ok.

aboroth00

No love for ATI? I'm running a 1505, 2 1502's and I'm loving it. Adcom sort of reminds me of ATI, no fuss, good build quality and good sound as well as their no nonsense face plates.

Log1x

Thanks for the replies. Hmm, I was unaware 0dB was pushing it. There's an Adcom GFA 555 in said to be mint condition on my local craigslist for $225 so I sent him an email. If it falls through I'll look into other options.

aboroth00

Log1x wrote: »

Thanks for the replies. Hmm, I was unaware 0dB was pushing it. There's an Adcom GFA 555 in said to be mint condition on my local craigslist for $225 so I sent him an email. If it falls through I'll look into other options.

Sounds like a solid deal. Should give you plenty of overhead to make yourself go deaf :biggrin:. But if you blow the tweeters again with the Adcom, then we have real problems.

cnh

What tonyb said above. I run a set of M-70s on an Onkyo TXSR-805 (a HT beast in its time) and I rarely get above 66 when watching a movie and maybe 70 on some music? Never had a problem but I've also never run at the levels you were running at. How big a room do you have?

I've also run M-70 on a Denon AVR-2807 with that very same Adcom (GFA-555) and I can tell you that the Adcom made a true difference from running them on the Denon alone. I'd recommend you get an AVR whose 'sound' you like. The Adcom is a nice bang-for-your-money piece that will not disappoint and keeps running and running and running, unlike some gear that likes to crap out. Yes, there are better amps out there. But for M-70s an Adcom is plenty of amp!

Good Luck with the hunt.

cnh

slk55amg

Before I added my EMOTIVA XPA5, I ran the 70s, with a CAIA4, and two pair of fxi,3,s from my SONY ES5300. That receiver provided more than ample power to the speakers i have just mentioned.

jenkzy56

a question about adcom, I am running my 60's with a 100 watt per channel stereo adcom (forget the model number and i am out of town at the moment)
I am planning on going up to the 70's soon, will that amount of power be enough for the 70's to breathe a bit more?

I am coming out of an Onkyo 708 which is 110 WPC, but having the 60's using the adcom seems to let the other three speakers (cs2, M30's) have a tad more
"umphh" for lack of a better word.

just wondering if it will be enough amp for the 70's.

cheers.

jenkzy

dnoyeB

Unless you have a high tolerance for distortion, you probably just got a borderline tweeter. I blew one of mine as well. I don't listen to theater that loud on this system. I think some of these tweeters are just suspect. Its all good so long as Polk is sending out new ones free...

I don't think getting a bigger AMP will change anything.

Log1x

Resurrecting the dead here but I thought I'd add since this has a ton of views that adding an XPA-2 easily fixed any blowing of tweeters to be had with the Monitor70's at the volumes I was attempting with the Onkyo. Not only that, but it'll easily drive them 10-15dB above those levels. Since upgraded to RTi12's though. Hopefully I'll find some SDA's one day!

Cheers