What is the highest-powered amp you've successfully used with Vandersteen 2ces?

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mudgetroy

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Hi, everyone,

I've been asking a lot of questions because I'm in the process of changing things up in my system. I recently moved from separates (McCormack amp, 100 wpc) to an AV receiver (Anthem MRX 520, rated at 100 wpc), and I'm finding a decrease in power, even though they're rated the same. I guess that's not unusual. Anyhow, I'm thinking of returning the Anthem and buying a less-expensive AV receiver that has pre-outs and purchasing a five-channel amplifier to get a little more power.

As you know, Vandersteen rates the 2ce Signatures at 40 to 160 watts per channel into 8 ohms. He also says in the manual, "amplifiers with more than 160 watts must be used
with caution due to the increased potential for speaker damage if they are misused or an accident occurs."

I'm not looking for ear-piercing volume; I mostly listen to classical music and opera. But I'd like a little more punch and depth than the Anthem receiver is giving me (and the McCormack gave me). Can I safely use a 200 wpc or 300 wpc amp with the 2ces? And is there anyone who thinks I don't even need to do this; that simply using a good 100 wpc external amp (such as the McCormack HT-1) or 120 wpc amp (such as the Outlaw 5000). Will do the trick? I'm running 2.1 but about to go to 3.1.

Thanks for your help,
Dave

JLM

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  • The elephant normally IS the room
Yes, too much power can fry speakers, but the common advice is that too much clean (undistorted) power is better than too little distorted power.  (As you've found out AV receivers, even the good ones, are notorious for being overrated in their power output.) 


Excuse me if this is too elemental but here's the logic:

1.)  Music is made up of peaks that can range from 10 dB (jazz/rock) to 30 dB (classical).
2.)  The relationship between dB's and power (watts) is logarithmic meaning an increase of 10 dB (twice as loud) represents 10 times the wattage and an increase of 30 dB represents a 1,000-fold increase in wattage.  So peaks can represent a 1,000-fold wattage increase!
3.)  When solid state amps are pushed into distortion they clip (the smooth rounded shape of the music is suddenly flattened off).
4.)  Drivers follow the signal so when shape of the music is clipped they must somehow try to instantly stop and hold position.  This is very hard on the driver and results in heat build up which can result in blown drivers.
5.)  However the heat build up from an occasional short term peak is minimal and so is the chance of driver damage from clean peaks even if the power exceeds the speaker rating.
6.)  Clipping is most likely to occur from using too small an amplifier than too big of one.


Note that tube amps (and a few solid state amps) exhibit "soft clipping".  In other words as the signal reaches the amp's output limit the signal is rounded off so the damage causing "hard" clipping doesn't occur and in fact often can't be heard except for the loss of dynamic headroom.  This is why 40 watt tube amps are compared to 100 watt solid state amps.


Because of the logarithmic relationship between dB and watts the human ear cannot hear the difference between 100 and 120 watts (it's less than 1 dB which is defined as the least humanly perceivable increase/decrease in sound pressure levels).  You'd have to double the wattage to sound half again as loud (3 dB) or go with a 10-fold wattage increase to sound twice as loud. 


Before buying a nice big amp I recommend picking up a sound pressure level (spl) meter or smart phone application to learn just how loud you listen.  Live performances of classical music peak at 105 dB.  Your Vandy's are rated to be 86 dB/w/m efficient, meaning that you need to add 19 dB of gain (+/- listening distance/room size/number of speakers).  19 dB of gain is 80 watts, right in the middle of the recommendations you stated.


I'd be more worried about how the amp outputs are rated versus the stated ratings.  Reliable companies would rate their amps to provide at least XXX watts at any frequency 20 - 20,000 Hz at a given impedance and distortion into all channels.  But most companies use 1,000 Hz at a given impedance with no mention of distortion or number of channels being driven.  That's a huge difference.  So I'd stay with a good 40 - 160 watt/channel amp (like the McCormack HT-1 and avoid A/V gear). 

I agree with Vandersteen's advice, but in general and with care, there is no such thing as a "too big" amp. 

dminches

JLM, thanks for a well written and explanatory post. I may make this a sticky.

mudgetroy

  • Jr. Member
  • Posts: 6
JLM, thank you for the very informative response, although I had to read it a few times to understand. I get what you're saying about 20 wpc being an unimportant increase. But, as you said, AV receivers often overrate their power output, so I wonder if the Anthem is actually producing more like 80 or 90 wpc. Audioholics' bench test on the Outlaw 5000 amp, a test it describes as "Continuous Full Power Bandwidth (CFP-BW) from 20Hz to 20Khz into 8 and 4-ohm loads," measured it as 170 watts in what it called "continuous sweep tests," even though the Outlaw is rated at 120 wpc. So is it possible that the 120 wpc Outlaw is nearly twice as powerful as the Anthem AVR?

I have an SPL meter and played the opening minutes of Bruckners' 8th, which is pretty loud, and found that I'm listening in the lower to mid 70db range.

The main reason I bought the Anthem AVR was for room correction. I have a difficult room with lots of windows and tile floors. Sure enough, room correction discovered a significant dip at 200hz which I was able to mostly correct by moving the speakers around.

But here’s the rub:

1.   Now that I’ve placed the speakers in a location where the frequency is flatter, I don’t see any difference in sound between having room correction on and off. So I could just get rid of the Anthem now that I've figured out the room's problems.
2.   I don’t like where I ended up placing the 2ces to correct that problem: I actually had to take them off their stands to get them closer to the back wall.

So I’m dealing with a few issues here.

Gbob

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+1 JLM,
also remember that power output is related to the speaker's resistance. In most cases impedance drops at the lower frequencies, thus causing the amp to deliver substantial increases in power. Lower frequencies require more power from the amp than higher- so that it can move that heavy woofer. As a result, your Anthem receiver is probably 'a bit out of breath'.
Since you mention both the McCormack and Anthem were a little 'lean', I wonder if your power is up to standard? Or, are you using a power conditioner or surge protector?

If possible, I would go back to the McCormack amp.
You don't mention if it was upgraded. If not, I would look into it. Those caps don't last forever, and Steve has a great upgrade path.
For clarification, I use a McC DNA-1 with my 3a sigs, just upgraded to Treo's. I just did the Gold upgrade last year, and hope to have him upgrade that and a second amp to monoblocks this year.

I also think adding a subwoofer or two would go a long way to give more 'punch'. Though the Vandy 2w/wq's are rather pricey, even used, they are worth it. A less expensive move would be to get some HSU subs-not quite as good as the Vandy, but they integrate well.
HTH
Bob

mudgetroy

  • Jr. Member
  • Posts: 6
Gbob, I used to use a power conditioner from Rotel. I liked how it organized my power cords but am convinced it's snake oil otherwise.

The McCormack was not lean. I though the Anthem might be, but now I'm starting to think I was imagining things. Even if the Anthem is only turning out 80wpc, not the stated 100, there's still no audible difference, right? That's why I was wondering if I could safely go to 200 or more with the Vandys. But I'm beginning to think that might be pointless, too, at my listening levels.

The McCormack was sold, but do the smc upgrades add power?
 
I have an SVS sub that's blending very nicely with the 2ces. I'm starting to think that adding a center channel and a more powerful sub might be the answer.

Gbob

  • Jr. Member
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SMc doesn't add power, just refinements.
You can run higher powered amps, though you have to be careful not to over power them. I thin the 2's have an internal cut off that will protect them. The Vandy website has more info.
Your sub should do fine, a pair even better.
Center channel-only for HT
I don't know Anthem amps personally, 80wpc should run the 2's fine. If you can get high pass xovers for the subs (X-2's or M5-HP), you would spare your amp the low frequency duty in favor of the subs.
Bob

ctsooner

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Great post about power up above.  Watts' is just a measure of something. Current is just as important as is the ability of an amp to give you instantaneous power for a few milliseconds for musical peaks.  That's what separates a decent amp from a goo done. 

You can easily run the 2's on an amp that is 350 watts, if it's a high current amp delivering very clean watts.  I have never had a power house amp.  A tubed amp rated at 50 watts will probably give you similar sound pressure as a SS amp rated at 100w.  I used to own a Quicksilver Silver Mono that measured at just over 100w per mono amp and it drove my various speakers louder and better than any of the Krell or other SS amps I had in and out of the system that were rated over 150w.

I know that my old Ayre AX7e ran the Treo's very nicely and then when I got the AX5/20 it was a whole new ball game.  Not saying you are looking at integrated's in this range, but the more clean power, the better.  Doubt that anything I just posted means anything new, but what the heck, lol.

tvyankee

Hello.  I would do double or triple the program rating is. I find with that the headroom is there and the amo has more control over the drivers. Yes you can damage them possibly but you wont. I would do a test with one that is 160 and one that is 400 and report back.

Have fun.