Was told "your new speakers would sing with 200w"

[luxmatic]

...and this threw me into a rat hole trying to understand if it was true, and then subsequently learning quite a bit about amplifiers plus the components I already had.

My new speakers were ESS AMT 1D Revivals, which I love. Specs say 6 ohm, 375 watts. I was driving them with a Simaudio Moon i-1, which puts out 75 watts into the speakers. Had that comment in the back of my mind when my son came to me a few days ago and said my speakers were distorting with some heavy organ track he was playing. This was all complicated by the huge room I have these in... 18x18 ft, vaulted ceilings, and tile floor. Need things louder than I'm used to. So, yeah, better amplification would likely be good.

Adjacent to my "music" system, I have my theater setup: Denon X4700H, HSU VTF-2 MK3 subwoofer, center, surrounds and height speakers. I'd use the Moon+ESS as a pre-amp destination for the Denon front channels in this case.

I wondered how I could include the subwoofer on the "music" side of things... learned about my speaker's frequency response, the Denon's bass management and its ability to have a separate 2 channel configuration, and how to the subwoofer can be tuned. Moved my music sources (tt, cd) to the Denon from the Moon, setting the Denon's crossover to 90hz in LFE+Main SW mode for 2 channel output and dialed in some changes on the subwoofer side. Honestly, it sounded much better when I was done.

Which then leaves me with the question - will my speakers still benefit with more amplification now that I've added a subwoofer to the mix for music? Had almost settled on a couple of Outlaw Model 2220s based on the review here, but thought it would be good to ask before spending the money.

 

[Chrispy]

First, define "sing". The max wattage rating isn't all that meaningful, especially if not listening with such requirements (if speakers are actually capable without issues). A sub may reduce the demands of the amp if it has bass management.

I'd skip the Simaudio thing altogether myself.

 

[Doodski]

The efficiency of your ESS speakers is very high and at a high wattage will be very loud.

 

[luxmatic]

That's all I got: sing - was a comment on a forum addressed to me. Plus my realization, over time, that the Moon was not able to drive the speakers well. Think of it as prompt that made me ask a bunch of questions and educate myself on things I hadn't paid close attention to.

 

[Chrispy]

I suspect that sensitivity rating is over-stated

 

[Doodski]

I suspect that sensitivity rating is over-stated

It's really high! I doubt it too but they say it's so.

 

[Chrispy]

That's all I got: sing - was a comment on a forum addressed to me. Plus my realization, over time, that the Moon was not able to drive the speakers well. Think of it as prompt that made me ask a bunch of questions and educate myself on things I hadn't paid close attention to.

You could well use more power if listening at higher levels/longer distances....

 

[luxmatic]

I had used the Moon to drive the speakers as the Denon could only power 9 speakers, but supported 11 when you have an external amp.

 

[Doodski]

Could it be that with that snazzy tweeter they don't need to pad it down and waste energy and the result is a very efficient speaker?

 

[luxmatic]

Extremely loud isn't the goal. Just want to make sure the speakers are fed appropriately for music and occasional theater use. I mean, they are good speakers. Want to enjoy them.

 

[Chrispy]

I had used the Moon to drive the speakers as the Denon could only power 9 speakers, but supported 11 when you have an external amp.

Generally if using an external amp I'd look to just power the front two and with significantly higher power than the avr (keep in mind a doubling of amp power is only a 3dB spl advantage), particularly for listening in 2ch mode.

 

[Chrispy]

Extremely loud isn't the goal. Just want to make sure the speakers are fed appropriately for music and occasional theater use. I mean, they are good speakers. Want to enjoy them.

Extremely loud may be more a speaker limitation, but as I noted, a doubling of power is only a 3dB spl advantage otoh.

ps Keep in mind they are rating nominal impedance of your speakers at 6 ohm, so it may significantly spend time at 4 ohm or lower....so an external more powerful amp may be an advantage (especially over a very limited 75wpc at 8 ohm amp).

ps looking at the Simaudio spec, it's only 50wpc at 8 ohm in any case. Just not a very powerful amp, your avr can do better.

 

[Doodski]

In hearing tests that I've done up to about a quality 130 W/ch is noticeable from a 40 or 80 W/ch amp. After that it gets more difficult to hear the difference. Your receiver is not a top shelf amp low impedance drive amp but with the efficiency (?) of these speakers it should be capable and able for up to loud listening levels with the 90Hz cutoff for the subwoofer. I would use the Denon for awhile and see how it runs in your room.

 

[Keith_W]

The first thing to find out is whether it is the speaker or the amp that is distorting. The best way to find out is to measure the output of the amp at the speaker terminals, but I suspect that you (like many of us) may not have this capability. The next best thing is to look at your VU meter or clipping indicator if you have one. Otherwise, the last recourse would be to borrow a more powerful amp and see if the clipping goes away. Make sure you take note of the volume of the output (with a downloaded SPL meter app on your phone) before you do this though. Remember that doubling the power of the amp gives you an extra 3dB of volume.

Speakers might have crazy impedance swings around the bass region so some amps might easily run out of juice, so it is quite plausible that it is your amp that is clipping. The best way to solve this problem is to add subwoofers and high pass your main speakers, rather than add a more powerful amp - although doing both may be necessary.

 

[mhardy6647]

I think the impedance and phase curves would be helpful to assess what the heck might constitute a "sing-worthy" amplifier for these loudspeakers.

If they are fed, say, orchestral music, and they are found to sing... something's amiss, I'd opine (with, of course, the exception of, e.g., Beethoven's ninth symphony -- but even then, only sporadically should they sing).

 

[kemmler3D]

If you're hearing distortion and you like to listen "really loud" then the amp could be at fault. Find a rough SPL and track that noticeably distorts, try and borrow a more powerful amp, and then see what happens.

 

[Chrispy]

If you're hearing distortion and you like to listen "really loud" then the amp could be at fault. Find a rough SPL and track that noticeably distorts, try and borrow a more powerful amp, and then see what happens.

A much more powerful amp, considering a doubling of power only is a 3dB spl advantage....

 

[Galliardist]

WIthout some measurements, this one's a bit hard to sort out. I have an i-1 that I used for years and it's an OK amp, measurements in various places tell me it's around 65 watts into eight Ohms and 100w into four: perfectly good for the tweeter, but the bass looks like it needs a lot more power just from the design, and that will be the case even with the sub.

So move on from the i-1.

If we assume low impedance in the bass as well, and that would hardly be a surprise, I suspect the Denon may not be any more suitable to drive those speakers. I also suspect that mating them into a multichannel setup with a quite different centre speaker will disappoint, but this is going off comments made about broadly similar designs elsewhere.

Still, I'd try the Denon on its own in the first instance and see if things still distort at levels you want to listen to. If it does still distort, then add more powerful amps. You could ask ESS for fuller measurements, or at least to confirm what and where the minimum impedance is, and take it from there.

 

[GD Fan]

Maybe buy an amp with a generous return policy? Either a class A/B from a major merchant such as a Rotel 1582 or a class D if any have trial periods.

 

[JLGF1]

when my son came to me a few days ago and said my speakers were distorting with some heavy organ track he was playing.

Yeah, I wonder if your son was using some pipe organ tracks as a (deep bass) extreme torture test. Which may not (I would have to assume not unless told otherwise) be indicative of the typical music you listen to. ie that could have been a misleading/not-really-meaningful test unless you listen to a lot of pipe organ music. I agree with others that adding self-powered sub(s) and high-passing the main speakers would probably make a better next step (imo) than a bigger amp which could always be added later if necessary.