Sierra-2s with an 8 watt single-ended triode amp?

[justthinking]

Of all the speakers I'm looking at the Sierra 2s have the lowest sensitivity. Just trying to figure out if they should remain in the mix or if I need to exclude them for that reason.

How good is Sierra-2? Maybe my story will help you make the decision to give it a try

Before I heard Sierra-2 at Ascend's office last August, I shuffled through a bunch of speakers looking for the perfect pair for my 2 channel setup..

The list includes MA RS1 & GS10, KEF IQ3, R300 & LS50, Paradigm Studio 20 & Signature S2, Focal Aria 906, B&W CM6S2 & 805D2, ML Motion 35XT, Totem Element Ember & Fire some I did in store audition while others I had them in my room for extensive in home listening

At the end, I went with a pair of 805D2 as I thought I have found the speaker for my taste and was really happy with them

It all changed last August when I was traveling down to Southern California and decide to finally listen to these Sierra-2 I heard so much about. I spend about 2 hours at Acend's office listening to Sierra-2, visiting their warehouse and assembly/test area and chatted with Dave, I was so impressed with what I heard I ordered a pair of S-2 shortly after

Once I have the S-2 home, I was truly amazed by how good they are, it is a toss up between the S-2 and 805D2 as far as overall performance in my book with S-2 comes out on top in some area and 805D2 holds the edge in others, consider 805D2 sells for more than three times of S-2, it is really astonishing what Dave was able to accomplish with the RAAL tweeter and custom SEAS woofer

[davef]

I've been intrigued by Ascend speakers for a few years but my stereo system upgrades sort of took me on a tangent that now might not be compatible with 87dB speakers. I'm currently running 300b tube based single-ended triode amp and pre-amp separates (DIY kits thought Bottlehead).

However, through 91dB monitors (Energy RC10) I'm now getting surprisingly good results. I have all the gain I could want/need in my modest listening area (~8' listening position from speakers). I'm even pleasantly surprised by the amount of bass I'm hearing from these 6" woofers that wasn't there when powering the Energy speakers through my Denon AVR. I've even crossed a future 0.1 or 0.2 subwoofer package off my upgrade list.

Originally I thought my upgrade path would next have to be to higher sensitivity speakers but now this has me thinking. Might Sierra 2s be back in the running? Has anyone tried powering Sierra 2s through a low watt tube amp?

Hi jmac2000,

Although Energy might list the sensitivity of the RC10 at 91dB - in all actuality, they are not even close to this. There are many ways manufacturers fudge these numbers. The proper way to measure / publish sensitivity is by listing the speaker's sensitivity as measured anechoically.

As measured at the NRC, the Energy RC10's anechoic sensitivity is 85.5dB. The Sierra-2's sensitivity is 86dB (anechoic). If you are OK with the output levels of your RC10 with your current amp, you will be fine with the Sierra-2 as well, (Sierra-2 actually have slightly higher sensitivity)

Here is a link to the RC10's true sensitivity measurements:

http://www.soundstagenetwork.com/mea.../energy_rc_10/

Hope this helps!

[N Boros]

Hi jmac2000,

Although Energy might list the sensitivity of the RC10 at 91dB - in all actuality, they are not even close to this. There are many ways manufacturers fudge these numbers. The proper way to measure / publish sensitivity is by listing the speaker's sensitivity as measured anechoically.

As measured at the NRC, the Energy RC10's anechoic sensitivity is 85.5dB. The Sierra-2's sensitivity is 86dB (anechoic). If you are OK with the output levels of your RC10 with your current amp, you will be fine with the Sierra-2 as well, (Sierra-2 actually have slightly higher sensitivity)

Here is a link to the RC10's true sensitivity measurements:

http://www.soundstagenetwork.com/mea.../energy_rc_10/

Hope this helps!

Dave,

Soundstage does an excellent job with their measurements! Not only do they do listening window, impedance and phase, but they also do the THD+ noise and the deviation from linearity. I did a little digging and it looks like the CBM-170s and the Sierra 1s were measured by Soundstage. The THD + noise curves are nice to look at since you can then match the main speakers well with the subwoofer in terms of output capabilities, right before higher distortion sets in. Audioholics has a table to help us get an idea of how much THD we are getting at various frequencies on the graph, using the table halfway down the page here: http://www.audioholics.com/tower-spe...t-measurements We more of less know the THD measurements for the Rythmik F12, since it should measure pretty close to the DIY Rythmik here: http://www.hometheatershack.com/foru...ealed-56l.html. We know how the Rythmik FV15HP measures here http://www.data-bass.com/data?page=system&id=51&mset=49 (as well as many other subwoofer brands on data-bass). We could then use the Rythmik table to compare ported models to the FV15HP and sealed subs to the DIY F12:

At 20 Hz, our subs vary in their maximum output capability. The output at 20 Hz is shown relative to F12.

F12: 0db (baseline)
F8/FM8: -1.5db
L12: -1db
LV12R: +2.5db
L22: + 4db
LVX12: +4db
E15HP: + 4db
F15HP: +4.5db
FVX15: +6.5db
FV15HP: +9.5db
F25: +8db

This gives us a pretty good idea of how each Rythmik sub will measure, more or less. Data-bass provides even more helpful graphs, since they give THD+noise for each subwoofer at 5dB increments, so we can really get an idea of how much the subwoofer has before it doesn't have much more clean output. The only problem is that we don't know how the Ascend lineup will measure in terms of THD + noise to match up with a Rythmik sub. Do you know know the Sierra 2 will measure as far as THD + noise? I'm mostly interested in at 75dB and 95 dB, since reference volume at home for movies is 75 dB continuously with up to 95 dB peaks. Reference volume is the loudest that I listen to movies from about 2.5 or 3 meters away, so I would be happy is I knew how much distortion there was at 2 meters like things are usually measured. Like I said before, I want to make sure I'm not potentially putting lots of distortion through the speakers and to be able to find a Rythmik sub that can line up in terms of output capabilities before distortion sets in.

[jmac2000]

Hi jmac2000,

Although Energy might list the sensitivity of the RC10 at 91dB - in all actuality, they are not even close to this. There are many ways manufacturers fudge these numbers. The proper way to measure / publish sensitivity is by listing the speaker's sensitivity as measured anechoically.

As measured at the NRC, the Energy RC10's anechoic sensitivity is 85.5dB. The Sierra-2's sensitivity is 86dB (anechoic). If you are OK with the output levels of your RC10 with your current amp, you will be fine with the Sierra-2 as well, (Sierra-2 actually have slightly higher sensitivity)

Here is a link to the RC10's true sensitivity measurements:

http://www.soundstagenetwork.com/mea.../energy_rc_10/

Hope this helps!

Thanks Dave! Very helpful information.
Jamus