Aspen FR30 - How much power required?

I’m very intrigued by the new FR30. However, the power required is grossly understated in the specs. 100-600w?! No way.

87dB sensitivity is very insensitive. At 4 Ohm you’ll need at least 1500W to power these brutes to 105dB peaks (at 15’ distance to listener). Add some headroom to the amp and you’re looking at about 2000W into 4 ohm. I don’t know many amps that can do that. I think you will need 4 of PS Audio’s monobocks to properly power these.

Use an online calculator to determine how much you’ll need, based on your listening position.

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Analog Domain would fit the bill🙂

That said, I once drove my 88db/4 ohm Magicos with 90 (Accuphase) watts to deafening levels in a 22’x18’ space. Not debating the science but no way a pair of BHK’s will not make these speakers sing and sing loud if that’s your thing…

Very interesting data, I enjoyed your post!



Good thing PSA makes 1200W-into-4ohms poweramps that sound GREAT AND are affordable; I sure love mine… :grin:


87dB/88dB is average sensitivity.

105 db is exceedingly loud, and a listening distance of 15’ is far in most circumstances.

Plugging in 80dB as a common listening loudness (a survey hear averaged 75dB or so) and a more typical 8 foot listening distance one needs only 1.2Watts. :slight_smile:

An insensitive speaker is the MBL Radialstrahler 101E Mk.II with a sensitivity of 81dB. But a PSA amp will handle these speakers just fine.


Hi Elk, I respectfully disagree- 87 dB is not really “average” sensitivity. But then my horns are about 104 dB, so I’m not that familiar with average ranges. It doesn’t matter though, what matters is having sufficient power to drive these speakers properly.

85dB+20dB (for peaks) is not exceedingly loud. It’s the recommended output level for a world class system (Just ask Paul :wink:).
But it’s not only 105dB, it’s that your amp has to power this cleanly, without clipping or distortion. Most systems cannot achieve this. But when you’re spending this much, your system should be able to.

Great! Yes, if you’re sitting no further than about 14’ away from the FR30, you should be fine with these.

Correct, on both counts.

Designing speakers to such listening specifications would not result in a “mainstream” product, IME/IMO.


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Not correct. It’s peaks of 105db, not continuous listening at 105. 85dB + 20dB headroom is the norm for any world class system. Ask Paul, and many others. It’s not really debated.
When you go to a classical symphony, you will hear peaks at least at 105dB. If you’re after reproducing a live concert, you must be able to hit 105 db, at least, cleanly and without distortion. Anything else is not really “HiFi”. Sorry to say.

For what it’s worth, my KEF reference 1’s sensitivity is 85db, I do have a pair of REL subs, but my BHK 300s drive the KEFs plenty loud. I have never gotten close to maxing them and I do sometimes play my system nice and loud….don’t know about 105db, yikes.


What is the real dynamic range of your source material? I listen at 83 dB “nominal” but I can say I ever see much above 90 dB peaks from that, or no more than 10 dB at best dynamic range from the nominal levels with a wide variety of material. I wish I heard more dynamics but I don’t. I seldom see 95 dB peaks at 12 feet listening distance.

I use 88 dB sensitivity T+A Solitaire 1000-40 Carbon speakers and the peak hold LEDs on the M40-HV mono amps stick at 100 dB maximum worst case. Of course, If I get a burr up my behind and play Nickelback, All the Right Reasons, they STICK at a maximum wattage and stay there…so compressed! Music that is far more dynamic and less compressed SEEMS louder on peaks as the contrast is so vivid.

My amps can deliver 850 watts into 8 ohm and 1200 into 4 but I could rent the extra power out.

My Vandersteen Quatros with a DNA-225 watts played plenty loud and they are a 87 dB SPL rated speaker.

Who here is shooting for 105 dB to “qualify” as hi-fi? That’s a new requirement in my book. I can’t say I’ve ever seen 100 dB EVER in my house. No criticism, just curious.

The physics and the practice don’t line-up for most of us. Yes, every 3 dB is twice the power but all sorts of things change what and how that power hits your ears. I also agree that a wide dynamic range is so much better sounding and would need far more power as you add to the average SPL. I just don’t see much music mixed that way. If a source is dynamic, the SPL contrast seems to satisfy more than just how loud the peak is.

EDIT - I looked at me LED peak meters and thought 10 watts was 100 from across the room. So I’m a power nit-wit and a tiny user of power. Yes, yes, yes even with Nickelback playing I see 10 watt peaky or JUST above that to maybe 90-95 dB SPL. This is in a 2000 square foot room about 12 feet away from the speaker.

If you are a head banger maybe 87-88 dB SPL speakers might be an issue. Not so much a 90 dB SPL headbanger though. 90-95 dB peaks seem plenty loud if the music is DYNAMIC. Compressed continuous 90-95 SPL is too loud.



This question has been answered many times. Real dynamics = the source you trying to replicate. And whether it’s a rock bank or orchestra, peaks can and do reach 105, even more. It’s not really up for debate :wink:

What do you mean by ‘I don’t see 100 dB’ in my system… how do you know? Maybe you’re getting too much distortion at <100 or your peaks are compressed.

The 85+20 rule is nothing new… Ask Paul, and many others.

My only point is this: if you’re going to spend close to $30k on a pair of speakers, make sure you have the amp power to drive them properly.

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Well, we can certainly agree on THIS point.


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Most people who are able to and would purchase the FR 30s
would also have the quality of amp necessary to drive the
FR 30s to a reasonable and comfortable level…

I know my JC5 could accomplish this easily…and certainly not
looking to listening with 100 db+ sound levels …my ears
are too valuable…

Best wishes

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I’m not suggesting listening at 100dB levels. I’m talking about peaks.
Next time you go to the symphony, set your iPhone to record the dB at your listening position. You’ll be surprised what peaks it records!

Sad to hear they FR 30’s are that low in sensitivity. I could not be happy with that as without tremendous power reserve dynamics would suffer.

Pretty sure that Paul and Chris discussed the sensitivity issue
and power amp requirements for the FR 30s, realizing that the speaker
sensitivity may restrict the market to large output sized amps.

Best wishes


The sensitivity rating certainly appears to be within the “normal” range for high-performance speakers.

The concerns expressed here baffle me a bit.



Under specifications in the Aspen literature, amplifiers from 100 to 600 watts are recommended. I’m not sure what all the fuss is about?

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Daren and Duncan with Chris have explained how low sensitivity numbers are a result of really good crossover networks and the makings of a good loudspeaker.
My Elacs are mid 80’s and a general consumer grade speaker that my Denon AVR drives quite nicely.
I think it’s a good thing.
I believe my DAW’s are also mid or high 80s FWIW. No need to bash the FR-30 as they are unheard in the marketplace yet.


Guys, I can tell you from first hand knowledge that the FR30s are easy to drive and you don’t need much more than 100 watts - a 200 watt amp’s more than good. Of course, more watts=more headroom so you can’t have too much.

The other thing to know is the FR30’s impedance curve is a near ruler-flat 4Ω and THAT makes a lot of difference. So many speakers have huge dips in impedance that it can trigger an amp’s protection even if you’re not overall using a lot of watts.

It’s an easy load.