15 ohm speakers yea or nay?

I just bought Falcon speakers that are 15 ohms. I have Harbeths that are 6 ohms. Both have the same sensitivity rating of 83db. I am using both with the same tube amps.

What has me scratchin’ my head is that the Falcons are much louder with the volume set the same on my preamp.

Any opinions on why a 15 ohm speaker would be that  much different than a 6 ohm speaker with the same sensitivity specs?






Efficiency and sensitivity are not the same. My speakers are JBL 4435 monitors and have a sensitivity of 96 dB SPL @ 1 watt @ 2 meters @ 8 Ohm and have an efficiency of 2.7%. See the JBL manual below specifications section, last page. As for the difference between sensitivity and efficiency see the link below JBL technical note first page section C. All three specifications, impedance, sensitivity and efficiency are important and must be looked at together to better understand their meaning and correlation to what you hear. Also, amplifiers produce more distortion in lower impedances then higher impedances. Hope that helps. 😎





@rodman99999 +2. Great article.

I would say Yea.  Because the only speaker that I know that has 15ohm and 83db spl ratings with the Falcon name attached is their Rogers LS 3/5a speakers.  After 40 years and many speakers have come and gone, I still love Rogers.

Now that you mention.  I do switch between 8ohm Quads with 86ish?db spl and the Rogers.  I don't hear any significant loudness between them with the same volume setting on the preamp. 

However, I did hear a hear a level difference when I went from a tube amp using the 16 ohm tap to the SS Spectral amp I'm using now.  I just figured it was the differing input sensitivity of the amps.

Why?  I don't know.  I just listen to the music.  I do use the Quads for large orchestral.  The Rogers for near field critical listening, smaller quintets, jazz or solo recordings.

If the Falcon speaker is their LS 3/5a, it has a minimum impedance of just over 7 ohms and Hi Fi News rated it as an 8ohm design. Also, it has a big peak in frequency response over 10k. Taking those aspects together, it might sound louder, partly through being optimally matched to the transformer tap and partly subjectively. It would be interesting to put an SPL meter on both speakers and see what it reads.

The Falcon Q7 are the speakers that I am using. They play much louder compared to my Harbeth P3 ESR!!

NEW! Falcon Acoustics Q7 “Complete@Home”LOUDSPEAKER SYSTEM

Falcon Acoustics is pleased to announce the re-introduction of the Falcon Acoustics Q7 “Complete@Home” Loudspeaker system. Designed by Malcolm Jones and sold by Falcon for many years, the updated Q7 features the same Falcon B110 and T27 drive units as used in the Falcon LS3/5a in a specially extended LS3/5a-type cabinet to produce an optimum Q=0.7 system with extra bass compared to the LSA3/5a (+2dB @ 50 Hz).

All you need is 1-2 hours to complete your own fully-specified loudspeaker system. Italian full “Production Grade” birch ply cabinets with veneered front panels and magnetic location for the cloth grilles. Falcon 23.2 factory-assembled pre-wired crossovers. No soldering required. All tools provided. An online Instruction Manual and YouTube video will guide you at all times.

The Falcon Q7 features matched pairs of Falcon B110’s and T27’s, a pair of factory-assembled Falcon 23.2 crossovers, and full Production Grade birch ply Italian cabinets in natural Walnut or Rosewood (regret Rosewood sold out for now) veneers. Made in the same factory as the renowned Falcon Acoustics BBC LS3/5a. Similar voicing to our LS3/5a but with extra bass extension.

Specially designed magnetic Tygan front grilles available.

Factory built options supplied built by Falcon, fully checked and tested are available.



2-Way Infinite Baffle (sealed box). Italian manufactured Plywood cabinet in 12mm and 9mm graded Baltic Ply Birch Cabinet. Natural wood Walnut or Rosewood veneer. Magnetic attached Cloth grille.

Drive Units Falcon B110 (5”) Bextrene Cone bass unit; 19mm ( ¾ ”) Falcon T27 Mylar dome tweeter. Matched pairs

Freq. response 60Hz-20kHz +/- 3dB

Impedance 15 ohms

Sensitivity 83dB/2.83V/m

Power handling 15-50W

Connector 4mm Custom-Designed nickel-plated binding posts

Dimensions(hxwxd) 309 x 190 x 230mm (+12mm for grille and binding posts)

Finish Natural wood veneer - Walnut

Weight 6.0kg each, 14 kgs per pair shipping weight.

Packing Pr speakers per shipping carton

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