How important is the efficiency of a speaker to you?


I went to an audio meeting recently and heard a couple of good sounding speakers. These speakers were not inexpensive and were well built. Problem is that they also require a very large ss amp upstream to drive them. Something that can push a lot of current, which pretty much rules out most low-mid ( maybe even high) powered tube amps. When I mentioned this to the person doing the demo, i was basically belittled, as he felt that the efficiency of a speaker is pretty much irrelevant ( well he would, as he is trying to sell these speakers). The speaker line is fairly well known to drop down to a very low impedance level in the bass regions. This requires an amp that is going to be $$$, as it has to not be bothered by the lowest impedances.

Personally, if I cannot make a speaker work with most tube amps on the market, or am forced to dig deeply into the pocketbook to own a huge ss amp upstream, this is a MAJOR negative to me with regards to the speaker in question ( whichever speaker that may be). So much so, that I will not entertain this design, regardless of SQ.

Your thoughts?

128x128daveyf

@lonemountain Brad, I think one of my points is that the free choice of speakers and amplifiers are connected. IOW, a highly inefficient speaker is going to severely limit your amp choice, and conversely a very low powered amp ( or an amp with minimal current drive capability) will also be a non-starter with a speaker that cannot be properly driven by said amp. Therefore, picking out either one of these designs invariably leads one down a path, that may or may not be where one wants to go.

@daveyf

One of my points is that this very issue of "what amp is enough?" is based around very fuzzy poorly defined/poorly understood info about speaker efficiency, Would you call a 90dB SPL 1w/1m speaker efficient or not?

Brad

@lonemountain Brad, you make an interesting point. While most folk would consider your example as efficient, the other variable, which could effect how an amp interacts with this speaker is how the load the speaker presents varies across it’s frequency spectrum. For example, I know of a very good metal box speaker that has specs similar to what you post ( not quite as good, about 89db vs.90db), but this speaker drops down to less than 1 ohm in the bass regions between 35hz and 55hz. Therefore, I’m not so sure I personally would consider this speaker as an efficient speaker, or easy to drive.

Asking the question "What is efficient enough?" brings up mutiple challenges.  the first being hardly anyone listens much over 90dB SPL!   

I was at AXPONA this weekend and in our room we are demong ATC.  I meassuredIf  the SPL when things got "loud" : it was around 92dB SPL.  If the 1w/1m spec of a passive was 90dB, it would require less than 2 watts to get that speaker to play at 92dB 1M.  If it was 86dB 1w/1M it would require 4 watts to get it to 92dB at 1M!  92dB SPL is very loud for many of us, most audiophiles wouldnt even want it at 90-92dB SPL in their living room or listening room. 

It appears in reading this thread that most would agree that above 90dB 1w/1M is efficient and 86dB 1w/1M is "not efficient". We need 2 watts to get our 86dB speaker to 89dB SPL, which is indistinguishable from 90dB to most of us.  This 2W instead of 1W is really a critical issue and one that drives a purchase?   

My point is that very very few of us listen at 92dB SPL. The argument for an "above 90dB 1w/1M speaker" is not a relevant argument as no one even wants to listen that loud.  90% of our listening is WAY under 90dB SPL.  If this is true, why is 90dB+ 1w/1M efficiency such a important spec that we all need to pay attention to it?

Brad