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This must have been asked before but I'm a lazy butt.
Is it +90db @ 1 watt, +95db, 100db or more?
Thanks in advance.
"If people don't want to come, nothing will stop them" - Sol Hurok
Follow Ups:
OK, maybe 5 watts.
I'm thinking 96dB or better but would have to include single driver speakers without x-over and an easy load (8+ ohms?) would qualify even in the low 90's dB-wise.
But then I ran Goodmans of England drivers (95dB maybe on a good day?) in open baffles with flea-powered amps (3 Watts or less) and they were perfectly happy.
Save your money and just get a Danley SH-50 and be done with upgrades. It easily meets all 10 of his criteria for high fidelity.
Edits: 07/22/17
Thanks!
Love the handholds.
Pro Audio.
Wonder how much. Sure isn't that big, physically.
"If people don't want to come, nothing will stop them" - Sol Hurok
I'll let the more knowledgeable inmates pontificate on this very complicated subject.
I'll go low tech and say that my personal experience is that at 100db (and at least a minimum of 8ohms) "things" start to get way more exciting: dynamics, inner detail, presence, amplification choices.
I agree with you about 100dB/1w/8 ohms. Through many many different speakers over decades about 100dB seems to me to be the point where things come alive.
Ah Hah! The TRUTH comes out on our forum!
Thanks for the accurate assessment, Lokie!
Hi-Eff does require some large and very good cabinetry.
There's more to this, however.
Really good Hi-Eff drivers are designed MUCH better, machined
MUCH better, and made from better materials, and are heavy weights.
Most medium or low-eff speakers-- many of them VERY expensive,
are using relatively CHEAP drivers.
These cheap drivers are CHEAP!
JUST LOOK at those CHEAP drivers in your Mega-Buck speaker!
-Dennis-
(nt)
i.e., "pretty sensitive".
I' m thinkin' anything less than an honest 100 dB @ 1 meter @ 1 watt ( and a benign impedance curve) need not apply ;-)
Anything's worth a try but SE 45 is gettin' down towards true fleapower.
all the best,
mrh
Maybe a 300B set amp
Alan
Well around 92dB 1w 1m is approximately 1% electro acoustic efficiency and 102 would be around 10%, 112 would be 100% (impossible). What makes this harder to gauge is that the above assumes a source with no directivity and directivity can raise the on axis sensitivity without rising the true efficiency.
If this wasn't complicated enough, then one can add horns to the mix where it IS possible to get say 40 or 50 or more% true efficiency BUT only in a relatively narrow range and there simply aren't any compression drivers which are efficient up high. If one wants to end with flat response, it is the efficiency at either end of the spectrum that governs what you have in the middle.
Hope that helps
Tom
What about the Fostex "supertweeters" (T90A, T900A, etc.)?
On paper at least, they seem to be sensitive & to have reasonable output "up high"?
Or are you specifically referring to broad bandwidth treble horns & drivers to support them, Tom?
Also, I do recognize that mfgr. specs are sometimes, shall we say, optimistic. :)
all the best,
mrh
Well lets say one wanted to use that driver as part of a broad band system.
IF you wanted "Flat response" on axis then you could get it between about 3K and 20 K with an on axis sensitivity of over 100dB.
Flat response is derived by attenuating the mid band down to the upper and lower limits of the desired bandwidth.
At the same time, without knowing the directivity, one cannot know the actual efficiency, the best one can get then is the on axis sensitivity.
Directivity makes the difference between a bare 75W bulb and a high beam headlight
nt
all the best,
mrh
Thanks, tomservo.
"If people don't want to come, nothing will stop them" - Sol Hurok
Efficiency is more than a sensitivity rating. A 95dB sensitive speaker that sits between 8 and 12ohms full frequency response is a FAR easier speaker to drive than a 100dB sesitive speaker that dips to 2ohm from 20hz to 120hz. Most SET amplifiers will wheeze and puff on the latter speaker and will have zero issues with the former.
The LS-3/5a is only 82dB sensitive but sits 11-16 ohms. So a SET has no problem with these speakers. And while you are limited by volume the speakers can only handle a max of 50watts so yoy are limited by volume regardless of the amp you choose.
The title of the forum should probably be called high sensitive not high efficiency and then there should probably be levels like high senstive 92dB-96dB and very high sensitive 97-102dB and ultra high sensitive 103dB+
I think some manufacturers suggest efficiency based upon ratings for the drivers utilized rather than testing the assembled whole. I had a pair of speakers rated at 90 dB but found that a minimum of 200 watts was needed in a medium sized room with playback levels averaging in the low 80s.I believe that was for two reasons. One, as RGA explained, was an impedance curve which dipped below 3 ohms at two different frequencies. The other was a very complex 1st order crossover designed for time/phase considerations. A friend brought over a 50 watt amp he'd built to test with those speakers and if fell flat on its face. Normally 50 watts should work with 90 dB I expect.
"The piano ain't got no wrong notes." Thelonious Monk
Edits: 07/23/17
I have 90dB Audio Note AX Twos. 7 watts is recommended. I ran my OTO on AN Js for 13 years. The OTO measures 4.2 watts undistorted. I could play AC/DC or Black Sabbath or Nightwish etc without any problems or having the system puff or wheeze. The AN J is 92.5dB in corners and 89.5dB free standing.
I think people need to simply try the stuff out. AN is likely the biggest selling SET maker globally and their matched speakers are around 90-97dB. And most of their amps are under ten watts. So to me it's one thing to discuss specs and measurements but the ear test is the final and only test that counts.
Now it could be their amplifiers are simply way more robust than average too and I did compare the Kit One to a 300b Cary. The KIT one had vastly better deep bass control. So this is not all about the speaker itself.
Well here's the real complication ... :)A 96 db /m/8 ohm @2.83V Speaker is less efficient than a 96db/m/16ohm @2.83v speaker but they both have the same sensitivity ...
How's that for magic ...!!!
Regards
PS , those AN sensitivity numbers were already debunked and are fake news ...
Edits: 07/27/17
so trials are absolutely called for.
"The piano ain't got no wrong notes." Thelonious Monk
Thanks, RGA.
"If people don't want to come, nothing will stop them" - Sol Hurok
At least, that seems to crop up more often than other numbers.
For what it's worth, that's about 2.5% efficiency; it's also a good minimum for a 2A3 SET amp (good for a bit less than 4 watts).
I wouldn't kick a 95 dB @ 1 meter @ 1 watt loudspeaker out for eating crackers in bed, you know?
:-)
I also wouldn't pre-judge the combination of an amplifier & loudspeaker without giving a listen first.
all the best,
mrh
"I wouldn't kick a 95 dB @ 1 meter @ 1 watt loudspeaker out for eating crackers in bed, you know?"
Precisely what I just acquired.
Wondering if I could be a member of the "club."
Thanks.
"If people don't want to come, nothing will stop them" - Sol Hurok
nt
all the best,
mrh
:^)
And my hifi (and my outlook on hifi) has benefitted greatly from your contributions.
This seemed like -- not a bad time -- to say thanks.
all the best,
mrh
It's really fairly simple:What are your goals?
Do you want to have your speakers small in your room? That's NOT GOOD!
Are you subject to WAF? (wife acceptance factor).OR would you like to have a decent facsimile of a real audio event appear
in your listening area?Would you be satisfied with only correct tonality? (many are).
OR would you like to sample the intentions and attitudes of the musicians
on your recordings?Do you value correct event timing and having the vertical components
of your speaker's output in the right place, or are you satisfied with slicing music into separate horizontal stripes, (caused by vertical stacking of drivers) thereby entirely destroying any possibility of reproducing a real musical event?Do you wish to sample the powerful dynamics that are on all good
recordings, or are you satisfied with amplifiers that put out lots of power but won't give you the dynamic picture in real time?The ultimate in all of these things, and more, is MINIMUM WATTS, and
MAXIMUM speaker efficiency from a POINT SOURCE ONLY. This, of course, demands speaker cables and interconnects that are extremely efficient
also.A minimum watt amplifier must have a maximum power supply to
work. It must be clean, but much more importantly, it must charge
and recharge fast enough to complete one musical event before the next one comes. It must also sort-out many musical events all happening at
once in order to be truly convincing.Only you can answer these questions: what do YOU want? How far will you go before you stop improving your setup?
-Dennis-
Edits: 07/21/17 07/21/17
that would be appropriate for almost any audio board in these parts.
Plus there's no real answer to his question.
"Once this was all Black Plasma and Imagination" -Michael McClure
"A minimum watt amplifier must have a maximum power supply to
work. It must be clean, but much more importantly, it must charge
and recharge fast enough to complete one musical event before the next one comes. It must also sort-out many musical events all happening at
once in order to be truly convincing".
This is not simplistic or convoluted.
I guess it was a stupid question.
Thanks for your considered response and your ten questions.
I think I could never afford a system that you are suggesting and so it becomes a non-starter.
"If people don't want to come, nothing will stop them" - Sol Hurok
Both depend on who you ask. A few will say 90 or 93, some will say 95 or 98, but others will insist over 100 or approaching 105. The correct question should be, "what is high enough efficiency for X?" with X being your preferred type of music, listening volume, amp typology and tube complement, listening room size, etc. And, don't forget out the impedance curve over frequency of the speakers as well.
Good luck on whatever your quest might be.
No quest. Just thought I might get a consensus from this forum.
Now I see it was not a good question but thanks for your response.
"If people don't want to come, nothing will stop them" - Sol Hurok
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