Eleonida, excellent afvice, IMHO!. A few rules of the thumb waiting for cognoscenti. The Ohm load doubles (or halfs, as it were) per 3 db rating. I would pounce on 91 vs 88 dbs (the difference could mean a bigger amp, try getting THAT past yr wife -- or mine, for that matter). Resistance plays with the sound spectrum and average 8-4 ohms is, usually, happily dealt with by most amps. It doesn't compensate in the way I think you think it does (i.e. make things easier, low load but low resistance, so my amp loses on one and gains on the other). Beware of low resistance, it requires mamouth efforts to control... in other words, it'll suck the juice (the life) out of yr amp.
Concluding, if U like yr music at reasonable levels and, worse still, listen to classical, go for sensitive -- 89 upward -- speakers, and check out their lowest resistance rating. Most modern speakers play around a minimum of 4; yr Pass can easily match that. |
While i don't know know what all the reviews or even Pass Labs will tell you, my experience with Nelson's older designs tells me that your amp should easily deal with lower impedance loads. While his amps may not have as much current as some of the other big boys, they don't "flinch" when put to the test like many other reputable brands that shall remain nameless.
One thing to keep in mind is that the lower you go on speaker impedance, the lower the damping factor will be. If the speakers use a BIG motor structure ( large voice coil & magnet assembly ) or are relatively reactive loads, you can expect less than the best in terms of control and definition.
Since you did not mention room size or types of music that you like to listen to, we're kind of guessing here as to what will work acceptably. As such, shoot us more info and you might get some better info.
I'm assuming that you don't normally try to "raise the roof" since you selected an amp that was rated at 30 wpc. With that in mind, something that is at least 87 db's should be acceptable with something in the low 90's being easier on the amp ( in most cases ). Only problem with this is that many speakers that are more sensitive use some type of bass loading ( port, passive radiator, bass reflex, etc..). As such, they sacrifice bass definition and timbre for extension and "better numbers". Like anything else, there are trade-offs involved in everything and not knowing your preferences makes it difficult to make a valid suggestion. Sean
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Eleonida: Good questions, but no hard fast answers. I have tried out some speaker/amp combos that looked good on paper as far as the manufacturers specs for the equipment went, but that were a total bust. I am running 90db, 4ohm speakers with a 7watt per channel tube amp and the low ohmage does not seem to add the dreaded flab to the bass response, it sound great. I tried running a pair of Linn Tukans with a 50 watt/channel (70+ in reality and 140+ into 4 ohms per the review specs) SS amp and it would not control the low end of the 4 ohm Tukan's. The same amp ran a pair of Reynaud Twins (also 4 ohms) fine. Either the specs are wrong or there is more to it than the numbers. If you can, go for 90db (which is fine) or more (it's a nice range for many amps and rooms), but try to home demo the speakers before you purchase them. If this is not possible then hookup with fellow listeners that have your amp and see what has worked for them. Perhaps list your complete system (with the room size and your current speakers) in this or a new thread and list what you would like to improve. I can't imagine that mismatches like this are commom place, but they do happen and I would hate to see you stuck with one, especially with your wife watching/hearing. I purchased my amp (not my speakers) without an audition, but did so after checking it out with other owner's that I located on the web and everyone else that ever wrote a review or commented on auditioning it. |
I have a Pass Aleph-3 and use Paradigm Studio-80's They are 92dB 8ohm.My room 20X 15X 8 I play lots of rock and I get more volume than I need.I does play loud.I know loud is a opinion, but in my opinion, most would say it plays loud if they heard my system.I wouldnt go below 90 dB's with the Pass.I can hear the difference between 1 dB up or down in a speaker. |
The Aleph 3 loves the ProAC Tab 50 sigs. Very musical. |
I'm on the hunt for a speaker upgrade. My current amp is, well, modest (30 wpc Pass Labs). I've been advised to confine myself to sensitive speakers (more sensitivity in the house has cheered my wife). What range am I looking for, and how big a difference is there in a couple of db's, say 89 and 91? Also, if I drop down in resistance (8 to 6, or even 4 ohms), does this compensate, or do sensitivity figures already take resistance into account?eleonida04-07-2001 10:26am~~~~~~~~~~~~~~~~~~~~~~~ Whoever gave you the advice to seek out High Sensitive speakers , knows his stuff. I have yet to read the ONLY 3 posts to your Q. Which firgures around here. Most folks here do not have a clue what sensitivity means, Ohms, well I am not sure what that means , but can say wide band/high sens speakers are always higher ohms. Yes each db gain or loss makes some difference. The cutoff twix low efficient and high efficient IMHO is 91db. 90db represents the high mark in xover designs, and wide band /FR lowest db mark is 91db. That is to say, all FR/WB start at 91db and rup up past 100db. The higher the db level = the superior the wide band. = The higher up the db you go, the more expensive is the driver/speaker. High sensitivity comes at a price. So now let me see the 3 lonely responses to your OP |
gregm3,252 posts04-07-2001 6:19pmEleonida, excellent afvice, IMHO!. A few rules of the thumb waiting for cognoscenti. The Ohm load doubles (or halfs, as it were) per 3 db rating. I would pounce on 91 vs 88 dbs (the difference could mean a bigger amp, try getting THAT past yr wife -- or mine, for that matter). Resistance plays with the sound spectrum and average 8-4 ohms is, usually, happily dealt with by most amps. It doesn't compensate in the way I think you think it does (i.e. make things easier, low load but low resistance, so my amp loses on one and gains on the other). Beware of low resistance, it requires mamouth efforts to control... in other words, it'll suck the juice (the life) out of yr amp.
Concluding, if U like yr music at reasonable levels and, worse still, listen to classical, go for sensitive -- 89 upward -- speakers, and check out their lowest resistance rating. Most modern speakers play around a minimum of 4; yr Pass can easily match that.
~~~~~~~~~~~~~~~~~ Excellent post, Now i clearly understand the ohm thing. Yes FR/WB/High sens speakers are amp friendly = higher ohms vs the xover design. 89db+.. I'd suggest 91db is the cut off point. All FR/WB/ high sens speakers, all specs start 91db ++ 89db is still xover low efficient type. **and wosre still if you listen to classical music*** Yes classical music, demands/equires higher sens speakers. xover designs fail at classical due to lower sensitivity. Very glad you posted the classical music as a drain on efficiency of a amplifier. |
If you can, go for 90db (which is fine)
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Close but no cigar
90db is still in xover territory
91db is the lowest acceptable rating for a true wide band/higher sensitivty speaker. |
system.I wouldnt go below 90 dB's with the Pass.I can hear the difference between 1 dB up or down in a speaker.
~~~~~~~~~~~~~~~~~
Yep
1 db makes a difference.
My Seas Thors at 87db, are unacceptable for classical music, And this goes for all dome tweeters as unacceptable to voice classical music due to its high demands.
xover speakers usually are below 90db , rarely if ever 91db, making xover speakers unacceptable for classical music.
If you like jazz only, wel then xover designs wil work for you.
But lets say you like both genres, Well now you will need 2 sets of speakers,
Or just get a higher senstivity speaker which can voice both genres.
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eleonida, to answer your question; as a rule of thumb efficiency drops with impedance. Your amplifier's power increases because current flow increases as long as your hand can pass the current.
As another rule of thumb, any high end system should be able to hit 100 dB. This assures you can handle all peaks gracefully. Most of us never listen this loud. Power doubles with every 3 dB. So if you have a speaker with 87 dB/1 watt/meter, 90 dB requires 2 watts, 93 dB requires 4 watts, 96 dB 8 watts, 99dB 16 and 102 dB 32 watts. This is wonderful except nobody listens to their speakers at 1 meter. Depending on the room sound pressure levels can be an easy 6 dB down at the listening position. So your 87 dB/1 Watt/meter becomes an 81 dB/watt/meter speaker and with 30 watts you are only going to make it to 95dB. 95 dB is a reasonable loud level that many rockers will listen at and if you do with 30 watts you will be clipping the peaks and the sound will be distorted. So, with your amp you should have speakers with a sensitivity of 93 dB/watt/meter or above and there are many available such as the Klipsch Heritage series speakers. If Your Class A Pass amp is a wonderful sounding amp and will drive a Klipsch loudspeaker to very pleasing levels without clipping. You can't expect rock concert levels out of it but those levels damage hearing. If a system has adequate low end you do not need to play at those levels to get the effect of being at a live concert. Unfortunately, most systems do not but, that is another subject. |
