I am trying to get a "feel" of how much power do you need for speakers. I've only built headphone amps so far.
Could you please:
1. tell me which speaker do you use (maybe a manufacturer link and effiency rating)
2. how much power does your amp produce?
Thank you very much
ps. I created the thread here as the amp i'm thinking of is a tube amp (thinking of SE but I can be swayed to PP if need be)
Could you please:
1. tell me which speaker do you use (maybe a manufacturer link and effiency rating)
2. how much power does your amp produce?
Thank you very much
ps. I created the thread here as the amp i'm thinking of is a tube amp (thinking of SE but I can be swayed to PP if need be)
Jarthel,
I use VAF Research DC-7 and DC-X from local Adelaide supplier.
These speakers are 95dB/W/m
I use them with the following amps:
Ultralinear Push Pull EL84 - approx 10W per channel (+10dB power)
giving 105 dB SPL at 1 metre max
Ultralinear Push Pull 6V6 - approx 8W per channel (+9dB power)
giving 104 dB SPL at 1 metre max.
845 SET - approx 20W per channel (+13 dB power)
giving 108 dB SPL at 1 metre max
The maths:
dB (power) = 10 log (output power).
Add that to the speaker efficiency in dB/Watt/metre to get max Sound pressure level (SPL) at 1 metre.
And as Eli said in his post you want a minimum of 102 dB SPL for a typical sized room).
Thats why you see you see the guys who build those little "Flea Power" SET amps of around 2 watts use 101 dB/W/m speakers with them.
Aside: The reason I like the VAF speakers is that they have really good self damping characteristic and therefore sound good with low damping factor valve amps. That means I can design the amps with very little or no global feedack because, within limits, the output impedance of the amp is not a problem.
Cheers,
Ian
I use VAF Research DC-7 and DC-X from local Adelaide supplier.
These speakers are 95dB/W/m
I use them with the following amps:
Ultralinear Push Pull EL84 - approx 10W per channel (+10dB power)
giving 105 dB SPL at 1 metre max
Ultralinear Push Pull 6V6 - approx 8W per channel (+9dB power)
giving 104 dB SPL at 1 metre max.
845 SET - approx 20W per channel (+13 dB power)
giving 108 dB SPL at 1 metre max
The maths:
dB (power) = 10 log (output power).
Add that to the speaker efficiency in dB/Watt/metre to get max Sound pressure level (SPL) at 1 metre.
And as Eli said in his post you want a minimum of 102 dB SPL for a typical sized room).
Thats why you see you see the guys who build those little "Flea Power" SET amps of around 2 watts use 101 dB/W/m speakers with them.
Aside: The reason I like the VAF speakers is that they have really good self damping characteristic and therefore sound good with low damping factor valve amps. That means I can design the amps with very little or no global feedack because, within limits, the output impedance of the amp is not a problem.
Cheers,
Ian
Jarthel
With the DC-X (95dB/W/m) and any of the amps (8 to 20W per channel) it gets louder than I can tolerate staying in the same room.
Then 6V6 Ultralinear (the 8 Watt amp) tends to start to grunge up a bit when pushed really hard so I don't use it for really loud listening.
If you are doing nothing tomorrow (Sat) or Sunday give me a buzz to check I'm home (82693539) and pop in for a listen to the 3 amps on the DC-Xs. I also have an AKSA Lifeforce55 SS Amp for comparison (55W into 8 Ohms and 90 W into 4 Ohms) which should deliver around 70 W into the nominal 6 Ohm DC-Xs. I should be around as a another fellow is popping in to pick up a couple of guitar amps I've just finished repairing for him.
Strangely I did'nt really notice the difference in the sound level with the DC-7 although I only had them for about a week. I'm currently contemplating upgrading the DC-X (older model not the new Generation 4) to a pair of I-91.
Cheers,
Ian
With the DC-X (95dB/W/m) and any of the amps (8 to 20W per channel) it gets louder than I can tolerate staying in the same room.
Then 6V6 Ultralinear (the 8 Watt amp) tends to start to grunge up a bit when pushed really hard so I don't use it for really loud listening.
If you are doing nothing tomorrow (Sat) or Sunday give me a buzz to check I'm home (82693539) and pop in for a listen to the 3 amps on the DC-Xs. I also have an AKSA Lifeforce55 SS Amp for comparison (55W into 8 Ohms and 90 W into 4 Ohms) which should deliver around 70 W into the nominal 6 Ohm DC-Xs. I should be around as a another fellow is popping in to pick up a couple of guitar amps I've just finished repairing for him.
Strangely I did'nt really notice the difference in the sound level with the DC-7 although I only had them for about a week. I'm currently contemplating upgrading the DC-X (older model not the new Generation 4) to a pair of I-91.
Cheers,
Ian
Amps: flea-powered SETS 1-2W: el84 / double dc darling / 6ck4
Speakers: modified vintage two-way bookshelfs: Fisher and Sansui SP-50, both around 89db/W, minimal crossovers components (zobel and cap on tweeter)
Turning the volume all the way up would be deafening in my quite small room BUT at normal listening levels there is some loss of dynamic range when I compare with el34PP (30W) on the same speakers or the tiny sets on 96db/w backloaded horns. Although mighty PP is better suited to drive the bookshelfs I still prefer them with the tiny sets so apparently not all stands or falls with dynamic range.
I think decware puts it about right when they say their <2W zen works with speakers of 90db/W but 96db/W is ideal. (given a not too large room and speaking in real-world terms, not theoretical should-be's)
Simon
Speakers: modified vintage two-way bookshelfs: Fisher and Sansui SP-50, both around 89db/W, minimal crossovers components (zobel and cap on tweeter)
Turning the volume all the way up would be deafening in my quite small room BUT at normal listening levels there is some loss of dynamic range when I compare with el34PP (30W) on the same speakers or the tiny sets on 96db/w backloaded horns. Although mighty PP is better suited to drive the bookshelfs I still prefer them with the tiny sets so apparently not all stands or falls with dynamic range.
I think decware puts it about right when they say their <2W zen works with speakers of 90db/W but 96db/W is ideal. (given a not too large room and speaking in real-world terms, not theoretical should-be's)
Simon
speakers: 18" cervine vega pa woofer, compression horn midrange, horn tweeter
amp: 2watts el84 se
normal listening level 10-200 mwatts, 0.5 -1 watt way too loud
speakers: line array (8 4" midranges, 6 line source tweeters, 2 15" woofers)
amps: 20 watts push pull 6V6 for mids/tweets, 150 watts solid state for woofers
nornal listening level again 10-200 mwatts, 2-20watts party level
power needed depend on speaker sensitivity and the highest spl level you will eventualy need, for normal listening level less than 1 watt is enough
Right now I'm using vintage 1978 era Altec 'Model 15' speakers - nothing all that great - but at least it does use the 802-8G tweeter. I'm not too keen on the WE designed horn (it has a 90 degree turn) or the 12" foam surround woofer... but they are 93db efficient. I'm using a pair of refurbed Dynaco Mark III amplifiers with them... an old Dynaco 70 just didn't seem to cut it with these speakers (I have a large listening area) and a 5W SE or Tri-path amp sounds terrible with any kind of music with big peaks.
For the future? Electrostats? or some type of OB speaker.
For the future? Electrostats? or some type of OB speaker.
Jarthel,
As discussed in your other thread there different schools of thought on this.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=103962
It might help if you were to determine your loudness requirements before we can offer suggestions. For example, depending where I am and what I'm doing, I use anywhere from an inefficient dual 4.5" with 10 watts right up to a large PA system with oodles of watts and drivers.
Have you determined how many decibels you consider loud?
As discussed in your other thread there different schools of thought on this.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=103962
It might help if you were to determine your loudness requirements before we can offer suggestions. For example, depending where I am and what I'm doing, I use anywhere from an inefficient dual 4.5" with 10 watts right up to a large PA system with oodles of watts and drivers.
Have you determined how many decibels you consider loud?
My system consists of a pair of homebrew 11 cu ft Onken cabinets with 16" Iconic woofers, JBL mid horns and JBL annular ring horn tweeters, efficiency including room effects from placement puts them in the vicinity of 100dBspl/W/m (about 97dBspl in free space)
The amplifier is a stereo 300B SE I designed and built back in 2004 and has a continuous output power of around 7Wrms per channel before the onset of compression and then clipping. Output power is about 9 - 10W @ 5 % thd (ouch) and at these power levels spls > 110dBspl at my listening position, totally clean is somewhere around 106 - 107dBspl. I suspect this is loud enough for most people..
(The above numbers are to the best of my recollection and were actually measured with my radio shack sound meter. My listening position is about 2.5 meters out from the speakers.)
Incidentally these high spl levels are sufficient to cause severe hearing damage in very short order, sustained listening at levels of much over 90dBspl will also cause longer term hearing loss.
My normal listening levels are probably in the mid 80's and depending on musical taste and bass content you may be able to get away with relatively low power levels even with relatively low efficiency speakers.
For years I listened to a pair of 91dBspl/w/m speakers with a 1.6Wrms per channel 45 based SE amplifier in my secondary system and rarely found myself wanting for more power.
The amplifier is a stereo 300B SE I designed and built back in 2004 and has a continuous output power of around 7Wrms per channel before the onset of compression and then clipping. Output power is about 9 - 10W @ 5 % thd (ouch) and at these power levels spls > 110dBspl at my listening position, totally clean is somewhere around 106 - 107dBspl. I suspect this is loud enough for most people..
(The above numbers are to the best of my recollection and were actually measured with my radio shack sound meter. My listening position is about 2.5 meters out from the speakers.)
Incidentally these high spl levels are sufficient to cause severe hearing damage in very short order, sustained listening at levels of much over 90dBspl will also cause longer term hearing loss.
My normal listening levels are probably in the mid 80's and depending on musical taste and bass content you may be able to get away with relatively low power levels even with relatively low efficiency speakers.
For years I listened to a pair of 91dBspl/w/m speakers with a 1.6Wrms per channel 45 based SE amplifier in my secondary system and rarely found myself wanting for more power.
I built some 19 litre cabinets with very heavy 3 layer walls and a thick U shape aluminium section for the front plate. I stuck a simple Monacor 130AL 5 inch full range speaker in each and it hasn't come out for the last two years. It's ridiculously cheap, but very clean and clear. Far from perfect but what it does it does very well. Bass is adequate, and treble is all there. My intention was to replace it with a Jordan unit but I'm reasonably happy as it stands. It's probably about 89 to 90 db.
With this setup I can use a 3 stage amp, all DHT.
1G4GT mu=9
112A mu=9
2a3 outputs.
I'm pretty happy with the clarity of this setup - it's very revealing - so I'm not very motivated to go back to building crossovers. In fact I'm not motivated at all! Full range units can work.
With this setup I can use a 3 stage amp, all DHT.
1G4GT mu=9
112A mu=9
2a3 outputs.
I'm pretty happy with the clarity of this setup - it's very revealing - so I'm not very motivated to go back to building crossovers. In fact I'm not motivated at all! Full range units can work.
Hi ,
I went for a 2 way . I've got Tad TD4001 on 340Hz Azurahorns on top and Seas CA25FEY in a 120litre EBS alignment cabs for bass (approx 93dB) . Amp is a zero NFB PP amp , about 8 watts a channel . I'm still tweaking the crossover after nine months of use and I had to implement a notch filter for the Tads after much frustration . The Seas were a stop-gap , I'm now keen to use the Usher 15HM once funds allow (15" 95dB 1w/1m) . Designing speakers is an art I'm yet to master but what I can say is that if you build with valves watts will be precious . Sensitive speakers for low powered amps always mean large boxes if you want any sort of decent bass . There's also the zero NFB issue , some speakers seem to want to be driven by a voltage source and sound farty with some valve amps . Good luck
cheers
316a
I went for a 2 way . I've got Tad TD4001 on 340Hz Azurahorns on top and Seas CA25FEY in a 120litre EBS alignment cabs for bass (approx 93dB) . Amp is a zero NFB PP amp , about 8 watts a channel . I'm still tweaking the crossover after nine months of use and I had to implement a notch filter for the Tads after much frustration . The Seas were a stop-gap , I'm now keen to use the Usher 15HM once funds allow (15" 95dB 1w/1m) . Designing speakers is an art I'm yet to master but what I can say is that if you build with valves watts will be precious . Sensitive speakers for low powered amps always mean large boxes if you want any sort of decent bass . There's also the zero NFB issue , some speakers seem to want to be driven by a voltage source and sound farty with some valve amps . Good luck
cheers
316a
EL86 SE driving alnico Tannoy Gold 12 inchers. Put my Mac240/Apogee Centaur Minor combo in the closet years ago.
It is kind of spooky when you first experience it. The bass has a weird way of projecting itself into the living room of the house across the street. It is louder inside their house, than outside in the street between our houses. Both houses are closed up with AC on.
I needed a set of speakers that fit in well with Sherri's decorating scheme in the living room, which contains a lot of antiques. She actually came up with the idea of using old radios for speaker cabinets. I found a matching pair of Zenith console radios from 1941. I made new front baffles for them and installed a pair of Hawthorne Silver Iris drivers. I saved all of the old radio parts, so they could be restored if I ever need to. These are 96db drivers, so they don't need a whole lot of power, but they claim a 100 watt rating. They could be deadly at this power level. A "HiFi guitar amp" is in the works with one of these.
I usually use a TubelabSE with 45's (or NX-483's) which makes about 2 WPC. This is sufficient for most music in a relatively quiet room. The detail and spookyness factor really stands out with this combo. The SimpleSE with cranked KT88's in UL (15 WPC) is extremely loud and the bass is amazing. Remember SE amps are supposed to be weak in the bass department. I use this amp when I feel like loud rock. I dragged the 300Beast (P-P) amp out and hooked it up, but it died on power up. It looks like one of the electrolytics in the power supply shorted out. I haven't had time to fix it.
Attachments
Hi all,
Speakers are so much of personal preference - like coffee, automobiles and many things...
Efficiency is all good in the tube world, down here I have a pair of pretty straight Klipsch Heresy Mk I's, 96dB/1 watt, driven by a SE 6336 with UBT-1 opts, prob about 5 watts depending state of lunar cycle, they're quite loud enough for most things unless there is a desire for something really raucous... But the midrange horn is a vicious wee beastie - sure get to hear mistakes with them! Open baffle is interesting, a friend has followed that path for bit, but I still enjoy the vividness of the ageing Heresys, very informative, and right now some old Al Green recordings are putting the funk back in the trunk!
Cheers,
'tron
Speakers are so much of personal preference - like coffee, automobiles and many things...
Efficiency is all good in the tube world, down here I have a pair of pretty straight Klipsch Heresy Mk I's, 96dB/1 watt, driven by a SE 6336 with UBT-1 opts, prob about 5 watts depending state of lunar cycle, they're quite loud enough for most things unless there is a desire for something really raucous... But the midrange horn is a vicious wee beastie - sure get to hear mistakes with them! Open baffle is interesting, a friend has followed that path for bit, but I still enjoy the vividness of the ageing Heresys, very informative, and right now some old Al Green recordings are putting the funk back in the trunk!
Cheers,
'tron
My 2 channel setup has 2 main and 2 passive bipolar subs. My mains are HiVi 7" aluminum/magnesium midbass units paired with Vifa (Peerless now) XT25TG30-04 tweeters. Crossover point is 3900Hz (6db/oct). I'd say the efficiency is somewhere around 88 or 89dbwm.
The front subs are bipolar, using 2x Peerless 10"s in each cabinet, one set facing inwards and one facing front. Wiring is done series 90 deg out of phase. It's silly to mention the efficiency of the 10"s because they are ungodly more efficient in their current configuration. Subwoofer crossover point to the mains is 80Hz, 12db/oct on the LPF and 6db/oct on the HPF.
The whole mess is driven by an Anthem MCA2, 2x 200w. I'm still looking around for a 5 channel version so I can drive my 7.1 setup as well, but I digress.
The front subs are bipolar, using 2x Peerless 10"s in each cabinet, one set facing inwards and one facing front. Wiring is done series 90 deg out of phase. It's silly to mention the efficiency of the 10"s because they are ungodly more efficient in their current configuration. Subwoofer crossover point to the mains is 80Hz, 12db/oct on the LPF and 6db/oct on the HPF.
The whole mess is driven by an Anthem MCA2, 2x 200w. I'm still looking around for a 5 channel version so I can drive my 7.1 setup as well, but I digress.
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