speaker that can be driven by tube amp

[milen007]

how to know which speaker can be driven by tube amp?

browsing web, looking at 300b amplifier kit, they only have 9w per channel, would spendor s53/5 speakers (recommended driven by 100watt+ amp and Sensitivity for 1W @ 1m is 84dB) being driven by the 9wpc? how to determine which speaker can be driven by 9wpc? look at the sensitivity?

or the speaker need impedance compensation circuit required?

aware that speaker can be damage when driven by smaller than recommended wattage, is that a risk say use 300b amp to drive them? or have to listen at not too loud volume?

[astouffer]

Yes you are correct to look at the sensitivity of a speaker. Spendor says the S5e is rated for 87dB. Thats a bit low for a 300b amp. I use a pair of Infinity Qe speakers rated for 89dB on a 15 watt 845 amp. I'm not sure how using too little power can damage a speaker?

[Rodango]

I have driven my Bohlender Graebener planar transducers to very loud levels with my 300B amp. Plus it's nice to have a speaker that does an excellent job at sound reproduction as the B&Gs do. They outperform my Proacs!

[Richard Ellis]

Myself now diving into tubes I have begun the search also for the 'ideal' speaker to be driven with a low power tube-amp.
My old DIY towers blowing out the surrounds has now made my move up manditory.
I would put sensitivity at the top of the list given that I do indeed want "Rock concert" SPL levels (Appx. 115 Db). Impedence response engineering is by no means an easy task to take on and I believe the net results will not be worth the effort.
The speakers I'm leaning towards are the Cerwin Vegas or the Klipsch brands..both offer very high SPL levels with the Klipsch being more accurate but pricier.
The Chorus and Chorus II line of Klipsch, now out of production for a while offer a good value for the tube-driven crowd...still too expensive for me sooo.I will be going with the Cerwin Vega E715 at an SPL of 102 Db @ 1M..out of production just recently at half the price of the Klipschs, not the greatest of accuracy nor imaging but I'm sure they will be fine for my application.
_________________________________________Rick..... .....

[milen007]

how to judge with speaker can be driven by 9 watt SE 300b? whats the minimum speaker sensitivity?

what the impedance compensation circuit do in the speaker? bring up the original sensitivity level?

[Richard Ellis]

YUkkk..
89 Db is way too low for tube stuff!
Do the math!!
89 Db @ 1W
92 Db @ 2W
95 Db @ 4W
98 Db @ 4W
101 Db @ 8W
104 Db @ 16W
Your system is already maxed out with only 104 Db! can't even compete with the vacuum cleaner.
Choosing high SPLs is paramount to giving you good transients, dynamic range and available headroom.
Damage to speakers occurs when low power amps hit clipping and when the amp bounces off the power supply rails squaring the signal the amp will "ring" making a very high frequency which the speaker cannot handle.....often times burning up a tweeter.
_________________________________________Rick..... ......

[gmilitano]

Originally posted by milen007
aware that speaker can be damage when driven by smaller than recommended wattage, is that a risk say use 300b amp to drive them? or have to listen at not too loud volume?

That is nonsense. It that were the case, turning down the volume on ANY amplifier would damage the speaker.

[mashaffer]

Originally posted by gmilitano
That is nonsense. It that were the case, turning down the volume on ANY amplifier would damage the speaker.

Not entirely nonsense, at least with solid state amplifiers hard clipping brought about by trying to push the amp beyond its capability can over heat the voice coil in some tweeters. With a SET this may be less of a problem given the different overload characteristics but I wouldn't dismiss it out of hand either.

Of course the solution to the problem of finding appropriate speakers is found on the Loudspeaker fora (esp the single driver forum). Make yourself a nice single driver DIY (Open baffle is easiest and IMO best option there) and supplement with a powered sub.

mike

[Eli Duttman]

Let's apply Joppa's Rule to the situation. The rule states that for "average" listening spaces an amp/speaker combination should be capable of producing at least 102 dB. SPL peaks at a 1 M. distance. Therefore, speakers with an honest 94 dB. sensitivity rating are appropriate in combination with SE 300B amps.

The Spendor speakers mentioned by the thread's originator are unsuitable.

[gmilitano]

Originally posted by mashaffer

Not entirely nonsense, at least with solid state amplifiers hard clipping brought about by trying to push the amp beyond its capability can over heat the voice coil in some tweeters. With a SET this may be less of a problem given the different overload characteristics but I wouldn't dismiss it out of hand either.

Speaker damage occurs only one of two ways; mechanical or thermal. Mechanical failure occurs when it is driven beyond its limits. Thermal failure occurs when the voice coil see more power over a period of time than it can handle. In short, too much average power over time is what damages speakers. A speaker will not be damaged thermally if the average power over time is less than the driver can handle.

A 1W amp that is driven into full clipping will not damage a speaker that can handle more than 1W of power. Go ahead, try it for yourself. Get a recording of a fully clipped signal. Turn down the volume and play it. No damage.