I’ve owned both and set them up side by side. I did not find much difference in efficiency in either one. BTW, I preferred the 3's in my 20x15 size room so I kept them!
13 responses Add your response
Thanks yogi. The P3's are quite special. I'm not selling them short, believe me. I think you have done it right with the V-4's, and having that type of power on tap. I don't consider them tube friendly, but I'm sure you have them singing with the Quickies. Pardon me if I have it wrong, but my memory is you have the Silver 70's or V4 Single ended version.Weren't you
limited as to how far you could pull them away from rear wall. I think that may have been your reason for preferring the sealed P3's, correct?
I have had both the C7s and the P3s. I do think the P3s require a bit more power and control from the amp than the C7s. In fact, one time as an experiment I tried a 6.5wpc single ended amp. The C7s sounded pretty good with it, at lower levels of course. But the P3s really couldn't be driven with it. The lower sensitivity and the sealed design probably combine to require more power from the amp. The Croft is very stable, but it is only 45wpc into 8 ohms and 50wpc into 4 ohms. These power rating will certainly place limits on ultimate volume, and perhaps that's what you're running up against.
Thanks smrex13. I figured with that 2.5 to 3 db difference the C7's would be somewhat easier to drive. I do feel the Croft does nicely with the P3's, and would have no problem recommending the combo. The C7's remain an interesting option...I also have a friend who has experience with both speakers, and he really liked the C7's.
No doubt the Croft is great with the P3s - I've heard it myself and enjoyed it a great deal. I thought I was making a step up from the P3s to the C7s. While I certainly got more bass and better dynamics from the C7s (and the beautiful Harbeth midrange) I missed the clarity of the P3s. That being said, many others would prefer the C7. And it would be a great match with the Croft. You'd be able to really turn it loose.
The P3ESR is a closed system and less efficient than the bigger models. So it needs more power for the same sound pressure (about twice as much). At the same time the driver is rather smaller so it cannot handle as much power. Remember, however, that a small amplifier driven into clipping is a lethal weapon for speakers. The conclusion, therefore, is not surprising: the P3ESR is a speaker for smaller rooms (and I love mine for that). So it needs a fair amount of power, but should not be driven into destruction. My best advice would be an amplifier that delivers something like 100 watt into 8 Ohm (like my Quad 405-2), i.e. some 130-150 watt into 6 Ohm). There is a video of Alan Shaw driving a P3ESR with exactly that, and he said it was on the edge. Much depends on how long you do this, and with what kind of music. There is quite a difference between playing low dynamic range but loud heavy metal (dangerous), and high dynamic range symphonic music that demands big power for the occasional peaks, but then lets the speaker recover (cool down). Powerful solid state is what Alan Shaw himself advocates. He designed the P3ESR using a Quad 405. It is a gloriously refined and revealing combination, as long as you respect and accept its limitations.
As for the Leben, see here for the test results: https://www.stereophile.com/content/leben-cs300-integrated-amplifier-measurements
Even though Harbeths are easy to drive, this load dependent frequency response implies that the amplifier is by no means a straight wire with gain, but effectively a tone control emphasing some frequencies at the expense of others. Any mainstream Japanese 2x100 watt amplifier will be far more natural for much less money.
There are exceptions, but in general, it seems like the majority are using SS (or Hybrid) amps with the P3's. I understand why an 83-86 db speaker will respond to power... But I have never heard a SS amp which (for me) had that ever so engaging quality of a tube amp. I have a feeling a good 75 watt tube amp would do nicely. That said, I'd certainly take the opportunity to try a SS amp with the Harbeths. willemj- thanks for your response. (-: