Andy,
If I may ask, what amplifier are you using with you Alpair 12P?
In my experience, I got more feeling of bass with the Alpair 12P when paired with higher output impedance amplifiers like SET or SE DHT tube amplifiers. That does not mean that the drivers do not work with solid state amplifiers, but given the low qts and higher internal damping of the driver itself, I found it quite suitable for listening with the aforementioned amplifiers.
If I may ask, what amplifier are you using with you Alpair 12P?
In my experience, I got more feeling of bass with the Alpair 12P when paired with higher output impedance amplifiers like SET or SE DHT tube amplifiers. That does not mean that the drivers do not work with solid state amplifiers, but given the low qts and higher internal damping of the driver itself, I found it quite suitable for listening with the aforementioned amplifiers.
Hi, Zman - and thanks for replying and for valuable information.
The current amp is the most recent incarnation of Papas Aleph J, a single ended class A construction putting out 25 watts into 8 ohms. I use different preamps: ACP+ SE class A with a bit of 2nd harmonic sugar, push pull class A with very low distortion, and incoming is a B1 Korg triode Nelson Pass construction.
I am not sure about the exact output impedance of my Aleph J. I have prototype boards, and more data will be available later. That said, I am pretty happy with the bass. It keeps improving, maybe indicating my drivers weren’t fully broken in when I received them, and quite possibly over driven at some point too
that is one of the tricks with many fullrange drivers, they were (mostly) designed to use the higher output impendance of tube and class A amps to give more bass (like raising the q of the driver). Mark Audio does that also, but in a lesser degree than many others. But it's true that tube and class A amps give more bass than class D or other low rout amps with these drivers. With multiway speakers with a passive crossover it's less an issue as the crossover add resistance and raises the impendance the driver sees. And most modern multiway drivers are tuned to work on most amps and don't rely on high rout from amp for that. You can simulate that response by adding resistance on the signal to the amp in your simulation software (if it has that option, most good ones have).
Dave, thank you so much for replying based on my initial question a couple of posts back. Tbh I was hoping that you would post, and maybe shed some light on my two till now unanswered questions. Could you please, given time, please elaborate on the advantages of 24awg solid core internal wiring, and a bit about how the sound and tonality changes during break in?
Hope all is well.
Regards,
Andy
I can’t say much, as i have not really listened thru a break-in for a long time. But better bass, smoother top, deeper DDR. And lots of changes a sit happens.
As to thin solid wire, for most of these speakers, it is sufficient to handle the current, higish-R pushes (a tiny bit) more towards current amp 9won’t be enuff to affect something with highish Rout amplifier but will one that has low Rout. It alos, althou this is still controversial, lead to a bit better time response, something usually lost in a speaker with an XO.
As to the loose spider: what do you mean by loose. Coming off, or just over-stretched (someone broke them in brutally?).
dave
As to thin solid wire, for most of these speakers, it is sufficient to handle the current, higish-R pushes (a tiny bit) more towards current amp 9won’t be enuff to affect something with highish Rout amplifier but will one that has low Rout. It alos, althou this is still controversial, lead to a bit better time response, something usually lost in a speaker with an XO.
As to the loose spider: what do you mean by loose. Coming off, or just over-stretched (someone broke them in brutally?).
dave
Thank you very, very much, Dave (if I can call you by your first name). That was really enlightening. Learning every day!
The Aleph J is single ended and uses little feedback, although has a higher damping factor than is predecessor the Aleph 3. I guess some trial and error is in order.
Wrt break-in I’ll give them approx 200hrs in open air in my modest workshop, the setup is in the living room and the rest of the break in will take ages anyways.
Wrt the spider, I kinda knew that needed elaboration and clarification. One of the spiders is over stretched. When the driver is sitting on it’s magnet, it even looks like the spider is hanging. Maybe jist a millimeter or so, but it didn’t look right to me. The other driver, had a significantly firmer spider. Given the looks of the cabinet and the original wiring job, a lot of sloppy stuff, I am not surprised really, and the price I paid for them kinda makes me deserve this. I don’t care, it is a good learning experience. Especially the damping and stuffing was cool. Excited to see how it measures down the line (don’t have the equip yet, new to speakers
).Another thing I noticed today, is that the driver with a «hanging» spider, seems a wee bit less sensitive than the other one. Volume is just lower on that speaker. Go figure… maybe that even makes some sense? I dunno.
Regards,
Andy
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Yes, if the spider has been stretched to that extent the mechanical properties of the driver wil have changed & I'd expect a loss of efficiency resulting in an SPL drop. The 12P is functionally more or less a single suspension unit -the spider does almost all the damping, the surround just acting as an air-seal.
Thanks a lot, Scott! That more or less confirms my suspision that the drives is shot. Fantastic! Problems are a hassle, solved ones provide fruitful progress. Now I can’t wait until the new drivers arrive, and initial break-in complete, so I can mount them in the SP’s and experience the true nature of these beasts.
Regards,
Andy
Thanks Dave.
That will give me some more time to figure out what enclosure to build.
Speaking of enclosures, I could really use some help. I do enjoy "audiophile" recordings but also listen to a lot of bass heavy electronica. I was thinking Super Pensil, but the room is just 15 m2 (161 feet2) and maybe smaller enclosures and a well placed subwoofer would be a better choice.
Any advise would be very appreciated.
The latter would be my choice. No wideband drive unit is ideal for LF heavy material, especially those with artificially generated tones, so supporting them or removing said from their remit will usually reap rewards. If you can stretch to a stereo pair of subs however, that will bring further gains.
Thank you Scottmoose for replying. I'm honored. I haven't had the opportunity to listen to any of your designs, but all the superlative comments here makes me want to go for it. It seems to me that the Super Pensil would make the most out of Alpair 12p and present the purest full range experience when listening to "real" music. For more synthetic (and less critical) stuff I can use a pair of subs and cut them at around 80-100 Hz. By the way, the Super Pensil plan refers to Alpair 12.2p. Is that a different driver than the 12p sold today?
Yes zman01, I already got the drivers. They're still unpacked but I'm really eager to get started. I just want to make sure I break them in properly, but have no idea if mounting them vertically on a temporary baffle (free air) or horizontally on its magnet makes any difference. I wouldn't surprise me if it did with these delicate drivers.
For the moment I have a pair of ACA (v1.8) balanced mono blocks to drive them, but I've had my eyes on Aleph J for a while and now it sure sounds like a possible future project. Thanks andynor for the tip.
Yes zman01, I already got the drivers. They're still unpacked but I'm really eager to get started. I just want to make sure I break them in properly, but have no idea if mounting them vertically on a temporary baffle (free air) or horizontally on its magnet makes any difference. I wouldn't surprise me if it did with these delicate drivers.
For the moment I have a pair of ACA (v1.8) balanced mono blocks to drive them, but I've had my eyes on Aleph J for a while and now it sure sounds like a possible future project. Thanks andynor for the tip.
Drives them with ease. Hold on for Zen Mods modified AJ boards to turn up in the store. Easier to assemble and sound great.
Regards,
Andy