thanks for your kind comment. I really like the 12pw, actually they are my favourite MA driver. That said they really only produce the magic at low excursion which is one reason I think multiple 12pw in a single box is a good solution. if you want SPL definitely look elsewhere. For high quality bass at low SPL i think they are truely excellent, especially considering the size of the actual diaphragm... My design was created for a specific listening room which has lots room gain due to its size. this is one reason why I went for a sealed box design, I have used them in ported boxes and they also sound excellent however not quite to my taste.
i hope this helps.
Highly underappreciated.
Just today on my walk i ended up thinking about a twin (push-push) A12pw metronome with A5.2/3 midTweeter. I thot that was kinda kool, but these!
dave
Hi Dave,
the amps are Modulus 86 from Neurochrome with a dedicated regulated power supply for each amp board.
For the crossover, I did initial testing with a mini DSP to work out crossover points and slopes. I arrived at 200hz and 3000hz with 4th order slopes after a little listening. I like Mini DSP for convenience but would never consider using one in a finished design so I bought some active crossovers to test from XKitz and am very impressed with them. Not sure they will stay in the design as I will likely build my own crossover, I doubt there will be a sonic benefit but I like making my own things. For the actives I use the designs in Doug Self's Active Crossover book.
Printer is a Formbot Raptor, you can see it behind the speakers in one of the photos. It has build volume of 400x400x700 although I wouldnt recommend trying to print something as large as a speaker box too high as the inertia of the moving print gets a little worrying above about 500mm. The speaker was built in 4 main parts and printed over a two week period. Quite surprisingly nothing went wrong which is a minor miracle in FDM printing.
I am actually printing a set of test speakers for my next design right now, I will add some pictures if you are interested.
Also, thanks for all your wonderful input on this forum Dave, I have followed your posts quite closely over the years.
Here are some more pictures... once again, sorry for the sideways orientation.
Attachments
Very nice!
How do you find the sound of the dual Alpair 10P (compared to a single Alpair 10P point source)?
And also, may I ask why you decided 3000hz as the crossover point?
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Hello RXV,
I used the Mini DSP to test a lot of different crossover points. I planned for somewhere around 5000hz but 3000 just sounded best, it wasnt based on measurements just listening.
Dual Alpair is interesting in the D'Appolito configuration, I am not sure there is an improvement in soundstage (as far as positioning of instruments etc) but there seems to be a definite improvement in the tangibility of the soundstage. In a listening session with a friend, we were listening to Skip James and Lisa Hannigan. My friend commented that the authenticity of Skip James' experience was more present in the D'Appolito. So while the soundstage didnt seem to have more resolution in terms of position it seemed to be able to convey an extra dimension where things like the authenticity of the performer is more present.
If I had to take a guess it seems likely to me that we have the inbuilt ability to judge authenticity through the tone of a persons voice, perhaps whatever auditory cues convey this are revealed in an articulate system... I dont know.
It also added an extra (and quite delicious) dimension where you feel as though you experience the shape of the singers mouth or the perceive the fingerprint on the guitarists finger as the string is plucked. I have heard this before in point source configurations but it seemed more present here somehow.
What may be of more practical value was the observation that this incredible soundstage suffered greatly from speaker placement. Not so much toe-in but the height of the tweeter and the tilt of the speaker... meaning that the 10p's needed to be an exactly equal distance from the ear for the soundstage magic to do its thing. I have never had to set up speakers as precisely as these ones.
that was long, I hope it makes sense.
Best wishes,
Ben
I have the last 4 pieces of Vifa/Tymphany/Peerless NE225 8 (really 9 inch) 8 Ohm with heat sink that were available in North America. These are some of the best I have owned or heard. I have MA Pluvia 7 PHD (paper) and love them. Dave and other disagree and that's OK with me; I use them as mids; not true FR. For the money; I think they have the most detailed and accurate mids. I am always curious what others do and always like to experiment. My best sounding system in the past was very wide band 4 inch mids and 8 inch woofers and Philips ribbon tweeter. I really wish there was a middle between Alpair 10 P and Pluvia 7PHD. A totally new very broad band mid or FR with guts; 100 Hz to 10 Khz; (MUST BE PAPER!!!) I would use them from 300 to 6000 most likely. I am in my mid 60's and therefore need a super tweeter regardless of FR or mids...
Blown away dude!!! Amazing! Looks like $50k! ��
I’m so curious to hear some of these amazing DIY designs! Wish you were in NJ ��
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Tom’s amps are good, you just need to ensure that the bass alignment is not overdamped.
I am considering one for just that. I would not use it for more.
That would work. I am not a big LR fan.
Have you looked at SY’s Synergy XO
SYclotron Audio | The Acheron: Electronic Crossover Design
Synergy "Active" Crossover - diyAudio
I am also enthised by Nelson’s B4 derived B!-like XO.
That has a serious print volume.
dave
Yes, that. Not sure why I called it a midrange.
How do you like the sound of those speakers?
new to Full range and open baffle
Gentlemen - Being new to these ideas, I have been wading through this thread and the time has come to dive in.
I am interested in building an open baffle speaker using a full range driver (MarkAudio?) and a (sub) woofer for the low bass, having come across these ideas in an article by Nelson Pass. He describes a slot-loaded woofer system mated to a Lowther full range unit using an active x-over. It so happens that I have a pair of 8" woofers that I removed from my present system to upgrade them ( 3 way active, 24db/octave, TL) and came across the Markaudio drivers in this thread while informally researching for a more reasonably priced alternative to the Lowthers!
I have come to the P-7PHD which seems to be favorable reviewed here and is very reasonably priced at Madisound. And I am comfortable with building the X-over etc.
Does anyone have any experience with Nelson Pass's woofer design?
Or any comments on the suitability of this MA driver to the application?
Thanks in Advance for your help!
MG
Gentlemen - Being new to these ideas, I have been wading through this thread and the time has come to dive in.
I am interested in building an open baffle speaker using a full range driver (MarkAudio?) and a (sub) woofer for the low bass, having come across these ideas in an article by Nelson Pass. He describes a slot-loaded woofer system mated to a Lowther full range unit using an active x-over. It so happens that I have a pair of 8" woofers that I removed from my present system to upgrade them ( 3 way active, 24db/octave, TL) and came across the Markaudio drivers in this thread while informally researching for a more reasonably priced alternative to the Lowthers!
I have come to the P-7PHD which seems to be favorable reviewed here and is very reasonably priced at Madisound. And I am comfortable with building the X-over etc.
Does anyone have any experience with Nelson Pass's woofer design?
Or any comments on the suitability of this MA driver to the application?
Thanks in Advance for your help!
MG