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At the end of the day the 12pw is not that big for a woofer, certainly not the 8” that’s advertised. In building a large-a5s box 2 way there would seem to be many better choices of large single cone woofers.
AFAIK ony Madiosund is calling it an 8”. I have corrected them more than once.
That is the thing… there are lots of woofers that can be used in a WAW. These are in the same league as all but the best standard 6-7” midbasses, are relatively effiicent (just the right amount to XO to the A7s with no padding), but importantly the same sonic character as the A7s so there is a seemless blend. And the design is proven and well documented and being turned free.
This is another WAW with the A7.3eN but using a pair of sealed SDX7eN*. Goes marginally lower (with a touch of EQ), has a nicer shape from a diffraction POV, but that “seamless blend” gives the much simplier ML-TLs the sonic edge (there is also a Trapezoid MTM for these drives).
*(with enuff encouragement these might phoenix)
dave
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In what way does a woofer have ‘the same sonic character as an A7’ ? How would you choose a woofer for a FAST / WAW to satisfy this need in general?
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LOL! 😀
The more things change, the more they remain the same!
In the beginning was the WORD and the WORD was the telephone BW was/is King, so made a huge 1" exit single driver horn that had a ~50-10 kHz BW and nominally flat from ~100-5 kHz to ensure a ~flat impedance through the pass band and as more LF BW was added to film strips to give more realism to movie vocals, music they added huge multi-driver OB 'subs' to match the horn's efficiency and blend to them below 100 Hz........
So in principle, here we are ~ a 100 yrs later back at square one. 😉 Me, I never left it, not into fixing what ain't broke, so having been 'beating this drum' since going online, ya'll got some catching up to do. 😀
In light of the above then, from a 'purist' POV it seems like we should call assembled speakers, compression horns 'loud speaking telephones', compression horn drivers 'receivers', horns, [flat] baffles haven't changed, but empty boxes/cabs were 'box baffles' and cone drivers were 'loud speaking telephones - dynamic'. 😉
GM
Well, the way the pioneers did was to create the widest BW woofer they could with the most extended upper roll off, then modded it to be 'full-range' and why those early systems sound tonally as one with usually just a cap and level control on the 'wide range' driver.
GM
There is a family resemblance amoungst (most of) the Alpair drivers. Essentiall we are taking a FR that goes quite low, with a FR that goes quite high and letting each do what it does best.
dave
Dave,
MTM Take 2 may sound great, but way too big for me. Looks like about 140 liters. I'm thinking more like 50 to 60 liters. And bass is not anywhere near the top of my list. More like the bottom of it.
Very low distortion, detailed, and wide dynamic range are what I'm personally after with enough mid range power to fill a fairly large room.
MTM Take 2 may sound great, but way too big for me. Looks like about 140 liters. I'm thinking more like 50 to 60 liters. And bass is not anywhere near the top of my list. More like the bottom of it.
Very low distortion, detailed, and wide dynamic range are what I'm personally after with enough mid range power to fill a fairly large room.
Indeed! Even if we limit the polar response to 90 deg/20 kHz: ~13560"/20,000 = ~0.678" eff. dia. driver is required, so from the get-go there's no single driver options.
If we compromise on a 27.5-20 kHz and rely on some sort of HF WG, then [27.5*20000]^0.5 = ~741.6 Hz/~18.28" eff. dia., so no joy.
Settle for the critical phone BW, then [250*20000]^0.5 = ~2,236 Hz/~6" eff. dia., so in [one] theory the pioneer's optimum = 8" frame driver and to get the desired power handling will require it be a compression loaded driver in a huge horn.
Play this 'game' out anyway you want, but multi-way is the only way with current technology, physics as we understand it.
Even the pioneer's huge 2 way horn systems aren't good enough for today's wide BW recordings, with three being marginal if we allow the bass system's distortion spec to account for the room's impact on it.
GM
How about these? Could be modified to accomodate up to A7.3. 2 push-push SilverFlute W14 in an ML-TL. (i really need to take pics of them now veneered)
dave
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with smooth roll-offs all around we can even do 1st order XO...
P.s. those Tysen V2 speakers are the makes-the-most-sense-to-me designs for a FAST.
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I have also done a Tysen-like box for the A7/some ScanSpeak woofers which the client did a fabulous job fabricating. They permutations are numerous.
dave
dave
Dave,
What I'm trying to do first is zero in on the best full range driver for my particular tastes and requirements. And those may not necessarily be the same as other people's. Which is why it's impossible to ever answer the question "what's the best driver".
In any case, the enclosure and woofer will come later. Driver choice first. Thanks.
What I'm trying to do first is zero in on the best full range driver for my particular tastes and requirements. And those may not necessarily be the same as other people's. Which is why it's impossible to ever answer the question "what's the best driver".
In any case, the enclosure and woofer will come later. Driver choice first. Thanks.
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More on WAW:
During diyFEST we ended up playing the big MTM TLs all evening. I put them back into the system Friday so a customer could listen to them.
That reminded me again how very good those WAW are. Relieved of bass, the A7.3eN really shines and has no isssues playing pretty loud (if you have the power) and the bass from the ML-TL loaded pair of 6.5/7” Mark Audio bass drivers is fantastic.
The Alpair 12pw is a fantastic bass driver (that goes up to 10k — better top than FRs such as FE208e∑ & FF225wk) but does not get enuff love. The design is flexible enuff that one could sub in A7ms/A6.2/A5.2 (but you will need to bi-amp).
Given that lack of love i am going to forgo any income on the plans for these, including passive XO, just in the hope that more people try the A12pw. I have some changes to make in the document before releasing it, but if anyone wants an early version, email me.
I do have a derivation percolating in my head that would use 4 bass drivers. That one i will charge for.
dave
Dave that's kinda what I stumbled upon early today. The simple 2 way with the Alpair 7p + Alpair 12,PW driver on the bottom of the ported cabinet. This seems like a very Ideal approach design that am thinking about? I just might drop the Single 8 inch fullrange driver and build this design? Dave what's your thoughts on this build or design? Thanks jm
I agree. This is what am thinking of doing getting the smaller driver and build around that with a helper fullrange woofer. Jm
How about these? Could be modified to accomodate up to A7.3. 2 push-push SilverFlute W14 in an ML-TL. (i really need to take pics of them now veneered)
dave
Wow dave. What a lovely upgrade to the reg. Tyson design. Very good eye candy. I hope they sound as good as they look? Thanks for sharing your desings and posting pictures and progress of the JM
I saw those. They looked really nice and he did a fantastic job on the boxes. Dave like always did a fabulous job on the driver's no question. Jm