The Eminence Beta 12LTA has some fans around here. It takes a good sized box, but should get plenty loud with a 2A3. Maybe not the most refined driver, but fun and inexpensive (at least in the States). Lots of threads about it, like this one:
http://www.diyaudio.com/forums/full-range/208347-ladies-gentlemen-emken.html
http://www.diyaudio.com/forums/full-range/208347-ladies-gentlemen-emken.html
The smooth path, althou pretty, often degrades the performance in terms of ripple, letting too much HF out the mouth.
dave
the best I've heard 12TA is in GregB's "Karlsonator" 2A3 can be beautiful -especially with old analog recordings. I don't think a SE 2A3 would have enough power for my tastes - maybe in a little room with simple material.
The amp below was pathetic with AR M1 mini speakers - but not too bad with an Edgarhorn setup. At some point a cheap digital amp will win if you run out of headroom.
Fane's 250 12" with double whizzer 😀 has an octave more HF than a 12LTA - its qts is very high so probably best suited for OB. It would be difficult to overdrive on OB as can handle 15vrms in the lows.
Karlsonator plan
a 2a3 amp I built 20 some years ago
The amp below was pathetic with AR M1 mini speakers - but not too bad with an Edgarhorn setup. At some point a cheap digital amp will win if you run out of headroom.
Fane's 250 12" with double whizzer 😀 has an octave more HF than a 12LTA - its qts is very high so probably best suited for OB. It would be difficult to overdrive on OB as can handle 15vrms in the lows.
Karlsonator plan
a 2a3 amp I built 20 some years ago
An externally hosted image should be here but it was not working when we last tested it.
Freddi,
That is really interesting that you got the 12LTA to work well in the K'nator. I always thought the Vas was such that it would have been undersized. +1 on the digital amps. Chrismmm has compared a TPA3116D2 with mods and it beat his class A and tube amp on FHXL and A10 as reference speaker. I think total cost with mods was under $200. Biggest cost were the Cinemag input transformers for $125. Even without trafo's sound is very good.
http://www.diyaudio.com/forums/class-d/237086-tpa3116d2-amp-441.html#post4027184
That is really interesting that you got the 12LTA to work well in the K'nator. I always thought the Vas was such that it would have been undersized. +1 on the digital amps. Chrismmm has compared a TPA3116D2 with mods and it beat his class A and tube amp on FHXL and A10 as reference speaker. I think total cost with mods was under $200. Biggest cost were the Cinemag input transformers for $125. Even without trafo's sound is very good.
http://www.diyaudio.com/forums/class-d/237086-tpa3116d2-amp-441.html#post4027184
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OK, Dolby's reference specs for broadcast TV movies AFAIK is still 81 dB with 20 dB dynamic headroom = 101 dB max transients at the listening position [LP], so ~96.2 dB/m efficient speakers required with a 3 W amp with little/no clipping and the loss over distance should be about right to drop average SPL/LP down to what folks tend to watch a movie, sports at on the 'boob tube'. That, or overdrive the amp into audible distortion.
Right, ideally we want a DF = 1 for best power transfer efficiency, which in turn requires an actual driver Fs tuning. Ignoring the small kitchen, the first room mode = ~344 m_s/2/4 m = ~43 Hz, so in theory this is the minimum Fp with ~30.4 Hz being the ideal.
GM
The Eminence 12lta is much more efficient than the TB 1808 and Fostex 168z (which are rated low 90s). The Eminence bristles with life with just a watt or two.
Chrisb, I like your back horn design. Thanks for posting.
All of the drivers I've used that are 90db or above per watt I'd consider efficient. The Eminence is a pro driver and even more efficient. It's not really an apples to apples comparison because the Eminence is much larger. I use mine on OB with a helper woofer and tweeter. I think it's better than just about anything I've ever heard regardless of price... but that's just my opinion.
Chrisb, I like your back horn design. Thanks for posting.
All of the drivers I've used that are 90db or above per watt I'd consider efficient. The Eminence is a pro driver and even more efficient. It's not really an apples to apples comparison because the Eminence is much larger. I use mine on OB with a helper woofer and tweeter. I think it's better than just about anything I've ever heard regardless of price... but that's just my opinion.
its tough imo to judge 12lta without a helper tweeter - then it comes alive. The Fane double-whiizzer cone 12-250TC will stand alone without help but probably needs to be on open baffle. It will take 15vrms below fs without mechanical damage.
thanks for the drawing. it's definitly worth consideration. both cabinets (pencil and averbury) utylize the same driver alpair 12p. that gives oportunity to playing and comparing more.
no corner access, sorry. but, could you please tell how you calculate shape and dimensions of your horn speaker?
I'm fan of BIG stuff 😉, but 12 inch starts to be a little scary 😉.
1st: I guess that will be my "a little louder" listening mode
2nd: ...er... I have just reached my incompetence level 😉, translation please ...
====================
apart from the above. I found a hungarian manufacturer Sonido.
Products - sonido.hu
and they have drivers like
http://www.sonido.hu/adat_pdf/sfr-200.pdf
and
http://www.sonido.hu/adat_pdf/sfr-200a.pdf
what do you think about those drivers?
Typical rooms are 1/2 WL resonators and below its fundamental resonance, room [cabin] gain rises at a theoretical 12 dB/octave [2nd order] just like in a mobile audio app, just not as much unless its an underground bunker or similar, with 4-8 dB/octave being the range for most rooms depending on how well made they are [built for harsh weather, noise abatement or not] and whether or not it's on a concrete slab or 'floating' floor.
To take advantage of at least some of this gain we want the driver’s Fs to be at/below where this gain is beginning in earnest. Anyway look at some of the JBL or similar mobile audio subwoofer specs/owner’s Manuals to get a better understanding of this rare ‘free lunch’ in audio.
This brand has had a number of favorable reviews; though don’t recall which models or their signal chains. These in particular look good, with both being excellent matches to a ~matching impedance SET amp if published specs are accurate, though the SFR200 is my choice since it more closely will theoretically mimic a field coil driver’s better [’tighter’] control as its response plot shows and either are close enough to having sufficient efficiency, so for your app, the best choice overall suggested so far IMO even though the Fs is a bit high. At the low SPLs you’ll be listening at though, tuning it a little below Fs shouldn't be a problem. Worst case, you have to add some form of EQ to hi-pass them.
GM
To take advantage of at least some of this gain we want the driver’s Fs to be at/below where this gain is beginning in earnest. Anyway look at some of the JBL or similar mobile audio subwoofer specs/owner’s Manuals to get a better understanding of this rare ‘free lunch’ in audio.
This brand has had a number of favorable reviews; though don’t recall which models or their signal chains. These in particular look good, with both being excellent matches to a ~matching impedance SET amp if published specs are accurate, though the SFR200 is my choice since it more closely will theoretically mimic a field coil driver’s better [’tighter’] control as its response plot shows and either are close enough to having sufficient efficiency, so for your app, the best choice overall suggested so far IMO even though the Fs is a bit high. At the low SPLs you’ll be listening at though, tuning it a little below Fs shouldn't be a problem. Worst case, you have to add some form of EQ to hi-pass them.
GM
thank you for the explanation. because of building technology used I think our flat is really bad for a listening place. wooden frame covered with thin plasterboard and not too firm wooden floor + carpet.
I had a response for my price inqiury from sonido. prices of MA Alpair 12.2p and Sonido SFR200 are almost the same.
that can take a while, but I would like to check both drivers. and as an extra option I would like to try to get Fostex FE206ES-R.
http://www.einklang-audio.com/treiber/fostex/fe206esr.pdf
a different question:
what type of plywood will be good and the best for building speaker cabinet?
I had a response for my price inqiury from sonido. prices of MA Alpair 12.2p and Sonido SFR200 are almost the same.
that can take a while, but I would like to check both drivers. and as an extra option I would like to try to get Fostex FE206ES-R.
http://www.einklang-audio.com/treiber/fostex/fe206esr.pdf
a different question:
what type of plywood will be good and the best for building speaker cabinet?
Hi ply count, no voids. Hardwood preferred. Some variation on Baltic Birch is commonly used.
dave
You're welcome!
'Sounds' like my house. We call it 'stick built' in the vernacular. The rooms 'breathe' like a flimsy sealed speaker cab. Open a door or window and you get a vented alignment that re-tunes the room 🙁.
Like Dave said, with 18-19 mm and 13 ply being the point of diminishing returns since this is enough to push the cab's harmonic structure well above a [mid]bass's, ergo it can't excite it enough to be audible even at just perceptible levels [ear up against it].
My stiffness Vs damping test is to balance a square edge coin on end and play the loudest, most demanding [not 'sub'] bass the speaker will be 'told' to do without falling over.
For subs using high excursion drivers, there's the rocking/coupling motion to consider, so to pass this test also requires either incredible weight, a bi-pole alignment or bolting to a rigid/massive floor, which won't work on my floating floor and I use the corners, I'm limited to multiple forward firing low Xmax 15" in dual ~245 lb cabs.
GM
GM said:
111kg for speaker cabinet it's quite a lot 😱
GM said:
ok, then thicker = heavier = stiffer = better 🙂
sonido sfr200 has Re (nominal impendance?) = 7.3 ohm. should it be connected to 6 or 8 ohm speaker outlet?
Correct, stiffness goes up at the cube of thickness.
Depends on the amp's DF, though most folks just try different taps to see what sounds best overall to them.
A primer: DAMPING FACTOR DEBATE
GM
Depends on the amp's DF, though most folks just try different taps to see what sounds best overall to them.
A primer: DAMPING FACTOR DEBATE
GM
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