Best way to highest efficiency?

[Carlp]

I know this is a wide open question with room for lots of opinions, but I'm looking for just a few basic ideas with a dash of theory thrown in. I've recently become a fan of single-driver/full range but worry that to get high spl, I'd need a much fatter bank account. Also, multi-way isn't out of the question, particularly in line arrays, but there doesn't seem to be a forum for questions that potentially cross topics like mine.

I'm working out my first tube amp design (lots of reading and building practice, but I'm slow at the theory) and it will have a very low output signal. I'm still working out the design, so can't give any particulars yet. What I want to do is find a good design that balances quality, cost and efficiency. I'm guessing I will need 105dB sensitivity or more, though that's truly a guess. I'm not trying to fill a concert hall though, just a small (13x15 ft or so) living room.

I'm happy to do the grunt work of design, layout, etc., but what I'm looking for is input on what direction to go. Line Array? OB? Full range? Bipole/Dipole? Some hybrid or a combination? I've mostly been reading about line arrays and dipole and bipole variations of line arrays (full range and multi), but am not yet convinced to spend time on one.

Thanks a ton, and sorry for the basic and open-ended question.

[Godzilla]

Large, efficient drivers.

[tinitus]

active 3way with "pro" drivers would my choise

[GM]

Originally Posted by Carlp

I'm guessing I will need 105dB sensitivity or more, though that's truly a guess. I'm not trying to fill a concert hall though, just a small (13x15 ft or so) living room.

My current system bests this a little, so dual HE 15" in ~20 ft^3 tuned to Fs plus 300-500 Hz compression horn, preferably corner loaded, though with flea power you still won't get to piano bar levels at low distortion.

GM

[Carlp]

I should probably have mentioned that there are some VERY inexpensive 2-4" drivers at PE (for instance Newcom QS760 Passive Speaker Pair | Parts-Express.com, which I've read someone did a line array), Madisound and elsewhere (my local electronics warehouse sometimes has great deals on lots that are fine but were mis-ordered or spec'd, e.g. a recent lot of 6" woofers that seem to run quite nicely and were dirt cheap). So a line array doesn't need to be out of the question just because of the number of drivers.

Godzilla, got any specific recommendations? I have a pair of BOFU drivers and I know you've experimented with them. I assume you mean BIGGER!

Tinitus, I don't know of any drivers, pro or otherwise, that would meet my criteria. I'd be grateful for suggestions.

GM, sounds intriguing. I can look into this, but wonder about "piano bar" levels. I don't need live performance levels, but decent upper register and fast response would be helpful.

Thanks all.

[c2cthomas]

Check this thread out S16 - Constant Directivity Dipoles
http://audiokarma.org/forums/showthread.php?t=150939

[ra7]

Funny you should mention this - my thoughts lately have been leaning towards high efficiency also. I think you will lots of folks here with big all horn systems that enjoy extremely high efficiency.

There seem to be lots of ways to get there. Compression drivers and horns, bass horns, subwoofer horns... horns horns horns. Line array is another option. Size matters and so, having enough space is probably a good start.

For me, more than being able to produce live levels, high efficiency is about getting that 'real' palpable quality in the reproduced music.

Following this thread intently.

[woody]

There is even a forum just for this.


High Efficiency Speaker Asylum

[frperdurabo]

Efficiency? Go big, or go home.

[Bigun]

Well now, I'll offer a completely different suggestion - just because...

I built my first tube amp last year, a SET with a gain of 1.8 and maybe a good solid 1W output.

I have plans for big speakers - but it's plenty of work and some expense and I'd suggest a smaller simpler project first.

Believe it or not, and I wouldn't have if not for having done the experiment myself - a very small inefficient speaker does work with a low power SET. I am currently using a pair of 85dB inefficient speakers with my SET until I get around to building something larger. The sound is fine in a fairly generous room for easy listening so long as the kids are not around.

The sound quality is fantastic - a long time tube fanatic friend of mine was gobsmacked.

So maybe you want to try something simple and inexpensive to get your hands dirty before you get the big driver and build that perfect BLH.