high efficiency speakers for 2A3

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Hi,

I would like to build a pair of high efficiency floor standing speakers. The amplifier is Sun Audio SV2A3. I have used this amp with a pair of old JM Lab speakers (94db sensitivity) with superb results and I have friends using the same amp with less sensitive speakers namely Infinity Primus 360 with no signs of stress at all. So I’d say anything with 92db and above sensitivity is ok for me. The speakers should go as low as 30Hz, is this too much to ask? The use of subwoofer is not an option in my set-up.

I listen to mainstream jazz, pop, rock, world, metal. I like nuances, thumping/fast mid bass and extended low bass, especially when I spin Portishead.

My listening room size is 10’ (W) x 16’ (D) x 7.5’ (H), solid side and back walls.

I am open to any suggestion but I tend to prefer/used to the sound of bass reflex speakers. Since I reside in London now, shipping components from outside of EU will cost me more and take longer, but I’m willing to take the plunge if it’s worth while.

Tentatively I’m setting my budget at GBP300/USD530/EUR450 (components and shipping), but excluding cost of the cabinet as I have access to table saws, cnc router and other tools, and I already have 2 pieces of 1” thick 3’x 8’ birch ply, no problem getting more if necessary, and I’m addicted to soldering fume.

Thanks in advance for your input.

Regards,
Moo.

P/S is the London Live DIY HiFi Circle still active?
 
unreasonable size is an option and no WAF to worry about. was considering speakers like Altec, TAD, etc. but aren't these hard to come by? besides, they're definately over my budget, right?

would it be wise in my case to spend all my money on the drivers and build OB as:
a)saving on component (no crossover, no extra wood needed)
b)high sensitivity easily achieved

but then again will i get the sound that i like with OB, or even close?

thank you for your input and feel free to keep them coming. i will process the information and report back.

moo.
 
Hello moo!

Of course this is all far above your budget.

With large frontloaded basshorns like Klipsch-style edge horns or Cerwin-Vega-style folded horns you can get the desired sensitivity and Fs with quite normal drivers (low Qts), but forget BR, sealed, or OB.
Crossover would be around 200 and above it a fullranger or professional coaxial, if you like compression drivers. If you REALLY like compression drivers you could do everything above 250Hz with BMS coaxial compression drivers.

greets, Oliver
 
Hi Oliver.

Thank you!

i will keep an eye on the item.

apologies in advance for being such a spoon-fed newbie but it would be much appriciated if you could point me to the right direction where can i find some construction ideas for building backloaded corner horns for these drivers. i shall bug you with tweeter recommendation if i got these drivers later on.

thanks again.

best regards,
moo.
 
the afterburner might to the trick for you. I didn't read the specs but i think its very efficient and the drivers supposed to be decent.

Ugly speaker though in my opinion.

http://melhuish.org/audio/DIYBX12.html

Maybe on of the Pi speaker designs will work for you. Too bad your budget is low. The JBL corner horns are probably one of the few speakers that will give you efficiency with low distortion. Mind you, Im making assumption about the distortion qualities of the JBL drivers but they certainly have the reputation.

http://www.pispeakers.com/

Have you looked at the fostex horn enclosures. Maybe the fe206 in a horn would work. That driver is about 95db efficient and Ive heard people say it sounds quite good.

Go to Madisound, select foxtex, and scroll to the bottom for the fostex recommended enclosures. They're certainly tried and true. I dont know if youll get the bass extension you want though.
 
looking at the ldsg (if you dont know it its here: http://ldsg.snippets.org/sect-8.php3#8+ ) most of the full range drivers that go low are very expensive. However the Pioneer B20FU20-51W is rated to 35 hz, is very cheap, and some people think its a very good driver. For the money, im sure your getting more then you should.

I dont know of any enclosure designs though.

Youll have to search around for the driver, i dont know who sells it.

EDIT: here it is

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=290-045

Edit: i might have jumped the gun there. I see that is a 51FW not 51W. The sensitivity is lower.
 
If you are looking at open-baffle, may I suggest a good candidate for subwoofer. The Dayton IB385-8 15" IB Subwoofer from Parts Express models very nicely in Thorsten's XL Baffle spreadsheet. On a 450 mm (17.7") wide baffle a single driver goes down to about 30Hz at a max SPL of 108.5dB. Now that is plenty loud. The efficiency is a bot lower than you'd like (90.0 dB 2.83V/1m), but it can work. If you parallel two of these per side, you will get the efficiency you need (96dB/W at 4-ohm). Add a high eff full-range driver (take your pick from Fostex and many others), and you'd have a great speaker.

With a XO at about 70Hz - 100Hz, you could also use a Gainclone amp just for the bass (and you'll get the tight, low bass you want). Just an idea.

Enjoy,
Deon
 
a word about open baffle. I dont know if you have read through any of the OB thread or looked at Linkwitz's site or anything like that, but they do come with certain complications. You will get phase cancellation from the back wave that would normally be contained in an enclosure. The amount of bass extention you get will be a function of the baffle size. I think there is a spreadsheet or something to calculate this but your on your own there. Maybe someone here knows were it is. Also, if i understand correctly, there can also be a substantial peak in the mid base that has to be dealt with. Im not sure if this is an issue with full range open baffle. If you dont go the large baffle route, you will need equalization and at least a two way XO to get a good response. There is potential to lose efficiency with this route.

That said, I once put together a frankenstien speaker with a small fullrange driver on some foam core and a couple different woofers in an old cheapo enclosure with the back cut out to make it OB. I used a first order xo to roll off the woofer and the full range naturally rolled off at aproximately the right place. It souded pretty good.

I think the selenium speakers at high efficiency loudspeakers are the closest to what your looking for. Id love to build a pair myself but theres so many projects.
 
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