Budget High-Efficiency Speakers?

[mathman]

Hi all. I’ve decided to build some inexpensive high-efficiency speakers, as I’ve never dabbled there before. Since I already have three pairs of speakers in addition to the surround sound setup, these will see garage duty – meaning my expectations aren’t that high.

I purchased some old Electro-Voice SP12B woofers, which have roughly the following:

Fs: 40-45Hz
Qts: 0.6-0.65
Vas: 160-180 liters

A vented box isn’t looking good. With a large sealed box I could get to about 50Hz, which would be OK. Would these be suitable for a TL? I think the answer is yes, but I’m also not terribly familiar with TLs. I’d like to get a bit more extension if possible. I have three woofers, so I suppose one could be used as a subwoofer of sorts to beef up the low end.

Also, I’m in need of a tweeter for these guys. I vaguely recall hearing that the woofer’s sensitivity is about 95dB so horns may be in order, or possibly a bullet tweeter. I don’t want to spend a ton of money – maybe $100 for tweeters and crossover parts. I’ve looked through the drivers at Parts Express and Madisound, but nothing looks remarkable to me. If anybody has experience with suitable tweeters, I’d appreciate some guidance. New or used is fine by me.

Any other thoughts? Am I crazy?

[Inductor]

They are bicones !!

here, they are selling two vintage boxes for $125. Half of that you will spend in wood.

http://www.ultraelectronicactive.com...-Speakers.html

I think you will spend more in (inexpensive high-efficiency speakers) than you want.

[mathman]

Originally posted by Inductor
They are bicones !!

here, they are selling two vintage boxes for $125. Half of that you will spend in wood.

http://www.ultraelectronicactive.com...-Speakers.html

I think you will spend more in (inexpensive high-efficiency speakers) than you want.

If by bicones you mean they have a whizzer cone, then yes. However, I’ve hooked them up and feel they could really benefit from a tweeter. Since I could probably get away with a 3.5kHz crossover, perhaps a dome tweeter would work if the sensitivity was right? I could really use some direction on tweeters.

Not sure where that company is, but if they’re not in Denver, shipping boxes that big won’t be cheap, and I’m fine with building enclosures. I just don’t know what to build. If a TL is practical I’d like to try that to get a bit more extension than a sealed box. I tried modeling a vented box and didn’t like the results – either bad response or a positively massive enclosure always resulted.

I already have woofers – paid $90 for all three. I’m looking to spend about $80 on a pair of tweeters. Add about $30 for crossover components, and another $60 for wood. $250-$300 total. Is that not in the realm of possibility? Again, these are going in the garage, and I’m setting expectations accordingly.

[sreten]

Hi,

I'd say aperiodic loading possibly, gets the box size downsomewhat.

Usual thing to do is add a supertweeter, with the driver raw.

As the drivers raw, wide and not deep cabinets against a wall.

http://www.partsexpress.com/projects...uma/index.html

possibly use the tweeters from the above, add L-pad tweeter level.

/sreten.

[tomtt]

http://www.partsexpress.com/pe/showd...number=270-049

[Duo]

The SP12 is really almost a full-range driver. No Goodmans axiom here, but still not bad.

I use them purely as mids in a three way system with phenomenal results. (Yeah, they're more directional than most of you guys will allow, but they do well.)

If I was to use these for a garage or even much better system, I would do them two way, very lightly loaded, with a nearly full transconductance amplifier. (Something like a Pass labs current mode amp.)

Something to critically damp and not over damp these will allow a lot better bass than you expect.

I don't know if you want to work so far on an amplifier for this, so if not, then a good cabinet design for wide range is in order. The aforementioned aperiodic loading could be very nice.

[Inductor]

" Hello
Better than that! Her are the T/S parameters.
Re=6.7
Sd=535 cm2
Bl=8.76 N/A
Vas=167 liters
Cms=411 uM/N
Fs=45
Qms=5.9
Qes=0.75
Qts=0.665
Pe=65Watts
Xmax=3.3 mm
Eff=94.96 dB

Believe it or not optimum volume is around 450 liters. But you could try 100-150 liters as compromise. This is normal situation considering Q value.

Luc Lacombe "

http://www.decware.com/forums/General/posts/1572.html

[Pano]

Originally posted by sreten
I'd say aperiodic loading.....
... wide and not deep cabinets against a wall.

Sounds like a good idea.
And all you need is a super tweeter.