I just got a bunch of speakers and want to build something that will work for us,
The music will range from the Rat Pack Ear to Eileens space music,, So I would like to build some speakers that will have real good radiating bass at low volumes,, Something that when you are in the room it will seem as thought the bass just floats across the floor,
I now have the following speakers in good clean condition which all sound good by them selves,
Two Magnavox 15"
Two Magnavox 12"
Several sets of 8" and 6" full range speakers,
a couple sets of 4" full range speakers
and a few sets of 3.5" RCA tweeters and 4" other brand tweeters,
I can build boxes and follow prints,
But I do not have the experience you guys have in making the right choice the first time.
We will be using a small Mono Amp, Most likely in the 10-12 Watt range which should be more than plenty to drive these 50s speakers,
Sp please let me know how to build what and attach to which speakers,
They are all in the 8 Ohm Range.
Diagrams would be great too !
Thanks all !
Peter

A three way is the best with what you have , if you use the 15 inch , the 8 inch would be the best choice for the midrange, then a tweeter .

http://freecircuitdiagram.com/2009/03/2 ... alculator/

A 6 or 8 inch full range driver used alone in each speaker can easily produce adequate volume with 12-15 watts. I suggest you build a single driver speaker using a TQWT pipe, or Vought or Voight pipe. Google them for design info.

Benefits:

Simple
Inexpensive
Quick to build
Coherency from a single point is amazing, must be heard to be believed
No crossover is needed or wanted
Bass is reinforced by the design; length of folded pipe somewhat determines lowest bass

The ones I built used cheap 93 dB RS speakers, filling the room with my 2-3 watt tube amp. Have fun!

There's not really enough information to work with. First off you need to ascertain voice coil impedances. The rest, SPL and Thiele parameters, are more problematic since they're probably not readily available, if at all.

If those Magnavox speakers really are from the 50's I'd be tempted to see if the console they came from could be identified and use that as a go by for making speaker cabs. The higher end models were paired with a compression horn, an elecro voice T35 I think. That driver is 105dB, so the 15 incher is probably close to that, with a 'low end' of 3500 Hz, so that would be the cross-over. Magnavox bi-amped them so the 'cross-over' was in the amp and not the speakers, although you could do it that way. You might could substitute your tweeters by guestimating their SPL and perhaps pairing them up to get 105, or more, dB and put an adjustable pad in to 'fine tune' them to suit. I.E. Put in 'too much' and then cut it down to match with the pad.

Trying to do 3 way gets progressively more problematic because of the lack of driver specs.

The 'full range' driver is simpler since, if you use just it, there's nothing to 'match up' but it won't go as low nor as high as multiple speakers because it simply isn't possible to make a 20-20KHz speaker.

I recommend building a four way 6 db/octave crossover.

Use the 15" for the bass (low pass 150-200 Hz) the 12" for the midbass (bandpass 150-200 Hz on up to 1,000-2,500 Hz) the 8" for the midrange (bandpass 1,000-2,500 Hz on up to 8-9 KHz) then the 3 1/2" or 4" tweeter (high pass 8-9 KHz) which should give you a good sounding system. You can simply use variable L-pads (equal to speaker impedance) to adjust the levels to each speaker except the 15" which wouldn't need one. I also recommend going with at least a minimum of 20 watts for the amplifier.

Would recommend going stereo unless you just want mono. Could always use one of those small kit amplifiers which can be installed in the speaker cabinet including the power supply.

http://store.qkits.com/moreinfo.cfm/FK660 is one kit. Manual says it does 50 watts into 4 and 8 ohm loads, but I am not sure. If it only does 25 watts into 8 ohms that kit will work. If it does more than 25 watts into 8 ohms then this kit would work http://store.qkits.com/moreinfo.cfm/FK658.

You should find out how loud your speakers are (efficiency) before committing to a crossover.

Then find out if the 12 and 15 inch speakers can stand alone (full Range).

Crossover capacitors are easy to find. Coils are not. Look into winding your
own with what wire you have on hand.

You might want to concentrate on losing stereo separation at the deep bass end
and moving the mids/tweets left-right and backwards and frontwards for cleanest
high.

Shelving T-pads might help , squawks and tweets.

Remember, only a crowd can decide if it sounds like crap.

I forgot to mention, if those really are 50's 'console' speakers then they're almost certainly accordian surrounds and intended for open baffle.

Accordion surrounds are for bass reflex cabinets too.

Sure. I only meant to say those 'console' speakers were usually open baffle... and usually had accordion surrounds... not that accordion surrounds 'meant' open baffle.

However, open baffle speakers will likely have a high QTS, which would make a bass reflex design more problematic and my reason for mentioning it.

Yes definitely go open baffle. Could build each speaker into its own enclosure and also incorporate a small amplifier in each speaker box along with the passive crossover or you could then build an active crossover using op amps.

Im glad I dont have a clue what you guys are talking about More like an alien language.

Connect big speaker to little speaker and take what you get is as far as Ive ever gone and if I want it to sound better I buy it already done

Carl

This is an exciting idea, build tone cabinets rather than just speakers. There is a market for
small amplifier/speakers built into classic small radio cases among guitar players. If you go
the tube route be sure to show the glowing glass so when you look at unit it is plainly see.

Will definitely simplify things and if the OP goes with one of those kit amps he can simply build a higher amperage DC supply and simply use a multi turn pc mount variable resistor to set the volume level of the amplifier. That way all which is required will be the power supply wiring and signal wiring while keeping the speaker wiring very short.