Building multi purpose speakers on a budget

[sanpt7777]

A year ago I bought an old Saba Breisgrau (with the green cones) and they gave me a couple of speaker cabinets with it all for 50 bucks.

Here is a thread about the speakers:
http://www.audiokarma.org/forums/index.php?threads/help-with-speaker-build.628295/

In that thread I learned they are most likely folded horns.
The speakers look like this inside:



What do you think I should do with them? I need advise because I am a n00b but I value good sound quality.
I'm on a tight budget.

These behemoths will be used as the front and right channels on the home theater I'll be building, but most importantly they will be used for music listening, genres I listen are varied, anything from Big L to CCR, Mexican 50's music, Death (the band) or Alice in Chains.

Right now I have a pair of Kenwoods and an old radio and sound is OK (weak link is the 1988 Hitachi receiver I believe xD), but the Kenwoods are my uncle's so I need to build something for myself.



They will be used in a less than ideal room. Here's a drawing of my layout, between the speakers there is a 100" projector screen:



The purple curved thing is my bar, the purple line next to it is an imaginary boundary (I plan on building a door there), but the room is open all the way to the blue door. The big green rectangle is an air hockey table and the small green rectangle opposite to the speakers is a piece of furniture where my projector and stereo are. The sofa is missing right now, I sit on a chair just in front of the furniture where my stereo sits.


The restored horns will take the place of the Kenwoods just like this:



Space is at a premium so maybe one of them (right channel) would sit on the right side of the door instead of the left, some balance trickery should do the job to keep sound centered.

I don't know what receiver I'll use with them, but I'm planning on getting a used Onkyo or Yamaha since prices are good and quality I believe is top notch for the money. Specifically, I'm looking at a Yamaha RV-X450 for around $90 (like this http://usa.yamaha.com/products/audio-visual/hifi-components/stereo-receivers/rx-v450_black__u/). I think it's a great deal and seems very well equipped with features. Most likely I'll get that but you never know...


Do you think horns will work in my room? If not, do you think it's worth it building them as "normal" speakers and use all the remaining space inside to integrate dedicated subwoofers down under (I'll make a drawing and post it tomorrow)? I believe this is the best idea but want to hear what you think. Dual subwoofers and a simple component set up for the mid bass and highs.

Any affordable drivers you have in mind that would do the trick (woofers, subs and tweeters)?


Sorry for long post, I'm not efficient with words.
Ask me please if there's something confusing on my post.

Cheers!

 

[Porkloin]

I'm always amazed at the hoops people will jump through to salvage a dilapidated piece of plywood in the garage. All of the effort spent locating the appropriate woofer for that special enclosure and redoing the veneer on a ringing plywood box would be better spent running down to Home Depot and picking up a piece of MDF for $20. Take a Schmidt Sport-Pack out to uncle Stan's and have him run that board over the table saw a few times. Build a box to the dimensions needed by the driver you choose rather than limit yourself to a particular driver for a particular box.
My version of industrial hearing loss doesn't take kindly to horns - they're a bit fatiguing on me , but you may like them for that cinema-like sound. Your room is of a good size as to be flexible on driver choices - not too big, not too small. That said, I'd be inclined to go with a large, efficient woofer. Finding a midrange to keep up with that woofer and a horn may prove difficult.

 

[sanpt7777]

I'm always amazed at the hoops people will jump through to salvage a dilapidated piece of plywood in the garage. All of the effort spent locating the appropriate woofer for that special enclosure and redoing the veneer on a ringing plywood box would be better spent running down to Home Depot and picking up a piece of MDF for $20. Take a Schmidt Sport-Pack out to uncle Stan's and have him run that board over the table saw a few times. Build a box to the dimensions needed by the driver you choose rather than limit yourself to a particular driver for a particular box.
My version of industrial hearing loss doesn't take kindly to horns - they're a bit fatiguing on me , but you may like them for that cinema-like sound. Your room is of a good size as to be flexible on driver choices - not too big, not too small. That said, I'd be inclined to go with a large, efficient woofer. Finding a midrange to keep up with that woofer and a horn may prove difficult.

Thanks for the forthright advise, I appreciate it.
I am certainly not jumping any hoops. I'm just considering repairing them since they are already there and the wood is very solid. They seem very well made. They are from the 60's. And they were pretty much free. The veneer I can fix with relative ease. That being said, I'm open to the idea of building something else from scratch as you suggest. As long as it works very good with music and its good for movies.

For everything else you said, well, that's exactly the reason I have not done anything to them But it ocurred to me now that I can build separate speakers inside this cabinets to suit each driver, since the horn design, --attractive as it may be-- seems too difficult to pull off choosing the right driver being my first build.

This is very similar in design to my horns:



This is how they look inside. Black represents air path. Blue means MDF panels that are there and orange/brown-ish means panels that were removed. I got a general idea of their original position studying the glue and paint marks.


Down right is the alternative I draw to the horns. A simple setup with a two way speaker on the top half and a sub woofer in the bottom. All for a 2.2 channel setup that can double as the subs and FR/FL speakers of a 5.2 or 7.2 surround when needed for movies.

I want to say last that I'm more into tight bass than the boomy sound. I've never heard a horn speaker but I can guess it would probably not suit my tastes?

 

[sqlsavior]

What is the diameter of the hole in the baffle? They look like a candidate for a full-range driver, or a simple two-way. You could make an adapter for a smaller driver if needed. I think I'd try some drivers out before committing to the woodwork...

 

[elitopus]

I agree I would try to find some driver and see how the speakers sound before fully restoring them. As long as you know the internal volume and figure out what they are tuned to you can find some woofers that will work.
They dont have to be super expensive either. You could start out with something cheaper and then upgrade when a deal comes along.
I would play around with the horn speakers for a bit. I personally like plywood boxes. I know Mdf is better acoustically but plywood is so much more durable

 

[Porkloin]

It would be a lengthy crap-shoot trying to figure which driver works with that folded horn design. It probably took a few guys with slide rules, Brylcream and Buddy Holly glasses to put that all together back in the day. I think your time and money would be better spent restoring to original condition. If you don't like them in your theater application, they'll be a lot easier to sell than something that's been modified, even if you improved upon the original design.
It may be tough, though. I Googled it a bit and couldn't find your folded horn out there anywhere. without a make and model name/number, laying hands on an original driver becomes almost impossible.
Your idea of removing the folded horn and partitioning the empty space for a more conventional scenario would be more pragmatic. It would allow you to choose your drivers and size the enclosures for them per their Thiele-Small specifications.

 

[sanpt7777]

Thanks a lot guys. Baffles are not complete inside, as you can see on my drawing all the brown panels are missing, so I don't really know the size of the original speaker. I do want to take the chance and give horns a try. My speakers have neither a brand or a model visible, all I know is they look like electrovoice and were owned by some rich german family along with a Saba stereo (which I bought, then got the speakers as part of the deal) in the 60's, which means these were not cheap speakers. Not necessarily top of the line either.

I can always try and measure approx volume. It can't be that hard, right? I can clearly see the marks from where the rest of the ply panels were glued.

I got the speakers for pretty much free so whatever I make if I ever want to sell them will most likely be a profit haha

 

[sanpt7777]

I agree I would try to find some driver and see how the speakers sound before fully restoring them. As long as you know the internal volume and figure out what they are tuned to you can find some woofers that will work.
They dont have to be super expensive either. You could start out with something cheaper and then upgrade when a deal comes along.
I would play around with the horn speakers for a bit. I personally like plywood boxes. I know Mdf is better acoustically but plywood is so much more durable

I decided I will build a set of bookshelf speakers as practice. I have my Saba Greencone drivers, I will build them with those so I already have an advantage and can spend money on better electronics.
I as you say, I want to build the horns so I can play around with them a bit, so I will do proper horns instead of multiple cabinets inside the old horn cabinet. But I think I'll be biting more than I can chew with that project, so I'll save them for later and practice building my bookshelfs and offer to build simpler speakers for my friends and brother, as long as they pay for the parts



Alright guys, looking at my possibilities, if I go with my 5 Ohm Saba drivers, is there a way to change the impedance so I can use it with an 8 ohm receiver? I'm guessing dummy loads will only add distortion?

 

[JoeESP9]

Why not look for and purchase a receiver that can handle loads as low as 4 Ohms?

 

[sanpt7777]

Why not look for and purchase a receiver that can handle loads as low as 4 Ohms?

I found a Nakamichi AV-2 for a good price. I'm set on buying it but can back off, is there any chance I can buy an amp that gets the signal from the receiver and then converts it to a lower impedance? I've heard so many good things from those Naks that I really don't want to pass on it.

 

[sanpt7777]

What's that little cylinder between the drivers? I don't even know how's it called so can't google :/

I have the four drivers out already

Will be going with an open baffle design.

I'd love to hear your suggestions. If you think it would be cool to use this or that or paint the cabinets pink just tell me.

 

[elitopus]

I cant tell from the picture on my phone but the little cylinder is probably a capacitor. Its a high pass filter for one or both of the woofers. A cap will have a value written on it in micro farads (uf). On alot of older speakers this is used as a simple crossover
Are the woofers the same P/N?

 

[sanpt7777]

I cant tell from the picture on my phone but the little cylinder is probably a capacitor. Its a high pass filter for one or both of the woofers. A cap will have a value written on it in micro farads (uf). On alot of older speakers this is used as a simple crossover
Are the woofers the same P/N?

Yes they are


I did not removed it so I can't read the uf value. Thanks a lot.