Technology Student Wanting To Build Full Range System

[morfius]

I made a post earlier asking about triple crossover systems, however, being a complete novice to speaker building, full range systems was suggested as a more realistic option for me.

What I would like to have is two separate speaker units (stereo sound).

I would like the speakers to be able to put out decent power and also be responsive in the lower frequencies, and higher as well. That was the reason I originally opted for the triple crossover layout.

I have been told, however, that I am able to still have both a subwoofer and mid range speaker without needing a complicated crossover.

I'm not sure, how I can do this though, because a crossover is designed to prevent distortion between multiple channels, and surely not using one would result in my system having distortion?

Secondly, in terms of amplification, should I even bother going down the 'do it myself' route? or is it too complicated to build one.

If I do, is a standalone, third unit recommended, or should I build the amplifier into one of the speaker units.

Also, can you give me an idea of the components that I will need, these are the ones that I know of so far:

Speaker cones (Mid range and possibly sub/tweet)
Input Jack
Amplifier

I also forgot to mention, that anything that I make can only use a maximum of 12 volts. i.e. if I make an amplifier, it must run off a 12 volt transformer or less. Would this be a problem?

The speakers can use more than 12 volts, however, that would have to be from a non DIY amp.

For speaker designs, what should I take into consideration? I have looked through many pictures, and have been surprised to see that some people place their cones facing backwards, others make blast channels etc.

Thanks for any replies.

[MartyM]

Well certainly you can do it yourself. If it is your first time it is probably helpful to keep your goals small and get the basics down.

When it comes to doing it yourself, there are a lot of things you have to be able to deal with, such as:
1. Speaker impedance and being able to compute total impedance
2. Understanding crossovers, how they work, and some math for that
3. General audio theory
4. Electrical terms
5. Finding parts in small quantities <-- Hard sometimes!
6. Constructing things yourself
7. Testing your designs

I bet other people have excellent suggestions also.

When I started I used a Radio Shack speaker crossover design guide, then moved to Vance Dickason's The Loud Speaker Design Cookbook for advanced topics.

You might just get started perhaps with a 2-way -12dB/octave crossover design. You can search the internet for "Butterworth" or "2 way crossover" designs to find out what you need.

Since you're not in the USA, not sure where you can get parts, but usually you will have to be creative to get the values you need.

If you have only +12V DC you can make your own low-end, lower power amps using amplifier ICs, but not sure if that's your goal. StMicro and National Semiconductor have some nice ones, along with design example circuits. They work!

Let me know if I can help!

[Scottmoose]

I think I've mentioned this before -forget volts. They're fairly irrelevant. I did a bit of theory on my posts on your original thread -have another read if it'd help.

OK, first up -buy either a T-amp, or scoure the classified ads for a cheap integrated amplifier you can plug your source (iPod / whatever) into. Anything will do to be honest. Don't try building your own -it'd cost more, and it's too complicated for a first project at your stage. One thing at a time. The amp just plugs into the mains. I can't see anybody complaining about that, you're being judged on the speakers, not what's powering them.

Subs have their own crossovers -forget them for the moment, forget tweeters, just concentrate on the FR units. Abandon your dream of having a hyper-cheap multiway system that could double as a club PA, at least for the moment. Make life easy for yourself, OK? Otherwise, you're going to come to grief, as (and this isn't meaning to put you down: we all had to start somewhere) you don't know even the basics yet, so you need to follow ye olde saying and Keep It Simple.

Next -buy a couple of Monacor SPH60X drivers. www.spectrumaudio.de have them. The site's in German, but it's all pretty obvious. Wolfgan, who runs the company, is a lovely bloke & speaks excellent English too. Total cost will be about £50 for the pair. Those are good 5 1/2in drivers that have a nice solid bottom end to them and a clean midrange. Great for the price.

So much for the drivers. You'll need a 2 pairs of binding posts & some wire -cheap speaker wire from Maplin will be fine. 79p per metre is about the most you want to spend. Some damping material will be needed too -how much depends on the box. Now, how big a box can you take? I ask this in all seriousness, because you might not realise just what 'any size' means to some of us. For example, most of the boxes I design for drivers of this size are at least 5 foot tall. What would really suit your requirements would be a BIB pipe-horn which is simple to build, has great artistry & great sound for the money. But will you be able to build a couple of boxes 64in tall x 7in wide x 14in deep for your project? We can do smaller of course, but it's up to you. The size box you fancy will, of course, determine how much material you'll need to buy to build the things. MDF from B&Q goes for about £13 for an 8'x4' sheet, so it's not going to break the bank, however big you go.

[morfius]

Thank you very much for all the help you have been giving me.

I looked up T amps, and came across the sonic impact t amp - is this one any good, or is it too underpowered?

So here is a list of parts that I need to buy:

2 Monacor SPH 60X drivers
2 pairs of binding posts
Some Wire
Wood
Bass reflex tube
Dampening (foam, wool etc.)
Rubber Feet
Amplifier

So the circuit will quite simply be this?

Amp -> Amplifier Outputs -> Wire -> Speaker Inputs(Binding Posts) -> Wire -> Monacor Drivers.

[Scottmoose]

You're welcome.

Correct re the the stages the signal will go through.

You might not need the reflex tubes. That depends if you build a bass reflex speaker. If you don't, no tubes needed!

As I said, how big a box can you go to?

[morfius]

As big as needed, what size would you recommend?

Of course, if it was ridiculously big i.e. over 2 metres tall then I would scale it down.

[Scottmoose]

Have a look at this:
http://melhuish.org/audio/DIYTQ8.html

This was one of our late friend Terry Cain's projects & perfect for your requirements, if you can cope with the size: 70in tall, 7in wide, 14in deep. The Monacor drivers are a straight replacement for the 1354 units Terry used (which aren't available anymore) -in fact, they're better. This isn't a reflex cabinet -it's a horn. Yup, one of the most exotic of all loudspeaker cabinet types. And a simple to build, 6 foot tall horn, with a mouth firing upwards at that. Creative enough?

BTW -they sound astonishing. No-one ever believes just how much bass is coming from a single, fairly small driver. The BIB ('Bigger Is Better' -TC's phrase) is a remarkable box & makes a fine first project. I've built quite a few. Some people, once they hear them, never go back to anything else. Not perfect, but they're the cheapest & easiest high end speaker in the world.

[planet10]

Originally posted by Scottmoose
BTW -they sound astonishing. No-one ever believes just how much bass is coming from a single, fairly small driver. The BIB ('Bigger Is Better' -TC's phrase) is a remarkable box & makes a fine first project. I've built quite a few. Some people, once they hear them, never go back to anything else. Not perfect, but they're the cheapest & easiest high end speaker in the world.

And for not quite as big, with a bit more finese (at the sacrifice of a bit on the bottom), there is probably a Spawn that will do the trick too (i expect if this Monacor doesn't shoehorn into one of the existing Spawn, there will be the specs for a new Chang family member in my mail after i get back from swap & shop tomorrow AM.

dave

PS: follow the frugal-horn link below.

[planet10]

Originally posted by morfius
looked up T amps, and came across the sonic impact t amp - is this one any good, or is it too underpowered?

Not with a good efficient full-range. The little plastic cheap Sonic Impact, has a built in rool-off that means for serious use you have to mod it up. Better to just start with something like the Sonic Impact SuperT -- tweaked from the factory and inspired by hot rodders of the little plastic one. There is a lot of activity in this sector -- I got a Treands TA10.1, there are amps from 41 Hz & Kingrex, and many others -- seems a new one is popping up everytime you look the other way.



dave

[morfius]

Originally posted by Scottmoose
Have a look at this:
http://melhuish.org/audio/DIYTQ8.html

This was one of our late friend Terry Cain's projects & perfect for your requirements, if you can cope with the size: 70in tall, 7in wide, 14in deep. The Monacor drivers are a straight replacement for the 1354 units Terry used (which aren't available anymore) -in fact, they're better. This isn't a reflex cabinet -it's a horn. Yup, one of the most exotic of all loudspeaker cabinet types. And a simple to build, 6 foot tall horn, with a mouth firing upwards at that. Creative enough?

BTW -they sound astonishing. No-one ever believes just how much bass is coming from a single, fairly small driver. The BIB ('Bigger Is Better' -TC's phrase) is a remarkable box & makes a fine first project. I've built quite a few. Some people, once they hear them, never go back to anything else. Not perfect, but they're the cheapest & easiest high end speaker in the world.

Thank you very much for the link, it has really amazed me what you can do with such a little speaker if you construct the housing correctly.

In terms of dampening, how much/where in the horn should it be placed, or should there be none?

Originally posted by planet10


And for not quite as big, with a bit more finese (at the sacrifice of a bit on the bottom), there is probably a Spawn that will do the trick too (i expect if this Monacor doesn't shoehorn into one of the existing Spawn, there will be the specs for a new Chang family member in my mail after i get back from swap & shop tomorrow AM.

dave

PS: follow the frugal-horn link below.

Thanks for the link, those designs look very good and appealing.

Originally posted by planet10


Not with a good efficient full-range. The little plastic cheap Sonic Impact, has a built in rool-off that means for serious use you have to mod it up. Better to just start with something like the Sonic Impact SuperT -- tweaked from the factory and inspired by hot rodders of the little plastic one. There is a lot of activity in this sector -- I got a Treands TA10.1, there are amps from 41 Hz & Kingrex, and many others -- seems a new one is popping up everytime you look the other way.



dave

Does the treands have enough power for the two monacors which will peak together at 120W?