DIY Speakers\Ipod Dock + Tuner ?

[wizer]

I'm on the look out for a new project. I've always wanted to build some speakers but I've never actually wanted a HiFi system in my living room. We'd quite like to have an Ipod speaker dock and I think it'd be really cool to have one made out of wood. I've been googling about and I'm surprised that I've failed to find much on the subject. Maybe I'm using the wrong search terms. The only thing I've found is this

http://www.parts-express.com/projectsho ... ct=Podzuma

Which would be ideal. The only problem is that 'audio' is like a foreign language to me and I have no idea what it's talking about when it goes into resistors, ohms, crossovers, etc. Whilst I want a relatively good sound, I'm not in anyway an audiophile, so this will be quite a budget project. I considered just buying a cheap chaiwanese ipod dock and bastardising it, but I'm not sure it I'll be able to get it to look right. Plus the cheap ones are really quite nasty. I would go up to £100 with my budget if I thought I was getting a quality (as in good parts with average sound quality) system on lemonade money.

One thing I really want to have is an FM radio tuner. I don't know if this would be complicating things too much. Not really fussed about DAB at the moment. FM is much more preferable. I'd like a proper FM out plug too, so I can plug it into an aerial on the roof. The FM reception here is terrible.

Anyway. Before I waffle on, has anyone done anything like this? Or know somewhere I can get some advice. What I'd really like is a 'shopping list' of parts (like on that website) and some basic assembly instructions. I can deal with the design\woodworking.

Thought I'd ask here first before I hunt down a suitable audio forum

 

[pren]

I think there was an episode of 'John's Workshop' on shed the other week where he made a pair of speakers from a kit he bought. He just made the housing and grilles (which looked bloody awful IMO).

No idea what the kit was called or where it was from, I'm afraid but I think it consisted of all the electrical gubbins as well as 4 speakers.

I suppose you could then get a DAB radio and mount it in the unit?

 

[wizer]

Cheers Bryn. I've actually got that episode recorded. It doesn't really give much technical detail towards the components. I have a link somewhere to the company that supplied his kit. What I want to do is quite a bit different. I need the speakers to be powered and have their own internal amp.

I think I'll have to follow the parts list on the link I posted above and try to work it out as I go. It looks like the radio bit might be too hard to integrate.

 

[RogerS]

Tom

It is possible. Maplin is a good source. You can buy an FM radio kit for £12.99. I got that far and then their site went on strike and response became slower than molasses in winter. They will do an amplifier kit. You'll need a power supply kit as well. Ideally one will drive both the amp (s) ...are you bothering with stereo..wouldn't have thought it worth while in just the one unit. Had a quick look at the link you provided. It's US oriented and so doubt you will get the speakers specified over here. Then their site started going slowly as well...BBC is fine so no idea why it's so slow. I digress.

Most difficult will be connecting the iPod. If you want to be really professional and pick up the signal from the bottom socket as you 'plug' in the iPod then you'll need to butcher something commercial I think but it would be very hit and miss as to wrking out which pin caried thr audio although i daresay it's out there on the web somewhere. easiest is simpy to plug in the wee jack plug that you'd use for feeding earpieces.

What else. You'll need a switch to select iPod or FM.

Nice idea for a project.

EDIT: the US site just woke up. I see he went for stereo but pointless IMO given the spacing between them. Why? Daft! He also goes for the simple...how to connect your iPod approach.

 

[RogerS]

Oh yes...another problem...how are you going to tune your FM radio?

EDIT: I see that the two £12.99 Maplin radios are mono but given earleir comments re speaker cabinet/spacing....

Oh gawd, Maplins' website's gone go-slow again. Why can't people put in enough bandwidth on their servers?

EDIT 2 : Ooh..Maplin just put more money in te meter. Amplifiers kits are cheap as chips. You might need a pre-amp..depends on the output level from the iPod and FM radio. Tech info is so minimal, it's a joke. Maybe the manufacturers link has more detail.

 

[wizer]

Cheers Roger.

Yes I thought he'd crammed in rather too much into a small box. I'd like to hear the difference between mono and stereo in this situation.

I've been looking at the amp that he used in that system. I'm not too concerned with it being ultra small. If it goes well then I may design a small portable unit for travelling. I think this first project will basically be about making an attractive, wooden ipod dock to my own design.

http://www.parts-express.com/pe/pshowde ... 80&scqty=1

The good thing about it is the fact that it already has the capability to run off batteries, which is a bonus for me.

I'm not sure I am up for building my own cross overs. So I'm thinking of either ripping off a 2nd hand set of bookshelf speakers or buying an off the shelf kit. Tho, the kits from Wilmslow Audio start at £260 which is way over my budget. I am even considering tearing apart my old floor standing Mission speakers, as we never use them.

Information overload at the moment. Trying to get my head around exactly what I need.

Off to look at tuners on Maplin.

 

[RogerS]

Tom

Your stereo sound stage will be zero. Positioning for speakers in stereo suggests that they are at two corners of an equilateral triangle, you being the third corner. Stereo also works on the relative phase differences between sound reaching your left and right ear. So in the case of the speaker box, your equilateral triangle means that you need to put your head about 3" away from the speakers.

My advice - forget stereo in this application. Why not buy a mono speaker together with its' crossovers and drivers then re-house in your own tiger veneered objet d'art?

 

[matt]

Try Garlands in Deptford. It's been a while but they used to be the destination for all things audio (in component form). It doesn't look much but it's an alladins cave.

http://maps.google.co.uk/maps?hl=en&q=a ... a=N&tab=wl

 

[wizer]

this is what I'm thinking Roger, certainly to get a prototype up and running.

So now I need to work out how to get the ipod to connect, drawing audio from the bottom connector as well as sending power in to keep it charged. I've found some bits and pieces of information but it's all foreign at the moment. I'll motor on.

 

[wizer]

Thanks Matt, will have a look.

 

[wizer]

Ok after surfing about and thinking about this, I think this is my way I'm going to do it. As a 'prototype' I'm going to rip the inards out of our current Mission floor standers, use one of theseT-Amps and one of thesenano docks. It'll be a bit cobbled together and will be an audiophile's nightmare. i.e it won't be a proper designed speaker system and the cheap nano dock only uses a 3.5 output which I'll have to convert to double phono jacks. If the concept works then I will look into designing the whole thing a bit better. The radio bit will have to wait for now, that looks too technical for my pea sized brain.

Now onto a design.

 

[xy mosian]

Tom, I worked in the design and development laboratory of a Hi-Fi loudspeaker manufacturer for most of the 70's. I agree with RogerS.

Tom

Your stereo sound stage will be zero. Positioning for speakers in stereo suggests that they are at two corners of an equilateral triangle, you being the third corner. Stereo also works on the relative phase differences between sound reaching your left and right ear. So in the case of the speaker box, your equilateral triangle means that you need to put your head about 3" away from the speakers.

My advice - forget stereo in this application. Why not buy a mono speaker together with its' crossovers and drivers then re-house in your own tiger veneered objet d'art?

The optimum design of a crossover is dependant on drive units and their immediate environment, proximity to each other, enclosure edges and indeed floors and walls. Not something to be attempted lightly.

As for the Mission speakers, selling them could well increase your available budget.

xy

 

[wizer]

xy, thanks for your input. Whilst I understand there is an 'optimum' setup for Hi Fi, I'm freally not interested in getting it 100% right. Remember, what I am designing is a portable stereo unit, just like the 80's boom boxes, but in a modern wooden design.

The Missions are worth about £35 on eBay. I'm happy to sell them if I can buy what I need for that price. But I'm also hapy to jut rip them apart and use the bits inside. I understand the mono vs stereo concept. So could you help me with some suggestions on what exactly to buy. My budget is bargain basement.

 

[Dave S]

Have you seen this?

Sounds like it could be along the lines of what you are thinking of.

Their site is here.

Dave

 

[xy mosian]

Tom, there are, of course, many routes to the device your after. I think that polished Owl Dave S suggested looks tremendous for example. However I think that a low-end ready built device re-boxed by yourself might be the easiest, and fastest answer. After all there would be no need to scratch around for matching components and all of the tricky bits would have been done.
If you want to delve deeper then I would recommend using, so called 'full range', drive units, that way you would have no need to create crossover units.
I haven't looked but I wonder if some of the portable Dab radios have Fm capability with an auxiliary input, for the Ipod. A lot of the lower priced models are cased in plastic and could well be improved by a wooden cabinet.

xy

 

[wizer]

Dave that's exactly what I'm shooting for. Perhaps without such a shiny finish. Oddly, I'd imagined using Zebrano and Walnut for my unit, which is one of their options. I think I want mine to be a bit wider, not keen on the speakers being quite so squashed.

xy, thanks for your help. I need to do some research into speaker terminology. I don't really understand it at the moment. For example, the Podzuma that I linked to above has 6 speakers plus 2 vents. I assume 2 of the speakers are tweeters and the vents are for bass response? But how then, has the one Dave linked to only got 2 speakers and one vent? What type of speakers would those be?

Off to research what full range means.


Thanks all.

 

[xy mosian]

Tom I'm a bit rusty with all this, but here goes.

The Podzuma is basically a two-way system, that is each audio, as far as speakers, channel has a bass unit and a tweeter. This design uses two bass units, per channel, wired in parallel which will almost give the same effect as a single unit of twice the area. For bass frequencies it is necessary to move large volumes of air, hence most designs use larger units for the bass end of the audio spectrum. The port in the cabinet acts as a resonator, usually designed at a frequency below the lowest available from the same cabinet totally enclosed, this extends the bass frequencies available from the system. It has to be said that running two units in parallel normally adds more load to the amplifier, a fact which has to be considered in design stages.

The thodio site has little real information about the loudspeakers. From a purely visual standpoint I feel that the drive units probably have separate treble units mounted concentrically. This helps with production, of the cabinet, and although a crossover is required, to separate frequencies to the drive units, this is much less dependant on the layout of the units as this is fixed.

As for 'Full Frequency' drive units. The most common form has a treble cone added to the top of the drive unit coil, these are sometimes known as 'parasitic' tweeters. This requires no crossover. Careful design can produce acceptable, though not Hi-Fi to my mind, results. These are commonly found in factory fitted speakers in the car industry.

Phew that almost hurt. I hope it offers some help and not more confusion.

xy

 

[xy mosian]

Tom, here is a link to a typical 'Full Frequency' drive unit. Sorry the information is in french.

http://www.cadaudio.dk/ht170a2.pdf

Audax have a good reputation for speakers, and although I could not personally recommend this particular unit, as I've not heard it, you could get much worse.

xy

 

[wizer]

thanks xy, the mist is starting to clear. I realise that you're obviously coming from a quality hi fi background and therefore are reluctant to recommend this route. I'm on a budget and just want a starting point. If it turns out sounding obviously rubbish, then I'll upgrade. I certainly don't mind spending money learning.

I've also found some Car Audio products which seem to be suitable. Thisis what I'm looking at. It looks cheap and nasty but hopefully it will do for a prototype.

Can you tell me if I'll be able to just wire these directly to the amp or will I need to do something else to make them work? i.e a cross over?

 

[xy mosian]

Tom, don't get me wrong. The music is the thing! Shakespeare in paperback is still Shakespeare. Hi-Fi just adds the Red Morocco binding, and perhaps some clarity

Now I've just looked on the BossAudio UK site and can find no link to this particular model, could be obsolete.
However it looks promising. Boss now show a range 'ONYX' which look similar and are full range. The power handling of the model you reference is said to be 350W, you are not likely to need that power rating. If you can track down anything with a rating of say 50W or 60W then it could well be less expensive, the power handling bits tend to be pricey parts of the drive unit. Of course you may like your music LOUD.
From what I can see you should be able to connect this directly to an amplifier. The amp should be capable of driving the 'Impedance' of the speaker, watch out if the impedance of the speaker is less than the stated load of the amplifier, measured in OHMs sometimes a greek letter omega which looks like horseshoe with feet.
This drive unit, and similar ones are not really likely to sound rubbish, after all the sound system in you car is generally acceptable. This is especially the case when mounted in a box.

xy