Getting started - simple basic - not audiophile but like DIY

[Inprogress]

Hi there.

I'm struggling to figure out the forum or where everything goes, please excuse me if this is yet another face-palm post but my forum searches yielded no results - probably cause I'm searching wrong.

I mean to build me a speaker set and amplifier. I am thinking two channel, but an additional free-standing subwoofer sounds appealing. I also want to build a amp for them and ever since I read about class D amps, I think class D cause of the efficiencies. A part of me wants a tube amp integrated into the enclosure of the amp purely cause I like old technology - I'm photographing with a 1968 Ashai Pentax Spotmatic 500 for pete's sake

Anyhows and being annoying to all of you, here is my needs:
- Easy build
- Not to interested in amp design and better and better this and that - I have more than enough hobbies as it is especially in electronics where I get my fill through Arduino
- I'm more interested in the design and build of the amp enclosure and speaker enclosure than I am in the electrical design - though I don't mind soldering everything together
- I was thinking 50W amps per channel, sub-woofer wise I have no clue.
- I can probably just buy a LG mini-hifi since its will most likely work me out cheaper and I will get good sound from it - but the DIY route still beacons me
- Budget not sure since I have no bearing on what costs will be - that might even drive me towards just a consumer product - might, or maybe a nice PC 2.1 set like Divoom or something.

I hope I make sense and hope someone can help at least pointing me in the right direction. When it comes to impedance I know only how to spell it. I'm probably more annoying and might be pointed to my nearest audio dealer - c'est la vie.

Thank you anyone who can assist this fool!

[birdyfoot]

I am beginning the same exact project with probably about as much experience, but I have been doing my research and I pretty much have my design worked out.

What I am doing is building a 2.1 channel system with a class-d amplifier in the sub-woofer enclosure, but in a separate partition.

I think 50watts per channel is enough, IF YOU HAVE A SUB-WOOFER to supplement them. If not they wouldn't have enough bass, but if they don't have to "reach down" they can be plenty loud and small. I will be using a 4" full range driver paired with a tweeter in my satellites, and a 6-1/2" sub-woofer in the box. I think I'm going to put kind of a high low-pass filter on the sub-woofer at around 200Hz, and not worry about the full range driver playing low frequencies. Then wire a crossover between the tweeter and the full-range driver only.

I can't decide weather or not to bi-amplify the system, satellites and sub-woofer. It would be easier, but more money.

[Inprogress]

Mmmmm, sounds like you are A LOT further along than me especially when mentioning words like "low-pass" filter, however your setup sounds very close to my needs.

I though about my need/want to build my own setup and I have a sneaky suspicion that I will probably end up spending more money going this route than just buying a hifi - yet that is just the thing about it - a commercial hifi is just so...commercial. I want something specific, clean lines, simplistic (might even use a iPod dock of some kind) with as little flashing lights and graphics and weird angles as possible. That and the fact that I am a creative person by nature!

I hope you have the time and energy to share your build on the forum - I say that since I have in the past made the effort to photograph and document my motorcycle rebuild and servicing - its a mission especially where oils is involved cause you have to take it a step further, clean your hands, take a picture (make sure its clear) or a few pictures, dirty hands again to take it a step further, etc etc etc.

Thanks for the reply, need to figure out what I need exactly, but like I said your setup sounds just right - nothing really BIG, just good clear sound.

[CopperTop]

I would buy some ready-made power amplifier PCBs off eBay (believe it or not I have had good experience with some ready-made Quad 405 clones which could provide you with the necessary antiquity -it's a 1975-ish design, and very unusual - but there is a huge error reproduced from the original that must be corrected before you switch them on!) so that all you have to do is wire them to a transformer, rectifier and smoothing caps and provide the heatsinking (although these things always become more complicated than you desire in that you really do want a soft start circuit - ideal job for an Arduino? - and maybe some crowbar protection for your speakers).

Then I would buy a USB-based (and powered) DAC from eBay (or maybe SPDIF?) and wire its output through an Alps Blue Velvet pot to your amps, and you've got the electronics sorted, ready to run the streaming audio service of your choice, or play CDs from your CD player or laptop or whatever. No analogue sockets or switches in the audio chain to worry about. Put it all in the minimalist enclosure of your choice.

Speakers-wise I'm thinking about building some myself, but I can't see the point of building anything too 'conventional'...

[planet10]

The Sure 4x100 W Class D amps are popular, (are cheap & come pre-built, just add powersupply, prebuilt switchers are often used). I haven't had a chance to audition mine. Leaves you with lots of power for sats & helper woofers, and for low cost you could just implement a PPLXO.

A ton of choice for speakers. My goto for budget systems (and still provide excellent performance) would be Mark Audio CHR70 or CHP70 (or cousin EL70). Don't know if you can buy any of those local, or whether you need to source overseas. Woofers you probably do want to source locally.

dave

[killa12222]

+1 on the Sure 4x100w. Great little amp!

[Inprogress]

@ CopperTop - regarding the audio part with Arduino - no thanks...but I confess the thought did cross my mind for a few seconds until I slapped myself and decided to keep the two apart. I'd rather invest in a nice component CD player and maybe an iPod dock...or maybe just an iPod dock and be done with it.

@ planet10 - I will see what I can find on ebay regarding the class W amps. As for drivers etc I will have to see what I can find locally - thankfully I got a buddy in the sound business, he is sourcing me a Berhinger C01U condenser microphone so that I can do some voice work. Those CGI movies always looked fun! He might be able to get me drivers, otherwise I'll just have to see what I can do with car speakers - or am I committing a cardinal sin by saying that??? Honestly, why can one not use car speakers for home use? I mean proper midways with tweeters, not those paper cone one's.

Thanks for all the advise!

Oh by the way, enclosures: I suppose each speaker (driver yes?) has a volume range wherein it must be placed for optimum performance? Does shape of the enclosure play a role?

[Inprogress]

Oops...where is my head..or rather my eyes - I meant I will look at those class D amps you suggest planet10.

[birdyfoot]

Errrr, on the i-pod dock... How do you feel about a nice, discrete, headphone jack?

DIY is the way to go, especially if you enjoy building things. You can't do better for the money.

A low pass filter allows the passage, or output, of only low frequencies. It is important in a speaker system for each speaker to only play certain desired frequencies based on it's function and it's position in the system. A tweeter needs a high-pass filter. Different drivers or speakers work together to produce a "flat" signal across the entire range of playable frequencies ranging from 0-20000Hz. For this reason a tweeter often also needs an l-pad to reduce it's volume. Speakers working in conjunction must stop and start playing at the same preconfigured frequencies using circuits called crossovers. These can be very easy to design and build.

Box design can vary. Some people use spheres or tubes, or very intricately designed cabinets. I will be building four-sided square/rectangular enclosures. I might do something a little less conventional with the porting. Both the inside volume and the port length are critical to get the best sound out of your specific drivers. This is also easier than it might seem (link).

planet10 -

The Sure 4x100 W Class D amps are popular, (are cheap & come pre-built, just add powersupply, prebuilt switchers are often used).

I would use this amp except I need to have independent volume for sub-woofer and satellites and a master volme would be nice too. I was thinking that up to three volume pots in some kind of arrangement could do this but I'm worried the signal will become too weak from an MP3 player. Do you know what specific audio switchers people have been using?

[birdyfoot]

Errrr, on the i-pod dock... How do you feel about a nice, discrete, headphone jack?

DIY is the way to go, especially if you enjoy building things. You can't do better for the money.

A low pass filter allows the passage, or output, of only low frequencies. It is important in a speaker system for each speaker to only play certain desired frequencies based on it's function and it's position in the system. A tweeter needs a high-pass filter. Different drivers or speakers work together to produce a "flat" signal across the entire range of playable frequencies ranging from 0-20000Hz. For this reason a tweeter often also needs an l-pad to reduce it's volume. Speakers working in conjunction must stop and start playing at the same preconfigured frequencies using circuits called crossovers. These can be very easy to design and build.

Box design can vary. Some people use spheres or tubes, or very intricately designed cabinets. I will be building four-sided square/rectangular enclosures. I might do something a little less conventional with the porting. Both the inside volume and the port length are critical to get the best sound out of your specific drivers. This is also easier than it might seem (link).

planet10 -

The Sure 4x100 W Class D amps are popular, (are cheap & come pre-built, just add powersupply, prebuilt switchers are often used).

I would use this amp except I need to have independent volume for sub-woofer and satellites and a master volme would be nice too. I was thinking that up to three volume pots in some kind of arrangement could do this but I'm worried the signal will become too weak from an MP3 player. Do you know what specific audio switchers people have been using?