Airplay Hifi Tower Speakers + Subwoofer

Thanks for checking out my instuctable on how I built my 2 living room Hifi Floor standing Speakers + subwoofer and centre speakers.

This speaker set includes a 200 watt RMS subwoofer, 2x 50 watt centre speakers and 2x 800mm high 3 way speaker towers @ 300 Watt each. My Onkyo HT-S3700 5.1-Channel Home theatre amp powers the system.

The amp comes as a kit with tiny speakers that are really loud but not as full bodied in the midrange frequencies. So I decided to build my own mid woofer speakers. The amp has front, rear and centre outputs but as I have only built 2 floorstanding speakers i'm still using the small stock rear speakers to keep the full surround sound effect.

The speaker drivers (Inc the subwoofer) were taken from a sony hifi system. (More on this later)

MDF, lots of MDF. Or a dense hard wood if you like that prestige look. To keep the cost of the build down, I used MDF.

Materials;

mdf sheets - I used 3 sheets in total (1.8m x 800mm @ 16mm thick)

Wood Glue

fibre padding (Bed sheet stuffing)

30mm wood screws

Audio materials:

Speaker drivers taken from sony HiFi system - (MGH RG440S) (2x mid woofers, 2x mid/high woofers, 2x tweeters, 1x 8" subwoofer) Centre speakers were from a previous build - unknown make/model. (3" 50watt drivers @ 6ohm)

Reel of speaker wire (I used copper premium oxygen free)

Onkyo HT-S3700 5.1-Channel Home Theater Receiver amplifier

3-way passive crossover - (to split the audio frequencies)

Tools;

table saw

router

cordless/ corded drill

General hand tools as required

Clamps were my friends in this build.

Speaker drivers are designed to work with a finite amount of free air within the enclosure. The free air resonates the frequencies produced by the drivers. So with this in mind, I needed to design my speaker enclosures so that they were tuned to these exact speaker driver requirements. The tweeter is self enclosed and so would perform regardless.

Ultimately I could not find the required parameters needed to design the speaker enclosure. So I designe my enclosures to match the internal free air volume of the original sony hifi speakers. Although mine are twice the height, there is a baffle half way up. Thus creating the same sized space of free air as the sony enclosure. So I get the correct sound from these drivers...

Unfortunately I had exactly the same issue with the subwoofer. I could not find any of the performance data needed to calculate the required volume for a ported or sealed unit. So I had to follow the existing enclosures internal volume and port size. In order to design the enclosure from scratch you need intricate details about the drivers like the resonate freq and the air displacement of the unit. Something you won't get looking at the manual of a hifi system or the back of the speaker. Although this may be outside the scope of this instructable, some may find it useful. Providing you know this information you can use this fantastic calculator to work our what type, shape and size your new enclosure needs or could be.

http://www.diyaudioandvideo.com/Calculator/Box/

The enclosure construction is relatively simple when you know the size requirements. My design used the following cabinet dimensions.

Tower speakers x 2

800mm tall

200mm wide

200mm deep

Each face is 200mm wide by 800mm long. Then I cut a square for the top and the bottom @ 200mm x 190mm. The 10mm decrease is for a curved strip 10mm thick. In retrospect I should have cut the top and bottom square at 200mm and used the router with an edging bit to achieve the curve. This is how I did it for the long edges.

Subwoofer and centre speaker enclosure

750mm long

350mm wide

250mm deep

Internal dividers as per image

2x 318mm by 218mm (outer dividers)

2x 288mm by 218mm (inner dividers)

These dividers form the slot ports. (More later)

So basically I cut my MDF to form the above enclosure sizes.

> Now it's time to put that pile of mdf together. I started with the back panel of each speaker, sat them side by side and glued the sides down. Sitting them next to each other kept the sides square. I also added curved timber strips to strengthen the joints. House bricks kept the pressure on while the glue set.

> I then glued in the middle baffle. Finally I glued on the front face and the curved strip at the top and bottom.

> I let the glue set overnight.

> Next, I fixed into place the top but not the bottom. This would allow me access later to wire in the crossover and the drivers.

> I then marked out where the speaker holes needed to be cut, drilled a 15mm hole as a start point and used a jigsaw to cut the three circles out on each face.

> Before screwing the drivers in place I added speaker wire.

> After fixing the speaker drivers in with 4 screws each I connected the corresponding speakers to the 3-way crossover. The crossover takes the full frequency range and splits it three ways - low hz go to the mid woofer. Mid hz go to the middle woofer suited to slightly higher ranges and the hi hz range is filtered and passed onto the tweeter. This dramatically improves the performance of each driver and ultimately the overall sound quality. Each speaker has less work to do relatively speaking thus allowing them to produce more accurate sound rather than trying to reproduce the entire freq range.

The crossover was similar to this one

http://www.amazon.com/PASSIVE-3WAY-CROSSOVER-SPEAK...

> I cut a square out the back of the speaker and screwed the crossover board/terminals into place.

> I filled the enclosure with bedding ( literally from a bed cover) and screwed the bottom cover on. No glue - so I can access the internals later if needed.

When the tower speakers were assembled I took my router and curved the front face edges

> To finish off the speakers I used self adhesive vinyl floor planks (silver grey wood effect) and stuck them onto the sides and top of the units. I used several sharp blades to trim the vinyl planks to size after they had adhered. This was a great easy way to cover the speakers.

> I decided to leave the front faces as virgin timber just because I liked the raw look. I think I will make a speaker grill for them at some point though.

The principals of the subwoofer enclosure are the same as the tower speakers. I build the box larger and created a smaller internal enclosure to house the correct amount of air volume required for the subwoofer based on a ported design. Ported designs offer lower base reproduction but require higher wattage relatively speaking. Sealed enclosures offer "punchier" mid level base but don't hit as low notes. The original sony subwoofer enclosure was ported, so I copied the port size and enclosure volume. I made the sub enclosure larger to accommodate the centre speakers powered by the centre channel on the amp. This is basically a sub/centre sound bar only larger I have it under the tv stand. Again as before I will make a speaker grill in the near future.

> Using the already cut mdf pieces i glued together the enclosure starting with the bottom panel. I used a square to everything true and straight.

> I glued the inner and outer baffles in place then cut out the long ports and the circles for the speakers. The ports were based on the original sony port halved and stretched to create two slots equal in size to the original.

> I then installed the speaker terminals and wired them all back through. The terminals I purchased of eBay. The were twist on so no soldering required.

> I filled the subwoofer inner area with bedding again.

I decided to leave the vinyl planks as where I have the speaker obscures all sides except the front face so it didnt matter. Otherwise I would have covered this too.

The connections are as follows;

Tower speakers connect to front right + left channel on the amp

subwoofer connect to "Sub out" on amp

Centre speakers connect to "Centre" on amp

These speakers sound fantastic. They are acoustically tuned for performance and produce a great all round sound. The subwoofer can be adjusted via the amp. The amp also has presets like movie, game and rock/pop etc.

The amp powers the speakers as follows

Left = 120w

Right = 120w

Centre = 120w

Sub = 130w

All at 6ohm

The main feature I wanted for this speaker was for it to be wireless and run using the airplay protocol. My apple Airport express connects to the amps aux in port. I can then set it up on my network so that I can connect to it and stream audio.
Weather you want to connect to this speaker with single device such as an Iphone or use it like I did in my multi speaker configuration the set up is the same. Your smart phone will see one or more devices and you simply select which one you want to use. If you're doing it the way I am, you need a windows platform and airfoil software. To keep things clean and simple I used a cheap Windows 8.1 based tablet. Small and light like an ipad but a fully functioning windows environment. More info on how I set up the speakers can be found in the last step.

As each home is different you may want to follow the official apple set up guid as this details each possible scenario.

http://support.apple.com/en-au/HT202192

This speaker was part of a set of 5 that make up my wireless multi-room audio hifi system. If you are not interested in making more than one speaker or playing audio in multiple rooms wirelessly you can skip this step.

I put together 5 speakers in total. Each can be found on instructable on my user page (Links below). Each one is designed with an apple airport express hidden inside. This allows them to connect to my existing wifi network at home. When each is connected, a piece of software called Airfoil can detect them as airplay speakers. (you can name each speaker for easy identification). I run this application on a small windows 8.1 tablet. (cost $199 of amazon.com).

In summary - I control each of the five speakers from the tablet. I can adjust the volume globally or individually on each speaker. Airfoil captures the tablets audio output regardless of the source. I simply tap the Airfoil icon and it auto opens Spotify and begins capturing its audio output and broadcasts it out to each of the speakers. It calculates the distance of each speaker from the router (directly related to transmission time) keeping everything in sync and eco/delay free.

Check the app out on the publishers website here...

http://www.rogueamoeba.com/airfoil/

I also listen to mixes on youtube and using this method allows me to hear it in every room. I can also play tunes on single speakers if needed. Just hit the mute button in the app on the other speakers. As a final added bonus - Each airport express can extend my wifi range by a significant radius and a USB device can be attached to each one. You can make a usb printer wireless or attached storage etc... I didn't utilise this feature but it was tempting and it may come in handy in the future.

Thanks for looking at my wifi speaker instructable. As mentioned, you can see the other four on my user page and if you think any of them are worthy, please vote for them. If you are looking to make something similar and have any questions, comments or issues please feel free to message me.

Speaker One - Minimal Tower Speaker

https://www.instructables.com/id/EGVDEVUI5YB0PIB/

Speaker Two - Minimal Cube Speaker

https://www.instructables.com/id/EGVDEVUI5YB0PIB/

Speaker Three - Apocalypse Robot

https://www.instructables.com/id/EGVDEVUI5YB0PIB/

Speaker Four - Full Hifi tower speaker & Subwoofer -(This Speaker)

https://www.instructables.com/id/EGVDEVUI5YB0PIB/

Speaker Five - Kandi Skull Portable speaker

https://www.instructables.com/id/EGVDEVUI5YB0PIB/