DIY Sound Group The 893 & Volt 8 Build Thread

[sjackson]

So my plan is to build a trio of DIY Sound Group's "The 893" speakers for my front left/centre/right in addition to 4 of their "Volt 8" speakers for surrounds and rears. I currently already have 4 Monitor Audio 265-IDC's in my ceiling for future Atmos duties. Depending on how the Monitor Audios work with the Volt 8's, I may think about replacing them (MA's) with Volt 6's.

I only ordered the kits and I did not buy the flat packs mainly as I felt they would add too much to the overall shipping costs to have them sent over from the USA.

As I don't have the flat packs, I'll call into B&Q and have them cut me up some MDF sheets. I'm aiming to have them as shallow as possible which means I need to build them taller to get the correct volume. With this in mind and the dimensions of an MDF sheet, my speakers will be the below sizes:

• 893's - 1224mm tall (full width of an MDF sheet), 260mm wide (width of the supplied baffle) and and around 200mm deep.
• Volt 8's - 611mm tall (half width of MDF sheet), 280mm wide (width of supplied baffle) and around 125mm deep.

At this stage I just want to point out to people that the baffles are supplied in 3/4 inch MDF which is not the same as our 18mm MDF. 3/4 inch actually adds up to 19.05mm so is slightly over 1mm thicker.

First impressions
The 893 baffle is smaller than I expected. Not sure why as I had measured it out a few times prior to ordering. The baffle is really solid and very well cut out. Having a supplied baffle will make this job and awful lot easier.

The Volt 8 baffle was much bigger than I expected and to be honest I think they are too big. I should have bought the Volt 6's as the 8's I'm expecting to be overkill for my smallish room. That said I did read that the 8's were a significant upgrade over the 6's. Maybe I'll change my mind once built but for now I may have made the wrong choice. People who buy the Volt 10's for surrounds in a small room are bat$hit crazy - I'd be afraid they'd blow my head off!

Anyway, the first of hopefully many photos. 4 of the 5 boxes of bits that DHL delivered.

All photos now here: 2015-12-12 - DIYSG Speakers

 

[sjackson]

First job to get working on was the crossovers. As I had a spare couple of hours today I decided to assemble and glue down the crossover components with my newly acquired glue gun. I will solder them at a later date, tomorrow maybe but for now I just wanted to get all the parts laid out.

All the crossover parts grouped together

My new glue gun. Only £7 or so off Amazon UK and worth every penny.

And all the components glued down, just waiting to be soldered.

 

[soupdragon]

Good luck!

Looking forward to see how you get on

 

[sjackson]

Paid a visit to B&Q today and had a 12mm and an 18mm sheet of MDF cut up to size. Also passed Maplins so picked up a new soldering iron as my last one must be 10 years old.

Decided to test fit one of The 893 speakers to get an idea of size. It's huge! The standard cabinet for these speakers is 12.5 inches deep (312.5mm) whereas I'm going 8" (200mm) so hence the height.

And a bottle of booze for scale

 

[LuisV]

Are you going ported or sealed? Quad woofer?

 

[sjackson]

Are you going ported or sealed? Quad woofer?

I'm going sealed. If I was to go ported, I'd need a box around 2.5 times the size of what I'm building which I don't have space for. I have two SI HT18" subwoofer drivers which I'll use to build a couple of subs with so that should handle the bass.

Dual vs quad is one I've been struggling with for a while but for now I'm building the dual version. The box I have designed will work perfectly for the quad version also if I add around 25mm to 50mm (1 - 2 inches) in depth. Once I have the duals built and tested I'll make a decision on whether to upgrade to the quads. I only need to order the extra drivers and a normal sized baffle to build the same box but a little deeper. For me it's about space and what I can fit behind the projector screen.

That said I think the quads would look amazing in my room and probably sound incredible. I dare to think what a pair of them ported for stereo duties could produce but in fairness now many people would have room for what I'm guessing would be a 250 litre box.

 

[LuisV]

Hmm... I though there was a change required on the crossover to go with the quads? If not, that's good to hear as it's it easier down the road to add the additional drivers. What size is your room? I was also thinking of going with the Volts, but haven't decided on the 6 or 8 yet.

 

[sjackson]

Hmm... I though there was a change required on the crossover to go with the quads? If not, that's good to hear as it's it easier down the road to add the additional drivers. What size is your room? I was also thinking of going with the Volts, but haven't decided on the 6 or 8 yet.

Sorry yes there is a change to the crossover which I forgot to mention. I don't think it's a change to the topology, just changes to the values of components.

Get the Volt 6 unless your room is about 20 or 30 feet wide.....

 

[LuisV]

No problem, just wanted to make sure about the crossover parts as I considered the quad setup, but I'm not 100% sure yet; however, I'm building towers for sure. Looking forward to your build as well as your impressions on how they sound within your room.

My room is approx. 20 x 18, with the screen on the longer wall. What's the size of your room?

 

[sjackson]

My room is approx. 20 x 18, with the screen on the longer wall. What's the size of your room?

About 22 x 14 but where the surrounds it's only about 10 or 11 feet wide. Too small for Volt 8's I think.

 

[sjackson]

Decided to list my Volt 8's in the classifieds if anyone is interested. Think they are just too big for my room so I'm going to get some Volt 6's instead.

 

[mattkhan]

Have you considered them sealed instead? Would reduce the enclosure volume and baffle size somewhat. I can model it if you need.

 

[sjackson]

Have you considered them sealed instead? Would reduce the enclosure volume and baffle size somewhat. I can model it if you need.

Sealed is certainly an option but would mean crossing at 120hz so they might be a bit bass light. The recommended volume is 0.2 - 0.3 cubic feet which is 260mm x 260mm x 130mm (with 12mm MDF so slightly larger when using 18mm)

 

[mattkhan]

Sealed is certainly an option but would mean crossing at 120hz so they might be a bit bass light.

A smaller coax might be a bit bass light too

 

[sjackson]

A smaller coax might be a bit bass light too

True that... According to the designer the ported Volt 6 is crossed at 75hz (0.15 ft3) and 65hz (0.35ft3).

The other option is cutting the Volt 8 baffle down to 230mm wide and 130 deep while leaving it around 600mm tall. Gives me about 70hz @ 0.4ft3. 230mm wide is not leaving much considering the driver itself is almost 210mm wide and the ports would only be a few mm's from the side walls.

 

[mattkhan]

Is it an in wall column or on wall? 10mm either side for the outer cutout is fine

 

[sjackson]

Is it an in wall column or on wall? 10mm either side for the outer cutout is fine

On wall and you can see where they are going in this post (where I've channelled out the walls and run speaker cable down)
Doing up the Sitting Room & a DIY Pelmet

If I cut the included baffle down to 230mm wide that means they are only 30mm wider than the Volt 6's which is not much really. Not too concerned with the height of them, just that they would be massive in that small space.

 

[mattkhan]

my bet is you won't notice them once they are in position and you've used the room a while, at least it usually works that way for me!!

 

[sjackson]

my bet is you won't notice them once they are in position and you've used the room a while, at least it usually works that way for me!!

Maybe so, just hope the kids don't crack their heads off them! I'll see how it goes anyway - have removed the ad from the classifieds.... Cheers

 

[sjackson]

A little more progress last night as I began soldering up the Volt 8 boards. I still need to add the 4.8mm female spades to the ends of the wires.

I have to say the included crossover boards make the soldering a very easy job.

 

[sjackson]

A little bit more soldering last night and now have The 893 boards complete. I'll probably get my little labelling machine out at some stage and label what all the little green terminals are for.

 

[sjackson]

I'm going to discuss my Left/Right speaker wall mounting options now and the train of thought I'm running with. Here's a photo of the room while I was building the pelmet.

The 893's will be going in place of the Apex 40's and I'll be positioning the tweeter at around 900mm to 950mm off the ground. From the side of the screen to the side wall I have around 400mm, from the bottom screen weight bar to the side wall is around 300mm and from the screen to the back wall it's 250mm. I'm building the speakers to be 260mm wide and 198mm deep.

So looking at the numbers, the speakers should fit nicely where the Apex 40's are but with one problem - I'll more then likely need to toe them in towards the MLP. When toeing in, I'm rapidly going to start eating up the 50mm space I have between speaker and screen so I had an idea...... Why not sound the speakers to TV cantilever brackets which will give me loads of flexibility to move the speakers around to get the right angle? Or even with a cantilever arm I could place the speakers in front of the screen if I wanted.

So my plan is to mount two sets of T-nuts like the below

on the back of each speaker in a VESA 100 or 200 pattern. I'll use two heavy weight TV cantilever brackets for each speaker which can be tightened up so the speaker should be quite solid (I have an impact gun should should get them tight). Here's the brackets I bought:
VonHaus Ultra Slim Design Wall Bracket for 26-55 inch LCD/LED/Plasma TV Max VESA 400x400mm Weight Capacity 40kgs: Amazon.co.uk: TV

I deliberately bought from Amazon as I can return very easily if I don't think they are up to the job.

While I'm sure I can tighten them up fairly good I'm guessing I'm not going to get them rock solid. I'll see how it goes but if I feel there needs to be absolutely no movement I can easily buy new "fixed" brackets or have ones made up. The fact that I'm using VESA spec gives me loads of scope for wall brackets. If I decide to sit them on top of a pair of subs I can just put bolts into the T-nuts to fill them and a drop of loctite.

 

[mattkhan]

So looking at the numbers, the speakers should fit nicely where the Apex 40's are but with one problem - I'll more then likely need to toe them in towards the MLP.

what's the angle from the speaker to the MLP?

 

[sjackson]

what's the angle from the speaker to the MLP?

20 degrees I think or thereabouts.

 

[mattkhan]

20 degrees I think or thereabouts.

SEOS waveguides are designed to offer control to 90 degrees in their target range so this means you wouldn't necessarily have to toe in to achieve a decent coverage of the listening position. The proximity of the wall means you might want to do so to attenuate the ipsilateral reflection but then that will just make the contralateral reflection stronger. The flexibility to adjust to preference is probably a good one to have though.