A (late) Statements Build.

[AdelaaR]

Thanks for the hints.
Must continue quest ...

One more question about the foam:
Is the thickness vitally important?
What if I use 2 cm foam whereas an inch is 2,54 cm?

[Jim Holtz]

Thanks for the hints.
Must continue quest ...

One more question about the foam:
Is the thickness vitally important?
What if I use 2 cm foam whereas an inch is 2,54 cm?

I can't answer that question. I don't know that anyone has tried it. The crossover was voiced with 1" thick acoustic foam so some experimentation to get it balanced correctly would probably be required. Try it and see.

Jim

[oneplustwo]

I doubt you will be able to measure or hear a difference using 2.0cm vs. 2.54cm thick foam.

[john trials]

Thanks for the hints.
Must continue quest ...

One more question about the foam:
Is the thickness vitally important?
What if I use 2 cm foam whereas an inch is 2,54 cm?

My full-sized Statements only have foam in two out of the four tunnels. My CC and Monitors don't have any foam in the tunnels. You can experiment and adjust the foam to your liking.

When I first built my full-sized Statements, I made a mistake and only bought enough foam for two of the four tunnels. I stuck my head behind the speakers and listened...the tunnels with foam have VERY little sound coming out, compared with no foam. The difference is huge.

So I guess I'm saying don't worry too much about the foam. You can run 'em without tunnel foam and then add it later (and also adjust the depth and thickness of the foam in the tunnel to your liking).

2cm foam should be fine (I agree with oneplustwo)

[AdelaaR]

Thanks for the responses ... cleared it up for me

Audio is indeed very personal and so I'll experiment and adjust the foam as you suggest.

[Jim Holtz]

Guys, not using foam in the mid tunnels may fit your tastes or your rooms but you should keep in mind, the Statements series speakers crossovers were all voiced using 1" foam in the mid tunnels with the speakers positioned about 18" out from the back of the speaker to a wall behind them.

However, experimenting is the "Y" in DIY so have at it.

Jim

[AdelaaR]

Today I went to pick up my preveneered MDF.
Turns out they have a huge CNC machine there that can automatically cut MDF to size
Only problem was that my plans used 19mm MDF and they only had 18mm so I'll have to adjust all my plans and send 'em over to auto-process.

I know it's weak to let them do it with the supermachine but it's dirt cheap and oh so accurate

I already had them cut the baffles for now:

Image not available

[AdelaaR]

Today I finally came around to adjusting my blueprints to accomodate 18mm MDF ... took me about 2 hours until I was sure everything was correct.

[BeerParty]

I already had them cut the baffles for now:

Image not available

Have you mocked up the drivers on these baffles yet? That is some pretty serious looking 'grain' on those panels, so you will want to make sure you figure out which way up looks best before you cut the driver holes.

[AdelaaR]

Yeah I did think about that but haven't tested it yet.
I thought of doing a simple photoshop overlay to get an idea.

[AdelaaR]

Made a simple overlay ... quality isn't great but it clearly shows to me that my initial thought of putting them like I did was best

Image not available

[AdelaaR]

Hi there ... quite some time of no speaker building as I have been way too busy training for cycling time trials and working on my house and whatnot.
I have since made some small cabinets for rear speakers in my car, but those were so easy I didn't even have the time to take pictures before they were done.
Soon, however, I will be making the multimedia room in my house where the statements will reside.
Most of this room will be covered in absorbing material to be almost anaechoic for doing recordings ... my new idea, however, is to integrate the reflecting rear corners of the walls necessary for the statements into the room itself by recessing that part and not covering it with absorbing material.

So my question is: what is best to make this out of?
Will painted MDF suffice?

[Curt C]

Yes, but drywall will be just as effective and much cheaper...

-That near anechoic room may sound a bit unsettling to some. You might experiment a bit to before you 'nail everything down'.

C

[john trials]

Yeah, I agree with Curt. You might want to read "Sound Reproduction: The Acoustics and Psychoacoustics of Loudspeakers and Rooms" by Floyd Toole, before you start your multimedia room. Sound reflections are good for music reproduction.

MANY years ago I went on a college tour, and at one college, I got to hear a talk about the mechanical engineering department while inside an anechoic chamber. I fell in love with the quietness of the room. I've wanted one ever since, but it would not be for music-listening enjoyment. Sometimes I just would like 'total' silence.

[AdelaaR]

Thanks for raising this concern guys.
I will actually build the walls in stages.
First I'll make a simple wooden cage construction inside the room with rockwool insulation in it and gyproc drywall panels to finish it off. That fake wall will be seperated from the actual brick walls behind it to be as sound proof as possible within my space and budget. That should suffice for the bass tones.
Then ... after that ... I'll add panels with rockwool and tissue to kill the reflections of the higher tones.
thin MDF isn't a lot more expensive around here than gyproc panels are so I think I'll go for the MDF then.

[Curt C]

I figured you had already considered this at length, but would have felt I'd been negligent if I didn't mention it.

Properly executed, the double wall construction may double as bass traps.

C

[AdelaaR]

I will look into that book you mentioned, John. Thanks.

[AdelaaR]

I have been busy lately reading the book you mentioned John ... thanks for that.
Apparently I was completely lost and now I'm found
After reading the book I have made a new plan for my audio room in which portions of the front and rear wall will be covered with absorbing material and the sides will remain drywall.
I have started constructing the room and the floor is now remade with rockwool under it ... later it will most likely be treated with cork panels.
I'll post some pictures soon.
Thanks again for the helpful replies.

[AdelaaR]

I've been reading up on room acoustics a lot lately and have decided to integrate QRD diffusers in my studio (I call it studio since it will be computer room, music making room, music listening room and home cinema in one)
I've made a 3D preview to get an idea:

Image not available

The diffusers will be DIY based on existing designs and they will be mounted on doors.
The door/diffuser on the front left will be the entrance door of the room and the door/diffuser on the far right will give access to a cabinet in which my computer and other networking equipment will reside. This cabinet will be externally vented to my garage just behind it to make sure no fan noise whatsoever can interfere with the studio.
The two remaining doors/diffusers will simply be cabinets to put stuff in.
The whole roof and parts of the walls will act as basstraps.
Obviously my computer desk will reside in the center between the statements ... I didn't draw it because that would take more time than I was willing to put into this image.
The computer desk will probably double as a subwoofer cabinet ... still contemplating that design somewhere subconsciously.

[Hdale85]

Isn't that too close to the walls?

[Jim Holtz]

The walls are too close and Statements are designed to be listened to off axis with no toe in. The Kahnspires will work that way but not Statements.

Jim

[AdelaaR]

Well ... sadly my room isn't very big
I was planning on adding basstraps in the walls at the height of the woofers to "make the statements believe they are further from the walls" ... could that work?
In fact ... the whole room is a room-in-room construction suspended on rubber with loads of rockwool insulation all over the place ... I hope this could make the proximity to the walls ok.
About the axis ... I want to use these speakers for both movies and computer so the idea is to place them "off axis" in the sense that the axis will be somewhere between the computer position and the sofa position ... I know that's a compromise but it'll have to be so I'm afraid.

[Jim Holtz]

Honestly, I don't think Statements are your best choice and may be a bad choice for your room. Speakers with open back mids require plenty of breathing room or they simply won't sound good. Also, look for a design with an offset tweeter. They are designed to be toed in.

Sorry, I'd not suggest the Statements for your room.

Jim

[AdelaaR]

Your concern is welcome, Jim.
However ... the wood for the statements is already cut and the drivers are already acquired, so not building the statements is simply not an option ... which is a good thing, because I'll have the pleasure and challenge of building them
I will add special basstraps around the top and bottom of the speakers to compensate for near wall placement and I will add recessed cavities behind the mid tunnels for more breathing room. I could even place custom diffusers in those for added dispersion.
I can also place them a bit more forward than in the picture, which is just a picture to get an idea and not an actual centimeter exact plan.

If ... after all this ... it turns out that I'm not satisfied with the statements in this way ... I can always still give them to someone I know and build something else.

The result is important, but the road to it is what makes it fun

[AdelaaR]

Construction has started:

Image not available

Still very basic at this point ... just the start of wooden frames and the basic of the floor is done.
The hole in the wall is where my computer/network cabinet will be and this way it's ventilation will be routed to the garage next to it.
The red plastic tubes will connect the cabinet to the rest of the cabling system in my house for domotica, networking and audio.

[AdelaaR]

Construction of the studio is slowly progressing ... special designated cabinets have been built to provide breathing room for the open mids.

Image not available

To have some experience with simple cabinet building, flush mounting and other things before actually starting the statements, I have decided to build the F4's, which will act as surrounds, first.
I changed the design just a bit to accommodate me and to complement the design of my custom statements to come ... that's why I used the same per-veneered MDF as front baffles and decided to use a tube port that looks almost identical to the one I'll use on the statements.

Image not available

I have very basic tools like a drill, a circular saw, a plunge router and an electric jig saw but they were enough to complete the work.
I decided to "cheat" a bit by putting the cabinets together with glue and a nail gun.
After a long afternoon of work, this is the result for now:

Image not available

I forgot to route the back of the driver-hole on the first cabinet I glued together, so I'll have to figure out a way tomorrow to be able to fix that from the outside ... a drill and an outward facing router bit should do it, I hope.

[mtmpenn]

Looks great! I suggest a sanding wheel in a dremel or a hand rasp.

[AdelaaR]

I managed to trim the sides of the driver hole from the outside by using a drill and a dovetail type router bit.
I'm now in the process of sanding and priming the cabinets.
It's going to take quite a few coats to get all of the MDF edges out, but I've got time since I have to wait for the cross-over components to arrive anyway.

Image not available

[AdelaaR]

I've been thinking about the concept of my studio lately and specifically about the compromise of having two different listening positions being the computer desk in front and the couch in the back.
I've finally decided that, since this is my studio being designed and build from scratch, I should not take the compromise option of having one set of speakers for both positions.

Taking the advice from Curt and Jim ... I shall place the statements as intended, facing directly in front and thus of axis to the couch and unusable for the computer. They were unusable for the computer position all along ... but now I finally came to admitting it
Then ... I decided to make an actual statement center chanel that will be suspended from the ceiling above the computer desk and aimed at the couch just above the projection screen.
In this configuration the F4's as surrounds will also be aimed directly at the couch position.
To sum it up: The couch position will have a projection screen with statements as main, statement CC and 4 F4's as surrounds.

For the computer desk position I will install a completely different surround system, be it far less advanced and far more budget. In fact, I have a basic Creative 5.1 set lying around somewhere that can be used and eventually upgraded with some 2-way monitors, for instance.
This set will of course be positioned in such a way that it is ideal for computer use.

I'm glad to have finally given in to the light ;x(

[AdelaaR]

I made a little drawing of the new system:

Image not available

[AdelaaR]

The crossover components and other things for the F4's arrived today.
I tried to assemble the crossover, but found it hard to fit 4 inductors on such a small space.
Here's a mock-up:

Image not available

Does that look right?
Is there a better way to position the coils?
I want to keep it small so to fit on a little 12mm MDF board and be placed in the top of the cabinet.

[Jim Holtz]

Here's a guideline to go by...



Jim

[AdelaaR]

Thanks for trying to help me there, Jim, but I had already found that exact same guideline floating around here somewhere.
Thing is: in such a small space as the inside of an F4 ... with 4 inductors on one crossover ... it's near impossible to not be in the "problematic" zone.
However ... I assume, since it makes sense, that the distance the inductors should be apart (when in the same planar field) is related to their inductance values, right?
In that case the guideline comes a bit short at fully explaining the problem.

[AdelaaR]

I made the crossovers for the F4's:

Image not available

They're not pretty, with all that Tec7 glue on them, but I'm a bit worried about crossovers and their copper wires vibrating with the low frequencies inside the cabinets and I figured: "a little more glue certainly won't hurt"

[AdelaaR]

The F4's are all done
Too busy listening to them right now to post pictures though.

[AdelaaR]

Here they are:

Image not available

As mentioned before, they're a bit customized with front port and removable back panel.
The finishing on the paint isn't all that ... but for a first build I'm pleased enough.
The sound quality is superb, for a single driver, but since I'm used to three way speakers I'm not overly impressed by their "presence" for stereo music listening.
This will not be a problem once hooked up to my 7.1 HT setup, where they will be used as surrounds only.

Big thanks to Jed for the design :T

[AdelaaR]

Construction of the actual Statements has started.
I did the front baffle of the center channel yesterday ... pics soon.

The parts arrived and apparently they sent me the new RS180-8's.
If I understand correctly what I've been reading about the new drivers ... I should reduce the cabinet volume to 80%, which would come in handy for a seperate crossover compartment, but I assume that means I need to re-tune the port, right?
I've been experimenting with WinISD a bit lately and so I could run a simulation of the new drivers in a smaller box
... but my question is:
"what frequency should I tune the port to?"

[Jim Holtz]

Here's the simple solution. Just build them exactly as speced with the new RS225-8's and the same port length. They'll work perfectly.

You do not have to change cabinet size or port length.

Jim

[AdelaaR]

Nice to know ... but as you can probably tell from my previous posts I do not like simple solutions.
I'll figure it out

[AdelaaR]

I did some calculations and they tell me the original CC was tuned at 32,57 Hz.
Reducing the box volume to 33 liters and keeping that same tuning ... I arrive at a 8.67" port of 2.5".
But indeed ... the response looks quite similar between the two.
Nevertheless: a reduce to 33 liters will give me some place for a crossover compartment ... in fact: according to some additional calculus that compartment could have a depth of about 6,5 centimeters, which is exactly enough to fit that huge inductor and those big 68µF caps

[Jim Holtz]

I did some calculations and they tell me the original CC was tuned at 32,57 Hz.
Reducing the box volume to 33 liters and keeping that same tuning ... I arrive at a 8.67" port of 2.5".
But indeed ... the response looks quite similar between the two.
Nevertheless: a reduce to 33 liters will give me some place for a crossover compartment ... in fact: according to some additional calculus that compartment could have a depth of about 6,5 centimeters, which is exactly enough to fit that huge inductor and those big 68µF caps

Full sized Statements? 33 liters? Nope.....

The original Statements netted at 100 liters plus the mid tunnels and bracing. The new woofers will work with 70 liters plus mid tunnels and bracing for the pair. But and it's a big but, the depth and width need to remain the same or VERY close to it.

Jim

[AdelaaR]

I was talking about the center channel there, Jim

A picture would help clear things up ... right now the front baffle is being pressed under a pile of beercrates to glue the two bafflepieces together, but I'll post pics tomorrow.

[AdelaaR]

Front baffle for the center channel:

Image not available

Backside:

Image not available

I put the speakers in it yesterday evening to check out how it'll look with drivers mounted and wow is that thing heavy already

[LesPaulMan]

Jim, or others.

What would be the minimum room dimensions to get the best 2 channel performance out of a pair of Statements?

TIA.

[AdelaaR]

Jim, or others.

What would be the minimum room dimensions to get the best 2 channel performance out of a pair of Statements?

TIA.

I think it's going to depend on the construction of the room, since the main problem with small rooms (and nearly all amateur listening rooms are small) is bass management.
I've got a pretty small room, but I have the option to design it completely the way I want it.
Here's a picture I just took of the progress so far:

Image not available

I know the main compromise is that my room isn't very big, but if you look closely, you will see that I have made special reflection cavities behind the midrange tunnels to let them breathe ... then, on top of that, the whole corner space under and above these cavities will be treated with bitumen (roofing), rockwool and cloth to absorb low frequencies.
In fact, the whole room is a "bass trap", making it virtually bigger (or at least it should).
Then ... I will add QRD diffusers on the first reflection points to make it sound even bigger. The fact that the Statements will be positioned off-axis pointing straight ahead will help here, since they are partly pointed at the walls where these diffusers will be placed

Here's a picture of the finished front baffles, with front ports mounted:

Image not available

I'm thinking of adding a 2D QRD on the back wall, so it will be behind the suspended center channel and also because it looks cool, especially with the multicolor LED system I'm planning