[audionut71]

I have been busy this week, here's my new experiment.
I have a lot of scrap wood and waaay too many drivers that don't have a project, so here goes...

This is my first crack at designing a crossover from the ground up. The drivers are a Focal 6.5" and the ever popular Dayton 1-1/8" silkie. I am finishing up an enclosure so that I can model both in the box. My first big question is about BSC since this speaker is made to be wall mounted (essentially 2 pi space). Has anybody played with this idea before? What were your findings?

I'll keep you updated.

 

[Aaron Gilbert]

That's a nice cabinet, looks very professional. I look forward to the final results. I don't know what to tell you about Baffle Step Compensation. I don't tend to use it on any of my designs, and like the results. Then again, most of mine are not wall mounted. My latest surround speaker is, and not only that, but it's in the corner of the wall and ceiling. So we'll see how that plays out.

 

[Usil]

I am finishing a Zaph center right now but have already started looking at design concepts for rear surrounds. I sort of envisioned a box like yours but wanted the airyness and 'where'd that sound come from' effect from a dipole. So, I envisioned speakers out of phase on both slanted baffles along with dual tweeters. Had you considered that design plan?

Also, I have found after using audisey I like to increase the decibles by +3 to both rear surrounds. This takes the experience from an occasional rear sound to a more balanced and interactive full time sound experience.

Usil

 

[audionut71]

Usil,
I am considering the possibility of building some dipole surround speakers for the side surrounds of my 7.1, but I think that I want direct radiating rear surrounds. Also I didn't have the appropriate drivers to experiment with the dipoles, but I like the look of these Peerless mid/tweets and a forward facing woofer.

I've been curious about how the Audessy system would account for the null spaces in a dipole surround setup. Makes me wonder....onder:

 

[Usil]

I just have a 5.1 system so my surrounds are located to each side and slightly to the rear of my sitting position. They currently consist of JBL speakers with a small woofer and tweeter. I want to replace these which is why I have been trying to find every DIY on surrounds I can find. Unfortunately, there aren't many.

I am not so much a speaker maker as a speaker assembler. I don't have the tools so I get the boxes from PE, gather the speakers and cross over components and assemble using an already designed cross over schematic. I take the front baffle to a wood shop to have them cut and router the holes. Unfortunately, I don't see any proper rear surround designed boxes like yours I can buy so I will have to see about doing this box myself. Also, I have not seen any cross over designs for dipoles so this may be a problem.

The 2" speakers are interesting as they seem to cover 300 to 3000 hz pretty well. I had not seen these. I have seen someone say in one of these forums that 3" is the minimum size they would use (I think they were bashing Boze) for any speaker but not sure why they said that. Also I am not sure of the power handling you may need but the 2" is maxed out at 60 watts and it might be safer to use 80 to 100 watts if your amplifier is in this range.

I will be following your further development of the cross over. I have read that dipole surrounds do not need BSC since they point in different directions. Mine will be flat on the wall too so this was another reason I thought the dipole might be a better configuration. Frankly, I just can't find enough about DIY surrounds to make an informed decision.

Anyway, I like your system. Let us know the final finished look and how it sounds.

Usil

 

[audionut71]

I got a bit more work in over the weekend, almost ready to start modeling the x-over.

front view (duh)

And the back. I still need to add the keyhole hangers (anybody got anything for flush mounting that is a bit more locked-in?).

I'm going to try to get a few more coats of hi-build primer on today, but it is awfully cold here and I'm not gonna stink up the house...:thud:

 

[audionut71]

Got some quick RTA's done to check out the tweeter level and the difference between testing on a stand 2' from the wall or testing with the speaker on the wall...

The top (blue) line is with the speaker mounted on the wall ( I offset the output by 20dB to make it easier to see) and the lower (green) line is on the stand. Both lines are smoothed (1/3 octave). I'm pretty happy with the x-over region (2500 Hz) and the tweeter to woofer level. The testing was conducted in the basement in a relatively live room (its currently 26 deg outside, so I'm gonna live with some room artifacts on the graphs for a while). Any thoughts?

 

[Aaron Gilbert]

That looks good to me either way, great job! The crossover area and match between drivers looks great. The wall mounting looks ever so slightly smoother on the top end, while the stand mounted looks a little smoother in the midrange. Can you tell much a difference in actual use? They're so close, that whatever it is probably is not major.

 

[JCD]

looks pretty decent to me.. but despite my pontificating around here, I'm an amateur.

When you do these tests, what's the setup? i.e., where is the mic located when you do the tests, where is the speaker in relation to the walls/ceiling/floor, etc?

My only thought is that MAYBE padding the tweeter down a LITTLE bit more might be beneficial. But then, I think I like my speakers less bright than the current mainstream tastes.

 

[audionut71]

Aaron, thanks for the kind words. I have yet to finish them, much less get them into my system. The RTA was to get the crossover finalized and see what the effect of wall mounting would be. They will be foam roller painted with the same flat wall paint (Saratoga Sand) that we painted the upper portion of the walls with.

JCD, My test setup for this round had the speaker on a stand 30" off of a carpeted floor, the wall behind the speaker is wood paneling over drywall, the side walls are both concrete (one is 5' to the left the other is 8' 4" to the right) and the ceiling is 1' square acoustic tiles. The mic was set up 1m from the center point between the tweet and woofer.As mentioned before, the speaker was either 2' from the wall or pushed directly against the wall.

In use the speaker will be mounted 2-3' above the listeners ear level, so I'm guessing that it will roll itself off a bit (I will be testing to confirm this as soon as i get the hangars mounted on the speaker so I can run the speaker on the wall).

 

[audionut71]

And they're up!

aaaand the other side...

My wife is not that enamored of them despite the paint job designed to minimize their appearance. These replace some tower speakers that were sitting on the floor. So much for using the matching paint to camouflage them.

 

[Usil]

They look real good. If you want to hide the speaker wires here is a solution.

http://howtoinstallflatspeakercable.com/

Usil

 

[audionut71]

Usil,
I had never seen the 4 conductor flat stuff before, it looks interesting. I will be running the wires in-wall with in a few weeks, I just wanted to get them up on the wall to see how the sound was. I am really happy with them so far. As I said before, we had towers in the previous iteration, so having these up 2.5' above ear level made a noticeable difference (esp getting them away from firing right into our ears).

 

[Owen Bartley]

Fred, they look good! Any plans for a white grille to make the wife a little happier?

 

[audionut71]

Owen,
No plans for grilles, I kinda like the drivers hanging out in the breeze!