ARES24

ARES24

Full Audioholic
New DIY ER15 Center Channel Speaker

After building a set of ER18 towers I tested a couple center channels. One I liked but it couldn't keep up at higher listening levels. So the search for a replacement was on. I went to a couple AV stores and picked out a couple that I wanted to try out (purchasing a speaker from Salk wasn't in the budget). Before I got to the testing phase I had the same thought that got me the ER18's "I wonder what's out there that I can do myself?"
I hadn't seen many options of DIY center channels that had the specs I was looking for;
1. I wanted to use similar drivers (wasn't a requirement but was taken into consideration) in hopes that the speaker would voice the same.
2. Equivalent(ish) power handling
3. Front port to help placement options

I asked on the forum but was told to simplify my life and just ask the guy that co-designed the ER18 towers, so I did. Dennis was VERY helpful. He didn't have the specs for the cabinet but did have a finished version. He sent me a couple pictures and the outside dimensions along with the crossover schematics.

The unit is 19.5" W (495mm) * 9.5" H (241mm) * 12" D (305mm) with a slot port 25.5mm H *132mm W * 123mm D. Dennis sent me the crossovers drawn up in the program that he uses to design crossovers but Swerd redrew them in an easier to read format. I had to guesstimate the location of the drivers based on the pictures I received. I came up with the tweeter 3.4375"([SUP]7/16[/SUP]) down from the top (exterior) centered. The woofers are centered 3.9375" ([SUP]15/16[/SUP]) from the sides and down 4.3125"([SUP]5/16[/SUP]) from the top (exterior). And the port directly on the bottom panel.
 
ARES24

ARES24

Full Audioholic
On to the construction;

I had some mdf in the garage so I designed a cabinet using ER18's as a reference point. For the build I dado'ed all joints. If you would like to butt joint you will have to do a little math :D. These are the exact measurements for the finished pieces (in reality I made many of them a bit large and routered the excess off with a flush cut bit after assembly)

Pieces;
Sides - 10.75" * 9"
Top & Bottom - 19" * 10.75
Back & Outer Front Baffle - 19.5" * 9.5"
Inner Front Baffle - 18" * 8"
Braces - 8.5" * 10.25"
Port Pieces - 5.6875 ([SUP]11/16[/SUP]) * 4.0625 ([SUP]1/16[/SUP])
2 - 2" * 4.0625 ([SUP]1/16[/SUP])
** note: In my design the two 2" pieces are dadoed. Dadoing pieces that small I would deem unwise, therefore dado a larger piece that you can then cut the small pieces off of. Remember; 38000 people in America visit the emergency room due to table saws every year.

Dadoing the pieces is somewhat more complicated, I feel that though it is possible with a router a table saw is far easier.

The braces are directly behind the woofers, centered 3.9375" ([SUP]15/16[/SUP]) from the outside of the cabinet. The cutouts in the braces are 5.75" (the same as the woofer outside diameter), one centered behind the woofer 0.5" in from the front and the other EXACTLY where I thought it looked good :D.
I could go through the minutia of how to dado each piece but pictures are so much better.
Dry fit everything before you glue anything!! Sounds obvious but DO IT!

The inner front baffle is glued and screwed to the outer front baffle. I did it before I did the driver cut outs. Doing the cut out for this tweeter is a pain, carefully cutting out a pattern out of scrap that you can then just copy would be the best. Especially if you ever need to cut out for another speaker.
After all the pieces are cut out I used a 1/4" rounding bit over all the square corners on the inside of the cabinet. After all this effort why stop short of this.

I assembled the crossover on a piece of peg board and installed it prior to attaching the front baffle. The crossover is installed on stands so that the dacron used for batting doesn't get crushed.
One inch dacron covers the interior of the cabinet on all sides except the front.

Finishing the cabinet is a personal preference so I won't bother detailing mine.

Listening Impressions; wow... The ER18's that I built are the best sounding speakers that I have heard. This center channel matches in beautifully. I would say that it doesn't have the same low end that the towers have but that is expected. Now when I say that it doesn't have the same low end I DO NOT mean that it lacks bass at all. I don't have any testing equipment but I would guess conservatively that the speaker might begin to roll off around 45Hz.
The bad thing about this speaker is that it makes me want to build more and use them for my surrounds :D But for now I still consider that overkill and have bigger fish to fry.

Apparently this speaker is gaining traction, there is now a kit put together available from Meniscus Audio (it is where I got the pieces for my build).

I highly recommend this speaker to anyone who wants a DIY center channel.
 
F

fokakis1

Audioholic Intern
Awesome work! I like how you went all out to timbre match your front 3. Your project should draw some attention. It seems that the ER18 MTMs have a bright future in DIY land. I'd like to see some pics.
 
ARES24

ARES24

Full Audioholic
I had pics of the crossover, finished pics of the center and a picture of all my DIY thus far but my phone bricked........
 
Swerd

Swerd

Audioholic Warlord
I had pics of the crossover, finished pics of the center and a picture of all my DIY thus far but my phone bricked........
ARES24

Thanks for the photos and drawings.

I thought I had posted the crossover schematics, but can't find them on AH. Do you know if they are on AH?

When I tried to upload images for these, I found I can't up load new pictures. Apparently my quota is full and I can't figure out how to delete some older ones.

At home tonight, I'll upload those schematics to a photo site, and get them in here that way.
 
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ARES24

ARES24

Full Audioholic
Thanks Swerd, I meant to put those picks up last night. My brain doesn't work late at night so it didn't happen :rolleyes:

I threw them into the album so they are all in the same place.
 
ARES24

ARES24

Full Audioholic
Here is the finished center


And the total DIY experience so far :D


(No this isn't how I have it oriented normally)
 
ParadigmDawg

ParadigmDawg

Audioholic Overlord
The stand for the center channel looks funny.....
 
ARES24

ARES24

Full Audioholic
The stand for the center channel looks funny.....
I call it active shelving :p

The sub actually goes next to the couch on the right (end table) and the center currently sits on the sewing machine :/ until I get the shelf built for it. Any ideas for a floating shelf?
I might make a stand if I have to...
 
D

Dennis Murphy

Audioholic General
Thanks so much for starting this thread, and I'm delighted you are happy with the results. And thanks to Swerd for the spiffy schematics. This model is available in finished form from Jim Salk under the Philharmonic label. A very similar model that substitutes the SB Acoustics 5.5" driver for the ER15 has been produced in limited numbers under the Alexis label. Although that model is considerably cheaper (due to sourcing of all parts from over there across the ocean), there are very few speakers available due to a shortage of the custom Fountek tweeters. Hopefully that can be remedied in the future.
 
F

fokakis1

Audioholic Intern
Pics look good. Nice match of sight and sound across the front.
 
W

WiseG

Enthusiast
Great work! I want to build them but It is a problem :confused:, they are too high for my system about 1.95 or 5 cm. Is it possible to keep the volum of the box but make it lower but wider?
 
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slipperybidness

slipperybidness

Audioholic Warlord
Thanks so much for starting this thread, and I'm delighted you are happy with the results. And thanks to Swerd for the spiffy schematics. This model is available in finished form from Jim Salk under the Philharmonic label. A very similar model that substitutes the SB Acoustics 5.5" driver for the ER15 has been produced in limited numbers under the Alexis label. Although that model is considerably cheaper (due to sourcing of all parts from over there across the ocean), there are very few speakers available due to a shortage of the custom Fountek tweeters. Hopefully that can be remedied in the future.
Can you clarify, you are talking about the matching center for the Philharmonitors (Alexis Rebecca)?

Can you provide pricing? Who would these be ordered from?
 
ARES24

ARES24

Full Audioholic
Great work! I want to build them but It is a problem :confused:, they are too high for my system about 1.95 or 5 cm. Is it possible to keep the volum of the box but make it lower but wider?
I don't believe that I am qualified to answer this question so get your grain of salt and take this...

The drivers are top notch and the crossover was designed by the best. It is my belief that they account for almost all of the awesome this speaker can do. With that in mind I would think that the cabinet can be modified slightly to accommodate your requirements without contaminating the sound too much.

Hopefully someone more qualified will answer too:)
(keep in mind that the breadth of my DIY experience is 3 speakers and a sub:eek:)
 
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fuzz092888

fuzz092888

Audioholic Warlord
Great work! I want to build them but It is a problem :confused:, they are too high for my system about 1.95 or 5 cm. Is it possible to keep the volum of the box but make it lower but wider?
It may affect off axis performance, but as long as you aren't trying to hit an area where the seats are 45 degrees off axis you should be ok I think.
 
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W

WiseG

Enthusiast
Ok thanks for the fast respons. I will build my versin of the center. One question to Ares. How much stuffing did you put in the center?
 
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ARES24

ARES24

Full Audioholic
I used 1" dacron and covered all the interior except the front baffle
 
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