EP like speaker

Gothover · « **on:** 7 Mar 2012, 11:52 pm »

Hello, I wanted to share some one of my newest projects with the O-B members.

Gothover · « **Reply #1 on:** 7 Mar 2012, 11:54 pm »

Here is a response plot taken from this speaker after progamming the Behringer.

Gothover · « **Reply #2 on:** 8 Mar 2012, 03:53 pm »

Rear photo.

Rudolf · « **Reply #3 on:** 8 Mar 2012, 04:35 pm »

Quote from: Gothover on 7 Mar 2012, 11:54 pm

Here is a response plot taken from this speaker after progamming the Behringer.

Impressive! Taken at what distance?

Rudolf

Gothover · « **Reply #4 on:** 8 Mar 2012, 05:34 pm »

In-room at 1 meter, on axis centered between the HF and bass sections.

saisunil · « **Reply #5 on:** 8 Mar 2012, 06:09 pm »

real nice ... is the design identical to 2.3?

audiobat · « **Reply #6 on:** 8 Mar 2012, 06:51 pm »

Considering the sound of the Emerald Physics speaker... maybe you will have better luck??

Gothover · « **Reply #7 on:** 8 Mar 2012, 07:46 pm »

Close

Gothover · « **Reply #8 on:** 8 Mar 2012, 07:53 pm »

Quote from: audiobat on 8 Mar 2012, 06:51 pm

Considering the sound of the Emerald Physics speaker... maybe you will have better luck??

I have never heard one, however I am hopeful that I can make it work.

Ric Schultz · « **Reply #9 on:** 9 Mar 2012, 07:20 pm »

Here is how to make the speaker 1000 times better:

1. Make the base way bigger and thicker.
2. Brace the magnets of all three drivers with 1.5 inch thick 13 ply birch plywood (two pieces of 3/4" glued together)....maybe 4 inches wide. The plywood would have the 1.5 inch side against the magnets. You make some magnet mounting plates out of same 3/4 plywood that are epoxied to the magnets but have overlap above and below the magnet so you can put two holes in it. You bolt the brace to this mounting plate using large long bolts (brass, of course). This way you can just unbolt the driver if you ever blow one or want to try another driver. You must have cutouts on you magnet mounts and brace to allow the woofs to vent.
3. Brace the baffle with the same braced used for the magnets: this brace would be connected to the base, to all three magnets and to the baffle at the top and in between the woofs and coax.
4. Damp the frames of all drivers with EAR SD40AL
5. Felt the insides of the frames of the coax so the highs don't bounce back into the cone.
6. Felt all around the edges of the coax on the front baffle including the step in front/below of the coax baffle.
7. Get rid of the passive xover and tri-amp (everyone who has done this on the 2.3s is amazed at how much better it is to tri-amp and how bad the passive xover is.)
8. Use no binding posts or connectors on your speaker wires. Hardwire the wires from each amp directly to the drivers.

You do all the above and you will take your speaker from very nice to OMG! Won't sound like the same speaker....at all. Will sound like an electrostat on steroids! No kidding!

mcgsxr · « **Reply #10 on:** 9 Mar 2012, 11:15 pm »

1000 times better seems a bit strong, but nice to make some suggestions.

Ric Schultz · « **Reply #11 on:** 9 Mar 2012, 11:41 pm »

Your right, its only 973 times better.

ttan98 · « **Reply #12 on:** 9 Mar 2012, 11:49 pm »

Quote from: Ric Schultz on 9 Mar 2012, 07:20 pm

Here is how to make the speaker 1000 times better:

2. Brace the magnets of all three drivers with 1.5 inch thick 13 ply birch plywood (two pieces of 3/4" glued together)....maybe 4 inches wide. The plywood would have the 1.5 inch side against the magnets. You make some magnet mounting plates out of same 3/4 plywood that are epoxied to the magnets but have overlap above and below the magnet so you can put two holes in it. You bolt the brace to this mounting plate using large long bolts (brass, of course). This way you can just unbolt the driver if you ever blow one or want to try another driver. You must have cutouts on you magnet mounts and brace to allow the woofs to vent.
3. Brace the baffle with the same braced used for the magnets: this brace would be connected to the base, to all three magnets and to the baffle at the top and in between the woofs and coax.

You do all the above and you will take your speaker from very nice to OMG! Won't sound like the same speaker....at all. Will sound like an electrostat on steroids! No kidding!

Thanks for these tips.

It is very difficult to visualize the description you gave from note 2 and 3. Is it possible you do a sketch to compliment you description. I think these 2 items are crucial to any open baffle speakers. Thanks.

Ric Schultz · « **Reply #13 on:** 10 Mar 2012, 04:10 am »

Look at my gallery and you will see a very crude version. He used one piece of plywood that he epoxied to both woofs and then connected to the base and then used another piece in the opposite direction (on end, not flat) to further brace. I was suggesting you have separate mounts for each woof with holes above and below the magnets that would be connected with bolts to a brace twice as thick as the one in the pic. Hope that helps.

I will be making a speaker with all the above features within the next two weeks. I will take close up pics of everything and present it here so you can see exactly how it is done.

Gothover · « **Reply #14 on:** 10 Mar 2012, 08:03 pm »

Quote from: Ric Schultz on 9 Mar 2012, 11:41 pm

Your right, its only 973 times better.

Thanks for the suggestions Ric.

The crossover I am using is a 60db per octave, 25db rejection at 1200hz extreme slope crossover.

When you suggest going 3-way active, are you keeping the same crossover points, and slopes?

Ric Schultz · « **Reply #15 on:** 10 Mar 2012, 10:29 pm »

When you have a behringer, you are the boss, you are the creator. Please play and listen for yourself. Set the xover around 1100 at maybe 12db per octave and equalize and listen. Then try different slopes and move the xover frequency around. Have fun......you get to decide what sounds best, not some engineer. This is how you learn. So you have analog crossover with 60db of attenuation? per octave?......my GOD that would veil the sound!

jtwrace · « **Reply #16 on:** 10 Mar 2012, 10:36 pm »

Actually get a mic and download some software (REW or Holm) and let your measurements dictate what sounds good.

Ric Schultz · « **Reply #17 on:** 11 Mar 2012, 05:45 am »

I did suggest he equalize (in order to do that you have to measure).....so yes, you have to have a measurement mic and software or you are just guessing. However, not everyone likes flat!!!!! Some like the midbass boosted or the highs gently rolled off or whatever. This is not just science....we want what we want...flat or not. And also the slope and type of xover can change the sound even if the thing measures the same. Not everything is in the measurements.....never. Some like butter others their links (butterworth and linkwitz-riley). yum yum. I'll take my links with butter, please! he he.

D OB G · « **Reply #18 on:** 11 Mar 2012, 06:39 am »

Hello Ric.
Why would 60dB per octave active veil the sound?
I could be very wrong here, but I believe that Thorsten Loesch usually uses shallow slopes, in particular 6dB per octave. I am under the impression that for a well received commercial speaker he designed, he found in that instance 60dB per octave passive! gave the best result.
In my experience, having the least interference between drivers being asked to produce the same frequencies actually reveals more detail! Certainly when going active.
Regards,
David

D OB G · « **Reply #19 on:** 11 Mar 2012, 07:04 am »

correction

It wasn't Thorsten's speakers after all.
I'll have to try to chase up the right ones.
David