Raal 140, Neo10, AE Dipole 15 in the works

studiotech · « **Reply #80 on:** 20 Apr 2011, 12:09 am »

Quote from: mcgsxr on 19 Apr 2011, 11:41 am

A very nicely turned out implementation, I like where the finishing is going!

Thanks for sharing.

Speaking of finishing, can I get some opinions on finishing techniques? I want a satin finish, just natural looking. Last time I did the bamboo cutting board speakers, I used about 6 thing coats of Minwax water based satin finish. Steel wooling btw each coat. Came out pretty smooth and even. Any better ideas? Oil, paste wax? Remember, the MDF layer in the middle will be showing if that makes a difference. Thanks guys.

Greg

studiotech · « **Reply #81 on:** 23 Apr 2011, 01:45 am »

Got some more done. One baffle glued up. Second done this weekend and then back to the woodshop to get the roundovers routed in and the rear leg cnc'd out of more bamboo.

As it stands right now, the lamination of Bamboo/mdf/bamboo is significantly stiffer than the plywood laminted prototype.

Last pict shows the opening of the wire channel beneath the tweeter. This keeps a nice, clean appearance on the back side with no wires showing until they terminate at the drivers. There is one down low for the woofer too. I will be using a Neutrik NL8 screwed in right over top of the routed wire channel for connection from the Digmoda amps.

Greg

DQ828 · « **Reply #82 on:** 29 Apr 2011, 10:08 am »

You need to fill the end grain with a sanding sealer, they have a lot more body ( can't think of the technical term) to them for filling the grain, if you don't the MDF will suck up lots of finish coats before you get a smooth finish. I sprayed on a Water-based Mirotone finish that worked very well & is very strong, but who knows if you can get it in the states.

Looking very good bye the way.

Why did you take the Dipole 15's out, there great.

David

studiotech · « **Reply #83 on:** 30 Apr 2011, 12:11 am »

Quote from: DQ828 on 29 Apr 2011, 10:08 am

You need to fill the end grain with a sanding sealer, they have a lot more body ( can't think of the technical term) to them for filling the grain, if you don't the MDF will suck up lots of finish coats before you get a smooth finish. I sprayed on a Water-based Mirotone finish that worked very well & is very strong, but who knows if you can get it in the states.

Looking very good bye the way.

Why did you take the Dipole 15's out, there great.

David

Thanks for the finishing info.

Dipole 15 are out because even though they played very low with minimal EQ, I was not pleased with above 50hz performance. Maybe it was just me, but I could never get them to sound pitch defined in their uper register. I don't know if the high Q of the driver gives this effect or not. Swapping in the low Q, B&C driver along with adding the Rythmik servos is giving me the best bass I have ever heard. Besides, bringing the sealed driver in for the lowest octave adds back a sense of slam and visceral movement that is not possible without MANY MANY open baffle woofers.

Greg

Ric Schultz · « **Reply #84 on:** 5 May 2011, 07:47 am »

I just want to say that it is a treat to see someone take so much care to make something of serious value and sound. Your baffle is seriously way dead with the two layers of bamboo plywood with MDF in between. The drivers you have choosen are some of the best on the planet. I have heard nothing but raves about the rythmic subs. It really must sound incredible! Great job!

JoshK · « **Reply #85 on:** 5 May 2011, 02:09 pm »

Quote from: studiotech on 30 Apr 2011, 12:11 am

Thanks for the finishing info.

Dipole 15 are out because even though they played very low with minimal EQ, I was not pleased with above 50hz performance. Maybe it was just me, but I could never get them to sound pitch defined in their uper register. I don't know if the high Q of the driver gives this effect or not. Swapping in the low Q, B&C driver along with adding the Rythmik servos is giving me the best bass I have ever heard. Besides, bringing the sealed driver in for the lowest octave adds back a sense of slam and visceral movement that is not possible without MANY MANY open baffle woofers.

Greg

Interesting! I have heard OB bass a couple of times with high Q woofers and never liked the effect. You might be on to something.

JoshK · « **Reply #86 on:** 5 May 2011, 02:12 pm »

Quote from: DQ828 on 29 Apr 2011, 10:08 am

You need to fill the end grain with a sanding sealer, they have a lot more body ( can't think of the technical term) to them for filling the grain, if you don't the MDF will suck up lots of finish coats before you get a smooth finish. I sprayed on a Water-based Mirotone finish that worked very well & is very strong, but who knows if you can get it in the states.

Looking very good bye the way.

Why did you take the Dipole 15's out, there great.

David

I agree with the using a heavy fill sealer to treat the edges of MDF. MDF will look terrible on the edges if you don't. I use Zinnser BIN primer and it works well. I put on a heavy coat, let dry sand and repeat a couple of times. Then finish to taste. If you don't seal it properly it will swell and you'll see all the joints.

nullspace · « **Reply #87 on:** 5 May 2011, 02:48 pm »

Quote from: studiotech on 30 Apr 2011, 12:11 am

Dipole 15 are out because even though they played very low with minimal EQ, I was not pleased with above 50hz performance. Maybe it was just me, but I could never get them to sound pitch defined in their uper register. I don't know if the high Q of the driver gives this effect or not.

Hi Greg,

I reached a similar conclusion using the AE OB15 up to 150Hz. I now use many low-Q Eminence woofers and like how they integrate with the midbass better, even if they don't go as low or as loud.

Regards,
John

studiotech · « **Reply #88 on:** 5 May 2011, 10:10 pm »

Quote from: Ric Schultz on 5 May 2011, 07:47 am

I just want to say that it is a treat to see someone take so much care to make something of serious value and sound. Your baffle is seriously way dead with the two layers of bamboo plywood with MDF in between. The drivers you have choosen are some of the best on the planet. I have heard nothing but raves about the rythmic subs. It really must sound incredible! Great job!

Thanks for the kind words. In fact, I am now adding a 4th layer of bamboo to the back side and getting the rear support leg cut out hopefully this Saturday. Not that the 3 layers could really used any more rigidity, but the profile from the side appears too wimpy for my taste. 4th layer brings it up to a full 3" thick.

You are quite right, this combo of drivers are working in complete harmony. As mentioned earlier, I tested many different chioces for mids. For my goals, Neo10 was by far the best. Raal was always the ONLY choice for tweeter after hearing several systems a few RMAFs ago using them and getting some personal accounts from people whose ears I actually trust. My goal all along has been to make the best possible system I can within the limits of how I wanted the resulting speaker to work. It hasn't been a cheap, easy or quick journey, but this is the first DIY project for myself that I am completely happy with in nearly 20 years of making speakers. It was the success of the studio main monitors I made several summers ago that inspired me to see if I could come up with something world-class. This used 2 Lambda TD12M and the Beyma TPL tweeter. I wanted to beat that design in every way possible...resolution, clarity, bass extension, etc. The only place these falls short is in ultimate SPL capability and just a little shy in dynamics, but I'm OK with that. I wanted active and DSP. Got hooked up with Digmoda and decided to give them a try. Initially, I was hoping for just a 3 way of resonable size, but the single Dipole 15 was not giving me the visceral impact I was looking for nor the upper bass clarity, so I modified plans to include the Rythmik. I decided that since I didn't need low bass from the open baffle anymore, then why stick with the Dipole 15 which was sort of overkill for only 60-300hz.

More soon.

Greg

studiotech · « **Reply #89 on:** 5 May 2011, 10:11 pm »

Quote from: JoshK on 5 May 2011, 02:12 pm

I agree with the using a heavy fill sealer to treat the edges of MDF. MDF will look terrible on the edges if you don't. I use Zinnser BIN primer and it works well. I put on a heavy coat, let dry sand and repeat a couple of times. Then finish to taste. If you don't seal it properly it will swell and you'll see all the joints.

Excellent. I'll check into this. Thx.

Greg

studiotech · « **Reply #90 on:** 5 May 2011, 10:16 pm »

Quote from: nullspace on 5 May 2011, 02:48 pm

Hi Greg,

I reached a similar conclusion using the AE OB15 up to 150Hz. I now use many low-Q Eminence woofers and like how they integrate with the midbass better, even if they don't go as low or as loud.

Regards,
John

Sounds like you need a pair of Rythmik tucked in under the Eminence around 50Hz then!

scorpion · « **Reply #91 on:** 6 May 2011, 06:38 pm »

Greg,

Do you have any experience of Eminence Alpha15 and AE IB15 comparison ? As you know I changed to IB15s with very positive effects some time ago.
It might coincide with your assertion that Dipole15s were not optimal also. However shouldn't IB15's 0.7 Qts be optimal any time ? OB-use wouldn't change this value any significant.

/Erling

studiotech · « **Reply #92 on:** 6 May 2011, 10:07 pm »

Quote from: scorpion on 6 May 2011, 06:38 pm

Greg,

Do you have any experience of Eminence Alpha15 and AE IB15 comparison ? As you know I changed to IB15s with very positive effects some time ago.
It might coincide with your assertion that Dipole15s were not optimal also. However shouldn't IB15's 0.7 Qts be optimal any time ? OB-use wouldn't change this value any significant.

/Erling

Hi Erling. I do not have any experience with the IB15 or any cheap Eminence. I wonder even if .7 is the correct way to get optimal results. Once again, it is good for down low to help with dipole roll-off, but after that, I'm not sure. Over the years I have tended to prefer servos or sealed bass with even lower than .7 If I had to start the project over from scratch, I might try the TD18H for the bottom of the panel and then fill in under it with the Rythmiks. Now THAT would look killer.

Greg

studiotech · « **Reply #93 on:** 8 May 2011, 06:43 pm »

Good and bad news today....

Good news, is that I finally got back to the CNC shop to get the 4th layer of the baffle cut and the rear support leg.
Bad news is that the guy programmed the machine to cut INSIDE the line rather than outside like last time. New pieces are now 1/4" too small all of the way around. Grrrrrrrrrrrrrrrrrrrrrrrr.

Not concerned that the support leg is thinner, but the rear of the baffle is going to be a problem. That is a lot of wasted $$$ bamboo plywood right there. I have one more sheet left, but was hoping to use that for 2 pairs of studio monitors for clients. May just make the rear piece of out something else now. I'm sure I could get the guy to throw in a perfectly good piece of baltic birch and more machining time after that big of a screw-up.

Here are some picts of the progress so far. I also got the 1" roundovers done on the front side of the baffles too.

Greg

studiotech · « **Reply #94 on:** 8 May 2011, 06:46 pm »

A few more....

Tyson · « **Reply #95 on:** 8 May 2011, 07:07 pm »

I think "Holy Crap!" sums it up nicely

Russell Dawkins · « **Reply #96 on:** 8 May 2011, 07:36 pm »

Looking at what's left of the sheet it would seem that 1/4" outside of the line would have left no material between cuts, or next to none. Could this even have been do-able?

studiotech · « **Reply #97 on:** 8 May 2011, 07:52 pm »

Quote from: Tyson on 8 May 2011, 07:07 pm

I think "Holy Crap!" sums it up nicely

studiotech · « **Reply #98 on:** 8 May 2011, 07:54 pm »

Quote from: Russell Dawkins on 8 May 2011, 07:36 pm

Looking at what's left of the sheet it would seem that 1/4" outside of the line would have left no material between cuts, or next to none. Could this even have been do-able?

Yes, there was room.....barely, but it would have worked. I'm sure whhat happened. He even asked me if all the cuts were to the outside of the lines, but then did not set it correctly.

Greg

kevinh · « **Reply #99 on:** 8 May 2011, 08:02 pm »

Beautiful job with the radiused edges on the baffle. I am very jealous.