Jeff B. Testarossa TMM, 2-Way, RAAL/Satori

[fuzz092888]

So I'm starting a new project. Since most of the work has been done for me, I'm thinking that it will most likely get done before the old project ever does. In fact, we shall not even speaketh it's name. In any case, I purchased a kit from Meniscus designed by Jeff Bagby and featuring the RAAL 70-20XR and dual Satori woofers. Even though it includes two woofers, it is not a 2.5 way, it is a two way. It also includes a side firing PR, but the plans included the option for a TL version later on if I choose to rejigger the cabinet. As it stands I'm going to rock the PR since I already have the ML-TL Phil 3's.

If all goes well this one should only take me a couple years to polish off .

Anyways, most of the kit I had CNC'ed for me is in so here are a few teaser pics. Note that the drivers aren't a perfect fit, but they are nice and tight. The woofers are just close enough that they could be pressed into place. I may have to do a little sanding to get the RAAL into place.

 

[annunaki]

Sounds like the makings of a good speaker. Will you be doing an active or passive crossover design?

 

[fuzz092888]

Sounds like the makings of a good speaker. Will you be doing an active or passive crossover design?

I'm not doing any crossover design However, my plan is to wire 3 pairs of binding posts at the back of the speaker, build the passive crossover externally and in a separate box. This would give me the option to wire it actively and play with the crossover a little bit.

I also have the box plans to rebuild as an ML-TL, but that wouldn't happen until after I finished the side project I'm working on and possibly the NaO Note II RS. So many projects, so little time.

 

[Swerd]

… my plan is to wire 3 pairs of binding posts at the back of the speaker, build the passive crossover externally and in a separate box.

Why 3 pairs of binding posts? I thought this was a 2-way design.

 

[fuzz092888]

Why 3 pairs of binding posts? I thought this was a 2-way design.

Well, if I ever decide to fiddle with it with an active crossover, I might try it as a 2.5 way.

 

[Swerd]

I see. You could install the passive crossover in a box that also works as the speaker plinth. Leave the box open underneath.

If you do build the MLTL modification, remember that the amount and location of the stuffing is critical. In the ER18 MTM tower, the plan calls for 17-18 oz. of polyfill, evenly dispersed within the top 22" of the tower's interior.

The best way to do that is:

• Weigh out the polyfill on a scale.
  
• Install cross braces inside the cabinet so one of them is 22" below the cabinet's ceiling. Staple some coarse netting above that cross brace to keep the polyfill from falling.
• Before the cabinet is closed, put the polyfill in place evenly dispersed. I know someone who used a mesh laundry bag to hold the polyfill, and simply dropped it in, bag and all.

Use that general method for your speakers.

 

[fuzz092888]

I see. You could install the passive crossover in a box that also works as the speaker plinth. Leave the box open underneath.

If you do build the MLTL modification, remember that the amount and location of the stuffing is critical. In the ER18 MTM tower, the plan calls for 17-18 oz. of polyfill, evenly dispersed within the top 22" of the tower's interior.

The best way to do that is:

• Weigh out the polyfill on a scale.
  
• Instal cross braces inside the cabinet so one of them is 22" below the cabinet's ceiling. Staple some coarse netting above that cross brace to keep the polyfill from falling.
• Before the cabinet is closed, put the polyfill in place evenly dispersed. I know someone who used a mesh laundry bag to hold the polyfill, and simply dropped it in, bag and all.

Use that general method for you speakers.

Thanks Swerd. I actually need to e-mail Jeff because the plans I got from Meniscus did not specify how much fill to use in either configuration or where it needed to go.

I know Paul K. recommends using this stuff because you can cut it into sheets and stack it without it compressing. Both sound like good ways and with yours I can just reuse the pillow fill I have lying around instead of buying new stuff

 

[Swerd]

I didn't know about those sheets. If Paul K. endorses it, then just do what he says .

 

[Swerd]

That reminds me of an early version of bass cabinet that Dennis built as he came up with what ultimately became the Salk SoundScape 10. He and Jim Salk wanted a MLTL cabinet for the Acoustic Elegance 10" woofer, only they asked that Paul try making the cabinet a bit smaller for cosmetic reasons. It produced such intense air movement out the port (6" diameter?) that it blew tufts of polyfill halfway across the room. It was like the evil spawn of a cotton-candy machine and a leaf blower . If those bonded Dacron sheets were available, that wouldn't have happened.

Now the SS series (8, 10 & 12) come with passive radiators. I believe Jeff Bagby designed them.

 

[fuzz092888]

That's too funny. Yup, that was Jeff who did the PR design.

Funny you should mention those AE drivers in a TL. I'm playing around with a little project that involves an AE 15" woofer in a tapered TL (design courtesy of Paul K.) mated with a 7" Illuminator mid and an unknown tweeter.

I e-mailed Dennis to get his thoughts about what I've got so far, but haven't heard back from him. I'll have to try him again this week.

That reminds me of an early versions of bass cabinets that Dennis built as he came up with what ultimately became the Salk SoundScape 10. He and Jim Salk wanted a MLTL cabinet for the Acoustic Elegance 10" woofer, only they asked that Paul try making the cabinet a bit smaller for cosmetic reasons. It produced such intense air movement out the port (6" diameter?) that it blew tufts of polyfill halfway across the room. It was like the evil spawn of a cotton-candy machine and a leaf blower . If those bonded Dacron sheets were available, that wouldn't have happened.

Now the SS series (8, 10 & 12) come with passive radiators. I believe Jeff Bagby designed them.

 

[fuzz092888]

Thought I'd try something new.

 

[ARES24]

Biscuit joiners work very good, I like mine a lot.

 

[fuzz092888]

Biscuit joiners work very good, I like mine a lot.

What size do you use? I'm currently cutting the braces for 10's, but I'm thinking about 20 for the panels.

 

[fuzz092888]

Got all the biscuit locations and brace locations mapped out today. I double checked everything so hopefully they all still line up after I cut and dry fit. Should be interesting tomorrow.

 

[Alex2507]

Dang your tools look new. Like an Italian war rifle. Never used. Dropped once.

I like to lightly sand my biscuits a bit on the leading edges. I think it helps the panels go together a little smoother. Maybe unnecessary but it might make things a little easier, especially if they swelled a tad from humidity.

 

[fuzz092888]

Dang your tools look new. Like an Italian war rifle. Never used. Dropped once.

I like to lightly sand my biscuits a bit on the leading edges. I think it helps the panels go together a little smoother. Maybe unnecessary but it might make things a little easier, especially if they swelled a tad from humidity.

Actually the clamps, tape measure, bench cookies and square are brand new. Moving and having to leave most of my tools home necessitated buying a couple new one's since I haven't really made a trip home to retrieve anything. Although with this project and hopefully a few others before school starts, they should start looking like real shop tools soon enough.

Thanks, I'll have to give that a try. Humidity is pretty good since they've been indoors for about a week at around 40%. I tried to shove one in and it was a little tight, but after a little banging it went all the way in.

^ Enjoy

 

[TheWarrior]

That Festool tape measure is mighty handy for tracing driver cutouts, eh?

 

[fuzz092888]

That Festool tape measure is mighty handy for tracing driver cutouts, eh?

I haven't used it for that yet, but it seems pretty good. With the last circle jig I had, I just measured however many inches the radius of the circle was going to be and moved the circle guide until the blade of bit met the mark. Worked pretty well, but hey I'll try anything twice

 

[fuzz092888]

Cut a few of the slots for the biscuits today. Only got the back panels done. Still need to do the top's and bottom's as well as the side panels before I can start gluing anything.

 

[fuzz092888]

Little progress