Finalist speakers, Tower version. Advice needed concerning TL vs Ported

[Jim Holtz]

Paul, how wide is that cabinet?

Hi John,

I'm not Paul but here's the TL cabinet for the Finalists on Curt's website. http://speakerdesignworks.com/Finalists_3.html

Now the bad news, the NE149-4 is NLA here in the US. No one is stocking it due to the distributor increase minimum purchase to 500 units. Solen may have some but I've not checked.

Jim

[Paul K.]

The internal width should be the same at that for the Finalist which I seem to recall is 9.5".
Paul

Paul, how wide is that cabinet?

[PWR RYD]

Now the bad news, the NE149-4 is NLA here in the US. No one is stocking it due to the distributor increase minimum purchase to 500 units. Solen may have some but I've not checked.

Jim

[Jim Holtz]

A dentists dream except they've blown all their money on drugs. :-)

[skatz]

The 8 ohm NE149 is available, maybe it can be used with suitable XO adjustments.

[Jim Holtz]

The 8 ohm NE149 is available, maybe it can be used with suitable XO adjustments.

Yes, that's a possibility if Curt had time and a pair of Finalists to develop with. He's so busy with work, home and family he is struggling to keep his head above water.

Jim

[johngalt47]

Well, I have intended to build Finalists for a long time and have a pair of the NE149s so I'm good to go.

[ontariomaximus]

I designed the ML-TL for the RS225 in the Finalist back in 2014. I'm attaching the cabinet drawing (for just the TL part) and the predicted anechoic system bass response (red line) from the TL modeling. An ML-TL with the same line volume will usually have an f3 several Hz lower than an equivalent tapered TL, while the tapered TL will usually have a significantly lower air velocity in its terminus than that in the port of an ML-TL for the same SPL output.
Paul

Hi Paul,
I have a quad of RS225's and was wondering about adapting this design for 2 woofers instead of one. Can you assist?

[ontariomaximus]

whoops double post

[Paul K.]

If you want the same bass extension (f3), the line and cabinet volume will have to double (the line's length would stay the same). That's going to end up as a pretty big box, don't you think? The design center for the single-woofer version is the center of the woofer, its location along the line's length; with two woofers the design center becomes the midpoint of the two woofers which entails some finagling. And, of course, the port area will need enlarging in order to maintain the same air velocity characteristics.
Paul

Hi Paul,
I have a quad of RS225's and was wondering about adapting this design for 2 woofers instead of one. Can you assist?

[ontariomaximus]

Hi Paul, what is the width of the RS225 TL above? And if I scale it up for 2 x RS225, what happens to the port?. I might go a little less than 2.0X. Maybe 1.7X
thanks

[Paul K.]

That same question was asked in a previous post in this thread and I responded that I was pretty sure the internal width was 9.5". For a revised port you could simply use two of the same length and diameter as the single port in the single-woofer design, assuming the line's volume was truly doubled. A volume increase other than x2 would require new new modeling to determine a new port(s) dimensions.
Paul

Hi Paul, what is the width of the RS225 TL above? And if I scale it up for 2 x RS225, what happens to the port?. I might go a little less than 2.0X. Maybe 1.7X
thanks

[Paperweight]

I'm working on a set of floor standing Travelers with Paul K.'s ML-TL for the woofer. Two questions.

Do you have any rough dimensions for the spacing of the braces inside the ML-TL?

Anything special about the port? Flared on one or both ends?

If I can ever get one of these together without every small goof driving me to smash it to pieces insane, it would be the first speaker I ever put together without step by step instructions.

[Paul K.]

In Post #8 I included a scale, side-view drawing of the cabinet with dimensions. While the dimensions for the locations of the braces weren't shown, you should be able to determine those locations from the drawing, but their locations aren't particularly critical either. The port is not flared on either end because Martin King's software I use for TL designing is correct only for ports without flares.
Paul
Paul

I'm working on a set of floor standing Travelers with Paul K.'s ML-TL for the woofer. Two questions.

Do you have any rough dimensions for the spacing of the braces inside the ML-TL?

Anything special about the port? Flared on one or both ends?

If I can ever get one of these together without every small goof driving me to smash it to pieces insane, it would be the first speaker I ever put together without step by step instructions.

[Paperweight]

Well, I did that right then. PE had 3" x 4 1/2" unflared ports for $2.92 and I did buy 2. I was almost tempted to buy the Precision Port kits. Good thing I asked. Thanks!

I'm tempted to break the cabinet into two parts with the tweeter and mid in the top cab and the woofer in the bottom cab. I guess I could move the top panel that encloses the woofer section down 3/4" and extend the bottom panel down by that much to make up the difference. I could use 1/2" ply in the bottom of the tweeter and mid cabinet with about a 1/4" gap I could use for a mounting scheme and to decouple the vibrations of the woofer cabinet from the top.

It certainly would make working on each half so much easier. Also, even in Baltic birch, this thing is going to be heavy. I'm also assembling it with hide glue this time. It is one of the few glues I know I can get back apart without tearing out the facewood on BB.

Any suggestions or comments welcome. There's lots of stuff I'm unfamiliar with when it comes to do's and don'ts.