My System

[Scottmoose]

Mark -yes, no problem. Just got your PM elsewhere. Sorry for the delay, was out all day yesterday -1st night for our play.

Bob -thanks for letting us know about the sensitivity issue with the RP too -useful to know. Sounds like a good idea, doing a preminum FB20. I guess you'd do the same for the '2000 MLTL if ordered with 207s & requested?

 

[Bob Brines]

Bob -thanks for letting us know about the sensitivity issue with the RP too -useful to know. Sounds like a good idea, doing a preminum FB20. I guess you'd do the same for the '2000 MLTL if ordered with 207s & requested?

That's my intent. I'll offer the FB-20 as 207 or 207/FT17H and in either of the two styles. I have to think this one out, but I will probably offer the LT-2000 as 207/FT17H or DX3 and suppress the other driver options. While there are no price guarrantees, today I can get DX3's for $200 more than the DX2's. So, for $100-200 more, I can offer a better speaker in both price ranges without confusing the customer.

Cosmetics is interesting. I started using the oval supra baffle because I though that a basic MLTL is too plain to be eye-appealing. About half my contacts love it, half hate it. So I started offering the alternate style with the grill. Clean, crisp, conventional and high WAF.

Bob

 

[fred76]

Bob,

I am not sure that dip is entirely caused by floor bounce. I have calculated a null near that frequency with many of my ML TL models in the second half of my worksheets where the geometry of the box and of the room is included. However, when I remove the room effects sometimes the dip is reduced but not completely gone. I believe some of this dip is caused floor bounce while the rest is caused by destructive combination of the driver and port output which is a function of the distance between the two sources. If it was purely floor bounce, you should see a series of dips at regular frequency intervals.

Martin: You are probably right about some combing between the driver and port. Your model assumes the port and driver are acoustically colocated and combined nearfield measurements won't see it.

Bob

Sirs,

Would a Dual Ported MLTL have this 'dip' issue too or make it worse? Thank you.

fred

BTW Bob, I really like the cozy room interior - stone walls.

 

[Scottmoose]

I'm not Bob or Martin, but re the twin port, it'll depend on exactly where the vents are located.

Agreed about the nice-looking space. I like stone walls.

 

[MJK]

Would a Dual Ported MLTL have this 'dip' issue too or make it worse? Thank you.

Hi Fred,

If you have a dip in the response with a single port, I would expect the same type of dip with two ports if they are at the same location. The dip is not predicted in all ML TL designs and the depth of the dip varies with different designs. In my Lowther ML TL design, I predicted a very deep sharp dip but was unable to measure it. I am not convinced that a single sharp dip should be a significant concern with a ML TL design.

 

[fred76]

I'm not Bob or Martin, but re the twin port, it'll depend on exactly where the vents are located.

Agreed about the nice-looking space. I like stone walls.

Hi Fred,

If you have a dip in the response with a single port, I would expect the same type of dip with two ports if they are at the same location. The dip is not predicted in all ML TL designs and the depth of the dip varies with different designs. In my Lowther ML TL design, I predicted a very deep sharp dip but was unable to measure it. I am not convinced that a single sharp dip should be a significant concern with a ML TL design.

Hello Scott and Martin,

Thank you for clarifying... Keeping certain variables equal, at least two ports do not make it worse IF there is a dip.

Regards,
fred