Good for transmission line?

[GM]

If you look at the top of MJK's various WSs you'll see he defines them.

That said, neither values are absolutes since they vary, with temperature being the dominant factor.

GM

 

[GM]

Ah! I see you found them.

Don't know what brand a M8A is or its specs, but AFAIK MJK's math will always calc a near IB response once damped.

GM

 

[Dr_EM]

Thanks for replying. Sorry, its a Hi-Vi driver:

http://www.swanspeaker.com/product/htm/view.asp?id=80

The response is very similar to IB yes, it actually rolls of faster below 30hz in the TL but is slightly stronger above that frequency. Excursion is reduced in the TL. I also realise I have been mixing up my IB and OB, of course and OB will roll off much faster! The response possibly isn't that bad then . Should also try to look at MLTL's I guess but thats even more confusion with my limited maths

 

[GM]

Ah! I thought that number seemed familiar, I did an MLTL some years ago for the Jordan JX150 that a couple of builders were quite pleased with and someone noticed the M8N was ~ a clone spec wise, so built a pair loaded with these with similar results.

Right, the TL ultimately rolls off like any other 4th order vented alignment, but its damping makes it less abrupt, so normally thought of as a way to get near IB response in a semi-reasonable size cab.

FWIW, for TLs, the M8N is a slightly better choice due to having a higher Vas and Qts, though the trade-off is a bigger cab.

Here's the JX150/M8N max flat MLTL sim:

GM

 

[Dr_EM]

Thats brilliant! That response looks really good, my sim didn't have that reinforcement down to the low frequencies, it pretty much just stayed the same as IB response. This is an MLTL anyhow so I hear that gives better low frequency than either TL or BR.

Do you have either a save file of the worksheet or even just the numbers I need to put into the worksheet for this cab? I have bought the worksheets so can play around with this concept. Might you even have plans for the finished box? I don't know if its a DIY project or commercial but if you can give me any of those details it would help me a lot!

 

[GM]

Well, I don't know about 'brilliant', but it is a reasonable expectation based on what others have experienced, though that was several years ago and there's no guarantee that the published specs are still valid since on many occasions manufacturers have made cost cutting changes that affect the specs and don't update their published data sheets.

Sorry, with rare exception I don't do drawings, just raw designs. I leave it to the builder to decide if/how to fold them, final tuning for best room blend, etc..

YGM.

GM

 

[Dr_EM]

I don't really do drawings myself either to be honest . Do you remember what you put in the MJK modelling worksheet or have a saved version of it by any chance? I don't know where to start with this MLTL design but if you know roughly what parameters to input for L, z driver, z port, sO, sl. etc that would help greatly!

 

[GM]

YGM = you got mail, so respond to the one I sent you through the forum the other day.

GM

 

[Dr_EM]

Oops, missed that . Have done now