Single sheet TH challenge

[mikeford]

I don't fully understand what is going on (big lol on the fully notion). Is the 5mH coil to do some kind of zoeble thing smoothing the impedance of the driver curve?

I'd be curious to know the DC resistance of the coil and the voltage across the coil and driver in a sweep.

[Matthew Morgan J]

Originally Posted by AndrewT

Mat,
can you show the input screens for the 4 examples in post1886

Andrew ,

I dumped the undersized box inputs when i realized that they were flawed and kept the larger box inputs ... The difference was only 25-30 liters ... I think I could recreate the original inputs again if I needed to ...
I am attaching the larger box inputs, which are more properly tuned in my opinion and works well with box 1x LE and 2x LE as opposed to the smaller box which didn't work well with 2x LE in sim (indicating that if i build it i might risk that the real world response even without an added inductor might also be less than ideal) ..
Andrew, the LE value in this set of inputs is the value given by Dayton for the driver, You can raise and lower this value in the sim to see the results .... Epa suggests multiplying the value by 2 to approximate what the real world measurements will actually be like (without an actual series inductor added)...

By the way, the voltage and output in the original example are overly optimistic , instead of 400 watts (56 v) I think a drive level of 200 watts (40v) is safer and more appropriate and still gives you 122db right down to 36hz and -3db at 33hz ... Not bad really for something that would cost you a total of 150 dollars or less to make, including plywood and driver ... It would have enough output for your typical listening room or living room or even a small house party, has enough extension for most any music, and only takes a up a very small footprint in your room if built as a single fold tower style TH .......
I know this P-380 TH not really a single sheet design, So i apologize to JBELL and everyone else for going off topic with this box ..... I will post a sketch of my SS-18PS76 here soon which is a single sheet design..

[djn]

What are good driver parameters for Tapped Horns??? I have unknown sub drivers that may or may not work in a TH....I don't know. Here is a screen shot from WT3 for these drivers.

[NEO Dan]

Is that sweep with a brick on the cone? Post pic of driver please.

[djn]

No, just sitting on the counter. I do know that they are Credance drivers but the guy at Credance was really put out that I would even as about a discontinued product and I can find nothing on the net. The number on the frame is 1173593 They are 12" by the way.

[NEO Dan]

You are a ruler and some nickles away from full TSP's, it's not looking like much of a TH driver to my eye though. Cms and Vas will be high, while Bl and Mms are likely low. Basically the opposite of what makes a good TH driver. You've got a monkey coffin driver there.

[djn]

Thanks Dan. What is a monkey coffin driver???

[NEO Dan]

You should finish measuring your driver, I could be wrong...
Monkey coffin info here

[djn]

Yep, it is on the list. I am working diligently, during the break, to get my system back up and running. There are 3 or 4 projects ahead of these drivers.

[Matthew Morgan J]

Originally Posted by NEO Dan

You've got a monkey coffin driver there.

hehe , so morbid!

Im not sure why but that term makes me giggle.. on the inside ... just a little bit ..

It just means rectangular box right?

I think if he could provide the VAS figure i could use software to figure out the other parameters, but yeah i believe your correct in that it probably wont be a worthwhile TH driver ... The FS is terribly low .... A very loose suspension perhaps?
How much extension do you need Djn? Need to be portable? If you are ok with only getting down to 60hz then a small sealed box will control excursion and allow for some power handling , or even better yet (for more output) if you have a good High-Pass electronic crossover you could set it at 40hz and make a 40hz tuned QWP (some call TL) or even a voight pipe or ML-TL or something along those lines ...