Lowther bipole

[britbug]

Has anyone ever simmed a Lowther Bipole ?
In particular, can a 'cheaper' driver of similar parameters (Fe206/7 say) be used on the back, with or without whizzer-ectomy?
I have DX2 in modded MJK-Voigt style cabs, but would be interested in getting rid of BSC and upping efficiency as amp is only 5 W max, and I do like loud, unclipped, music. And, my woodworking skills are very limited, so I don't think I'll be making horns in the near future.
Thanks.

[GM]

Greets!

You'll need dual HE 15"/channel to allow the Lowther to 'sing' uncompressed in either a sealed cab or OB.

GM

[BudP]

Brit,

Before you cut away at your Lowthers, there is another way to gain uncompressed head room and extraordinary clarity. Look at this thread starting about page 13 Post #128

EnABL Processes

Then look here, in post #4 & #9 for pictures of what Ultrakaz did to his Fostex drivers and read his results, treating his set of Fostex drivers, in Post #16, of the thread.

Help me kill a fostex artifact.

I will be actually treating the Lowthers shown in the pics in the EnABL thread. You might want to read the whole thing, it is a compilation of three separate threads.

Bud

[hm]

Hello,

give the BG20 Visaton invers no crossover a try.

I´ve done it in my SAXOPHON,
but it is a horn.

Lowther without horn sounds bad.

[britbug]

Hi, no, I wasn't going to cut up the lowthers!
Cost me way too much to mess round with them.
I was thinking more of the fostex or similar on the back side to avoid to much HF reflections etc.

[MJK]

Lowther without horn sounds bad.

That seems like a very definitive statement. So your conclusion is that under all conditions if you do not have a Lowther mated with a horn it is absolutely not going to work well. I can not agree with that statement.

If you analyze your SAXOPHON speaker, I bet you will find it acts more like a TL then a horn at ow frequencies. Or if you simply measure the electrical impedance, it will more then likely have multiple and predictable peaks indicative of a number of axial standing waves just like a TL. If I am correct, I am not sure I would classify your design as a horn over the low frequency range.

[MJK]

To address the original question. I have simmed a Lowther bipole and if I am not mistaken the default set up in my MathCad worksheet is a pair of DX2 drivers in a dipole configuration. It was a quick sim so I did not optimize the design or look at other driver possibilities. You can look at a pdf of the results on the Upgraded Models page on my site.

[hm]

Hello britbug,

take it invers than you won´t get HF,
but you can win a better K2.

Hello MJK,
if you look the single simulations you are right,
but membran movement cross setting makes it like that,

look the data:

http://www.hm-moreart.de/86.htm

look a Lowther measurement group by AER:
phase plug yes /no

http://www.aer-original.com/html/hob..._jan_2002.html

[Scottmoose]

I have to say I'm with Martin and GM on this. Lowthers do not require a horn as a given in order to sound good. They work perfectly well in other enclosures, or run OB, particularly with decent LF support from additional woofers.

Wouldn't Saxophon just make for a combined system of two differentially tuned expanding QWRs with an additional waveguide loading the other side of one driver? Don't get me wrong, I'm not knocking it, I think the design's very creative. But a genuine horn is about the size of the average garage, and anything less is still a hybrid QWR / horn.

[hm]

Hello Scottmoose,

if you look the single simulations,
you will see no bass below ~70 Hz !!
and a rise at 150-200 Hz of ten dB,
worse as can be, but you see the measurement,
I am most astonished.

The amp "see" only one horn imp.
movement cross setting makes one oktave
deeper than expected, mouth distance
cancle the rising.

look the free plan TROMBONE, two driver with 120 Hz reso
going down to 38 Hz !!
Test it for lowest costs than you might believe me.