Lowther in MLTL Enclosure


2009-08-11 8:56 pm
Hoping to get a clearer sound.
Have got the impression that there are some colouring of the low midrange from the horn, the small Acousta is quite folded. MLTL is not a horn and shouldn't have this problem. Have not the opportunity to go up in size to achieve a proper horn as the Hedlund.
Long term plan is to add a couple of JBL2203H for the bass.


Paid Member
2008-07-17 8:47 am
I see. In my opinion, a MLTL should sound more neutral but definitely with the recommended baffle step circuit. The foldings actually attenuate the midrange going out of the horn. I do not think that the Hedlunds perform much better, they are only much better looking IMHO. And maybe the driver is in a better height. The funny thing is that my (second hand) Lowthers are not shouty at all and I measure them quite flat at the listening position, slightly off axis. The only thing I miss with some music is real bass.

I built a pair of large MLTLs with Beta12CX long time ago and they are still in use by my brother, blowing any consumer grade loudspeakers away. It was designed by GM and I would bet on his opinion how the Lowthers would work in a MLTL compared to a backloaded horn. Maybe he could recommend some other quarter-wave style box, he is the real QW expert here:) The design by MJK you linked can be definitely trusted as well.

Last year I heard some tapered QW tubes with the Sonido 8" full range and they were amazing on percussions. I bought a pair intending to build some, but then I found the Hedlunds for a great price and the Sonidos are waiting for their box still. They will definitely get some sort of QW tube enclosure, they are very easy to build and look great with the 8" FR speakers.
The Acousta isn't one of the better-designed back horns unfortunately; the folding itself isn't the major problem, it's just that the acoustic low pass is likely a bit high (and shallow). Depends on the amplifier output impedance driving them as to where Fhm actually lies though and the necessary BW of the enclosure.

Be that as it may, an MLTL may be a bit more linear than the 109, but the price will be reduced efficiency & dynamic range when a suitable low-pass shelving filter is added -that latter is more or less mandatory with Lowthers, which already have a rising IB response (especially the aluminium coil versions of the DX2). So depends on how large your room is, what kind of material you listen to, how far away you sit, how loudly you listen & how much you value dynamic range. If you've space, a big horn is likely to be preferable, but depends on how large a cabinet you can accomodate.
The Lowther has a frequency balance similar to the Philips 9710 althoug different in many other respects. I have had the 9710 both in Accousta Cabinets and "Decca Horns". The Deccas are quarter wave pipes not horns. The Accousta was a huge dissapointment but the Decca was a pleasant surprice. The large Golvhornet from Danish High Filelity and then improved in HiFi& Musik is a good option.


2009-08-11 8:56 pm
Unfortunately I have never got the opportunity to listen to Hedlund Horns.

Voigt horn with CoralFlat-8 was actually one of my first DIY project. The main problem was that there was some resonance frequencies colouring the sound. That was the reason for building Accousta with PM6c, a clear improvement. As I recall it, the PM6c didn't perform that well in the Voight, resonances still a problem. Now many years later I had the opportunity to pick up a couple of DX2 and replace the old broken PM6c. Was actuality a bit disappointed, maybe listening to a lot of other high end systems over the years has biased the memory and expectation.

Want to justify and find the motivation since time and possibility for a larger project is limit at the moment. Otherwise had some simulation and calculation been fun to do.
I'm in the process of building the MJK MLTL design using DX3 Lowther's. Would have finished them by now if not for some surgery. One thing I know for sure is if using 3/4 MDF they are really heavy. Got my wife involved and she did the sewing for the cheese cloth stuffing sleeve that fills much of the interior. So far it has been a fun project except for the lifting.
Most of my speakers are MDF roller painted satin black except for the open baffles which are MDF covered in heavy vinyl wall covering. I've had mixed results with some uneven staining on plywood. No doubt there are plenty of negatives with MDF but BIN primer and Bondo glazing on the edges are a Godsend.

I've enjoyed the DX3's in open baffles for a number of years but I'm anxious to see how they perform in MLTL enclosures.