Open Baffle Lowthers

MerRev · « **on:** 14 Feb 2010, 06:46 pm »

I thought the Single Driver Circle would be the best place to continue the story from "what are you currently working on" thread.

http://www.audiocircle.com/index.php?topic=65752.80

We're in the home stretch here and I think I owe it to Scott to really finish them with a nice stain. Scott's meticulous attention to detail and patience throughout the build surprised me a bit but I'm so much happier we took the time and effort and am really proud of the almost completed open baffle Lowther project. I'm also glad Scott took a few pics to document the journey.
The version we are working on will use the Alnico based Lowther PM6A which I know Scott likes as well and both Jon Ver Halen and Nelson Pass have really good things to say about it too. The plan thus far includes driving them with a 2A3 amp and crossing them over to a pair of Altec Valencia's minus the horn loaded tweeter.

Many AC folks that have been around here for awhile know Scott Faller's listening room but I would like to recap as he has generously given his time and skill to help me realize an open baffle Lowther combo very similar to his. Scott is proud of his room and for good reason. The local guys are terribly lucky to have Scott and Laura open their house to as many audiogeeks that will come each year and almost everyone I have spoken to throughout the years really is in awe of his setup. His main rig is in a huge room but it fills it so well. The Lowther PM2A serves up the majority of the listening frequency & is crossed over to a vintage Altec 15" driver in a 5+ cubic foot stereo sub in each corner. Scott knew early on the Lowther driver did something really special for his ear and started his personal evolution. They started life in a MLTL cabinet then progressed into the Medallion style cabinet which Jon Ver Halen still offers. The Lowther in the Medallion cabinet did some extraordinary things which made for many involving listening sessions. I think a few of us still miss some of the unique aspects offered in this setup (dynamics with a capital D & great imaging). The last step in Scott's Lowther journey led him to the open baffle plexiglass panel design and it too offers some really sweet sounding music. The soundstage grew considerably and things felt a little more refined and relaxed. Of course, like all of us Scott, continues to tinker with new things and his room has continued to improve with every change. The Altecs drivers replaced the Goodmans and all seemed well in his little audio heaven.

I've kicked around the Lowther idea for many years now but never really thought I would see it come to fruition. Scott always offers his time and skill to everyone in the group & some of us have made out like bandits. Here are a few pics of the incredible sounding custom Open Baffle Lowther PM6A's.
The red oak frame has been coated with 6 coats of Ebony stain and a few coats of Birchwood Casey high gloss poly. I love the finish and hope they show well here.

Blackmore · « **Reply #1 on:** 14 Feb 2010, 08:20 pm »

Beautiful work Chris! When can we hear them?

Hebrew Hammer · « **Reply #2 on:** 14 Feb 2010, 08:34 pm »

rock on.... me likey!!!!

Scott F. · « **Reply #3 on:** 14 Feb 2010, 10:43 pm »

Hiya Chris,

A gracious thanks for the many kind words

I like the ebony finish. I can't quite tell from the pics but it looks like you can just see a hint of the red in the oak we used broadcasting through the finish. Very cool

Now you guys just need to build that house you've been talking about for so long so that you can design a big room where the OBs have room to breathe.

I'm with Mark...so when is the PM6A coming out party?

MerRev · « **Reply #4 on:** 15 Feb 2010, 02:19 am »

thanks Scott and Randy, the Ebony finish really looks good when there is a little bit of light on them. They really turned out quite nice and hopefully one of these days I'll have some unique lighting as well to make them come alive. The Open Baffle Lowther coming out party could be fairly soon as a bigger room is right around the corner.

I'll post some more pics of the Altec Valencia's and crossover once settled.
Thanks again for all of your help Scott!

&, for folks who may be more interested here is Scott's latest madness and talent at work (work for fun that is).
http://www.enjoythemusic.com/Magazine/equipment/1009/lowther_high_efficiency.htm.

Merrev

jhm731 · « **Reply #5 on:** 15 Feb 2010, 03:46 am »

MerRev speakers look great!

What's the dimensions of the base?

Does anyone know where I can find the QTS, QMS and QES specs for the Lowthers?

Scott F. · « **Reply #6 on:** 15 Feb 2010, 04:02 am »

Quote from: jhm731 on 15 Feb 2010, 03:46 am

Does anyone know where I can find the QTS, QMS and QES specs for the Lowthers?

Hi Dan,

I think Martin King has accurate TS parameters on his Quarterwave site. The measurements the Lowther site has aren't accurate.

jhm731 · « **Reply #7 on:** 15 Feb 2010, 06:34 am »

Quote from: Scott F. on 15 Feb 2010, 04:02 am

Hi Dan,

I think Martin King has accurate TS parameters on his Quarterwave site. The measurements the Lowther site has aren't accurate.

Scott-

Thanks, I found this:

http://www.quarter-wave.com/General/Lowthers.pdf

I'm just trying to figure out the best driver for you OB plan.

Based on the specs, I don't understand why MerRev switched to the PM6A,
or why I shouldn't try the Audio Nirvana Super 8 Alnico.

Dan

Scott F. · « **Reply #8 on:** 15 Feb 2010, 03:00 pm »

Hi Dan,

Well, MerRev and Blackmore are both using the PM6A for a couple of reasons. The first is cost. The 6A runs just about half what the 2A costs. Next is the the 6A gets pretty darned close to the 2A in terms of sound quality. Guessing, it's probably 90% of the way to the 2A. The highs aren't quite as extended but they are pretty close.

Regarding the baffle, MerRev and I are cutting the Lowthers off at about 150Hz so. That means we aren't asking them to do any bass at all so their TS parameters don't play as important a roll as other designs.

I can't speak to the AN drivers as I've not heard them. My buddy Geoff Husband over at TNT Audio had a pair and wrote about them. [edit] I just realized, these aren't the Alnicos.

TNT Audio article

Keep in mind Geoff's reference speakers are the Loth-X which uses [essentially] a modified Lowther driver. That will give you a slight frame of reference. You can see from the measurements Geoff ended up using a notch filter to tame the treble down on the AN driver. MerRev, Blackmore and I have no need for a notch filter because the Lowthers are that smooth. If you get away from the 2A, 6A or the 5A, you will run into that same rising treble issue in the Lowther line.

MerRev · « **Reply #9 on:** 15 Feb 2010, 03:19 pm »

hi Dan, the bases are roughly 25" deep, 19" wide and the panel is set back from the front approx. 7". The footprint is large enough to support the weight of the 3/4" plexiglass. I added a 8x12" piece of scrap marble tile to underneath backside of the base to help offset the weight in the front and it feels pretty balanced now.

Blackmore, are you toying around with a supertweeter in your setup or are you letting the Lowthers go full range from 300hz or so on up?

-merrev

Blackmore · « **Reply #10 on:** 15 Feb 2010, 03:24 pm »

No supertweets allowed in the Blackmore house

(come to think of it, no tweeters allowed either) I'm using mine from 440 hz on up. Heck, mine don't even qualify for the the single driver, wide-bandwidth circle. It's just a two way. Still, the Lowther Music Posts sound mighty good right now.

Hebrew Hammer · « **Reply #11 on:** 15 Feb 2010, 03:32 pm »

Lowthers on a stick rule... can't wait to build something crazy as I feel it would be the best solution for an art gallery showing...

Blackmore · « **Reply #12 on:** 15 Feb 2010, 03:37 pm »

Hey Randy,

If you want to get some measurements off my Pm6A we could unbolt them from the LMP. Maybe we could even draw up some ideas????............

p.s. it can't look like something from Alien, too scary for me.

pardales · « **Reply #13 on:** 15 Feb 2010, 03:46 pm »

Quote from: MerRev on 14 Feb 2010, 06:46 pm

Inspiring!

Hebrew Hammer · « **Reply #14 on:** 15 Feb 2010, 03:47 pm »

I'm down... I need to get away one of these nights as this Mr. Mom stuff is for the birds

Quote from: Blackmore on 15 Feb 2010, 03:37 pm

Hey Randy,

If you want to get some measurements off my Pm6A we could unbolt them from the LMP. Maybe we could even draw up some ideas????............

p.s. it can't look like something from Alien, too scary for me.

Scott F. · « **Reply #15 on:** 15 Feb 2010, 04:58 pm »

Hey Hammer,

Here's an idea for you......

roscoeiii · « **Reply #16 on:** 15 Feb 2010, 05:01 pm »

Scott,

What's the story on the no-baffle Lowthers in the pic?

Scott F. · « **Reply #17 on:** 15 Feb 2010, 05:26 pm »

Those are Blackmore's LMPs (Lowther Music Posts). Here are a couple more pics of Mark's creations;

He crosses them over at 400Hz then uses the bass bins and amp from his Innersound's to fill in the bass region. It works really well. He uses a Yamamoto A08 300b to drive either the Lowthers or the Innersound Panels. Great part is its really easy to switch back and forth between the speakers. He gets the best of both worlds, panels and OB Lowthers.

roscoeiii · « **Reply #18 on:** 15 Feb 2010, 05:32 pm »

Very interesting. Wow a 400Hz crossover is higher than one usually encounters. No integration issues? Another rabbit hole for me to explore I suppose....

Hebrew Hammer · « **Reply #19 on:** 15 Feb 2010, 05:37 pm »

I had to hear it to believe it.. and all I can say is wow.. I have listened to a few things the past 20 years of my hifi life and these were just beautiful..

IMO, not pushing a driver to play it's full passband is the way to go.. it just makes the passband played that much more linear.. but at the same time you still get insane time/phase coherency in the areas that we are very susceptible to as you have a single driver playing 6ish octaves