DIY M19 idea's

**DaveCan** · February 11th, 2010, 07:34 PM

I've been real curious lately as to making a new modern DIY M19 following the same idea but different etc..

My thoughts are same size cab pretty much, and making the horn out of wood instead like the Fostex with stepped pieces etc.. Seems easy enough if one had an idea how big etc..

What about creating a diy version for both the new recommended drivers from GPA, and also a cheaper alternative poor mans version using Eminence or something?

Here's the idea from the Fostex horn, they have one that goes lower too but no pic.. I'm thinking a wooden horn done right may sound better than the original with metal possibly.. An all wood cab, no mdf though..

Also was just thinking on a plain rectangular box, instead of the reveal look that is on the real M19 just for simplicity...

Anyone want to explore this? I'm not a designer and suck at math, just curious..

Fostex H400 Wooden Horn from Madisound

Dave

GM · February 11th, 2010, 08:52 PM

Well, some years ago, a few of us tried to get more folks to DIY M19s or slightly more room and/or woodworking friendly variants rather than 'beat the bushes' and 'pay through the nose' for M19s in decent condition, but was mostly a waste of time. Regardless, there's a one box M19 and 'mini'-M19 set of drawings available and I've published, or at least simmed, many various designs including MLTLs using other drivers including GPA's; so while I don't do drawings, I'm set up to calc all the critical dims fairly quickly, just post the max outside dims that can be tolerated, the driver specs, general horn size (311, 511, 811, whatever), whether or not it's inside or out of the cab and last, but not least, active or passive LF XO and tubes or SS power. If tubes, then I need its output impedance (not tap rating) for best simming accuracy.

AFA making an 811 or similar out of wood, this would be no trivial pursuit and frankly, much better performance can be had with a proper WG similar/same as Dr. Geddes uses in his Summa, etc. speakers or even a radial conic expansion. In either case you want a horn driver optimized for HF response, so forget anything older than an 802-8G unless a super tweeter system is planned.

GM

**DaveCan** · February 12th, 2010, 11:25 AM

Interesting that no one was really interested?? Could it maybe be a size and wife issue thing I wonder? They are big! It's too bad that the speaker cab's don't get their due respect and allotment in the furnishing arrangements nowadays and worked into the design etc..

I remember as a kid almost everyone who was older had one of those big console beautiful wood stereo cabinets, some sounded really good too. My Grandma and all the older Aunts had them as part of the required pieces of the living room function back in those times etc..

I'm not sure so much about how I'd go about it, just at the thinking point right now.. Which high frequency driver would be the choice from GPA to go along with the 416-8c driver they make? Also they have some HF horns on the site now, could one of them be a good choice to do an M19? Guess I was thinking passive x-over like the original ...

**rontec** · February 12th, 2010, 01:21 PM

Well, I was considering building a speaker using model 19 componets. The cabinet would be at least one foot taller than the mod 19 and only as wide as the 811b, but with the same internal volume for the 416-8c. I would also use the same crossover values in the n1201-8a crossover.
I was wondering if anyone has ever tried fabricating a 811b out of fiberglass?

**Panomaniac** · February 12th, 2010, 02:56 PM

I've made horns from paper mach?. They sounded great. But very labor intensive and slow.
Have thought about layered hardboard - should be faster, at least.

**DaveCan** · February 12th, 2010, 04:39 PM

Yes that layered method looks easy enough compared to other types.. Fostex seems to use this method in pretty much all the cab designs they provide also.. Probably just for ease and simplicity for all level of build skills to make a decent cab..

They sure want a ton O $$$ for those wooden horns though, yikes!! Can't imagine they would sell many of those?? Seems like a person could diy one for way way less coinage!!

GM · February 12th, 2010, 05:55 PM

Originally Posted by DaveCan

Interesting that no one was really interested?? Could it maybe be a size and wife issue thing I wonder? They are big! It's too bad that the speaker cab's don't get their due respect and allotment in the furnishing arrangements nowadays and worked into the design etc..

I remember as a kid almost everyone who was older had one of those big console beautiful wood stereo cabinets, some sounded really good too. My Grandma and all the older Aunts had them as part of the required pieces of the living room function back in those times etc..

I'm not sure so much about how I'd go about it, just at the thinking point right now.. Which high frequency driver would be the choice from GPA to go along with the 416-8c driver they make? Also they have some HF horns on the site now, could one of them be a good choice to do an M19? Guess I was thinking passive x-over like the original ...

Dunno, some 'talked the talk' including for some other designs I did, but none that I can remember ATM 'walked the walk' with any of them. Guess 'life' got in the way like it has me for right at a decade now.

Yeah, when I started building speakers, 4-5 ft^3 was a shelf speaker, but the AR was getting some attention by then and stereo was the coming 'thing' along with SS power, so by the mid 60s the ability to trade efficiency for a much smaller bulk and lower retail price without compromising bass response too much became a marketing tool to 'mine' all the 'baby-boomer' college campus/apartment dwellers and the pressure was on to go into a downsizing 'feeding frenzy'.

For GPA, there's only two choices AFAIK, so 902 for most folks and 909 for the folks that like to go ~'live' on occasion.

Since I don't see it at GPA, find some MR994 Mantarays which is a step up from an 811 and is the same depth, so should work with the M19's adjustable XO with minimal change at most.

GM

GM · February 12th, 2010, 06:00 PM

Originally Posted by rontec

Well, I was considering building a speaker using model 19 componets. The cabinet would be at least one foot taller than the mod 19 and only as wide as the 811b, but with the same internal volume for the 416-8c. I would also use the same crossover values in the n1201-8a crossover.
I was wondering if anyone has ever tried fabricating a 811b out of fiberglass?

A narrower cab will have a higher baffle step, so the XO may not work all that well unless some outboard frequency response shaping EQ is done.

No, and frankly not worth the effort since for far less time/$$$ expended you can tweak the 811s to a fare-thee-well.

GM

**bfish** · February 12th, 2010, 10:22 PM

Originally Posted by GM

... find some MR994 Mantarays which is a step up from an 811...

GM

I shouldn't say it because I'm looking for some 994s, but I think a pair of them would be the simplest, best bang-for-the-buck upgrade for M19s (or wannabe likenesses) there is.