Hey Romy,

Goto makes 12" and 15" woofers at 100db. I recently found out they make a small two way system using an 8" woofer. The 8 incher's range is 55hz-8000hz so I'm thinking it might be a good candidate for use with 60Hz horns. Looking at Goto's 12" and 15" woofers, they seem to be paper cones and "altec looking". Too bad the website didn't state the efficiency of the 8" driver but I'll try to find out... if it's a 100db like their 12"/15" drivers then it might be something worth looking into... heck I'll be impressed even at 98db...

Keith

Kcct82 wrote:

Hey Romy, Goto makes 12" and 15" woofers at 100db. I recently found out they make a small two way system using an 8" woofer. The 8 incher's range is 55hz-8000hz so I'm thinking it might be a good candidate for use with 60Hz horns. Looking at Goto's 12" and 15" woofers, they seem to be paper cones and "altec looking". Too bad the website didn't state the efficiency of the 8" driver but I'll try to find out... if it's a 100db like their 12"/15" drivers then it might be something worth looking into... heck I'll be impressed even at 98db...

Keith, it is hard to say. I think you need to talk with somebody why use GOTO drivers. I do not know what contrary you are in but you might find some collaborators on line. How accurate and objective would be their comments is another subject – you decide foe yourself.

Generally you do the very same mistakes as anybody else does – you name the rate of horn but you do not specify what the throat size. There are 3 parameters that are critical in horns: moth size (or frequency), throat size and profile type. So, 60Hz horn with 8” throat and 60Hz horn with 18” throat are different horns as you understand.  Usually if to use 8" driver then we are talking about 7” horn – it looks very good. How the driver will work in there – who knows? I would pay attention in case of 8" driver in it’s excursion.  Pressure is excursion + surface. Less surface = more excursion. Mores excursion with lower resonance frequency and consequential softer sustention = less disable driver for horn. (You would need for horn hard-suspended driver with fewer excursions). Evan if the driver has a long excursion then how much of it in homogeneously saturated gap? (The underhand paranoia…) Well, be advised that it all might have no relation to sound. Be also advised that smaller throat = more LF equalization but this rule is not infinite. Lowering throat smaller and smaller we eventually get very nasty sound, particularly with slow opening horns. Where is the golden rule of throat/mouth ratio? I do not know. I think with each driver and each construction techniques it might wary.

Somebody at this site was trying to equate the throat/mouth ratio for MF channel and to apply it to upperbass horns.  It “sounds” like right thing to do but I do not think that the “rule” will be preserved in midbass world. So there is no definitive answers, at least that I know.  If I go for my 55Hz horn I would go for 15” driver with 10-12” throat  but I think that I would it ONLY BECOSE I do not know any good  8” driver. Your GOTO might be such a “better” driver but it might not be. Hey might do good 15" woofers and they make “cheap” 8” versions for “easy” systems. The people who use GOTO would know it. The best bet would be if they send you 8’, 12" and 15” drivers and you would compare them with TAD, Altec, JBL, Vitavox, Klangfilm… but if you do then… you would not post your questions on internet….

Thanks Romy, your comment above cleared some of the questions I had regarding 50/60hz midbass horns.

I found some info on the driver after digging through Japanese sites. I don't know if these info will help interpret wither the woofer will be good for MB horn but perhaps you can see something interesting from these specs... thanks.

GOTO SG-20WR:
20cm (8 inch)
20W
8 ohms
96 db/w/m
100,000 Maxwell
8,000 Gauss
55hz (Qo 0.25)

Kcct82 wrote:

Thanks Romy, your comment above cleared some of the questions I had regarding 50/60hz midbass horns. I found some info on the driver after digging through Japanese sites. I don't know if these info will help interpret wither the woofer will be good for MB horn but perhaps you can see something interesting from these specs... thanks. GOTO SG-20WR: 20cm (8 inch) 20W 8 ohms 96 db/w/m 100,000 Maxwell 8,000 Gauss 55hz (Qo 0.25)

Got today from web pictures of the Keith midbass horn.  So, it is GOTO SG-20WR loaded to 50/60hz midbass exponential like ½ size, interesting…. The picture with a person in front dives an idea about the dimensions but it would  be nice to know from Keith the mouth size, the length, the throat size, and the mass of the horn.

Formally the KCCT82’s installation was mentioned in here:

http://www.goodsoundclub.com/Forums/ShowPost.aspx?postID=10333

The Cat