Acoustic 126 Speaker

Jhtjon · #1 08-12-2011, 10:01 AM

I have a new to me Acoustic 126. The Eminence square mag that is in it is not in the best of shape. Any thoughts on a replacement?

lfh · #2 08-12-2011, 11:19 AM

A good starting point would be to contact Eminence for suggestions. Chances are that they still have basic driver data on file (cone weight, compliance, BL), and hence are able to identify similarly specified current models.

You could also discuss the matter with a reputable repair shop, such as Orange County Speaker. Minor tears can sometimes be patched up, and they might have an appropriate recone kit.

billfitzmaurice · #3 08-12-2011, 11:39 AM

Quote:

Originally Posted by lfh

A good starting point would be to contact Eminence for suggestions. Chances are that they still have basic driver data on file

Not on an old square magnet jobby. It may even pre-date specs.
OP, you need to post complete accurate inside measurements of the cab, including the port/duct if it has one, and the power rating of the amp you intend to use with it.

Fender4Me · #4 08-12-2011, 11:54 AM

This is the speaker that I put in my 126: http://www.guitarcenter.com/Eminence...LAID=54981143#

It is a BEAST! my favorite amp. You will not believe the difference.

lfh · #5 08-12-2011, 02:29 PM

Quote:

Originally Posted by billfitzmaurice

Not on an old square magnet jobby. It may even pre-date specs.

This piqued my interest:

Are you saying that they (as late as 1977) didn't care about quantifying fundamental acoustical properties? How then did the manufacturers back in the day specify the OEM drivers ("We want the thin cone with the dual roll cloth edge, a 2" VC, white dust caps and an 80 oz magnet")? I know that MI manufacturers typically lag 20 years behind the rest of the industry w.r.t. speaker design, but this would still be almost chocking to me

OnT:

The amp has a large, tapered port ("bass reflex horn") that was in vogue in the late 70:s and early 80:s, see

Acoustic 126 1x15 bass combo

Mr. Foxen · #6 08-12-2011, 02:33 PM

The port extends a way up the back of the cab, so it is pretty long. The actual cab volume is pretty small because of that.

Jhtjon · #7 08-12-2011, 03:00 PM

I think that I have an odd ball amp. It is an '82 mine does not have the foot switchable eq it is in the circuit all the time and mine is constructed differently (circuit boards are different).

nashvillebill · #8 08-12-2011, 03:13 PM

I emailed Eminence last year about an OEM woofer that was made in '85 and they were able to send me a little info on it, but no T/S data (or perhaps they wouldn't release that since it was OE-specified.

**Thor** · #9 08-12-2011, 03:19 PM

Quote:

Originally Posted by lfh

This piqued my interest:

Are you saying that they (as late as 1977) didn't care about quantifying fundamental acoustical properties? How then did the manufacturers back in the day specify the OEM drivers ("We want the thin cone with the dual roll cloth edge, a 2" VC, white dust caps and an 80 oz magnet")? I know that MI manufacturers typically lag 20 years behind the rest of the industry w.r.t. speaker design, but this would still be almost chocking to me

OnT:

The amp has a large, tapered port ("bass reflex horn") that was in vogue in the late 70:s and early 80:s, see

Acoustic 126 1x15 bass combo

Having lived through the dark ages, this is not shocking to me. A lot of cab development back then was throwing big drivers into big cabs and seeing what they sounded like.

billfitzmaurice · #10 08-12-2011, 03:52 PM

Quote:

Originally Posted by lfh

This piqued my interest:

Are you saying that they (as late as 1977) didn't care about quantifying fundamental acoustical properties?

The first JBL drivers to employ T/S in their design was the E series, circa 1980. That's probably when most followed suit, though some like Celestion stuck with empirical design for much longer.
Prior to T/S all drivers were empirically designed. They knew about Fs, Pe and Xmax, but little else. It was mostly a matter of trial and error, as were the cabs they were loaded into.

lfh · #11 08-12-2011, 06:17 PM

Quote:

Originally Posted by billfitzmaurice

The first JBL drivers to employ T/S in their design was the E series, circa 1980. That's probably when most followed suit, though some like Celestion stuck with empirical design for much longer.
Prior to T/S all drivers were empirically designed. They knew about Fs, Pe and Xmax, but little else. It was mostly a matter of trial and error, as were the cabs they were loaded into.

Sure, but in addition to the above I'd expect them to at the very minimum know the mass of cone plus VC (w/o air load), BL, R and L -- don't you think? (My apologies if you know for a fact that they have no data for this generation of drivers.)

(Side note to others than BFM: T/S parameters per se are not at all a prerequisite for predictable designs (the properties can be expressed in other terms). The fundamental principles and the methodology with dynamical analogies were well understood in academia in the 40:s and tabelized alignments based on standard filter designs, as well as even a few more general design methods, were published in the 50:s and 60:s. That said: Most "rock'n'roll companies" for sure weren't into that stuff...)

bottomend! · #12 08-12-2011, 07:32 PM

Quote:

Originally Posted by billfitzmaurice

The first JBL drivers to employ T/S in their design was the E series, circa 1980. That's probably when most followed suit, though some like Celestion stuck with empirical design for much longer.
Prior to T/S all drivers were empirically designed. They knew about Fs, Pe and Xmax, but little else. It was mostly a matter of trial and error, as were the cabs they were loaded into.

I always thought Electro-Voice were the first company to use T/S in their design. Learn something new everyday...

I dont know why, but it's fascinating to me reading about the history and developments of loudspeakers. I met a guy recently who used to work for JBL as a quality control demolition technician ( i.e. got paid to break stuff) and it was a joy listening to him tell stories about the factory and the engineers and all the things that they were doing "back in the day".

(sorry for the hijack)

Bassmec · #13 08-12-2011, 08:09 PM

Quote:

Originally Posted by billfitzmaurice

The first JBL drivers to employ T/S in their design was the E series, circa 1980. That's probably when most followed suit, though some like Celestion stuck with empirical design for much longer.
Prior to T/S all drivers were empirically designed. They knew about Fs, Pe and Xmax, but little else. It was mostly a matter of trial and error, as were the cabs they were loaded into.

AT Celestion we tended to build the best speaker we could,
then experts like Jeff Knights developed and tuned a cab that made it sound best, then we stuck various OEM labels on the
speakers as they came off the production line and then the gear manufacturers put them in the least favorable cabinets the sales/design team could cobble together.
Totally ignoring any information celestion provided of course.
PS. Bill What is OEM specified parameters exactly, the color of the label, a voice coil cap with trace elliott on it, what's that all about?.

billfitzmaurice · #14 08-12-2011, 08:33 PM

Quote:

Originally Posted by Bassmec

Bill What is OEM specified parameters exactly, the color of the label, a voice coil cap with trace elliott on it, what's that all about?.

In the case of Fender Special Design drivers of the 60s the only thing special about them was the sticker on the back that said 'Fender Special Design'. Today there are many OEM variations but 99% of them are slightly modified versions of stock models, if even modified at all.

Quote:

I always thought Electro-Voice were the first company to use T/S in their design. Learn something new everyday...

EV was ahead of the curve, they adopted T/S in 1970. JBL probably used it as well prior to the E series with their hi-fi products. Part of the problem figuring out who did what and when lies in the lack of records, especially as many of these companies changed hands repeatedly after the mid '60s.

Fender4Me · #15 08-12-2011, 09:22 PM

Make sure you get a 4 ohm speaker for the 126. You will loose a lot of volume if you install an 8 ohm. Yours should have came with a 4 ohm speaker. The link I posted was for the 8 ohm version but they make it in a 4 ohm.

will33 · #16 08-12-2011, 09:35 PM

Quote:

Originally Posted by Fender4Me

Make sure you get a 4 ohm speaker for the 126. You will loose a lot of volume if you install an 8 ohm. Yours should have came with a 4 ohm speaker. The link I posted was for the 8 ohm version but they make it in a 4 ohm.

You won't lose any noticable volume with an 8ohm. A bigger concern is the fact that ad copy / link lists an external depth of 12-5/8". That means considering the amp portion, the cab is lucky to be 2 cu.ft. At 105lbs. it also likely made of either concrete or lead.

Fender4Me · #17 08-12-2011, 09:46 PM

Mine lost alot of volume with an 8 ohm. These 126 combos are very unique. Mine blows everyone away that plays or hears it. It has tone and gets super loud. I tried many speakers in it though to find the right one.

will33 · #18 08-12-2011, 09:50 PM

Was it a 8ohm legend cb15 or some other 8ohm speaker?

Fender4Me · #19 08-12-2011, 10:03 PM

Yes, I tried an 8 ohm legend as well as a vintage JBL D140F and a Emminence Beta. These were speakers that I had on hand. I finally ordered a new 4 ohm legend with the cast frame and 80 oz. magnet, bingo! It was a night an day difference.

will33 · #20 08-12-2011, 10:22 PM

The 4ohm legend is a pressed steel frame, 56oz. Magnet and a good deal higher fs. Other specs differ as well. Something's screwy.

Speaker Detail | Eminence Speaker

Anyway, with similar spl, the power increase going to 4ohms will get you 2-3db. Noticable but not a big difference. Although if that means going from 50-60 to 100 watts it might make the difference of getting loud enough, clean enough to hang in a band setting. That could make it seem a bigger difference than it really is.