Bang and Olufsen and Dynaco Speakers

[Dchristie]

Hi folks, in my current quest to try and find replacement drivers for my damaged A-25 XL speakers ( see buying and selling listings), I came upon some postings on Ebay where bass and tweeter components for Bang and Olufsen speakers are being advertised as being the same as used in some Dynaco models. When looking at the B&O drivers, they certainly apper to be very similar ( even the B&O woofer and tweeters in a couple of postings are listed as models 25F-EW and H-086, respectively - same as Dynaco A-25 XL). However, they are 4 ohm and not 8 ohm drivers so I don't think they are direct replacements for vintage Dynacos ( such as the XLs) .

So my question is this - can anyone confirm that the 2 companies were both being sourced from the same supplier ( the above example would certainly appear to indicate that they were). Also, when you look at some of the B&O speakers ( such as the 2600 model) the bass and tweeters do look very much like Dynaco drivers. It is also interesting that B&O speakers are fairly well regarded for their sound qualities on the various internet WEBS and they appear to have more elaborate crossovers compared to the simple crossovers in the A-series Dynacos. While Dynaco was very successful in just using a single capacitor and a few resistors to adjust the high frequency 6 db rolloff in many of its most popular models, it appears that B&W also used inductors (even in their 2 way 2600 speaker) to provide an electrical rolloff on the bass driver as well. They also used midrange drivers more frequently so their speakers once again appear somewhat more complicated than the simple Dynacos.

Dynaco was certainly very successful and seems to have almost universally good comments regarding sound quality so they obviously did something very right.

I have never had the pleasure of hearing a B&O speaker so I am making the above comments based on limited 2nd hand knowledge only but I would like to hear from anyone who may have more in depth information.

I am really wondering if you could use B&O drivers to replace damaged Dynaco drivers as long as you observed the polarity and model numbers.

Dean

[justw]

Both used many drivers from Seas. As long as the impedance matched I would think they would have similar sound.

See attached document. You will see that the 25F-EW, for example, came in 4 and 8 ohm versions.

I owned a pair of B&O S60's, original version, for several years. They are one of my favorite speakers though they went with some others to make room for my Dahlquist DQ-10s.

SEAS speakers from_the_70s.pdf

[dynaco_dan]

Hi there

Dynaco used both Scan and Seas drivers.

B&O used some drivers that were made by Seas also.

European speakers tended to be 4 ohms and North American 8 ohms.

The original A-25 prototype was 4 ohms and Dynaco insisted that they be made in 8 ohms.

You need to check the paper label for model numbers and if missing use a VOM to verify impedance.

Whether swapping out both drivers in a Dynaco speaker with 4 ohm drivers or visa versa with B&O's would be up to experimenters to try.

There may be an improvement or not in each case.

I was recently given a pair of Dynaco A-25 XL's and the tweeters had been replaced with a brand of other manufacture.

My hearing is poor so I cannot say if there is any difference in output between Seas and Scan drivers.

Dynaco A-25's tweeter had a commented peak at about 9 - 11 kh in many reviews.

I cannot comment on the A-25XL's tweeter reviews..

Even the Dynaco's woofer either had horned baskets or round baskets and were both were from Seas.

These may or may not have performed exactly the same.

I have not read the complete story of Dynaco's relationship with Seas and B&O, and the A-25 birth.

While Scan drivers were used early on there was a switch to Seas.

There was no fanfare or announcement to that fact that I've seen.

There was tweeter on the right and left of center versions.

Different grille cloth frames.

There is no Dynaco internal information of any of their speaker systems.

They may have experimented with a mirror image pair but found it difficult to keep paired in distribution.

The A-25XL came out when I was transitioning and never saw them for sale.

I own AR-LST's which are 4 ohm.

Their tweeters tend to have a disintegration of the tweeter cavity padding.

I bought 4 ohm versions of the Seas Dynaco/B&O tweeters for future replacement.

They won't perform the same but will last longer than me.

As long as you are happy with the xL's, enjoy.