Heybrook hb3 differents type A and type B

[basbas]

Need help.
What is the differents between the (Hb3 p2 type B) and (Hb3 p2 tybe A)
Both have the mid woofer on top.
but it looks like the bass woofer is differents. tybe A woofer is black.

Is there more bass from the Type A model?

Because my Heybrook is the B type.And i can get a second hand pair.

best jan

[Shane]

I'm relying on a 30-year-old memory here, but as I remember it, the history of the HB3 was as follows:

The original 1981 HB3 had the tweeter at the top, the mid-range in the middle and the bass at the bottom, with an alloy strip across the middle of the baffle carrying the Heybrook logo. Internally, the cross-over circuit board was fitted to two studs in the middle of the top panel, (which was a bitch to fit due to having to feed it in through the bass unit hole, up out of sight past the mid-range enclosure tube and on to the two studs, then holding it in place with one hand whilst doing up the mounting nuts with the other!) The back of the cabinet was painted with Portafleck, and had two very small 4mm terminals at the bottom. It also had an alloy badge on the back which carried the serial number. As the speakers were handed, with the mid and tweeter being offset either to the left or the right of the centre of the baffle, they were numbered in pairs, so the first pair were numbered 00001A and 00001B. This type later became known as the Mk1.

After about two years there was a major re-design. The biggest change entailed swapping around the positions of the mid-range unit and the tweeter, and the tailoring of the crossover to match the change. PJC must have liked this arrangement, since his current Mission range have the same layout! At the same time the cross-over board was moved from the top panel to the back of a removable section of the back panel, to which it was attached by the mounting nuts of the re-located terminals. There were two reasons for this. Firstly, moving the mid-range enclosure tube right up to the top of the enclosure meant that the inside of the top panel could no longer be reached, and secondly, it was designed so that the cross-over board could be removed and replaced with an assembly of three power amplifiers and a signal-level cross-over, giving fully active operation. There was a small hole in the front baffle which was there to take a mounting bolt to support the amplifier assembly. On the passive version this was blanked off with a plastic plug on the inside and a black sticker on the outside. This version was known as the HB3 Mk2 Type P (for passive). The planned active version in the end sadly never went into production, but would have been known as the HB3 Mk2 Type A. Again these were numbered in pairs carrying the numbers *****A and *****B.

The reason why they were labelled A and B rather than Left and Right was that in some rare situations they worked better with the mid-range and tweeter to the outside rather than the inside. As far as I know, the A and B designations were only ever used to distinguish the individual speakers of each pair. There was no HB3 Type B model.

I left Heybrook in 1984, some time after the introduction of the Mk2. In all the time I was there the same drive units were used for the HB3, although there were various experiments with doping the mid-range unit and I think also the bass unit, which may account for the different colours. I think the bass units were always a mid-dark grey colour. As far as I know there were no major changes after I left.

Cosmetically, the Mk2 differed by having the back panel painted black and a black plastic strip across the front carrying the Heybrook name. This was later changed for a printed vinyl sheet that covered the whole of the front baffle (and looked awful in my opinion!)

As I say, I'm relying on memories from thirty years ago, so there may be much that I've forgotten. If your speakers don't match my descriptions, I'd love to see some pictures!

[basbas]

Hi shane
Two differents bass woofer maybe.
What do you think.
best jan

[petercom]

Difficult to tell from the photo as the lighting seems to show different shades of colour from the baffles. If there is a difference in colour then it could be that one of the bass units was replaced from a different batch. Otherwise the bass units look identical and I agree with Shane that there were no alternative specs for this unit.

[Shane]

Agreed. They did vary slightly in colour, and would also have faded over the years to a greater or lesser extent, depending on their environment.

Any differences between the bass units in your photo will be within the normal variation of the type.


Good to hear from you, Peter. How's life in the Orient?

[Shane]

Woah! Just spotted the second photo in your link! OK, those bass units are a lot darker, but I'm still sure they're just a different batch. There won't be any significant difference in performance.

See what I mean about the vinyl-covered front baffle . That would indicate that the black pair are three or four years newer than the teak pair.

[basbas]

Hi
My hb3 series 2 is now playing.Wow really sing.
New surrounds on the mid woofer.
And with Croft Series 7r / Croft micro 25RS

best jan