2 pairs of Heybrook HB3's that sound very different !!?

[JwEs]

Hello. To be honest, I originally registered here to get help on my HB3's about a year ago, which I guess is somewhat a DIY work, since some of these oldies need some tweaking. Now, I'm finally taking some time to tackle it more seriously (I hope). I got 2 pairs, one from eBay that got knackered during transport and are not visually the best (did post a thread about restoring them bout a year ago, but still haven't...). They seem to work ok though, with a similar sound between both speakers, despite one of them having a big bump on one corner. They're pretty bass shy with my preamp settings on flat. If I turn up the bass they can actually deliver some powerfull bass, not extreme but it's not bad at all, at least in what concerns sound level (it does seem a bit undetailed, but that's relative....).
By the way, the mid was refoamed by a local with some experience but I don't think he messed with the crossover at all....
I was very disappointed, as I got these after hearing about how dynamic and fast and pleasant they can be.

Now the complete shock.....
Today, more than one year after I got them (I got both pairs one after the other cause the deal was good and I didn't like the first pair not being the best visually), I decided to try the second pair, which is visually very good (it's venered black, the 1st pair is brown), with only a few small cracks on the varnish on one of the corners. The bass is much bigger and dynamic with the same amp settings!!! And I couldn't even try with the volume at higher levels because this pair has the mid foams rotted too, so I didn't want to risk damaging the voice coil (or maybe I'm imagining things, but I think it's a good idea to be cautious). I can only imagine that they were a marvel when new.
This second pair is indeed in a very different location and I have of course to try them in a similar location but I'm almost sure this won't make up for the difference, as my living room is very big (8,5m x 5 m, approximately) and the difference is so noticeable.

What could be the cause ? Has the 1st pair got used in a bar or disco in the 80's and the bass drivers are demagnetized ? Has something got off place during transport ? How can I test it ? I think it's unlikely cause both speakers of the 1st pair sound alike. Maybe the previous user tried to replace the woofers and messed up with the crossovers or used the wrong drivers ?

I don't even have the allen keys to mess with these things, but I'm gonna get them. I'm no expert but I tend to be a bit of a perfectionist, so I'll get there with time and patience and will post some good photos. But of course I'll need you guys help, can't take a course in crossover and speaker design at the moment, thought it would probably be interesting... So where should I start looking ? I can't wait to hear how they sounded originally, imagine if I get both pairs to original spec, that would be a blast

I have another question, cause I'm definitely going to refoam the mids on the 2nd pair, should I try to get foams with the same shape ? I don't know if I'll be able to find them...

Thank you all
José

[bob orbell]

Hi Jose, well, first, can I ask, have you ever heard any modern speakers? what amp. are you using? and why do you want to thow money away on trying to fix these old Heybrooks, they were OK in there day, but thing,'s move on and most of the time get better. A pair of new speaker's ( floor stander's to suit your large room ) will be, I think much better than the one's you have, I don't know how much you want to spend, but I would not spend it on these old thing's, so can't make any suggestions but feel this would be a better option. BOB

[naimart]

Hi José,

It's impossible to know why exactly, but it may just be that the first pair are not fully sealed or are damaged structurely.

Why not get the the second pair of mids repaired - then at least you have both in the same state to compare 'like for like'.

Are they the same versions - HB3 I (tweeter at the top) HB3 II (mid at the top)?

This forum is all about 'giving it a go' for old good quality Hi-Fi, In my 28 years of owning a pair of Black HB3 II's, I would say they fall into that category - for sure

Regards
Robert

[naimart]

Originally Posted by JwEs

I have another question, cause I'm definitely going to refoam the mids on the 2nd pair, should I try to get foams with the same shape ? I don't know if I'll be able to find them...

Thank you all
José

Available on Ebay for 10-20 euro - 4 "

[pre65]

Originally Posted by bob orbell

Hi Jose, well, first, can I ask, have you ever heard any modern speakers? what amp. are you using? and why do you want to thow money away on trying to fix these old Heybrooks, they were OK in there day, but thing,'s move on and most of the time get better. A pair of new speaker's ( floor stander's to suit your large room ) will be, I think much better than the one's you have, I don't know how much you want to spend, but I would not spend it on these old thing's, so can't make any suggestions but feel this would be a better option. BOB

Just cos something is "old" does not necessarily mean it's automatically inferior to something more modern.

In fact, the reverse can sometimes be true.

Thats why (as an example) things like Garrard 301 and 401 transcription decks are still so sought after by the cognoscenti.

[bob orbell]

Yes I do agree with your comments Philip, but worn out drive units and poor chipboard cabinets, hmm, lets face it, speakers have one hell of a hard life.

[JwEs]

One question, would I be better replacing the whole cone around the driver or just the small black ring (is this what's made of foam ? Looks more like rubber to me).

Here is a pic, I'll post more. This photo does make it seem worse than it is, I think.



Ok, to answer your questions.
Both pairs are HB3 II's.
Yeah, I've heard modern speakers at showrooms but I can't afford them I have both a Pioneer M90 and a Technics SE-A5, both bought second hand and in good condition. Also have a Technis SU-V9.

I don't think they're made entirely of chipboard, the front and back is VERY hard, I don't know much about materials but that is not the chipboard they use on furniture for sure, only the upper/down and lateral sides seem to be. I read somewhere this makes sense as the chipboard is better to absorb the standing waves.

These things were hand made right ? How hard would it be to adventure myself in replacing the worn out drivers ? Would I be better off making a new design by hand, I don't have the skills but know a local carpenter with a lot of skills who would probably make me the necessary parts for a good price.
At least the cross over would be worth something but it probably wouldn't be adapted to another design. So my plan right now is to ask for a budget on restauring the brown ones and repair the foams on the black ones.

I don't think there is structural damage in the brown pair, because both speakers sound alike, which probably indicates worn out drivers like Bob said. Could it be some cross over components have gone off spec ? I read somewhere these do not have electrolytic capacitors on the cross over...
Anyway, I gonna stop typing and try to provide better pics next post, just help me out a bit with info so that I make a decision.

Cheers

[JwEs]

Ok, finally got the picture showing....

[naimart]

Hi, sorry can't speculate about the 'brown' pair, but as far as the mids on the 'black' pair are concerned, only replace the surround rings. The original was foam with treatment by Heybrook, I think!, but can't be sure.
IMO, Change as little as you can from the original, you need to be a very special designer (PC ) to get the drive units to integrate well.

I've attached a couple of photos of the fixes I did to mine (though they have recently been sold).

Good Luck!

Regards

[Shane]

The cabs were MDF front and back, with chipboard sides, top and bottom. The cabs themselves were definitely not hand-built, being produced by Greaves of Sheffield, who were responsible for building about half the speakers on the UK market in the eighties! Refoaming the surrounds is not too tricky, and kits are available from ebay. Some of the mid-range units were coated with PVA iirc, but not the surrounds. They rotted just fine without any outside assistance!
I don't recall any electrolytics in the crossover, so components should be fine. If you're not sure, just unbolt the crossover panel and pop a picture of the crossover on here. Once you've refoamed the midrange units, then providing the other units haven't been abused and none of the crossover components has been bunt out (unlikely), they should be as good as new. It's always worthwhile checking the tightness of all the drive unit and crossover panel mounting bolts; other than that, there's not a lot to go wrong.