Replacing tired drivers.

[Horizontalste]

Just curious as to what factors should be taken into account when replacing existing drivers in front ported cabs.

I have a couple of 12's that are rated at 200w each & they are starting to sound a bit tired. I'd rather keep the cabs & upgrade the drivers (with a higher rating) than buy new ones but I know there's more to it than just chucking anything that fits in.

Any advice gratefully received.

Ta

[Lozz196]

Hmm, the science says that cones should be matched and there`s a lot of on-line help - plus Bill F on here is pretty exceptional on this. You can luck out and get good results by just swapping, I have on the times I`ve done it, but I am aware that it could have gone horribly wrong.

[Bill Fitzmaurice]

The driver T/S specs need to be matched to the cab, via speaker modeling software.  The driver thermal rating is one of the least important specs, as it has no relationship with either frequency response, sensitivity or maximum output. Perhaps most important when contemplating a swap is that if you don't model the existing drivers for low frequency results and have a data sheet SPL chart for the midrange and high frequency results you have no way of knowing if a different driver would be an improvement, or if it is even as good as what you have.

[Horizontalste]

Thanks for your input chaps.

I guess then @Bill Fitzmaurice without the modelling software or the data for the existing drivers any change could just be an expensive & futile experiment.

The cabs in question are Genz-Benz so I wonder if Mr Genzler could advise on suitable replacements 

 

[Gottastopbuyinggear]

If you can post the cab model you may find that someone already knows something about the cab and could suggest a suitable replacement.

Alternatively if you are able to take measurements to confirm the overall dimensions of the cab, and importantly the exact dimensions (including length) of the ports, then someone will probably model it for you. In fact, seeing as I have another thread on the go here where I’m hoping for some relatively expert comment, I’m happy to put something back into the community and model the cab myself, though being relatively inexperienced I might ask for someone else to mark my homework!

[Gottastopbuyinggear]

I should caveat the above with - assuming you’re convinced you want to try this?  To echo what others have said, there’s no guarantee that it’ll sound any better, and every possibility that it’ll sound different

[Horizontalste]

That's very kind of you @Gottastopbuyinggear the cabs are Genz-Benz Focus 1-12's, I'll get the engineers rule out & take measurements if you are sure you don't mind.

I'm not really after massive improvements in sound I'd just like to be able to drive them harder & one has started to crack & pop at higher volume's.

[Bill Fitzmaurice]

Most manufacturers are quite loathe to reveal any information about the drivers they use. The usual reason given is that they don't want people reverse engineering their cabs. That's silly, as any decent amateur engineer can borrow a cab, measure the driver specs and get the cab dimensions in a matter of a couple of hours. The real reason is that they don't want users to know how inexpensive the drivers are that they use, and don't want people buying replacement drivers from alternate sources for much less than what they sell them for.

Your best bet is to post the cab dimensions and you can be given a few drivers that are compatible, but they probably won't sound the same as the stock drivers.

[Horizontalste]

Thanks again for all your help!

 

The cab dimensions (external) are: H410mm, W440mm, D300mm & the port is a full width shelf and is 120mm from the front grille to where the wood ends & the void begins.

Thanks again chaps.

[Bill Fitzmaurice]

Internal dimensions are a must.

[Horizontalste]

5 minutes ago, Bill Fitzmaurice said:

Internal dimensions are a must.

Aaaaah of course, I'll get on it!

[Gottastopbuyinggear]

Can you measure the exact width and height of the port?  Also, is it completely open to the full width or divided?  If it’s divided then can you give the width and height of each division, and is/are the dividers the full 120mm depth of the port or just at the front part of it?

Finally, can you tell the thickness of the cab walls at all? I’d guess they’ll be 12 or 15mm or thereabouts

[LukeFRC]

31 minutes ago, Horizontalste said:

Aaaaah of course, I'll get on it!

google, esp on talkbass - I think I remember a discussion about what the drivers are where someone said what they were relabelled versions of. AgedHorse on there used to work at Genz and now at Mesa and can be quite helpful. 

How tired are they? Is that a euphemism for "I've overpowered them" or is it a euphemism for "I want a different sound/to something louder I can hit with more power" ... either way it may be easier to sell them and get something that suits. 
 

[Horizontalste]

1 hour ago, Gottastopbuyinggear said:

Can you measure the exact width and height of the port?  Also, is it completely open to the full width or divided?  If it’s divided then can you give the width and height of each division, and is/are the dividers the full 120mm depth of the port or just at the front part of it?

Finally, can you tell the thickness of the cab walls at all? I’d guess they’ll be 12 or 15mm or thereabouts

I shall get it apart & get all the measurements including the internal dimensions, the port does have dividers & I'll investigate those too.

 

1 hour ago, LukeFRC said:

google, esp on talkbass - I think I remember a discussion about what the drivers are where someone said what they were relabelled versions of. AgedHorse on there used to work at Genz and now at Mesa and can be quite helpful. 

How tired are they? Is that a euphemism for "I've overpowered them" or is it a euphemism for "I want a different sound/to something louder I can hit with more power" ... either way it may be easier to sell them and get something that suits. 
 

I'll have a Google but I do try to avoid talkbass as a rule 

In terms of euphemisms I have definitely pushed one harder than I perhaps should have but it's still useable. I think they're great cabs but underpowered by today's standards hense the desire to load them with something more capable.

I could buy something else but I'm all for experimenting.

[LukeFRC]

18 minutes ago, Horizontalste said:

I shall get it apart & get all the measurements including the internal dimensions, the port does have dividers & I'll investigate those too.

 

I'll have a Google but I do try to avoid talkbass as a rule 

In terms of euphemisms I have definitely pushed one harder than I perhaps should have but it's still useable. I think they're great cabs but underpowered by today's standards hense the desire to load them with something more capable.

I could buy something else but I'm all for experimenting.

They were only released (to much acclaim) 4-5 years back weren't they? 

 

[stingrayPete1977]

5 minutes ago, LukeFRC said:

They were only released (to much acclaim) 4-5 years back weren't they? 

 

They were a budget range complimented by the Uber range either side of the regular Genz-Benz cabs, Fender bought them out and closed them down! That's probably one of many reasons why they are millions of dollars in debt.

[stevie]

The Focus 12 looks like a fairly standard 12" bass cab to me. It certainly looks smart and would probably benefit from a driver upgrade. 200 watts was great twenty years ago but today it signals a cheap driver. Even the bottom-of-the-range Eminence Betas are 250 watts.

Obviously, it would be nice to know the internal volume, but assuming that Genz Benz have done their homework, any 12" driver designed with bass guitar in mind will work. The porting looks like it will handle more powerful drivers. I see they are plywood cabs, but what's the cabinet construction like? There's not much point installing an expensive driver in a cheaply constructed box.

 

 

[Horizontalste]

20 hours ago, LukeFRC said:

They were only released (to much acclaim) 4-5 years back weren't they? 

 

They were but as Pete says they were the budget end of the range. Price point aside most 12 offerings these days are all 300w and above.

 

20 hours ago, stingrayPete1977 said:

They were a budget range complimented by the Uber range either side of the regular Genz-Benz cabs, Fender bought them out and closed them down! That's probably one of many reasons why they are millions of dollars in debt.

Agreed 

 

5 hours ago, stevie said:

The Focus 12 looks like a fairly standard 12" bass cab to me. It certainly looks smart and would probably benefit from a driver upgrade. 200 watts was great twenty years ago but today it signals a cheap driver. Even the bottom-of-the-range Eminence Betas are 250 watts.

Obviously, it would be nice to know the internal volume, but assuming that Genz Benz have done their homework, any 12" driver designed with bass guitar in mind will work. The porting looks like it will handle more powerful drivers. I see they are plywood cabs, but what's the cabinet construction like? There's not much point installing an expensive driver in a cheaply constructed box.

 

 

I wouldn't know about the construction aspects other than they seem pretty solid. I'm going to take one apart to get the internal dimensions so I guess I'll know more then.

They are good as they are but I do think they're ripe for the pimping :-)