Choosing drivers for a given enclosure and desired sound.

[YNWaN]

You have to match the bass/mid driver to the internal air volume of the cabinet - that is why the cabinet is designed after the drive units have been chosen.

[Reid Malenfant]

In brief though, could I choose any tweeter/woofer pairing (that work well together) and adjust the crossover for the cabinet/driver combo or do I have to match the drivers to the cabinet?

Is it only bass resonance that I need to match up with the drivers?

The Kingston cabinets are sealed designs with a tapered rear.

If you were to pick a pair of drivers that already happen to have a crossover designed to pair them up then you won't need to mess about with the crossover at all, in theory. In practise you may need to alter the DC resistance of the choke feeding the bass/mid driver, depending on if you are going to change the bass loading of the enclosure. If you aren't then you won't need to do a thing, if you are you still may well not need to, it just depends on how anal you want to be

You have to match the bass/mid driver to the internal air volume of the cabinet - that is why the cabinet is designed after the drive units have been chosen.

I agree, you do have to match the driver to work with the enclosure.

However, I think you'll find that it best to decide on what size enclosure you can live with & then look for a driver that'll work with the allotted volume.

Doing it arse about face & buyng a driver first can often end in tears, when the designer realises that he'll need to build something the size of a coffin to work with the driver, isn't a good idea

[nat8808]

You have to match the bass/mid driver to the internal air volume of the cabinet - that is why the cabinet is designed after the drive units have been chosen.

Yet most of the speakers in the world use generic drivers and the designs are all completely different...

Volume of a set cabinet can always be reduced too (I even have some jesmonite/alpha crystal to use) so as long as the driver doesn't require a minimum volume that is greater than these then there should still be a good choice.

These share exactly the same drivers as the wooden, square box of the Celestion 100 so if it comes to it I can at least resort to devouring some 100s - normally about £150 sometimes less, just not many around.. Probably not much different to the A1's drivers either.

Having had a brief look, the choice might be mostly restricted to driver size and mounting arrangement. The hole for the mid/bass runs very close the edge which makes the common 5 or 6 hole mountings difficult to use and most four hole mounting drivers with square basket edges are the cheap crappy ones...

Unless there are some top drivers of the last 10 years or so now out of production I could find?

[YNWaN]

Yet most of the speakers in the world use generic drivers and the designs are all completely different...

But they don't - that may be your perception, but it is a gross over simplification.

However, I quite agree that the drive unit must be chosen with a target volume in mind - you can't set out to make a small stand mount and then find that your chosen drivers need a cabinet the size of a wardrobe!

What you can't do is choose two random drivers you like the look of and put them in a box with a random internal volume (well you can, but the result will be very coloured and uneven). If you look at some of the software that was recommended to you earlier in this thread, you will quickly see that the volume and loading of the box has a profound effect on the speakers output, depending on the Thiele-Small parameters.

[nat8808]

But they don't - that may be your perception, but it is a gross over simplification.

However, I quite agree that the drive unit must be chosen with a target volume in mind - you can't set out to make a small stand mount and then find that your chosen drivers need a cabinet the size of a wardrobe!

What you can't do is choose two random drivers you like the look of and put them in a box with a random internal volume (well you can, but the result will be very coloured and uneven). If you look at some of the software that was recommended to you earlier in this thread, you will quickly see that the volume and loading of the box has a profound effect on the speakers output, depending on the Thiele-Small parameters.

Probably is a gross over simplification I agree - was thinking of all the Kef drivers of yore and scanspeaks in different guises, accutons recently, focals, volts, ATCs, blah blah. Appear to be drivers created as OEM and then integrated into manufacturer's designs.

I think what I was interpretting from your post was that matching is very specific and that there is only one driver to match any one cabinet size.

Of course there will be many designs that match a driver, dependant on the construction and how much of the volume the driver 'sees'.

I would only need a driver to match the volume in a general ball park and the cabinet can be adjusted, stuffed differently (not sure what would have been in an original Kingston). As I say, I can reduce the volume easily.

My SL700s have had the internal foam removed and that kind of circular-ribbed matting placed on the internal walls instead. Cross-over has been re-worked and placed on the outside. Someone else did it and quite well and I'm loving their sound.. I wonder if they just re-built the xover based on the standard values or adjusted to account for the change in internal properties..

[diyer]

hi Nat,
stuffing a speaker doesn't alter the internal volume , on the face of it making speakers is simple BUT as others have said theres a lot more that goes on than most realise.

[Toppsy]

nat8808 It seems to me from your posted replies you have made up your mind to go your own way with these speakers and ignoring the vast knowledge of those who have tried to help you regardless the advise given . If you want go ahead, buy some drivers that you like the look of and are of a size that fits your box but don't expect them to sound good.

I find such folk annoying in the least. You ask for advice, are given it, then post up arguing that advise and knowledge of those that know. So why ask the question(s) in the first place when you have no intention of taking up that advise?

[nat8808]

Sorry you feel that way.

The cabinet design is FIXED.

Your advice Toppsy was:

You will need to input all the theile parameters into the program for your drivers to get a suitable cabinet volume after choosing which type of cabinet alignment you want.

What drivers? I don't have any drivers! That is the whole point.

If you want to ramble on about best speaker deisgn practice then add your own blog to list of hundreds around the web. I guess in asking for advice I'm seeking true response rather than monologue - maybe that mismatch has caused the annoyance you've experienced previously? Certainly it's a bit annoying for people to ignore the original post content and go off on one about something else and then complain I'm not taking their advice..

To be clear, I have these cabinets already and I would like to turn them into a working pair of speakers best I can.

I can find the original drivers (same drivers are used in different Celestion design too, yes different design/same drivers) but hoping I might be able to improve on the original design given more modern technology and commercial cost constraints of the original.

I guess people's own blogs/threads (real experiences) of upgrading/replacing drivers to improve things gives me the belief I can do it too! Hoping someone might have previous experience and be able to give advice..

So far I've taken the infered advice to investigate what parameters I need to go for for the given volume. I might cop out a bit in that I've asked Wilmlow Audio too and so they might be able to come up with a selection.

I was also wondering about how wide a range of parameters values I can choose from to then hone in the match via the crossover design, if you see what I mean.

[nat8808]

hi Nat,
stuffing a speaker doesn't alter the internal volume , on the face of it making speakers is simple BUT as others have said theres a lot more that goes on than most realise.

Depends on accoustic density/properties surely? Stuffing a cabinet with something with the same properties as the enclosure would be the same as making the cabinet smaller for example.

Maybe it can be equally considered mathematically as an integral of all the different 'seen' cabinet sizes by each frequency when finding the overall response of a speaker by using internal stuffing?

[nat8808]

So is there a way to or will those programs mentioned before be able to guide me to the right driver parameters for the given/fixed enclosure volume of these infinite baffle cabinets?

I'll work out the volume of them by filling them with water I suppose. One of the benefits of a resin cabinet!