What size is this speaker cone?

skyripper

skyripper

skyripper

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19 Jul 2011
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Dear experts,

Quick boring question, I bought a pair of KLH outside speakers second hand, I can't return them as it's not economical to post them back to the netherlands and I cant be dealling with etsy for it.
They were described as used but fully working, but while one is spot on and sounds great, the other is knacked flat, lacking bass and mid.

So I stripped it down, to see if it was the crossover, or one of the drivers.
Turns out its an all in one speaker, with mid/bass and a separate tweeter, and testing confirmed the tweeter worked fine, the voicecoil for the mis/bass was shot. Given the amount of dirt and crud I had to wash off the speaker, I guess it had too much life outside and died.

ibb.co

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Ruler not banana for scale.

I'd like to reuse the cabinets because they're dead weighty solidly built and having an odd pair of speakers would do my feng-shui right in.
So, before I go and try and find a cheap replacement driver, am I right in thinking this is an 8inch cone or it a 7.5 or a 7 ??? Cos I dunno which bit to measure from. Bit like something else I suppose!
Then I can order something off ebay or amazon, caulk it, screw it, and be back to glorious stereo in my garden.


Thanks
 
My personal view is that just dropping another mid/low range driver in purely because it’ll fit is not really the best option.
Different drivers are quite likely to have different efficiency, frequency range and impedance.
So just putting a cheap driver might work, but could sound like a dogs dinner. Would be a lot easier to find a direct replacement
 
I've built my own speakers from a design and also looked at designing my own.

The driver data sheet should provide a lot of the information you will need:

a) shape of the driver - this is not only the size of the cone but also how the spider/frame sits and if you have any fitting issues.
b) Volume - basically it provides the volume of air of the box for drivers are designed to work with.
c) self resonance (f0) - this is the lowest frequency the drive can do before it starts falling off.
d) frequency response this will be a graph.
e) driver impedance (it's a frequency graph, or at the most basic a "nominal" impedance).

Drivers are normally designed for a specific purpose or "full range" which is a single driver for the entire range supported.

In general small drivers do not have the area to move enough air for low bass without large cone extension (ie like a sub moves far in and out) and large drivers often suffer from not being able to support high frequency without breakup (the cone can't move in and out fast enough without flexing).

I take it the cabinet is 18mm heavy MDF. Does it have anything inside?

As Mr_S has said - typically the cabinets are designed for a driver or similar characteristic drivers unfortunately.
 
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I think my friends, you're overthinking this a bit. We're not talking the height of hifi audio here.

They're garden speakers, and they were cheap [although now I suspect why they were quite so cheap]. They're used next to a hot-tub and barbecue, which means any subtlely about hifi characteristics I can pretty much ignore. If I can bang out absolute radio on a saturday while sizzing sausages, that'll do me.

I'd just like to know if its an 8in coaxial driver [which I think they are], or a different size [because I'm not meant to measure the cone, but somewhere else?]. They're 8ohm, and tbh as long as it fits and survives being accidentally got by a hose, that'll do me.
I'm driving them from an old sonos amp in the garage. The as supplied cables were brown and blue mains cable!

Cabinets are a resin construction, heavy, really heavy for the size. About 3x the weight of my wharfedale or q-acoustics for less than twice the size. They're not ported in any way.
And they look like a rock, so they can be hidden in the flowerbed.

Inside is a mixture of rockwool and sprayed on foam. There is no crossover or anything fancy in there, its wires in, lots of sealant on any ingress holes, soldered to the speaker terminals, just like in the back of a 80s vauxhall Astra.

And if the recommendation is replace the driver in both units so they match, I may just do that if they sound that bad.
Just looking to get them both up and running cheap and cheerful because I hate throwing away stuff unless I have to.

Ta
 
I'd suggest your best bet is measure up dimensions of what you've got and compare to drawings/dimensions of replacements - I'm not sure it's as simple as 8" is 8" - the fixing dimensions etc. may differ between otherwise apparently similarly sized items.
 
It's a 7" anyhow, based on finding an 8" and a 7" speaker online looking at the specs and where they measure from and checking the duff one I have.



Thanks all.
 
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