Oh how I lurve the Celestion HF1300

[florin]

I bought a pair of DM2's a while back and found that it had the DW200 replaced with a driver built on the same chassis but made of polypropylene. I found it to be 750g heavier than the original DW200 so larger magnet.
Now from what I've read speakers built on bextrene drivers have some adjustment in the crossover to address some resonance issues so wondering whether these poly drivers would be a good for for the DM2 crossover.
I've been thinking of using them in a ported cabinet using the same drivers but hook them to a DM4 crossover which is smaller than DM2. I also have a pair of Infinity 1001A which have a 12inch bass driver the speakers themselves handling up to 200w. I was wondering what is the power handling limit (wattage) limit for the Celestion HF1300 / Coles 4001G combination? I don't listen loud but what to be on the safe side, just in case of a slip oh hand lol.
Planning to use the cabs of a pair Radford Monitor speakers for the above project.

[spendorman]

I was under the impression that polypropylene cones were lighter than Bextrene cones.

[florin]

I was under the impression that polypropylene cones were lighter than Bextrene cones.

Indeed, they are definitely lighter.
I'm a beginner so don't know whether the polypropylene driver would be a good replacement considering the fact that the crossover has been designed for the Bextrene.
In this article on is mentioned that a notch-filter equalisation to flatten the Bextrene driver is usually being used in designs of the time. I wonder whether this has an effect on the polypropylene replacement.
The author of this article on the Spendor BC1 ends with: "On the web I've seen the suggestion of the BC1 midbass driver being replaced by a Vifa 8" paper cone driver, but I would never do this. This is likely to totally change the sonic character of the BC1 speaker. Not even a polypropylene driver may come near this driver. Not that it necessarily would be worse, but only different from how the BC1 was intended to sound."

My polypropylene drivers would have to be looked at first as whomever has made them left the core tube on which the wire goes too long at it hits the magnet if driven too hard. More on that here.

[florin]

Managed to find out the power limit for the two:
Coles 4001G - 120W
Celestion HF1300 - 60W

[spendorman]

What makes you certain that the cones are polypropylene?

I have tried the Vifa units as replacements for the BC1 bass units (suggested by Wilmslow Audio), and they are not suitable in my opinion.

[walpurgis]

My polypropylene drivers would have to be looked at first as whomever has made them left the core tube on which the wire goes too long at it hits the magnet if driven too hard. More on that here.

I think that may indicate that the system bass resonance with that driver in use is too low. In a reflex cabinet, port tuning may help, but with a transmission line things get more complex. Also, bear in mind some bass drivers are intended strictly for use in sealed systems and will behave as described used otherwise.

(the "core tube" is generally referred to as the 'voicecoil former')

[florin]

they've been seen by an audio engineer. You can also see in the video here that the surface of is smooth, bextrene is covered in damping paint so it's got some texture to it.

Probably doing the DM4 setup after I fix these drivers then makes more sense since the DM4 also uses a polypropylene driver. It would make a DM4 on steroids.

[florin]

Still it doesn't explain as to why the "core tube" (thanks for that) hits the magnet. I've never seen a speaker doing this. It's either that the space was limited in side or left it like that by mistake. Can't know unless I take them to someone to look at them.

[spendorman]

they've been seen by an audio engineer. You can also see in the video here that the surface of is smooth, bextrene is covered in damping paint so it's got some texture to it.

Probably doing the DM4 setup after I fix these drivers then makes more sense since the DM4 also uses a polypropylene driver. It would make a DM4 on steroids.

As far as I know, B&W did not use a polypropylene cone. In my view, the bass unit in the video has a fault. I have similar units that don't do this.

[spendorman]

DM4 uses a Bextrene unit, I believe polypropylene coned bass units were pioneered after the DM4 and DM2 were designed.