Quality of foam surrounds

[Guest sparky]

Hi all,

I just refoamed a pair of "the loudspeakers", #s U3 66918, 66941, woofer said 78 on it. I used surrounds from simply speakers, and installed them with the foam below the cone as original. The included glue was a sticky mess to work with, and the results are not particularly pleasing to the eye, but mechanically sound.

When gluing the foam to the frame I was careful to fix it in a neutral position, neither pushing or pulling on the cone.

So here's the question. Are some foams much stiffer than others?

The woofers feel slow when depressed and released and the foam seems thicker than my boston A150 foams from another source.

Also will re-capping the crossovers make big difference?

thanks much for any info or opinions

[Carlspeak]

>Hi all,

>

>I just refoamed a pair of "the loudspeakers", #s U3

>66918, 66941, woofer said 78 on it. I used surrounds from

>simply speakers, and installed them with the foam below the

>cone as original. The included glue was a sticky mess to work

>with, and the results are not particularly pleasing to the

>eye, but mechanically sound.

>When gluing the foam to the frame I was careful to fix it in a

>neutral position, neither pushing or pulling on the cone.

>So here's the question. Are some foams much stiffer than

>others?

Yes, some foams are thicker than others. Simply speakers should have supplied the correct foam - assuming you gave them a good description of your speaker.

>The woofers feel slow when depressed and released and the foam

>seems thicker than my boston A150 foams from another source.

You shouldn't compare foam surrounds from one brand to another. The key question you haven't answered in your post is: How do they sound?

Is the bass clear and tight?

It may also be the surround needs a little braking in with some hours of music.

>Also will re-capping the crossovers make big difference?

I heartely endorse recapping with good, audio-grade PP caps. They may sould a bit bright at first but will smooth out over time.

>thanks much for any info or opinions

Remember, it's all about the music

Carl

Carl's Custom Loudspeakers

[Doug G.]

If the woofer is out of the cabinet, the cone should be very easily pushed in and should spring right back out. This shows that the surround is not restricting the movement of the cone. The spider is the controlling factor. This is as it should be with a woofer used in an acoustic suspension speaker such as the Advents.

Once the woofer is mounted into the cabinet and sealed, there should be a pretty good amount of resistance to your pushing in on the cone and it should return to rest slowly. This shows that the cabinet is air tight. This is also as it should be with an acoustic suspension speaker.

The air trapped inside the cabinet is used to control the movement of the cone, not the surround.

A too stiff surround will raise the free air resonance of the woofer and, in turn, the effective low end response of it.

Doug