Using Shoot Thru Umbrella

For portraits I am currently using a 45 inch Westcott soft white umbrella in shoot thru mode. I have the umbrella 3 feet from the subjects face. The umbrella is 45 degrees above the subject and about 45 degress to the side. I am using a Sunpak 611 which is an older version of the Sunpak 622 as the light source. I also added a Sunpak diffuser to the flash that changes the coverage from a 35mm lens to a 20mm lens so I am sure that the flash is covering the full 45 inch umbrella plus I am getting quite a bit of diffusion of the light. I am very happy with the results except that the spectral highlights on the forehead, cheeks and chin are still way to bright for my liking. Is there anything else I can do to my setup to tone down the highlights. Will a softbox of the same size give me more toned down spectral highlights. Or do I need to tone down the spectral highlights in Photoshop.

Any help would be appreciated.

I definitely rather not do much post processing and try to get it dialed in right at the shoot.
Do you have a light meter? Does this happen to all your subjects or multiple ones? Maybe try to just bounce it off the umbrella?

Chris

Chris, thank you for responding.

Yes I do have a light meter.

Normally I do bounce the light into the umbrella and it works quite well but with bouncing light into the umbrella I get really bright spectral highlights on the face when I photograph either the bride or groom. When I photograph both of them together the spectral highlights are not really noticeable because I am not as close to the face. I have been experimenting with shootthru method because I can place it closer to the subject for softer light and I was hoping that using shootthru and the diffuser on the flash would tone down the spectral highlights, but the highlights are just as bright with shootthru method as they are bouncing light into umbrella. There is a noticeable difference between using bounced light and shooting thru the umbrella but really not enough for me to change to the shootthru method.

I don't own a softbox so I have no way of knowing if a softbox of the same approximate size will tone down the spectral highlights much more than using the umbrella. I was hoping that someone on this forum would know the answer to my question. I could purchase a softbox and use it but I really like the convenience of using the umbrella for weddings. Plus I still have lots of stuff I need to purchase when I have the money.