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Old 21st Apr 2017, 8:37 pm   #15
mhennessy
Dekatron
 
Join Date: Jul 2007
Location: Evesham, Worcestershire, UK.
Posts: 4,241
Default Re: Radio sound quality - some measurements

For completeness, we need to include measurements of the Celestion. So, after much hunting through boxes, I eventually found one:

The Open University RP37A (with Celestion).

This one isn't terrible by any means, but has a surprising lack of treble extension. As before, the traces are no EQ (bass/treble at min), and after adjustment by ear for best sound quality. I wanted more treble, but couldn't because of the painful 4-5kHz peak...

Out of interest, I put the Goodmans (blue), Celestion (black), large-magnet Elac (green) and the small-magnet Elac (red) on the same graph. Sorry it's a bit of a mess!

At low frequencies, they are pretty similar, with the large-magnet Elac giving a bit more extension, and the Hunter Elac having a bit more output (higher Q) at 100Hz. You'll note similarities between all 4 in this region - such as at 300Hz, 400Hz and 600Hz - which will be in-part caused by the sizes of the boxes (all much the same).

It's really above 1kHz where they vary most, and this is where we're most critical*. The Celestion and Goodmans have the largest peaks in the 3-5kHz region before rapidly falling away at 9kHz. The large-magnet Elac shows a much smaller peak at 4.5kHz followed by a dip at 7kHz (remember dips are fairly benign subjectively), before recovering and holding out to about 13kHz. The Hunter Elac is smoother through this region, but not quite as extended. Overall though, I'd take either Elac over the Celestion and the Goodmans without hesitation.

* It's worth saying that human hearing is at its most acute in the 2-5kHz region, so these differences really are quite noticeable, especially when you have the sets in front of you. How much the >10kHz bothers you is naturally age-related (and other factors too) - so that's where I'd expect most variation in opinions on a listening panel.
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