- I haven't done any work with my 902s so I don't know how linear I can get their response ( with or without the loading caps ) .Originally Posted by Skywave-Rider
- Give it a go ( measure, add the loading caps, & then remeasure ) / I just wouldn't expect miracles .
- Conversely, I've demonstrated that 802s ( with either type of phase plug ) can give very linear response ( on non-Altec, older-style horns ) .
- The 802s have guide pins for the diaphragms making a fit-up a one-shot deal ( unlike the 902s ) .
- If I had Altec drivers on 811b horns , I'd be looking to reduce their roller-coaster response as well as reducing the inherent coloration .
- Below ( on the left ) is a CSD sonogram ( from Zilch ) of your 902 on the 811b horn . This CSD is normalized and ( IMO ) quite clearly shows the horns' inherent coloration's are just 10 db below the fundamental frequencies .
- Since I like radial horns,( & if I had a pair of 811s ), I'd be working at reducing those coloration's into the more typical sub 20 db range .
- The work done by Urei back in the late 1970s can be used a starting point in the practice of adding different types of foam to the interior surfaces of horns / when wanting to affect the frequency response .
<> cheers EarlK
ps ; One could see if they could get the CSD colorations down to a level such as I've shown on the right hand CSD ( this is an Altec 802-8T on a Sammi BiRadial , normalized quite flat with passive EQ ) .