Hello, testing a pair of the sam1hf horns. Does this look normal the difference between the two 045ti's ? ?
Printable View
Hello, testing a pair of the sam1hf horns. Does this look normal the difference between the two 045ti's ? ?
Quote:
Originally Posted by dezmond
Well it looks a bit off. Where is the rest of the measurement???
Did you double check the set-up?? Doesn't take a lot to skew measurement's that high 10-20 K. Mike placement and distance can trip you up. They absolutely need to be measured same distance and axis WRT driver.
How close??? Might want to try say 1 ft instead of a meter if that's where you are measuring from.
Rob :)
Hello, the microphone was on axis 1 meter away. I'm using a xilica xp4080 for dsp. These measurments were made to basically isolate the 045ti band with no dsp used. Both speakers fed the same input and same amp channels used. I will post more full measurments tonight. These are from a pair of sam1hf's with 2430h's installed.
These are from 18 inches, 800-20k
Here is both drivers using same peq's.
I have measured brand new 077s that were near consecutive serial numbers and there were 4dB differences between them at certain frequencies.
Sadly I don't think JBL's tolerances are as tight today as they once were, so this level of variation is probably typical. The swings above about 12kHz are the most egregious but also least likely audible... agreed, in a perfect world they would align more closely, but in reality with musical content I doubt you'll hear the difference and I doubt it will affect imaging.
Widget
Hello WidgetQuote:
Originally Posted by Mr. Widget
I think you may have hit the nail although I am surprised. Also agree probably not hear it and too high for imaging. Attached is my Array passive using pair matched rebuilt 2435's and 045Be Red and Blue. You can see a mismatch in the 045's. Those are stock as received only a couple of dB mismatch. These were done 2010 when JBL still was JBL.
I just expected the Ti's to be similar as the only difference is diaphram material.
I have a pair of SAM HF's, If I get a chance I will measure them.
Rob :)
Hi Dezmond,
I think you should very careful to run the 045's below 4-5 kHz. They diaphragms are very delicate and 800Hz may well destroy them given some power.
Kind regards
//Rob
Good point I assumed he had the 2430 midrange in that measurement as well.Quote:
Originally Posted by sebackman
Rob :)
Hello, the tests were done through the sam1hf crossover. Its a 2430h mid and the 045ti. I'm starting to think there must be a issue with one of these 045's. The specs on every system using the 045ti lists +-2db to 20k. After installing the 2430's the first test there was no output from the low 045ti. I had to move the terminal connector on the driver to get output. Starting to wonder if perhaps a drop from ups maybe knocked something out of spec. Luckily i know a jbl authorized repair tech and he is going to take a look at it. And see if diaphragms are available.
Hello Dezmond
Well I hope they have diaphragms and it's not a driver swap if needed. Watch those terminals when you take it out, really fragile have seen several for sale with the tabs broken at the base.
Rob :)