I have a pair of Monitor Audio GR20 speakers and I was wondering if anybody could identify the mid/bass unit (I've seen mentioned elsewhere that MA often use modified SEAS units):
Mid Bass:
It doesn't look like any SEAS unit i can find on their website. To start wtih I can't find any SEAS aluminium coned driver that has that inverted surround. But there are older units on the site that don't ave actual pictures. This one for example:
http://www.seas.no/images/stories/vintage/pdfdataheet/h1008_l17rep.pdf
Barring anyone here knowing anything about this mid bass unit, what would be the best way of finding out it's frequency response and impedance curves? (not worried about it's t/s paramaters as obviously it's already in a cabinet designed for it by MA).
I've asked MA for advice on replacing the tweeters in the past, but go no response to two emails. So i don't hold any hope that they'll give me the tech specs on one of their drivers. Must admit I was very surprised by their lack of response, as I was half asking them if there were any units they could sell me that would be better than the originals.
Mid Bass:
It doesn't look like any SEAS unit i can find on their website. To start wtih I can't find any SEAS aluminium coned driver that has that inverted surround. But there are older units on the site that don't ave actual pictures. This one for example:
http://www.seas.no/images/stories/vintage/pdfdataheet/h1008_l17rep.pdf
Barring anyone here knowing anything about this mid bass unit, what would be the best way of finding out it's frequency response and impedance curves? (not worried about it's t/s paramaters as obviously it's already in a cabinet designed for it by MA).
I've asked MA for advice on replacing the tweeters in the past, but go no response to two emails. So i don't hold any hope that they'll give me the tech specs on one of their drivers. Must admit I was very surprised by their lack of response, as I was half asking them if there were any units they could sell me that would be better than the originals.
Seems a pretty competent 2.5 way metal speaker to me. Hard to improve, you would think.
You should be looking at the crossover. A little notch on the metal mid and bass might help.
I don't know what those drivers are, but usually a tweeter is 104mm front plate. The midwoofers might be replaceable with SEAS metal units.
You might be able to place the breakup resonances with sweepgen direct to the midbasses:
Audio Tools - from David Taylor, Edinburgh
You ought to hear any ringing breakup nasties, then notch them at a slightly higher frequency. But you must look at the crossover first.
You should be looking at the crossover. A little notch on the metal mid and bass might help.
I don't know what those drivers are, but usually a tweeter is 104mm front plate. The midwoofers might be replaceable with SEAS metal units.
You might be able to place the breakup resonances with sweepgen direct to the midbasses:
Audio Tools - from David Taylor, Edinburgh
You ought to hear any ringing breakup nasties, then notch them at a slightly higher frequency. But you must look at the crossover first.
Thanks for the reply. I'm not acually looking to replace the units, but i have replaced the original tweeters with off the shelf SEAS units (thread about it is here if you're interested: Tweeter attenuation help ), and i'm trying to model the speakers with the new tweeters but dont have even basic data about the existing mid-bass unit to use.
Thanks for the software link.
Thanks for the software link.
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If you are recycling unknown drivers.. .buy one of these. The time and money saved throwing more and more passive xo parts (unless going active) will pay for itself. Even if active - being able to measure the frequency response will get you to your goal that much quicker.
Acoustic Measurement Tools : UMIK-1
With a simple impedance jig - you can use the same software (REW) for free to do an impedance sweep.
Acoustic Measurement Tools : UMIK-1
With a simple impedance jig - you can use the same software (REW) for free to do an impedance sweep.