Out of curiosity, I have been playing around with a couple of PT2522-4 tweeters.
I bought them for €38,- each but for a week the price raised to €50,- each.
Hopefully, they don't follow the B&G trend with neverending price increases.
Anyways, for the money, this is a truly amazing tweeter. I think I have never had a tweeter below aprox. €150,- sounding this good. I have compared it with my ess air motion transformers and B&C de250 on an RCF h100 horn.
All were used in the same active system from 2500Hz/60dB/oct crossover and eq'd to flat response.
Offoarse both the de250 and the AMT's have quite a bit more dynamics than the GRS tweeter but the GRS has a better top-end than the de250. They do have a little bit of 'sizzle' though but not in an annoying way, I guess they have a bit higher distortion than either the de250 or AMT's. All in all, it is a highly listenable tweeter which had made me curious about the bigger ones but at the moment I can't decide whether I would buy the PT5010 or the PT6825. Did anyone try both in the 700Hz-1kHz to 3-5kHz range? The PT6816 seems to be more of a real tweeter which is not my intended purpose. I have had large ribbons, AMT's and planar in the past, and I really can't live with such a narrow vertical dispersion. I have abandoned them all, including various RAAL ribbons and the Beyma AMT for this reason.
I bought them for €38,- each but for a week the price raised to €50,- each.
Hopefully, they don't follow the B&G trend with neverending price increases.
Anyways, for the money, this is a truly amazing tweeter. I think I have never had a tweeter below aprox. €150,- sounding this good. I have compared it with my ess air motion transformers and B&C de250 on an RCF h100 horn.
All were used in the same active system from 2500Hz/60dB/oct crossover and eq'd to flat response.
Offoarse both the de250 and the AMT's have quite a bit more dynamics than the GRS tweeter but the GRS has a better top-end than the de250. They do have a little bit of 'sizzle' though but not in an annoying way, I guess they have a bit higher distortion than either the de250 or AMT's. All in all, it is a highly listenable tweeter which had made me curious about the bigger ones but at the moment I can't decide whether I would buy the PT5010 or the PT6825. Did anyone try both in the 700Hz-1kHz to 3-5kHz range? The PT6816 seems to be more of a real tweeter which is not my intended purpose. I have had large ribbons, AMT's and planar in the past, and I really can't live with such a narrow vertical dispersion. I have abandoned them all, including various RAAL ribbons and the Beyma AMT for this reason.
Did I miss anything, or has no one looked at what they do above 20K? Do they have the same kinds of breakup that dome and cone drivers do?
I am particularly interested in this aspect as how it related to my theory of some audible distortions. ( IM based) Likewise, how ribbons and AM driers behave.
I am particularly interested in this aspect as how it related to my theory of some audible distortions. ( IM based) Likewise, how ribbons and AM driers behave.
Not that I can measure with my Earthworks M23 microphone. Popular USB measurement mics like the Minidsp U-mik are not very reliable above 10kHz anyway. Any distortion measurements up there with these mikes are useless for absolute values but can be meaningful for comparison only.
Most people over here (including me) measure with REW which does not measure IM distortion and it is not very accurate in measuring THD either. Again, nice for comparison one example to another but completely useless in absolute terms.
Most people over here (including me) measure with REW which does not measure IM distortion and it is not very accurate in measuring THD either. Again, nice for comparison one example to another but completely useless in absolute terms.
A couple quick picts of my WIP NEO8/Ribbon line array baffles.
(6 foot midrange line) flush mounted 9 x GRS NEO8's per side paired with (5 foot tweeter line) flush mounted ribbons in 12" wide baffle.
4" center to center. Half-round outside vertical edges and 45'd slot backs.
Top end of a 4-way system.
(6 foot midrange line) flush mounted 9 x GRS NEO8's per side paired with (5 foot tweeter line) flush mounted ribbons in 12" wide baffle.
4" center to center. Half-round outside vertical edges and 45'd slot backs.
Top end of a 4-way system.
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Depends on what I finally end up with for the bass. I initially started testing with 1 NEO8/side, then 4/side and then decided to go all the way to 8 or 9/side.
I ran the 4/side down to @ 250Hz with steep symmetric XO's now. Shallower symmetric XO's between the mid/tweets. I hope with 9/side, @ 250Hz with steep slopes will be more in their comfort range but may end up @ 300Hz or so.
I have a set of tympani iva's that I bought which were refurbished by Magnapan then sat in their boxes for 10 years. Not sure what sort of condition they will be in when I get them unboxed and set up. I have a 20 neo-8's and 2 AE-18's on hand. I am going to test the tympanis and if they have issues, I am thinking of making a baffle much as you have with the neo-8's and the maggie ribbon tweeter, then use the AE-18's below the neo-8's. Interested to see how this works out for you.
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Yeah, wasn't planning on putting the 18's on the same baffle as the mid/tweeters...Look forward to future updates on your project!
I hope so. I made the baffles so both line arrays are centered vertically/equal-distant from the floor and the 8-foot ceiling.looks like endless dynamics
Should cover all seated and standing listening positions unless you are Lurch from the Adams Family.
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Hi Chris, just came across your post and wondered if you would help with a few questions I have about the RD75s, I have some repairs to do and would appreciate a few pointers if possible. regards Tom
emailtim: Have you narrowed down your options for below the Neo8 with Maggie Ribbon design.
Are you planning on running a upper-bass/lower to mid, and also add a sub, or are you considering a single driver up to the Neo8?
I'm doing something similar with planar mids and a Maggie ribbon. I'm considering an OB line array using (8) 8", or (6) 10" down to 50-80Hz, and then a sub below that. I'm also going to try making a protoype OB "Vee"-shaped structure for the mid-bass drivers in a manner similar to what I've seen Magnepan showing with their prototype Condo Maggie system. Any thoughts?
Thanks, Dave
Are you planning on running a upper-bass/lower to mid, and also add a sub, or are you considering a single driver up to the Neo8?
I'm doing something similar with planar mids and a Maggie ribbon. I'm considering an OB line array using (8) 8", or (6) 10" down to 50-80Hz, and then a sub below that. I'm also going to try making a protoype OB "Vee"-shaped structure for the mid-bass drivers in a manner similar to what I've seen Magnepan showing with their prototype Condo Maggie system. Any thoughts?
Thanks, Dave
I have OB/Dipole subs and Maggie bass panels so will be running them 4-way. I may try making some OB/Dipole bass panels to compare as well later on.
I got side-tracked over the summer and have recently resumed the project. Finished the milling (front flush mount drivers, 3/4" roundovers in the back slots and 180 degree 1.5" bull nose on the sides to minimize edge diffraction). Sealed the baffles prepping for paint which appears to have put a harder shell on the MDF that shouldn't suck up the paint. Ordered more parts that came in last week and this week. Ready for paint soon and then mount, wire and fire up.
Decided to use Canare 4S8 and 4S11 for the hookup wire and cables in a 3S3P configuration (fast free shipment from PerfornanceAudio dot com). 3 serial strings of 16 gauge in parallel makes 11 gauge at the speaker terminals. 4S11 star quad is then 11 gauge back to the midrange amps. 16 gauge from the ribbons to the binding posts and then 4S8 going to the tweeter amps.
I will determine the NEO8's low end XO once I have the array up and running but currently starting at 250-300Hz from my prototype experiments. It may change if I use DIY OB/Dipole bass panels and am able to run them higher.
Here is a simplified wiring diagram that does point-2-point connections with no splices, only junctions at the binding posts.
I am rotating the drivers in each group of 3 to make the wires as short as possible in each group (not indicated in the picture below).
The arrangement (drivers and wiring) will be mirrored between the 2 speakers so the wires run down the same portion of the back of each speaker with out crossing over one and not the other.
The resulting NEO8 array should have the same resistance as an individual driver.
I am rotating the drivers in each group of 3 to make the wires as short as possible in each group (not indicated in the picture below).
The arrangement (drivers and wiring) will be mirrored between the 2 speakers so the wires run down the same portion of the back of each speaker with out crossing over one and not the other.
The resulting NEO8 array should have the same resistance as an individual driver.
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