Series crossovers seem interesting, and too advanced for me. 
Looking at the kit though it seemed altogether too expensive when all was said and done. I'm going to attempt to make a 2 way with the Mundorf AMT tweeter and a 7" SS Revelator woofer instead. Also, the distortion and energy storage of the Accuton driver I thought was high for the price. I wish I had heard the Mundorf kit in a better room setup though, it might have changed my mind.
Looking at the kit though it seemed altogether too expensive when all was said and done. I'm going to attempt to make a 2 way with the Mundorf AMT tweeter and a 7" SS Revelator woofer instead. Also, the distortion and energy storage of the Accuton driver I thought was high for the price. I wish I had heard the Mundorf kit in a better room setup though, it might have changed my mind. 
Series crossovers seem interesting, and too advanced for me.
I've done what you intend to do, but with a smaller SS Revlator (15W). It's a 3rd generation tweeter update. I started with SS dome, then Vifa ring radiator, and lastly, the AMT.
Intimates newest update with Mundorf AMT tweeters
You should be able to give a listen to my design if you are attending the RMAF in Denver next weekend. Visit the Madisound rooms. They will be in one of them.
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I don't think they have much to hide at all. I got to see it and the crossover parts in person as well as chat with Norbert Mundorf. The cabinet is very solidly built and cross braced, very high quality parts in the crossover and drivers. I just think the woofer is a bit over-rated is all.
At the same time, I haven't seen much in terms of specs, and the room it was presented in was not damped.
Thanks for the offer. Maybe I should go!
I think we are using slightly different tweeters though, the one I'm going to use has a claimed 90 db efficiency, which matches up with the 4 Ohm 7" revelator.
Also, i know it's heresy, I don't want very wide dispersion. I listen in a cramped living room, hence the satellite form-factor. So that's one reason for the 7",and being OK with a high crossover point. Another issue is of course efficiency. The 7" 4 Ohm at 90 db voltage efficiency is just too attractive compared to the smaller drivers in the range. Put that all together and I have a nice bit of kit I can fit in a Dayton enclosure. Now all I need is a van to sell them in parking lots.
Slightly off topic, but I was able to listen to a pair of Golden Ears for exactly 5 minutes before I had to ask the dealer to change them to something else. Painful treble. At the time I had not read any reviews for them, just knew they weren't for me. Painful and screechy to listen to. My suffering was on par with Triangle and older Thiels. Of course, we all hear things differently, but these are just not experiences I'd like to repeat.
And this is totally off topic, but I have looked in several places and I can't find anyone to explain it to me. Just how do AMT's work?
I remember they "squeeze" the air, which is fine, but I can't figure out the accounting of the space. So if I have a ribbon shaped like this: "WW" , and the points squeeze togther and push, doesn't there have to be expansion elsewhere along the surface area which would "suck" ? It's not like an accordion where the distance between the ends move, so I don't get it. Are AMT's just fancy urban legends like a moon landing?
I remember they "squeeze" the air, which is fine, but I can't figure out the accounting of the space. So if I have a ribbon shaped like this: "WW" , and the points squeeze togther and push, doesn't there have to be expansion elsewhere along the surface area which would "suck" ? It's not like an accordion where the distance between the ends move, so I don't get it. Are AMT's just fancy urban legends like a moon landing?
I agree the cabinet is nicely finished and rigid with good looking parts.
The so called high quality parts is irrelevant for the speaker
performance. What counts is the overall sound pressure at the
XO frequency with individual curves of the drivers with
filter as well as far field measurement of the system. Off axis
plots would be useful. They have shown nothing except raw
tweeter response and similar, something a driver manufacturer does.
I suppose you are not familiar with it, but you can't have high
sensitivity with this kind of hifi speaker even when you don't
completely account for the baffle step. What they have done
to crossover is nothing special, in fact a purely subjective
discourse (no parts in parallel with the driver).
Hi,
You can see a front volume and and a rear volume.
I'll label the air spaces left to right A to H.
Pleats are 1 to 9 left to right.
Current goes up and down each pleat. Say even pleats
move left, so odd pleats move right. So B, D, F and H
get smaller whilst A, C, E and G get bigger. Dipole.
rgds, sreten.
It works with the WWW analogy if you think about
the top and bottom points not moving but each
slanted line bending in the middle. It cannot
work if you keep the slanted lines straight.
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The MA-30's apparent lack of BSC is audible when it is placed well away from the rear wall of the listening room, but disappears when the rear panel is within 60cm of the rear wall.
In addition to being a fairly easy load. efficiency does not feel particularly low compared to some of the other speakers that were played during the same listening sessions. Subjectively probably in the upper 80's.
hth, jonathan
In addition to being a fairly easy load. efficiency does not feel particularly low compared to some of the other speakers that were played during the same listening sessions. Subjectively probably in the upper 80's.
hth, jonathan
Here's a link to Mundorf's latest MA30 12 pg brochure. They will have a pair available for listening at the RMAF show this weekend in Denver. Only $1750 U.S. M.S.R.P. w/o cabinets and more for the 'upgraded' XO version.
http://www.mundorf.com/PDF/Mundorf_MA30_Catalog.pdf
http://www.mundorf.com/PDF/Mundorf_MA30_Catalog.pdf
Hi Mike!
I'm really curious what the setup was at the RMAF. I heard them at the California Audio Show and the room was untreated and the electronics didn't do it for me. I did get to meet Norbert Mundorf though, which was a treat,
and I ended up using some larger Mundorf AMT tweeters in my own project.
Please let me know how the room was there.
Best,
Erik
Hi Erik,
The room was just a regular hotel room, nothing special. Not a lot of treatments, I think they had a curtain in back and there were folding chairs set up. The electronics were just a DAC and a couple of modest SS amplifiers, nothing over the top and machined out of a solid billet. No "magic box" room correcters or anything special.
I ordered up a full kit from Grant Fidelity and it arrived in short order, the boxes and wiring from China and the drivers and XO's from Canada. All went together easily and they sounded as good in my living room as they did at the show. I'm using a Cambridge Azur 551R (now obsolete) to drive them and they just sound wonderful.
The room was just a regular hotel room, nothing special. Not a lot of treatments, I think they had a curtain in back and there were folding chairs set up. The electronics were just a DAC and a couple of modest SS amplifiers, nothing over the top and machined out of a solid billet. No "magic box" room correcters or anything special.
I ordered up a full kit from Grant Fidelity and it arrived in short order, the boxes and wiring from China and the drivers and XO's from Canada. All went together easily and they sounded as good in my living room as they did at the show. I'm using a Cambridge Azur 551R (now obsolete) to drive them and they just sound wonderful.
Hi Mike!
I went online and peeked. Looks like they were using a passively bi-amped Benchmark set-up.
This explains why you liked them!
I'm not a huge fan of BM, but the electronics and choices of music playing at the CAS was not encouraging anyone to buy. I'm so glad you like your kit. I really like the small size and design for close wall placement. More speakers need to be designed with living rooms we can afford.
Best,
Erik
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