60 Degree DIY Mid Hi - AKA PM60

Peter Morris said:
Hi Fabio - The mid section of the PM will make more SPL than the NDS1460n can when crossed at the frequency needed to get this design to work i.e. 700Hz or less. For HT I would probaly just use a standard MTM design with 10" or 12" mids, the 18sound horn and driver and cross them at about 700 - 800Hz (as a guess). Depending on the sub you use / the crossover frequency needed you could select either a sealed or reflex alignment for the mid drivers.
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Thanks Peter. So if I want to mantain the mid section, I must change the NDS1460n with a BMS or another driver capable to work under 700Hz. Do you think that ND3ST can do it? In this review it seems better than ND4015BE ?
 
Hi Fabio, You could still use the mid section but it’s complicated to build and tricky to EQ correctly, it’s just that the NDS1460n (and other 3" diaphragm drivers) will run out before the mids when pushed and may (???) sound a little strained when crossed that low, but I doubt if you will ever reach those levels with home theatre.

FWIW I have used the NDS1460n in my double 10" design but I eventually changed to the BMS and lowered the crossover to 650Hz - this was an improvement. I have not heard the ND3ST but I believe it’s excellent, one of the best you can buy. I have heard the ND4015n but not the BE version. These are excellent drivers and I suspect with the larger diaphragm they may be capable (along with some of the new B&C and RCF 4' diaphragm drivers) of the performance needed. There is a big improvement in the sound quality of these new drivers compared to the older designs. To me the VHF is not quite as nice as the BMS. I suspect the ND3ST with a smaller diaphragm will be as nice, just lacking the low frequency output needed for this design.

When I get some spare time I'm planning to post some information about cheaper options for the PM60/90 - I have had a lot of people asking about this including DSP settings for processors other than the lake.
 
Peter Morris said:
Hi Fabio, You could still use the mid section but it’s complicated to build and tricky to EQ correctly, it’s just that the NDS1460n (and other 3" diaphragm drivers) will run out before the mids when pushed and may (???) sound a little strained when crossed that low, but I doubt if you will ever reach those levels with home theatre.

FWIW I have used the NDS1460n in my double 10" design but I eventually changed to the BMS and lowered the crossover to 650Hz - this was an improvement. I have not heard the ND3ST but I believe it’s excellent, one of the best you can buy. I have heard the ND4015n but not the BE version. These are excellent drivers and I suspect with the larger diaphragm they may be capable (along with some of the new B&C and RCF 4' diaphragm drivers) of the performance needed. There is a big improvement in the sound quality of these new drivers compared to the older designs. To me the VHF is not quite as nice as the BMS. I suspect the ND3ST with a smaller diaphragm will be as nice, just lacking the low frequency output needed for this design.

When I get some spare time I'm planning to post some information about cheaper options for the PM60/90 - I have had a lot of people asking about this including DSP settings for processors other than the lake.
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Ok Peter, here in Italy I can buy a pair of ND3ST for 584€ unlike BMS for 1488€... I think it's worth a try ;)
Thanks again and I'll keep you informed on the results.
 
Peter Morris said:
When I get some spare time I'm planning to post some information about cheaper options for the PM60/90 - I have had a lot of people asking about this including DSP settings for processors other than the lake.
Click to expand...

I'd be especially interested in DSP settings(especially FIR) for 4 series XTA processors. The later model 4 series are FIR capable.
 
Peter Morris said:
Hi Fabio, You could still use the mid section but it’s complicated to build and tricky to EQ correctly, it’s just that the NDS1460n (and other 3" diaphragm drivers) will run out before the mids when pushed and may (???) sound a little strained when crossed that low, but I doubt if you will ever reach those levels with home theatre.

FWIW I have used the NDS1460n in my double 10" design but I eventually changed to the BMS and lowered the crossover to 650Hz - this was an improvement. I have not heard the ND3ST but I believe it’s excellent, one of the best you can buy. I have heard the ND4015n but not the BE version. These are excellent drivers and I suspect with the larger diaphragm they may be capable (along with some of the new B&C and RCF 4' diaphragm drivers) of the performance needed. There is a big improvement in the sound quality of these new drivers compared to the older designs. To me the VHF is not quite as nice as the BMS. I suspect the ND3ST with a smaller diaphragm will be as nice, just lacking the low frequency output needed for this design.

When I get some spare time I'm planning to post some information about cheaper options for the PM60/90 - I have had a lot of people asking about this including DSP settings for processors other than the lake.
Click to expand...
I for one am patiently awaiting those DSP settings both IIR and FIR for the cheaper options... because I've already purchased a cheaper CD (b&c DE1090TN) as recommended earlier....
 
Peter Morris said:
Stef, you beat me to it - I think this driver will be perfect. I suspect even better than the BMS 4594. I'm planning to get a couple ASAP to try in this box ...and some others :cool:

https://www.bcspeakers.com/en/products/coaxials-hf/1-4/16/DCX464-12
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With the top B&C HF-only compression drivers being £334.00GBP, and the BMS4594HE at £496.00GBP I'm not holding out too much hope of the DCX464 being desperately cheaper than the BMS, although the old 2" coaxial is currently a shade under four hundred pounds in the UK... Fingers crossed - it looks like a very exciting development whatever the outcome. One can bet that they've torn the BMS to pieces in their labs and made the new driver equal in quality at the very least, regardless of the final selling price.
 
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It will be a while before I can gets some ... I think Bennett said manufacturing in July, so i suspect availability in September for the US maybe a bit sooner for Europe.

In simple terms B&C had the 4594 as a bench mark. With all the new FEA computer modelling improvements since then and five years in development I would be surprised if the B&C is not better, louder, lower distortion and hopefully slightly better pricing, but this will not be a cheap driver to make.
 
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Peter Morris said:
In simple terms B&C had the 4594 as a bench mark. With all the new FEA computer modelling.......
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The B&C is 20mm greater in diameter(20mm shorter also though). Is it not looking a bit tight in the existing design???

Interestily the B&C is considerable heavier.. BMS, 2.3kg B&C 3.7kg. With any luck the weight means extra value and quality!
 
Peter Morris said:
It will be a while before I can gets some ... I think Bennett said manufacturing in July, so i suspect availability in September for the US maybe a bit sooner for Europe.
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If you are desperate to test a pair and they turn up in the UK before you can get hold of them, I would be happy to help ship a pair over to you (sadly not for free!) as thanks for your free speaker designs and knowledge so very freely and generously shared.
 
Hiya! I just took a look at the drawings I posted, and there is just about enough room to accommodate the DCX464 in my version of the 60 degree design, which is pretty close to Peter's original. Granted this is with the B&C 12NDL76 drivers, so my assessment is only valid for these. In the 90 degree design there is more than enough space.
 
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