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A big three way system based upon the Volt RV4564 18" Bass unit

James said:
I have a soft spot for Hiquphon tweeters. I've used the OW-1 and OW-3, but I've also had great results from Seas, Scan-speak and Morel.

My last design entailed a very low XO between woofer and mid (circa 150Hz, actively filtered) to enable the mid to cover the full range of the human voice. But I think asking a mid to go that low compromises mid and upper bass impact. If I were to redesign that again, I'd cross at 300Hz or above. So your instincts on using the 13M from 400Hz upwards accords with my experience, and it's easy enough to use a passive filter without the fs resonance of either driver pair getting in the way.

I'm curious about your choice of 3rd order filters. I've used first, second and third order electrical filters but they are always targeted at even order LR2 or LR4 acoustic transfers. Are you referring to 3rd order acoustic or electrical?

You are getting me itching for another design.
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Like you I have had experience with all kinds of filters and drivers, but I selected third order (electrical) filters for this project as the drivers I am considering will likely work best with these. The three ways systems I have built seem to measure better with them. Obviously driver selection will also dictate which filters work best.

One project I built 20 years ago now used just an inductor on the bass a resistor and Capacitor on the tweeter and this was one of the smoothest systems I have ever heard or measured!! Both drivers were from Seas and no longer available, alas.

As an aside and inspired by my love of that design, I may also, again on paper look at an NS1000 type 3 way system, so what drivers for that? I did play with the big Scan but may also go a bit larger to consider what the 15" SB driver would do.
 
darkmatter said:
Yes, wished they had a UK distributor.
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Just go direct. Very helpful people who will advise and model for your recommended application. I just bought six drivers for my project and the shipping to Oz was only $US260. If you only need a pair to the UK you may be surprised how reasonable it is.
 
I've been wanting to build a design with these Volts for a long time just because they look so frickin' cool. Up till now I've not been able to persuade the more techie half of my brain that I should use that as a selection criteria. I'll get a pair when it's not looking one of these days though.
 
What about the SB Acoustics mids? The Satori series have a very modern motor, with vented pole piece, copper sleeve for low inductance and modulation effects.

I saw some measurements somewhere on one, showing very low distortion. The UK dealer is Falcon acoustics, and the 4Ohm versions will give about 91dB sensitivity, which is enough.
 
good to see so many interested in diy 'speakers. I started building in the 60's, with a BBC 3/5A copy, but was never totally happy with them. Even when I 'graduated' to an IMF TL copy, total satisfaction was still lacking.

After a few more attempts, I gave up and bought proprietary offerings, including a loverly Hacker three-way, EPOS M5's and Usher 604 floor standers.

Presently working on my last loudspeaker venture, with two (per side) JPW Sonata mid range units in their closed boxes, Fountek CD3 real ribbon tweeters and EPOS 10 inch bass drivers, all in separate sealed boxes (apart from the tweeters, which have open sides to dispense the heat from the neo magnets). The bass unit will be used like a sub bass unit, and the tweeters more like super-tweeters, as the mid range units are said to go from about 60Hz (I measured) to above 5kHz (I did not measure, yet!). Amplification is a 300 watt class D unit for the bass, with variable electronic crossover, and a 100 watt VSSA FET amplifier feeding each midrange unit with series inductor. The ribbon tweeter will be fed from one of the 100 watt amplifiers feeding one of the JPW units, via a third order network at 4.5kHz, the original JPW tweeters will not be used.

I've been listening to the JPW Sonata 'speakers for over a month, and I am very pleased with them. I have used different stuffing to the extant JPW stuff (BAF) and I'm trialling rockwool type roof insulation, and egg carton foam with sheep's wool (Herdwick). ATM, I'm pairing the JPW's with one of my Ushers, and they do sound very similar (to me), even though the Ushers have more bass, although it is lumpy.

Voices on the prototypes sound very real, as do drums/timpani, no doubt due to the closed box loading.

I tried putting the tweeter boxes (pultruded aluminium) between the Sonata boxes in a D'Appolito configuration, and the image size grew quite a bit. Great for large orchestras, but not good for singer/guitar and small ensembles. So I am toying with the idea of a variable D'Appolito design, where the amplifier to the bottom speaker with tweeter) is constantly on, and the speaker on top is variable, from totally off to totally on, and every station in between (set by a stepped attenuator on the input to the 100 watt amplifier. Hopefully, I can get a variable sound stage with this set up.
 
Still investigating drivers, but as an aside someone has asked me to design for them a very high efficiency three way, now there's a challenge :)
 
darkmatter said:
Still investigating drivers, but as an aside someone has asked me to design for them a very high efficiency three way, now there's a challenge :)
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I've often been asked for a bespoke design, but they tend to shrink away quietly when I ask for my commission fee to at least cover the cost of a set of drivers for prototyping.
 
With care and some attention the VM752 could be used with the 18" Bass using third order networks, I am a fan of 3rd order networks anyway so this is one option I will look at carefully. Volt have mentioned in earlier correspondence that this is possible but with careful filter implementation.
 
darkmatter said:
With care and some attention the VM752 could be used with the 18" Bass using third order networks, I am a fan of 3rd order networks anyway so this is one option I will look at carefully. Volt have mentioned in earlier correspondence that this is possible but with careful filter implementation.
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Have been modelling and this is the direction of travel I will be taking, likely tweeter ? I have several to choose from including a couple of Seas models, the big Audax, a top Morel and the same Vifa that PMC use. a tweeter sub baffle means that I can play with several and just listen. I have working filters for all.
 
Have you made a decision on your bass drivers? I wouldnt have a clue on convenrtional tweeters. However, is there a quality commerically available EMT/AMT tweeter like Heil/ADAM use? That could be an interesting thing to consider, I loved them in my ADAM's.
 
I think for this theoretical exercise the Volt RV4564 / VM752 combination is a given, I have another design which specified an AMT unit.
 
darkmatter said:
The Satori units look good certainly smoother than many, this makes crossover design simpler.
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I can highly recommend the Satori drivers. I’m using this midbass in my speakers along with a non Satori SB tweeter. https://www.falconacoustics.co.uk/d...coustics-satori/satori-mw16p-4-midwoofer.html

I’m currently running a single Dayton Um-18 sealed sub, but intend to build a second sub and make a pair of sort of 3 way speakers, albeit with a low crossover of 80-100hz.
 
I have a pair of Seas Full range units to play around with really light cones, all the ingredients for an exciting dynamic sound. will be building a pair of small test enclosures to see how they perform.

If I like them then the Exotic will be a serious contender.

MattSPL I am looking at the possibility of using a near full range two way part design, then using an active filtered board from say BK electronics to power the bass again from possibly as low as 80 Hz.

Configured like a normal three way design, the bass driver will be separately driven by say the BK 500 watt board.
 
this may have a terrific sub bass but i doubt it will have any decent, fast and precise mid bass - if you plan to stay 3 way, unless you actually find a midbass driver capable of reaching from say 150 to 1.5-2k (could be audax PR170m0 or PHL derivates) plus something like beyma TPL-150 on top or that strange planar mid-hi driver with a scandinavian name
 
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