Here's a better pic, don't know why the last one came out so small...
I can't really test the woofer section yet, as I have 2 more units to build on 4/19. And then the crossover. Been thinking about that bit....
I'll build some really thin boxes to house the AMT tweeters too.
I lied, the 2 middle Pluvia 7's are wired for sound along with the super tweeters, and I swear I hear deeper bass notes resonating out of the sub boxes without even being wired in.
Regarding crossovers, I really want to go (2x) miniDSP PWR-ICE250. Power each sides' Pluvia set + AMT on one channel and the 2 subs on the other channel with a high order high pass and low pass.
Yes, I was not having that tweeter hang out all nasty like that. That was just a quick and dirty to see if the super tweeter was even necessary. Which it is IMO, crossed over with a 2uF cap.
Thank you!
I can't really test the woofer section yet, as I have 2 more units to build on 4/19. And then the crossover. Been thinking about that bit....
I'll build some really thin boxes to house the AMT tweeters too.
I lied, the 2 middle Pluvia 7's are wired for sound along with the super tweeters, and I swear I hear deeper bass notes resonating out of the sub boxes without even being wired in.
Regarding crossovers, I really want to go (2x) miniDSP PWR-ICE250. Power each sides' Pluvia set + AMT on one channel and the 2 subs on the other channel with a high order high pass and low pass.
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Hi there D: Try shorting out the unconnected sub drivers terminals, to see if you are getting acoustic driven resonances from the sub drivers. ...regards, Michael
I wasn't suggesting that approach if that is what you thought. This is a very short line with a large centre to centre distance.
By doing this the outer drivers are more off axis than the inner which will roll off the high end of those and stop them from interfering as much. Putting the tweeter in the middle closer in it is no surprise that this configuration sounds better. You may also be introducing a bit of directivity from the curve, a very mild version of Keele's CBT array.
I was thinking more of an WMTMW with the drivers on a flat baffle. By crossing at the right points you keep the CTC distance below half a wavelength and they add together nicely.
The full range and tweeter is probably a bad choice for MTM in the traditional sense because the AMT can't go low enough to cross at the right point.
What you have in your last picture might well be a better way to use those drivers in combination.
Fluid, thanks for commenting!
I forgot to mention the 4x Dayton 8" woofers are separately powered by an Audiosource Amp 3 which gets its signal from a 100Hz subwoofer ouput from the Pioneer D812 amp. The pluvia's are wired parallel/series for 8ohms with the AMT and 2uF cap in parallel. A 1.5uF cap may sound better... No crossover for the pluvias yet.
@wesayso: Yes! I was going to experiment with concave next. I choose convex initially to try to simulate a point source maybe 20ft away.
I forgot to mention the 4x Dayton 8" woofers are separately powered by an Audiosource Amp 3 which gets its signal from a 100Hz subwoofer ouput from the Pioneer D812 amp. The pluvia's are wired parallel/series for 8ohms with the AMT and 2uF cap in parallel. A 1.5uF cap may sound better... No crossover for the pluvias yet.
@wesayso: Yes! I was going to experiment with concave next. I choose convex initially to try to simulate a point source maybe 20ft away.
I was in the middle of listening to Pink Floyd Live At Pompeii. Is it these speakers or is that another recording that should be a "midrange test"?Do you have Slayer's "Seasons in the Abyss"?"War Ensemble" should be a good work out...
No doubt it's been done before, but now we've got better tech! I've chosen D'Appolito config, although modified I give the man credit instead of saying MTM.so, some of this has been done before - in fact, even before the current century?
It's the combination of the entire thing that sets the quality, some of the older guys used different ways to get what they wanted with what was available. Having a 'better' driver is of no benefit if you don't use it properly.
In order for it to be closer to what D'Appolito did you need to use a fairly specific crossover to put the lobes into alignment. I have a feeling that he would not consider what you have done to be what he was aiming for
I think you will get better results if you take some more measurements and work up a better crossover if you are able to.
Sam - my allusion was actually to the work of John Dunlavy that Ronald referenced. Another late lamented ( perhaps except by the wives of his enthusiastic customers of the mid-late '90s?) genius.
Some of the tech we DIYers get to play with may certainly have improved in the last 20-25 years, but solid engineering is timeless.
) genius.Some of the tech we DIYers get to play with may certainly have improved in the last 20-25 years, but solid engineering is timeless.
True, very true. I'm using the Markaudio Drivers as full rangers, augmented in the high end with the AMT in the middle. In the near future, I would like to add an active crossover with a high pass filter selectable from 100-500Hz on the Pluvia's/AMT and a low pass for the 4 woofers. so 2x 2-way dsp class D amps.....I have a feeling that he would not consider what you have done to be what he was aiming for
I think you will get better results if you take some more measurements and work up a better crossover if you are able to.
2 companies come to mind with the programmability that I'd like: Hypex and miniDSP. I'm leaning miniDSP because Hypex is currently out of stock at Madisound. Nothing on eBay for either...
Although I'm very happy with the midrange and high end on most everything I've listened to, I'm most disappointed in the bass. It's not consistent is all I can say. Maybe all the Pluvia's are cancelling out the low end from the Dayton's?
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I don't think that is the reason.
Adding multiple drivers together without a proper crossover is bound to cause cancellation.
Take a measurement of the Dayton drivers on their own to see what they can do alone. Take a measurement of the whole lot together and compare. Otherwise it is just a guess as to what is going on.
Minidsp is probably easier to program and easier to get help with as there are a lot more users. The 2x4 HD looks like a good device to me lots of options.
For measuring FR, would you recommend pink noise? Or log speed sin wave with peak hold? Or both? And why?
Log sweep in REW for a static measurement, I would only use noise for an RTA type measurement or on line level electronics. Noise is good for steady state and averaging.
Log sweep will get you the best measurement in REW with the highest signal to noise ratio if you set it up properly. The REW help has more information on why if you want know.
Sam - my allusion was actually to the work of John Dunlavy that Ronald referenced. Another late lamented ( perhaps except by the wives of his enthusiastic customers of the mid-late '90s?
Some of the tech we DIYers get to play with may certainly have improved in the last 20-25 years, but solid engineering is timeless.
+1
I'll have to wait till this Wed to test the FR of this current setup. I just wanted to chime in and say that after putting the speakers right up against the wall, inches away, the bass is MUCH improved. Sometimes I'm slow like this but after all there's alot of variables here. Watching and listening to the Hobbit series of movies is very enjoyable.
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