Grant Slack Posted August 6, 2019 Posted August 6, 2019 Hi Matty, if the supertweeter is not aligned with the next driver, then may I suggest a higher-order HP filter on it, perhaps fourth order. Being non-aligned, it doesn't need to match the LP on the next driver, which can still be first order. My reasoning is that bullet tweeters can be quite bad out of their intended band, and that could be the harshness, rather than actual volume. A sharp cutoff is the best solution for that, IMHO. regards, Grant
MattyW Posted August 6, 2019 Posted August 6, 2019 34 minutes ago, niss_man said: Matty are those kit speakers or something you built from scratch? Have you got any measurements of them? I built those from scratch, all materials from Bunnings. My notes are a weird mix of inches, centimeters and millimeters so I'm not sure how useful it will be. Not all wood cut outs are even in my notes..... Top 425x300mm Sides minus 2x thickness 17x37" front 17"x260mm top & bottom 37"x278mm Not even sure what some of that meant myself now.
MattyW Posted August 6, 2019 Posted August 6, 2019 34 minutes ago, Grant Slack said: Hi Matty, if the supertweeter is not aligned with the next driver, then may I suggest a higher-order HP filter on it, perhaps fourth order. Being non-aligned, it doesn't need to match the LP on the next driver, which can still be first order. My reasoning is that bullet tweeters can be quite bad out of their intended band, and that could be the harshness, rather than actual volume. A sharp cutoff is the best solution for that, IMHO. regards, Grant Mmmm, anything more complex than a single cap is a bit beyond me. I'll try dropping the levels first. If that doesn't work I'll swap for a pair of 98db ribbons I have. Will just have to enlarge the hole so it'll fit 1
niss_man Posted August 6, 2019 Posted August 6, 2019 I take it you didn't do any speaker measurements and are tuning by ear. That's all good, but you can't beat accurate measurements and a good crossover program. Final tweaks done by ear though.
MattyW Posted August 6, 2019 Posted August 6, 2019 (edited) All by ear yes. It'll get there, sooner or later EDIT: I reduced the output of the super tweeters using L pads. Sounds much better now Edited August 6, 2019 by MattyW
The_conductor Posted August 7, 2019 Posted August 7, 2019 Just thought I'd add to this thread as I've been considering for a while building some OB stereo subs to work with my magnepans. Considering GR research 12" drivers in a 2x or 3x config per channel. Anyone have any design tips for this application, or any experience supplying/ using GR research OB drivers? They're available through the rhythmik subs distribution chain. Red spade audio mention custom build capability on their website - anyone used them? Currently I'm Thinking frames from 1" birch marine ply to match my upgraded Maggie frames, 500x1200 baffle for 3x12" with some H frame sides to reduce dipole cancellation.
denimhunter Posted September 10, 2019 Posted September 10, 2019 On 30/06/2018 at 4:58 PM, ModnMelbn said: Hi Stereonet community. I’m considering buying a pair of open baffle speakers for a lounge room setup. I think I’ve narrowed them down to the Spacial M3 Turbo s. I like thir minimalist look and their 20 year warranty! Unfortunately I’m in Melbourne and the authorized retailer is based in Sydney and due to work commitments a Sydney trip may be a while away. So, who in the community like/use/recommend open baffle speakers? Is there anything I should me mindful of and are here any other types I should be looking at? Thanking you all in advance. I heard Supravox open baffle speakers in the recent Munich high end show and was very impressed. As most of you would know, Supravox is a French speaker driver manufacturer from way back. They make field coil drivers as well. Their open baffle speakers uses alnico drivers and have very wide baffle for the bass. The interesting thing seems that the side panels of the baffle are hinged and the angle can be adjusted to suit the room. I spoke to Supravox recently and they said there is a distributor in Melbourne. Trying to get more info. At the moment.
sfdoddsy Posted September 10, 2019 Posted September 10, 2019 On 07/08/2019 at 1:39 PM, The_conductor said: Just thought I'd add to this thread as I've been considering for a while building some OB stereo subs to work with my magnepans. Considering GR research 12" drivers in a 2x or 3x config per channel. Anyone have any design tips for this application, or any experience supplying/ using GR research OB drivers? They're available through the rhythmik subs distribution chain. Red spade audio mention custom build capability on their website - anyone used them? Currently I'm Thinking frames from 1" birch marine ply to match my upgraded Maggie frames, 500x1200 baffle for 3x12" with some H frame sides to reduce dipole cancellation. The SB Acoustics SB34NRX75-16 is designed for open baffle and is available locally through Wagner. The GR stuff might be better if you go the servo route with a Rythmik amp.
davewantsmoore Posted September 11, 2019 Posted September 11, 2019 On 06/08/2019 at 11:13 AM, MattyW said: Mmmm, anything more complex than a single cap is a bit beyond me. You'll need to the filter to start at very high frequency to get away with using only a 6dB/octave high pass filter on this type of driver.
davewantsmoore Posted September 11, 2019 Posted September 11, 2019 (edited) On 07/08/2019 at 1:39 PM, The_conductor said: Just thought I'd add to this thread as I've been considering for a while building some OB stereo subs Building the enclosure + driver is the simple part. Due to the OB cancellation, the driver will have a very strong roll off..... designing the EQ require to get the driver to have a flat response is the tricky bit. So unless you have experience with this .... or the confidence to take good acoustic measurements (can be tricky at LF) and correct the response ..... then you'll likely get a very haphazard result. If you want to build something look for a well documented build project that has all the EQ figured out for you. Quote Red spade audio mention custom build capability on their website - anyone used them? Or this. They can calculate the filters required for your driver and baffle shape so the driver produces a flat response. Edited September 11, 2019 by davewantsmoore
andyr Posted September 11, 2019 Posted September 11, 2019 On 07/08/2019 at 1:39 PM, The_conductor said: Red Spade Audio mention custom build capability on their website - anyone used them? Yes, Paul delivered a pair of very fine subs to complement my active 3-way Maggies. They have certainly delivered what I was hoping for. Andy
MattyW Posted September 21, 2019 Posted September 21, 2019 (edited) Well, changed the 3.3uf KZK White Line bypassed with Miflex KPCU-1 for a 5uf Cornell Dubilier SF motor run cap bypassed with a 0.47 Duelund JAM cap and even before burn in things sound more open and airy. The crossover point was previously set too high. Likewise I think the KZK were the wrong cap for the job. These Cornell Dubilier SF are cheaper and sound better.... The Duelund JAM also tend to be a bit more critical with more sparkle up top than the Miflex, and I needed a bit more of that in my system. Edited September 21, 2019 by MattyW
MattyW Posted October 8, 2019 Posted October 8, 2019 Ok, changed the Plat Audio RT4-DP planars for Aurum Cantus G3Si, removed the L-pads and rewired the woofers so they can be individually amped. My god what a massive improvement! More open and airy, more three dimensional with greater fine detail and richer tonality. I noticed some vocals are slightly more sibilant and believe that because this driver is 6 ohm rather than 8 the crossover point has shifted up. I'll need to increase the value of the crossover caps. If I weren't so fussy I'd leave it as is. I want it perfect though. 1
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