Yes, 4 15a drivers would seem to be about equivalent to 4 10" Peerless XLS. I really can not comment on sound quality, just potential. Once thing about the 15a is that it's mechanical excursion limit is much greater than the Xmax limit. So, the possibility exists that they could play louder, but I would suspect with a lot more distortion.
Two of these perhaps, you would need eight XLS10 woofers for the same VD!
http://www.beyma.com/getpdf.php?pid=21PW1400Fe
http://www.beyma.com/getpdf.php?pid=21PW1400Fe
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2 questions for John K (and anyone else who might be able to answer) regarding this design:
1. I'm going to use an OpenDRC-DA8. The miniSHARC software provides settings for driver offset. What should these be set at? Is time delay for the offset drivers built into the filter (XML file) as you built it, John K?
2. The W-bass driver arrangement isn't quite like the original setup Linkwitz created for the late versions of the Orion... also used by Gainphile. I understand that setup has the benefit of complete vibration cancellation of the 2 woofers. But he's veered from that in the LX521, while physically separating the bass module from the rest of the drivers, and you've not adopted it either, John. In fact both his and your current designs are using the same sideways-V cross-section for the dual woofers. Can you comment on this? Wouldn't the original W arrangement offer lower vibration? Are there "costs" associated with it?
Much thanks in advance for any illumination.
1. I'm going to use an OpenDRC-DA8. The miniSHARC software provides settings for driver offset. What should these be set at? Is time delay for the offset drivers built into the filter (XML file) as you built it, John K?
2. The W-bass driver arrangement isn't quite like the original setup Linkwitz created for the late versions of the Orion... also used by Gainphile. I understand that setup has the benefit of complete vibration cancellation of the 2 woofers. But he's veered from that in the LX521, while physically separating the bass module from the rest of the drivers, and you've not adopted it either, John. In fact both his and your current designs are using the same sideways-V cross-section for the dual woofers. Can you comment on this? Wouldn't the original W arrangement offer lower vibration? Are there "costs" associated with it?
Much thanks in advance for any illumination.
Sorry I didn't get to your email yet. To your first question, the config files that come with the plans have time delays for the upper mid and tweeter. The delays depend on which order crossover is loaded. They delays compensate for driver offset and slight deviation in the phase response of the driver/filter combination from ideal conditions.
I can't comment too much on the W woofer as I have never used it. But force cancelation is only a net effect. Each driver is still transmitting its vibrational energy to the frames and will still excite possible resonances. The force cancelation basically would limit forces transmitted to the floor or that may the cause the speaker to rock or walk. But I have never found that a problem since my speakers are on a carpeted floor. I placed on hardwood I would recommend some form of padding under the speakers.
The only reasons I when to the optional cabinet with V frame were, easier to construct, cosmetically better appearance, and elimination of possible sources of rattles since the entire cabinet is a single glued piece with the exception of the woofer access cover.
Thanks for your answer, John.
Only the last xml file you sent me works with the OpenDRC-DA8. You commented that ity would be the only one you'd support at that point. I presume it's the one with 4th order slopes?
OK, so the force cancellation is a net effect, much like active noise cancellation, but that still must mean the wood frame (not really a cabinet or enclosure, is it?) vibrates less to whatever is mounted on it -- to be specific, surely there must be less vibration reaching the higher freq drivers baffle for if W-frame push/pull woofers are used?
Gainphile states here -- Gainphile: S19 4-Way Dipole Radiator --
I can't help thinking this must improve the clarity of the sound reproduction at higher volume when bass energy is high. Surely the mids & tweeters would benefit from the lower vibration?
ps -- gainphile, if you're lurking, please jump in and comment!
Only the last xml file you sent me works with the OpenDRC-DA8. You commented that ity would be the only one you'd support at that point. I presume it's the one with 4th order slopes?
OK, so the force cancellation is a net effect, much like active noise cancellation, but that still must mean the wood frame (not really a cabinet or enclosure, is it?) vibrates less to whatever is mounted on it -- to be specific, surely there must be less vibration reaching the higher freq drivers baffle for if W-frame push/pull woofers are used?
Gainphile states here -- Gainphile: S19 4-Way Dipole Radiator --
I can't help thinking this must improve the clarity of the sound reproduction at higher volume when bass energy is high. Surely the mids & tweeters would benefit from the lower vibration?
ps -- gainphile, if you're lurking, please jump in and comment!
The preferred crossover uses 2nd order slopes between the upper and lower mid. This has the same group delay through the crossover region as a 1st order (as used in the LX5221) but provides less overlap and more importantly, greater protection from over excursion of the upper mid.
One could argue that vibration of the baffle would cause a lack of clarity. But you need to consider the magnitude of the baffle excursion compared to that of the midrange. Potentially it could introduce Doppler or intermodulation distortion. However, in reality such distortion is below audibility. Realize I am referring to vibration at the woofer frequencies, not panel resonances. In effect, vibration of the baffle has less impact on the sound and clarity than you would find in a 2-way speaker where the woofer is reproducing the range from40 to 2000 Hz. The woofer cone of such a 2-way will have much greater excursion at low frequency than the excursion of the baffle in the Note when the woofers are at their limit.
So, in a perfect world you might want to separate the woofers. But then you have another issue, vibration of the baffle due to the lower mass, less stiff structure. There are trade offs however you do it.
I'm posting for a fellow Note builder/friend. For personal reasons he is selling the drivers, miniDXSP 4x10 HD and Emotiva X-A-100 amps from his system. All for 1/2 of the list price plus shipping. Located in the USA. All as new. Anyone interest contact me at Johnk @ musicanddesign dot com and I'll put you in contact with him.
Hi Silent Mike, I did not investigate the audibility of vibration, but the visual difference is dramatic between woofer on a plane and w-frame. I just did not like looking at wildly vibrating baffle (and vibrate it did!). I could only assume the quiter baffle yields better sound
I use the same upper mid (10F) and the same Vifa tweeter in my OB project.
The project has been on the backburner for a while but I hope to start messing with it again this winter.
http://www.diyaudio.com/forums/multi-way/266524-you-active-multi-way-5.html#post4158184
is there a passive XO recommended for this combo high up (6-7kHz) that would perform well? care to share or drop a hint? you can PM me if you do not feel like posting it here. my use is strictly one off for diyfun.
Thanks and sorry for not-quite-Note-related question.
The project has been on the backburner for a while but I hope to start messing with it again this winter.
http://www.diyaudio.com/forums/multi-way/266524-you-active-multi-way-5.html#post4158184
is there a passive XO recommended for this combo high up (6-7kHz) that would perform well? care to share or drop a hint? you can PM me if you do not feel like posting it here. my use is strictly one off for diyfun
.Thanks and sorry for not-quite-Note-related question.
I've been thinking about building the Nao Note II RS, and I have been mulling over the options for the DSP and amplifier.
Would the Emotiva A-800 be sufficient to drive the speakers? It's a class A/B amplifier with 50 watts RMS per channel; 1 kHz; THD < 0.1%; into 4 Ohms. For $499 it seems reasonable.
Would pairing this with the miniDSP 2x8 kit be a reasonable option? Am I right in understanding that I would place the miniDSP between a stereo pre-amplifier and the 8 channel amp? What considerations should I make when chosing a pre-amplifier in this kind of setup?
Sorry for these basic questions. I am just trying to get my head around what kind of setup would work. FWIW I live in central europe, so shipping anything heavy from the US would be quite expensive
Would the Emotiva A-800 be sufficient to drive the speakers? It's a class A/B amplifier with 50 watts RMS per channel; 1 kHz; THD < 0.1%; into 4 Ohms. For $499 it seems reasonable.
Would pairing this with the miniDSP 2x8 kit be a reasonable option? Am I right in understanding that I would place the miniDSP between a stereo pre-amplifier and the 8 channel amp? What considerations should I make when chosing a pre-amplifier in this kind of setup?
Sorry for these basic questions. I am just trying to get my head around what kind of setup would work. FWIW I live in central europe, so shipping anything heavy from the US would be quite expensive
pkaro,
yes, the minidsp must sit between your source or preamplifier and poweramplifier(s). The 2x8 board can take only analog stereo signal in unless you purchase an extra I2S module, which is included in 4x10HD. I have the 4x10HD, input is analog RCA from my AV-receiver, which I use for input selection and volume control. Works just fine with no noise issues (remember to set gain switches right!)
I think that 50w/channel is not enough for bass an lower midrange. You can use any analog power amplifier for each channel (preferably same types for left and right) I purchased B&O ICEpower modules an put them in one box per speaker, but used some random second-hand multichannel(AV) amplifiers before that for my 4-channel dsp-speakers. My suggestion is that you should use a powerful (150W with high current output) stereo amplifier for bass and low mid and a nice sounding mid-power (30-100W) amp for upper mid and tweeter (per channel)
Power amplifiers are easy to update later on! Just check what is available near you, remember to check also flea markets!
Go for it, I am sure that You will enjoy the 4-way dipole sound!
Juhazi
yes, the minidsp must sit between your source or preamplifier and poweramplifier(s). The 2x8 board can take only analog stereo signal in unless you purchase an extra I2S module, which is included in 4x10HD. I have the 4x10HD, input is analog RCA from my AV-receiver, which I use for input selection and volume control. Works just fine with no noise issues (remember to set gain switches right!)
I think that 50w/channel is not enough for bass an lower midrange. You can use any analog power amplifier for each channel (preferably same types for left and right) I purchased B&O ICEpower modules an put them in one box per speaker, but used some random second-hand multichannel(AV) amplifiers before that for my 4-channel dsp-speakers. My suggestion is that you should use a powerful (150W with high current output) stereo amplifier for bass and low mid and a nice sounding mid-power (30-100W) amp for upper mid and tweeter (per channel)
Power amplifiers are easy to update later on! Just check what is available near you, remember to check also flea markets!
Go for it, I am sure that You will enjoy the 4-way dipole sound!
Juhazi
Thanks for your detailed responses.
Juhazi, alright I see. I have a nice marantz receiver/preamp/2 channel amp which I could use in a pinch, though I guess I would have to go easy on the gain in order not to fry the minidsp and amp! I play exclusively digital media, does anyone have perhaps a good suggestion for a USB DAC which can function as a preamp with volume control for the mini dsp input?
I'm leaning towards the 2x8 purely for economical reasons, but I read that it doesn't have an output quite as high as the 4 x 10HD. Will this be a problem?
adason, I would love to build some chip amps and wire it together, it would be the first time building an amp for me though.
I read a post by gainphile about how he did it for his dipoles - so I was thinking of a couple of Sure Electronics 4x100W at 4 Ohm Class D boards and a 24 V 350 W Power supply. Are these currently "state of the art" implementations of Class D amplifiers? I can see the sense in getting higher power for the sub woofers, perhaps an additional 2 x 300 W board, but that would require a second power supply I imagine, at least the Sure Electronics 2x300W requires 25 - 50 VDC input voltage
Anyone have suggestions for a nice case and how wire it safely with a front panel on/off switch? I have built my own speakers before and have a working knowledge of soldering and electronics, but I've also been zapped before (wasn't entirely my own fault) and would like to avoid that if possible! Any guides or tips & tricks would be greatly appreciated!
A question - how is it with building your own electronics and house insurance? Is it enough to be using an off the shelf power supply? Or would I not be covered in case of a fire because it hasn't been certified etc?
Thank you for taking time!
Juhazi, alright I see. I have a nice marantz receiver/preamp/2 channel amp which I could use in a pinch, though I guess I would have to go easy on the gain in order not to fry the minidsp and amp! I play exclusively digital media, does anyone have perhaps a good suggestion for a USB DAC which can function as a preamp with volume control for the mini dsp input?
I'm leaning towards the 2x8 purely for economical reasons, but I read that it doesn't have an output quite as high as the 4 x 10HD. Will this be a problem?
adason, I would love to build some chip amps and wire it together, it would be the first time building an amp for me though.
I read a post by gainphile about how he did it for his dipoles - so I was thinking of a couple of Sure Electronics 4x100W at 4 Ohm Class D boards and a 24 V 350 W Power supply. Are these currently "state of the art" implementations of Class D amplifiers? I can see the sense in getting higher power for the sub woofers, perhaps an additional 2 x 300 W board, but that would require a second power supply I imagine, at least the Sure Electronics 2x300W requires 25 - 50 VDC input voltage
Anyone have suggestions for a nice case and how wire it safely with a front panel on/off switch? I have built my own speakers before and have a working knowledge of soldering and electronics, but I've also been zapped before (wasn't entirely my own fault) and would like to avoid that if possible! Any guides or tips & tricks would be greatly appreciated!
A question - how is it with building your own electronics and house insurance? Is it enough to be using an off the shelf power supply? Or would I not be covered in case of a fire because it hasn't been certified etc?
Thank you for taking time!
1) The 2x8 should have plenty of output to drive a 50 watt amp, 2V RMS peak, unbalanced. That will drive most amps into hard clipping.
2) 50w/8 ohm should be sufficient unless you listen at what I would consider very high volumes. With higher power you have to be carful about over extending the woofer at lower frequencies. I've tried to protect the woofers against over excursion by giving them a 4th order roll off at 30 Hz.
2) 50w/8 ohm should be sufficient unless you listen at what I would consider very high volumes. With higher power you have to be carful about over extending the woofer at lower frequencies. I've tried to protect the woofers against over excursion by giving them a 4th order roll off at 30 Hz.
My two cents, as done by Juhazi go for 50ASX2 SE modules for high, lower and upper midrange and 125ASX2 SE for bass.
I use 50ASX2 SE modules and I found them VERY good sounding. They are almost plug and play if your pre-amp or DSP can drive 6k Ohms impedance wich has been reported OK for mini-dsp DSP.
You can find few threads here on diyaudio concerning those modules.
You can have a look also on this blog, few projets with IcePower modules :
https://theslowdiyer.wordpress.com/2016/05/16/surrounded-again/
https://theslowdiyer.wordpress.com/2013/08/25/past-projects-6-channel-icepower50asx-amp/
Ghent audio is selling cable set and nice cases.
I use 50ASX2 SE modules and I found them VERY good sounding. They are almost plug and play if your pre-amp or DSP can drive 6k Ohms impedance wich has been reported OK for mini-dsp DSP.
You can find few threads here on diyaudio concerning those modules.
You can have a look also on this blog, few projets with IcePower modules :
https://theslowdiyer.wordpress.com/2016/05/16/surrounded-again/
https://theslowdiyer.wordpress.com/2013/08/25/past-projects-6-channel-icepower50asx-amp/
Ghent audio is selling cable set and nice cases.
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The 50ASX2 SE is only rated at 50W into 4 ohms. The Note midrange is an 8 ohm driver. So that amp will deliver around 25W into 8 ohms. I would not recommend it for the Note. Also, minimum load Z is said to be 3 ohms. If the Note tweeters are connected in parallel they represent a 2 ohm load. Thus, with this amp the tweeter should be connected in series yielding an 8 ohm load and the tweeter channel gain must be increased by 6 dB. Again, this amp would only deliver 25 W into the series connected tweeter.
The 125ASX2 SE is rated at 120W into 4 which would be about 60 into 8. I would suggest two 125ASX2 SE amps per speaker (4 channels) when using the SLS woofer. Build two 4 channel amps and place each amp near the speaker.
The 125ASX2 SE is rated at 120W into 4 which would be about 60 into 8. I would suggest two 125ASX2 SE amps per speaker (4 channels) when using the SLS woofer. Build two 4 channel amps and place each amp near the speaker.
Thanks for the response john.
I really like the idea of two 4 channel amps with 2 125ASX2 modules each. With cases and wiring I expect this to cost just north of 1K, and that's about the price of a Lexicon DD-8 which reviews favourably (though it has only half the power into 4 Ohms). Is it still a value proposition to build my own at that point?
I'm also leaning towards the 4 x10HD because of the volume control and digital inputs, which would mean I could skip having a separate DAC and preamp. The two additional outputs would also come in handy if I wanted to add a separate subwoofer in the future, I suppose.
I really like the idea of two 4 channel amps with 2 125ASX2 modules each. With cases and wiring I expect this to cost just north of 1K, and that's about the price of a Lexicon DD-8 which reviews favourably (though it has only half the power into 4 Ohms). Is it still a value proposition to build my own at that point?
I'm also leaning towards the 4 x10HD because of the volume control and digital inputs, which would mean I could skip having a separate DAC and preamp. The two additional outputs would also come in handy if I wanted to add a separate subwoofer in the future, I suppose.