Hi there,
I built a 45 SET amp to replace my Audio Nirvana 300B. The results have been very satisfying so far, using a pair of AN Classic 10 (96 dB/w/m) in AN-designed Monitor cabinets. The only issue I have now is that going from 8W to 2W output, I have to crank the volume at over 3/4 of the scale to get some decent listening level.
So I am thinking about improving the efficiency of my speakers. Following the same principle of simplicity of design that led me to stick to SET + full-range, I have ruled out layouts such as open baffle + servo or loaded horn (too complex to build, too many things can go wrong with my limited equipment).
I have set my eyes on the most efficient, high-end quality drivers I could find, the Lowther DX4 (99.5 dB). Unfortunately, bass reflex seems to be discouraged with this driver. I saw Martin King's ML TL design at http://www.quarter-wave.com/Project04/Project04.html but, after an exchange with Martin, I learned that the passive filter used to balance the highs and lows takes 10dB off the driver, which is a nonstarter.
Another option I contemplated would be building larger enclosures for my AN. I don't know how much I would gain from that, even a couple dBs would help. And of course, I would consider another driver in the >98dB range that is bass-reflex-friendly. I would rather give up some bass extension than overall sound quality and response.
Anybody has any good suggestions, either for the Lowthers or alternatives?
Thanks.
gm
I built a 45 SET amp to replace my Audio Nirvana 300B. The results have been very satisfying so far, using a pair of AN Classic 10 (96 dB/w/m) in AN-designed Monitor cabinets. The only issue I have now is that going from 8W to 2W output, I have to crank the volume at over 3/4 of the scale to get some decent listening level.
So I am thinking about improving the efficiency of my speakers. Following the same principle of simplicity of design that led me to stick to SET + full-range, I have ruled out layouts such as open baffle + servo or loaded horn (too complex to build, too many things can go wrong with my limited equipment).
I have set my eyes on the most efficient, high-end quality drivers I could find, the Lowther DX4 (99.5 dB). Unfortunately, bass reflex seems to be discouraged with this driver. I saw Martin King's ML TL design at http://www.quarter-wave.com/Project04/Project04.html but, after an exchange with Martin, I learned that the passive filter used to balance the highs and lows takes 10dB off the driver, which is a nonstarter.
Another option I contemplated would be building larger enclosures for my AN. I don't know how much I would gain from that, even a couple dBs would help. And of course, I would consider another driver in the >98dB range that is bass-reflex-friendly. I would rather give up some bass extension than overall sound quality and response.
Anybody has any good suggestions, either for the Lowthers or alternatives?
Thanks.
gm
A Fane Sovereighn 12-250TC is in reality a 98dB sensitive driver, and on low wattage (<20w) and a in a huge reflex box it can be tuned to 30Hz. I did build a box like that and with a 15W class A amp (the aca bridged), a pair of it was enough for a garden party (30ppl in open air) last weekend. The crowd laughed at the 2x15w soundsystem untill i cranked it up...
The cabinets are large altough, mine in the picture is 456mm wide, 1200mm high and 400mm deep, with an internal frame and. Internals were fully covered in felt sheets and the driver has a double baffle (mounted on the internal that is screwed to the external one.
edit: i use some filter to tame the treble, and that is needed (see scheme)
The cabinets are large altough, mine in the picture is 456mm wide, 1200mm high and 400mm deep, with an internal frame and. Internals were fully covered in felt sheets and the driver has a double baffle (mounted on the internal that is screwed to the external one.
edit: i use some filter to tame the treble, and that is needed (see scheme)
One of my daily used loudspeaker is AN 10 Super in 2.8 ft3 enclosure.
It's produce -about- 96dB (from 1m, 2.83V) in my living room.
The 10W 300B SE is more than enough for this (usually below 1W), but ordinary #45 SE (5K OPT, 1.5-2W) amps not sure will be enough in the bass.
I'm planning to build OB with this driver (from about 100-150Hz) and use N. Pass SLOB2 solution for bass (15" SB Audience BIANCO-15OB350).
N. Pass LxMini active (FET) crossover, over 100-150Hz 45SE, below 100-150Hz Hypex few hundred Watt D type amplifier block.
Thanks both for your replies.
@waxx aren't the Sovereign more for PA applications? That's what I gather from their description at least.
@euro21 I had a great experience with my drivers on a 300B as well, but the 45 is on a different league. Where I had plenty of volume on the former at less than 20% of the volume scale, the 45 needs at least to be at 70-75%.
After some more reading, especially this article that basically only saves the Altec 755A/C/F as a viable pure single-driver solution, I came across other models that aren't hype-taxed as the 755s, which have reached ridiculous prices. The Lafayette SK98 is reported to be similar to the 755C and to achieve 99.5 dB/W according to this article. Has anybody tried that in a classical bass reflex enclosure?
@waxx aren't the Sovereign more for PA applications? That's what I gather from their description at least.
@euro21 I had a great experience with my drivers on a 300B as well, but the 45 is on a different league. Where I had plenty of volume on the former at less than 20% of the volume scale, the 45 needs at least to be at 70-75%.
After some more reading, especially this article that basically only saves the Altec 755A/C/F as a viable pure single-driver solution, I came across other models that aren't hype-taxed as the 755s, which have reached ridiculous prices. The Lafayette SK98 is reported to be similar to the 755C and to achieve 99.5 dB/W according to this article. Has anybody tried that in a classical bass reflex enclosure?
The Fane is ment for P.A. but very usable as hifi driver also. It has a light cone and a high resolution for a p.a. driver. And when you keep it low power it's goes lower than most fullrange drivers. It's used a lot for hifi speakers actually, altough most keep it in a sealed cabinet so it would be smaller.
Btw: pa drivers are used a lot in hifi also. Many build here with drivers that were ment for pa and those are often as good as high end hifi drivers. Some of the more rated drivers in this world, including the Altec (that was actually a rebranded Western Electric driver) you mention, were p.a. driver, not ment for hifi. The legendaric Altec 604, a coaxial driver, is the same. They were ment for smaller cinema system, not for hifi (but are used a lot for hifi). The division between hifi and pro audio is a bit artificial, there is no real border for me...
Btw: pa drivers are used a lot in hifi also. Many build here with drivers that were ment for pa and those are often as good as high end hifi drivers. Some of the more rated drivers in this world, including the Altec (that was actually a rebranded Western Electric driver) you mention, were p.a. driver, not ment for hifi. The legendaric Altec 604, a coaxial driver, is the same. They were ment for smaller cinema system, not for hifi (but are used a lot for hifi). The division between hifi and pro audio is a bit artificial, there is no real border for me...
Measures at 94dB, i found the top end quite painful. Do note that David Dicks knows ittle about box design.
Where the volume control is is not necessarily an indication of how much power but is often more indicative of gain structure of the system. 2W should be more than enuff to drive your loudspeakers.
Not really possible. Adding a sub may help make them play louder but will nt increase efficiency
The only Lowther that seems to be suiyable for reflex is PM6.
Figure out your gain structure. Your speakers, IMO, are a problem, but not because you do not have sufficent power (unles syou have a really big room and listen really loud)
dave
You mean using a different volume pot in my amp? That could be the cause since it wasn't in the original design and I guessed the value. I had the same problem with another amp I built, where a too high value caused the perceived gain to be very steep at the ends and very flat around the middle.
Are just the cabinets a problem, as you mentioned, or the drivers too? Do you have pointers to a good design or hints on how to design a BR enclosure for the 10" Classic? I have been using the Enclosure Calculator for lower-quality speakers, I don't know if that's good enough for this system.
Given that the AN drivers were not cheap, it would be great to tune them to work right rather than chasing the best FR driver out there. But if there are clearly much better options, I'd be willing to experiment. Thanks.
It usually means you need a pre-amp (or sources)with more gain.
Or is it an integrated amplifier? What is it?
Just my opinion but i think they are way overpriced. I worked as hard as i good to tame them but failed. They were better after, but really need to be cut-off above 1-3Khz. I could not live with them FR even after being tarted up.
dave
Or is it an integrated amplifier? What is it?
Just my opinion but i think they are way overpriced. I worked as hard as i good to tame them but failed. They were better after, but really need to be cut-off above 1-3Khz. I could not live with them FR even after being tarted up.
dave
Wow, that's quite some modding. Good news is you could use them as turntable strobes now 🙂
I have a phono pre (Roy Mottram's PH-16) plugged into an "integrated" 45 (meaning I just added a volume knob and channel selector to Gordon Rankin's Bugle 45). The cart is a Denon DL103 with Sowter step-ups. The same setup, with an AN 300B instead of the Bugle, provided more volume than my ears can tolerate (and yes, I admit the highs kind of scream sometimes).
I have a phono pre (Roy Mottram's PH-16) plugged into an "integrated" 45 (meaning I just added a volume knob and channel selector to Gordon Rankin's Bugle 45). The cart is a Denon DL103 with Sowter step-ups. The same setup, with an AN 300B instead of the Bugle, provided more volume than my ears can tolerate (and yes, I admit the highs kind of scream sometimes).
This one: https://www.wavelengthaudio.com/bugle.pdf
It is meant to be used with a preamp so you have lost all the gain that provides.
dave
It is meant to be used with a preamp so you have lost all the gain that provides.
dave
Yes. I assumed that this: http://tubes4hifi.com/PH16.htm would provide the adequate input level, no? (pardon the ignorance if I'm confusing the gain with input level)
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The only Lowther that seems to be suiyable for reflex is PM6.
dave
those trapezoid mar-kens look nice, can I ask the LxHxW of the cabinet?
Also, as a side note, are the foam surrounds on current production PM6 A (15Ω), any better than they used to be longevity wise?
Yes. Today’s foam surrounds have few issues with longevity.
Those a 35 liters, with silver coli 16Ω PM6A (or PM6c copper 8Ω)need a bit of a stand, the 8Ω copper coil PM6 jumps to 50 litre and is a floorstandder.
Size later. Attachment predates the larger enclosure.
dave
Those a 35 liters, with silver coli 16Ω PM6A (or PM6c copper 8Ω)need a bit of a stand, the 8Ω copper coil PM6 jumps to 50 litre and is a floorstandder.
Size later. Attachment predates the larger enclosure.
dave
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Dave, these are nice enclosures. Do you find they have an acceptable range without any sub (accounting for the limitations of single-drive systems)?
Gordon Rankin confirmed your statement that the Bugle needs a pre, especially for the phono, and it should be in the 15÷20 dB gain range. So that will be my next priority before I move on to improving the speakers.
Gordon Rankin confirmed your statement that the Bugle needs a pre, especially for the phono, and it should be in the 15÷20 dB gain range. So that will be my next priority before I move on to improving the speakers.
I have not heard them but the builders are very satisfied, estimated F10 is in the low 30s (PM6 copper 8Ω), but how that plays in your room is of question. Ceratily woofers can be added but they will need to be substantial to gain you much.
dave
dave