I was mostly referring to series resistor, since you can see the effect in isolation.
If you manipulate negative feedback then you'll also change distortion, bandwidth and gain, which is ok, but it will be harder to judge what was it that led to the change in sound you're hearing.
On F4 there is no feedback so playing around with some series resistance might be fun to try. I only recommend trying it on full range drivers though.
If you manipulate negative feedback then you'll also change distortion, bandwidth and gain, which is ok, but it will be harder to judge what was it that led to the change in sound you're hearing.
On F4 there is no feedback so playing around with some series resistance might be fun to try. I only recommend trying it on full range drivers though.
The F4 is all about a pre that can drive 40Vpp cleanly (to get 25w into 8ohms) as it is a 0dB gain power amp. What preamp were you planning on using because it takes on the signature of the pre.
Like to bring this back from the vaults if I may. I have had tucked away for a good few years a pair of Super 15's which I'd now like to do something with, however they are the coaxial version- I cannot find any threads specifically referring to these, and looking at the specs they appear to differ substantially to the other versions. Can anyone advise what a good cabinet volume would be for these please?
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That driver indeed has a large Vas, meaning it wants to have a large volume of air behind it. Whether an Infinite Baffle (IB) or a large box. Not everyone can do an IB in their house, so try a large box, big as you find practical such as the size of box I built in this thread.
Ooooooo.
I tried to crunch some numbers.............
Sealed qtc 1.1 (+3db bump at fsb ?)
Sealed qtc 1.3
Open baffle, even 4' wide baffle, it would dip maybe 300hz, peak 150hz, then roll.....................
I tried to crunch some numbers.............
Sealed qtc 1.1 (+3db bump at fsb ?)
| VB = | 22.94 | Ft3 |
| fsb = | 38.72 | hz |
| F3 = | 29.30 | hz |
Sealed qtc 1.3
| VB = | 12.94 | Ft3 |
| fsb = | 45.76 | hz |
| F3 = | 32.96 | hz |
Open baffle, even 4' wide baffle, it would dip maybe 300hz, peak 150hz, then roll.....................
Thanks all, most useful. Since I now have a man cave I'll go for IB 22.94 box, should be interesting!
Looking at a box 170cm x 85cm x 45cm width, so a reasonable size (!), will put the driver at seated ear height. Will need a fair bit of bracing..
I'll also have to build a crossover for these, would you advise passing the woofer at 2k or so, or let it run full range?
I can put a cap on the tweeter for the high pass- specs show 1.2k minimum, maybe pass at 1.5?
First order be best?
I can put a cap on the tweeter for the high pass- specs show 1.2k minimum, maybe pass at 1.5?
First order be best?
Good job @Bigun
Your project is probably the latest take on Audio Nirvana Super '15 I could find.
For some reason most of the information on the web about Audio Nirvana drivers is outdated while people are raving about inferior Chinese drivers all over the web.
However, I made my project in Israel using Audio Nirvana Super Ferrite '15 drivers in 2023.
Before I decided to build a 2 channel stereo sound system for a small Wine Bar in Tel Aviv I auditioned different speakers in a big enclosure based on Audio Nirvana drivers and Lii Song drivers, to my ears th Audio Nirvana was a superior sounding driver!
Here is a quick pic of the first prototype designed by myself in a superheavy front ported internally dampened 287 liters plywood cabinet.
I tested the speakers on my roof using an analog setup, no fancy components used, everything is pretty basic with a big $500 Harman Kadron receiver.
Those huge speakers with AN '15 drivers on my roof produced a silky smooth sound with very warm bass from my vintage Funk, Soul, Latin, Disco, Reggae vinyl records pressed in the '70s.
I don't understand people who think there is not enough bass from a full range speaker, maybe not enough in those ugly open baffle designs, but in a classic ported cabinet there is more than enough bass response in the music where the bass guitar and rhythm section plays a very important role.
It was a cost effective solution for a sound system designed for a public place - a wine bar where people usually talk loud while selectors spinning vinyl records.
Of course the overall presentation was much better on my roof with no walls than in a small bar, because of all the reflections in a room without acoustic treatment (which is a common problem for all those "reviewers" in their typical small apartments with low ceilings etc).
I don't know why AN drivers are forgotten now, in my opinion they are much more lively than their Chinese contenders in the same price range.
Your project is probably the latest take on Audio Nirvana Super '15 I could find.
For some reason most of the information on the web about Audio Nirvana drivers is outdated while people are raving about inferior Chinese drivers all over the web.
However, I made my project in Israel using Audio Nirvana Super Ferrite '15 drivers in 2023.
Before I decided to build a 2 channel stereo sound system for a small Wine Bar in Tel Aviv I auditioned different speakers in a big enclosure based on Audio Nirvana drivers and Lii Song drivers, to my ears th Audio Nirvana was a superior sounding driver!
Here is a quick pic of the first prototype designed by myself in a superheavy front ported internally dampened 287 liters plywood cabinet.
I tested the speakers on my roof using an analog setup, no fancy components used, everything is pretty basic with a big $500 Harman Kadron receiver.
Those huge speakers with AN '15 drivers on my roof produced a silky smooth sound with very warm bass from my vintage Funk, Soul, Latin, Disco, Reggae vinyl records pressed in the '70s.
I don't understand people who think there is not enough bass from a full range speaker, maybe not enough in those ugly open baffle designs, but in a classic ported cabinet there is more than enough bass response in the music where the bass guitar and rhythm section plays a very important role.
It was a cost effective solution for a sound system designed for a public place - a wine bar where people usually talk loud while selectors spinning vinyl records.
Of course the overall presentation was much better on my roof with no walls than in a small bar, because of all the reflections in a room without acoustic treatment (which is a common problem for all those "reviewers" in their typical small apartments with low ceilings etc).
I don't know why AN drivers are forgotten now, in my opinion they are much more lively than their Chinese contenders in the same price range.
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When I was a teen my father gave me a summer job to reshingle the roof. I tossed my speakers up there, at the edge of a shallow slope covering the "back porch", so as to be entertained while I worked on the same side. I immediately noticed the sound was so much better than inside. Yeah, I bet those sounded pretty good with just a floor.