Aw, thanks- let's not go too much further down this path since this is Lynns thread, but here's the writeup on them. Finishing took place after the writeup, but it gives the pertinent details on replicating them.
Ultimate Bass Cabinets Article By Jeff Poth
Thanks for that. It has been added to my Amazon WishList. Sharing music is one of the big reasons I enjoy this hobby.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Lynn, I was wondering about that ever since I read that article. Did they only floodlight the ceiling with HF content, or with full-range content? And why does it seem like the tweeter fires at the bottom of the fold of the cabinet first? That means the HF content gets dispersed by the cabinet a lot. Would it not have been better to put the floodlight driver on top of the cabinet? That design has really been puzzling me.
On another note- I can get a pair of those JBL 'baby buttcheek' HF drivers as used on the Audio Kinesis Zephrin 46 speakers, as well as a pair the larger versions (the midbass drivers look like the Faital Pro 8PR200 8" Mid-Bass Speakers). How do you rate these units JBL HF drivers? Are they difficult to use and get the XO right? Just curious, because the price they want for the locally is quite tempting.
Thanks,
Deon
Lynn, did you listen to the system with the Infinity IRs Beta loudspeakers (the PS Audio room)? Here is the PF report on that room by Myles Astor:
RMAF 2014: The Show of Shows: Opening Day
RMAF 2014: The Show of Shows: Opening Day
An externally hosted image should be here but it was not working when we last tested it.
Look at it as a sort of half of the 'synergy horn'. Tweeters are at throath.
Placing flooder drivers at the top results shorter delay of reflected sound at the listening position.
.
Lynn and I did visit the PS Audio room. Shortly after we arrived, Paul McGowan was photographed by a TAS writer and then put on an orchestral recording (yay!). My happiness didn't last long. The string sound was hideously nasal. It very well could have been a perfect rendition of an awful recording, but I noticed that no one else in the room reacted as if something was wrong.
Doesn't anyone know what orchestral instruments are supposed to sound like anymore?
Gary Dahl
Doesn't anyone know what orchestral instruments are supposed to sound like anymore?
Gary Dahl
A few of our DIY Club Members attended a Concert just last weekend to reacquaint ourselves with how an Orchestra actually sounds! It was wonderful (we certainly had excellent seats) and thankfully it wasn't too different from my memories of previous Concerts. At my age, that in itself was a welcome sign that my memory is still largely intact!
(In case you're wondering...that gate at Kiev? It was still pretty darn Great!)
Best Regards,
TerryO
Newbie Build Part 2: Subwoofers, Construction Notes & Hi/Mid crossover q&a
Alas, a free lunch is not to be had here. But I want lows down to at least 35Hz or so and great transient response. Yet, thankfully, as Lynn Olson notes:
In the more esoteric world of subjective listening, there is a lessening of the sensation of tonality below 60 Hz. Tone lives in the essential 70 Hz to 7 kHz region, but things are less critical above and below that.
Thus, a pair of sealed servo subs seems to be the most logical choice, such as Rythmik Audio • 15" servo subwoofer F15 specs or Salk/Rythmik - home
I don’t expect my next listening room to much exceed 13 x 22 x 7.5, if at all. Would a pair of 15” sealed servo subs be overkill, or would it provide noticeably lower distortion, better transient response or other sonic benefits for my room size?
Also, I believe I recall reading here and in an enjoythemusic review that the 416-8Bs can reproduce their full midbass range even at low SPLs -great for, say, for “light night” listening. Likewise, would a 15” sealed servo sub do its job any better at low SPLs than would the 12” version?
So are the any trade offs? Or how complete would a free lunch be from a sealed servoed sub?
I have indeed also considered Dr. Geddes multi-sub approach for reducing ring nodes (?), though four passive subs would likely be more expensive and/or harder for me to implement than would two active and equalized subs. But at least this paper http://www.harman.com/EN-US/OurCompany/Innovation/Documents/White Papers/multsubs.pdf does mention that two (not three) subs are nearly as good as four against ring nodes, and thereby come closer to achieving the goal of equal dispersion of LF content regardless of listener location. Or am I unaware of other advantages of a four subwoofer system?
Another question for g3dahl, Lynn Olson, et al: My brother Richard (the carpenter) will build the sealed 3 cu ft boxes for the 416-8Bs, based on g3dahl’s construction notes. Might I know the outer dimensions?
But whether I chose the 3 or 4 cu ft 12" or 15” sealed (Rythmik) subs, would problems arise if I placed these midbass speakers on top of the subs?
Likewise, if these alnico “tweeter/midrange” coaxials
https://www.madisoundspeakerstore.c...-exotic-t35-x3-06-tweeter-with-alnico-magnet/ were placed on top of the 416s-with the latter on or off the subs?
Apparently yes, but Salk Sound solves these problems by using a molded polymer, “….even more dense than MDF, Baltic birch plywood or bamboo…..develop another type of polymer that would help isolate the midrange/tweeter section from the woofer section. “ Can someone provide any tips for achieving the same with a specific wood or MDF, 3/4” (or thicker?)?
Btw, should the sealed box we build for the high/mid coaxials or separate midrange and tweeter drivers also be made with those pre-made LARGE MDF edge rounds,
that g3dahl used for building the 3 cu ft sealed boxes for the 416-8Bs to reduce cabinet edge (radius) diffraction effects CABINET CORNERS ?
And are there standing waves of consequence in the high/mid boxes? If so, would they best be minimized if the box is triangular, polygonal or half circular SoundScape 12 ?
I’m glad I found this DIY Audio Speaker Box Building FAQ - Tutorial
Any other good how-to box construction links?
Why do SEAS and/or Madisound call the SEAS T35 a “tweeter/midrange”? Not that I’ve settled yet on any tweeter or midrange driver, but if the midrange covers the 300 to 5000 Hz range, the T35’s spec sheet says it does 20kHz down to 1600Hz. And if g3dahl crossed the 416-8B to where its only doing 70Hz up to 700Hz, how would these two drivers be crossed for them to best reproduce that 900Hz band?
Are the benefits and limitations of actively http://www.firstwatt.com/pdf/prod_b4_man.pdf versus passively XM16 48 dB/Octave Electronic Crossover Network bi-amping driver dependent?
For example, if I went with a pair of tweeter/midrange coaxials to use with the 416s-driven by my First Watt J2 and F4 amps, respectively-would active bi-amping
be sonically preferable to passive bi-amping?
But since I won’t be tri-amping, would any sonic benefits from active bi-amping be offset if the J2 amp were instead driving both separate tweeter and midrange drivers-which would have to be passively crossed?
Alas, a free lunch is not to be had here. But I want lows down to at least 35Hz or so and great transient response. Yet, thankfully, as Lynn Olson notes:
In the more esoteric world of subjective listening, there is a lessening of the sensation of tonality below 60 Hz. Tone lives in the essential 70 Hz to 7 kHz region, but things are less critical above and below that.
Thus, a pair of sealed servo subs seems to be the most logical choice, such as Rythmik Audio • 15" servo subwoofer F15 specs or Salk/Rythmik - home
I don’t expect my next listening room to much exceed 13 x 22 x 7.5, if at all. Would a pair of 15” sealed servo subs be overkill, or would it provide noticeably lower distortion, better transient response or other sonic benefits for my room size?
Also, I believe I recall reading here and in an enjoythemusic review that the 416-8Bs can reproduce their full midbass range even at low SPLs -great for, say, for “light night” listening. Likewise, would a 15” sealed servo sub do its job any better at low SPLs than would the 12” version?
So are the any trade offs? Or how complete would a free lunch be from a sealed servoed sub?
I have indeed also considered Dr. Geddes multi-sub approach for reducing ring nodes (?), though four passive subs would likely be more expensive and/or harder for me to implement than would two active and equalized subs. But at least this paper http://www.harman.com/EN-US/OurCompany/Innovation/Documents/White Papers/multsubs.pdf does mention that two (not three) subs are nearly as good as four against ring nodes, and thereby come closer to achieving the goal of equal dispersion of LF content regardless of listener location. Or am I unaware of other advantages of a four subwoofer system?
Another question for g3dahl, Lynn Olson, et al: My brother Richard (the carpenter) will build the sealed 3 cu ft boxes for the 416-8Bs, based on g3dahl’s construction notes. Might I know the outer dimensions?
But whether I chose the 3 or 4 cu ft 12" or 15” sealed (Rythmik) subs, would problems arise if I placed these midbass speakers on top of the subs?
Likewise, if these alnico “tweeter/midrange” coaxials
https://www.madisoundspeakerstore.c...-exotic-t35-x3-06-tweeter-with-alnico-magnet/ were placed on top of the 416s-with the latter on or off the subs?
Apparently yes, but Salk Sound solves these problems by using a molded polymer, “….even more dense than MDF, Baltic birch plywood or bamboo…..develop another type of polymer that would help isolate the midrange/tweeter section from the woofer section. “ Can someone provide any tips for achieving the same with a specific wood or MDF, 3/4” (or thicker?)?
Btw, should the sealed box we build for the high/mid coaxials or separate midrange and tweeter drivers also be made with those pre-made LARGE MDF edge rounds,
that g3dahl used for building the 3 cu ft sealed boxes for the 416-8Bs to reduce cabinet edge (radius) diffraction effects CABINET CORNERS ?
And are there standing waves of consequence in the high/mid boxes? If so, would they best be minimized if the box is triangular, polygonal or half circular SoundScape 12 ?
I’m glad I found this DIY Audio Speaker Box Building FAQ - Tutorial
Any other good how-to box construction links?
Why do SEAS and/or Madisound call the SEAS T35 a “tweeter/midrange”? Not that I’ve settled yet on any tweeter or midrange driver, but if the midrange covers the 300 to 5000 Hz range, the T35’s spec sheet says it does 20kHz down to 1600Hz. And if g3dahl crossed the 416-8B to where its only doing 70Hz up to 700Hz, how would these two drivers be crossed for them to best reproduce that 900Hz band?
Are the benefits and limitations of actively http://www.firstwatt.com/pdf/prod_b4_man.pdf versus passively XM16 48 dB/Octave Electronic Crossover Network bi-amping driver dependent?
For example, if I went with a pair of tweeter/midrange coaxials to use with the 416s-driven by my First Watt J2 and F4 amps, respectively-would active bi-amping
be sonically preferable to passive bi-amping?
But since I won’t be tri-amping, would any sonic benefits from active bi-amping be offset if the J2 amp were instead driving both separate tweeter and midrange drivers-which would have to be passively crossed?
oltos,
For even room bass, a mic at the listening position can be used to create a complex room-unique digital equalization file that can be used with a PC or separate MiniDSP-type product to drive your woofer(s) amplifier(s). A more powerful and normally better sounding solution than the limited equalization offered in most servo woofers.
I'm still a fan of modest moving mass, wide bandwidth, 18" woofers which remain flat several octaves pass the Xover freq. Using the GPA 416-8B in a sealed box midbass already establishes a wide polar pattern which is better matched by boxed woofers than bass horn polar patterns.
This thread is only 12,060 posts long. PLENTY of room for a discussion of FAST BASS!
Fast Bass = wide bandwidth bass = flat for several octaves above the Xover freq.
For even room bass, a mic at the listening position can be used to create a complex room-unique digital equalization file that can be used with a PC or separate MiniDSP-type product to drive your woofer(s) amplifier(s). A more powerful and normally better sounding solution than the limited equalization offered in most servo woofers.
I'm still a fan of modest moving mass, wide bandwidth, 18" woofers which remain flat several octaves pass the Xover freq. Using the GPA 416-8B in a sealed box midbass already establishes a wide polar pattern which is better matched by boxed woofers than bass horn polar patterns.
This thread is only 12,060 posts long. PLENTY of room for a discussion of FAST BASS!
Fast Bass = wide bandwidth bass = flat for several octaves above the Xover freq.
Newbie Build Part 2: Subwoofers, Construction Notes & Hi/Mid crossover q&a
Something like this IK Multimedia ARC System 2 Advanced Room Correction System | Sweetwater.com ? Of course, its better than nothing, but I wonder how large the listener window is? That is, it's probably great when you're seated but if you stand up and move more than a few feet......? That's probably why four subs are best, if you manage it (I can't).
What subs producing what "bass horn polar patterns are you referring to?
And by "boxed" do you mean sealed? Sealed subs (properly built, of course) give superior transient response; one of my reasons for considering the Rythmik (or the Salk built version). Rythmik seems to cover all the bases for implementing a sealed sub via a servo-controlled design Rythmik Audio • Servo subwoofer products.
I wish some of us on this thread would post their opinions about it.
Something like this IK Multimedia ARC System 2 Advanced Room Correction System | Sweetwater.com ? Of course, its better than nothing, but I wonder how large the listener window is? That is, it's probably great when you're seated but if you stand up and move more than a few feet......? That's probably why four subs are best, if you manage it (I can't).
What subs producing what "bass horn polar patterns are you referring to?
And by "boxed" do you mean sealed? Sealed subs (properly built, of course) give superior transient response; one of my reasons for considering the Rythmik (or the Salk built version). Rythmik seems to cover all the bases for implementing a sealed sub via a servo-controlled design Rythmik Audio • Servo subwoofer products.
I wish some of us on this thread would post their opinions about it.
Me too. I use four b&c 18PS76's under 12" coaxials or seos 12/10" mid. Good mid bass snap.
That is such a pity. Have you had the chance to hear the Infinity IRS Betas before? I wonder if it was the speakers. They seem like they should be good.
The Beta's are the antithesis of nasal
The Betas can sound bad in just about any way imaginable depending on setup and seating position. Getting them to sound merely nasal in a hotel room is no easy feat.
I hadn't heard the Betas before, but I have heard my friend's RS-1B's countless times, which don't sound nasal at all. This is what they look like:
I am left with the assumption that the recording was to blame. I was disappointed by the experience not only because I had anticipated a spectacular-sounding demo, but because it left me feeling as if the way orchestral instruments really sound has become a foreign concept to so many.
I believe that designers of audio equipment should have a highly-developed sense of what their results should sound like with various types of music. If they are in control of the program material used for their demonstrations, the results are a reflection of their level of sonic discernment. Of course, all bets are off when visitors bring their own recordings.
Gary Dahl
I am left with the assumption that the recording was to blame. I was disappointed by the experience not only because I had anticipated a spectacular-sounding demo, but because it left me feeling as if the way orchestral instruments really sound has become a foreign concept to so many.
I believe that designers of audio equipment should have a highly-developed sense of what their results should sound like with various types of music. If they are in control of the program material used for their demonstrations, the results are a reflection of their level of sonic discernment. Of course, all bets are off when visitors bring their own recordings.
Gary Dahl
oltos, I was thinking.....
Speaker designers who can hear differences from: NdFeB compression drivers; Beryllium domes; autotransformers; underhung Alnico motors; are very likely to also find that all woofers do not sound the same, and end up with modest Mms, high BL, wide bandwidth designs.(Like Gary) Room equalized. No Servo.
Your 3cuft sealed box GPA 416-8B with have a total Qtc of about 0.7. A sealed woofer with a similar Qtc = 0.7 would provide a good transient match, and deep bass with enough equalization and power.
The large 4" radius edges will reduce diffraction. If you put your woofer under the midbass, give some consideration to vibration reduction or counter-force woofers.
====================
Some very horny audiophiles really like control. They use horn tweeters, and horn midranges, and horn midbass, and build special rooms for horn woofers in order to maintain pattern control through most of the audio output.
Geddes/Olson designs only use a horn tweeter crossed to a boxed midbass. At the midbass baffle step frequency the polar response becomes 360 degrees. More energy into the room, less energy reaching the listener's ears. Balanced with midbass compensation boost. A boxed woofer would want the same polar and SPL. Avoid dipole or cardiod woofers with a 4.77x higher Directivity Index. Avoid horn woofers with an even high Directivity index.
Speaker designers who can hear differences from: NdFeB compression drivers; Beryllium domes; autotransformers; underhung Alnico motors; are very likely to also find that all woofers do not sound the same, and end up with modest Mms, high BL, wide bandwidth designs.(Like Gary) Room equalized. No Servo.
Your 3cuft sealed box GPA 416-8B with have a total Qtc of about 0.7. A sealed woofer with a similar Qtc = 0.7 would provide a good transient match, and deep bass with enough equalization and power.
The large 4" radius edges will reduce diffraction. If you put your woofer under the midbass, give some consideration to vibration reduction or counter-force woofers.
====================
Some very horny audiophiles really like control. They use horn tweeters, and horn midranges, and horn midbass, and build special rooms for horn woofers in order to maintain pattern control through most of the audio output.
Geddes/Olson designs only use a horn tweeter crossed to a boxed midbass. At the midbass baffle step frequency the polar response becomes 360 degrees. More energy into the room, less energy reaching the listener's ears. Balanced with midbass compensation boost. A boxed woofer would want the same polar and SPL. Avoid dipole or cardiod woofers with a 4.77x higher Directivity Index. Avoid horn woofers with an even high Directivity index.
