Though a stone cold value compared to the GOTO you used before
Sorry friend, I don't know what you mean by "a cold value compared to...."
I've only built the GOTO bass horn...and I've not been lucky enough to hear the GOTO compressions drivers...they're reserved for the elite...I'm a mere humble DIYer/creator/horn enthusiast....
My idea of high end is a set of new Be diaphrams ($400) in my JBL 2445's.
The magic comes from the horns and how the system is put together.
I could build a $10,000 system that would compete well with a $50,000 system...boils down to sensible purchases, good horns, etc
Sorry, just a joke. I was under the impression the GOTO bass drivers were several thousand each.
Lynn, are you not going for the 416-Alnico + 416-ceramic combination anymore? I remember you hypothesizing that this will give you more tonal colors.
I don't want to drag the thread off-topic, so I'll keep it brief.
Gary Dahl is really happy with his AH425+Radian745NeoBe & GPA 416-Alnico (2.5 cubic foot closed box, F3=60 Hz) & subwoofer AE TD15H (5 cubic foot passive-radiator box, F3=30 Hz).
All good, I just want a little more dynamic range, but don't have the space for a bass horn, particularly a bass horn that's acoustically time-aligned with the compression driver.
Which is where two GPA 416-Alnico's come in. They're almost in parallel, except the one closest to floor will have a Bessel/Gaussian lowpass around 500 Hz or so, and the one closest to the AH425 will have a Bessel/Gaussian lowpass around 800 Hz or so, and they will be offset and time-aligned so the wavefronts are the same at the listening position. Since I want all three wavefronts (AH425+Radian 745NeoBe, upper 416, lower 416) to be matched within 5 to 10 degrees in the overlap region, dissimilar drivers introduce too many complexities for no benefit.
As for the subwoofer, either Gary Dahl's or Gary Pimm's versions will be fine, since all they have to do is cover the range between 20 Hz and 60 Hz, which isn't asking all that much. If I was using a bass horn, the subs would have to go a bit higher.
Really pleased to see how people are using the various models of the Azurahorn, which are first-class horns with very good impulse response and very low coloration (which are probably related).
Lyn
I've often thought of the dual 15 approach. Why not consider an altec 18 inch for lower freq, plus 416 on top?
I guess jbl got it right with their large earlier monitors with dual 15's and a 12 or 10 inch mid.
Those Kenrick Sound pics sure do look nice....
The 4350 would be wonderful.
JBL 4350 ?????????? ?????? ??? JBL5234?
JBL 4355 ?????????? ???????????????? - ??????????KENRICK SOUND? - JBL????? 43XX???? ?? ?? ???
I've often thought of the dual 15 approach. Why not consider an altec 18 inch for lower freq, plus 416 on top?
I guess jbl got it right with their large earlier monitors with dual 15's and a 12 or 10 inch mid.
Those Kenrick Sound pics sure do look nice....
The 4350 would be wonderful.
JBL 4350 ?????????? ?????? ??? JBL5234?
JBL 4355 ?????????? ???????????????? - ??????????KENRICK SOUND? - JBL????? 43XX???? ?? ?? ???
I'm proud to say that very good friend of mine made JBL 4355. Guys from Lansing heritage forum helped with plans for cabinets, and xover schematic.
He bought four JBL 2235H chassis and reconed them and two totally destroyed JBL 2202H and reconed them too (while these kits were available). Lenses were the biggest problem but he ordered them from Kenrick.
I must say that JBL 4355 is easily the best speaker i heard so far. Best by my criteria, of course. Tiny bit better than Oris Swing.
L-pads are moved to the side where tweeter and supertweeter are mounted to shorten the wires leading to the drivers.
30mm MDF is used. Here is video - cabinet building process: JBL 4355 Studio monitor - YouTube
They look like this:
Attachments
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On the 18" vs 15" subject - the same guy who made JBL 4355 also made a pair JBL 4345 studio monitors so i had unique opportunity to compare two great JBL speakers in absolutely same conditions (room, electronics, listening distance). JBL 4345 has 18" bass. xover frequency between bass and mid is at arround 270Hz similar to JBL 4355. Both were listened biamped with active xover between bas and mid - the rest of crossovers are passive in both cases.
I like dual 15" approach better. 18" goes lower in frequency but not without a cost. It has lower definition than 15". 15" is well defined and low enough and i think that integrates better with 12" mid.
Both 4355 and 4345 are excellent speakers but 4355 is better performer in my oppinion. Bigger mid (more body to the voices and instruments) and 2x15" instead 1x18" did the trick.
I like dual 15" approach better. 18" goes lower in frequency but not without a cost. It has lower definition than 15". 15" is well defined and low enough and i think that integrates better with 12" mid.
Both 4355 and 4345 are excellent speakers but 4355 is better performer in my oppinion. Bigger mid (more body to the voices and instruments) and 2x15" instead 1x18" did the trick.
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atilsley:
I heard a the "same" GOTO system at the Capital Audiofest 2 or 3 yrs. ago. It belonged to Ming Su, and it sounded great. It was one of the best speakers I ever heard. The clarity and dynamics were to die for. I knew then that a front loaded horn was the only way to go for me.
Are you worried that mounting the driver face down will cause the suspension to sag over time ?
Excellent workmanship !!!!!
I heard a the "same" GOTO system at the Capital Audiofest 2 or 3 yrs. ago. It belonged to Ming Su, and it sounded great. It was one of the best speakers I ever heard. The clarity and dynamics were to die for. I knew then that a front loaded horn was the only way to go for me.
Are you worried that mounting the driver face down will cause the suspension to sag over time ?
Excellent workmanship !!!!!
A pair of 15" drivers double the efficiency (3 dB gain) and quadruple (6 dB) the headroom (compared to a single 15" driver). This isn't as much performance gain as a bass horn, but it's a good part of the way there, and doesn't take quite as much space.
The drawback with 18" drivers is that 18" is approaching the outer limit of acceptable performance for paper cones, with lower-midrange the first thing to go. 18" is a great choice for below-80 Hz applications, not so good for 500 Hz on up.
Since my goal is integration with the AH425 with a large-format compression driver, a 12" driver dedicated to lower-mids/upper-bass was considered as an option, but based on measurements and subjective impressions, the Altec/GPA 416 has very good performance through 800 Hz. Some 15" drivers are good choices for 800 Hz, and others are better choices for lower frequencies (cone and spider construction, voice coil magnetic design, etc.)
The Altec/GPA 416 (and 515) has an unusual underhung voice coil, which has low IM distortion ... provided excursion is limited to keep the coil within the magnetic gap. This is why each driver has its own 2.5 cubic foot closed-box enclosure, with an F3 around 60~65 Hz. If the same drivers were used in traditional 7~10 cubic foot vented box enclosures, excursion would be much more of a problem. (The JBL equivalents have overhung voice coils and can handle long excursions with less problem.)
Below 60~65 Hz, a conventional long-excursion subwoofer (for each channel), with its own power amplifier and equalization, handles the range from 20 ~ 60 Hz. The majority of 15" professional drivers are optimized for high power and long excursion, so there's a broader choice in this frequency range.
The same set of tradeoffs apply to bass horns. A bass horn that goes down to 30 Hz is very, very large, so for most people, a transition to a direct-radiator deep-bass system is necessary.
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I'd like to gently return to the topic of bass horns. One of the real differences between direct-radiator bass and bass horns is the much higher directivity index (DI) for bass horns; by comparison, direct radiators in the 100 Hz ~ 500 Hz region are nearly omnidirectional.
Since room response is dominated by very severe modes and standing waves in the 100 Hz ~ 500 Hz region, there's a big difference between a near-omnidirectional radiator and one that is pretty directional. The modes will be at their worst with the near-omni radiator, since all the wall reflections are driven. With a higher DI, much less energy goes into the rear, side, floor, and ceiling reflections, and modes are not as strong.
In practical terms, when you allow for the contribution of room modes, the higher-DI horn system may deliver flatter response, even if the horn itself has rougher response compared to a simple direct-radiator.
Since room response is dominated by very severe modes and standing waves in the 100 Hz ~ 500 Hz region, there's a big difference between a near-omnidirectional radiator and one that is pretty directional. The modes will be at their worst with the near-omni radiator, since all the wall reflections are driven. With a higher DI, much less energy goes into the rear, side, floor, and ceiling reflections, and modes are not as strong.
In practical terms, when you allow for the contribution of room modes, the higher-DI horn system may deliver flatter response, even if the horn itself has rougher response compared to a simple direct-radiator.
I'm not an expert on horns, but to the best of my knowledge, if a horn is providing gain over the efficiency you'd see on a flat baffle, there's a directivity gain as well. That said, some horns are primarily optimized for directivity control (waveguides), while others are optimized for constant diaphragm loading (LeCleac'h and others).
At wavelengths that are several times the size of the diaphragm (say, 100 Hz to 500 Hz), direct-radiators are very close to omnidirectional, and all room modes are driven. So long as the horn is above cutoff, any horn will be several times more directional than the equivalent direct-radiator, much less energy will be directed into room boundaries, and more energy directed right at the listener. That's where some of the efficiency gain comes from ... what's sometimes called "antenna gain".
Take a look at the unsmoothed response of a typical direct-radiator in a domestic listening room and you will see very large response deviations in the 100 Hz to 500 Hz range ... 10 to 20 dB peak-to-dip ratios are not usual, thanks to room modes, and complex summation of first reflections off the rear, side, floor, and ceiling surfaces. In this frequency range, damping materials have limited effect, carpets do very little, and the walls have an acoustic reflectance of more than 90% (more than the mirror in your bathroom).
The wavelengths are long enough that direct-arrival and room reflections cannot be separated by the listener, and the nulls are deep enough they cannot be equalized. (Equalization can smooth out the peaks.) In effect, the room and the loudspeaker merge, with the loudspeaker acquiring all the colorations of the room. This is why small changes in location change the modal patterns, as well as the complex summation of first reflections, which then changes the sound of the loudspeaker. It's not a good sign when a 1" change in location results in a noticeable change in sound; that means the room is controlling the sound of the loudspeaker.
This is the region where increased directivity will have a strong effect on room interaction. Dipoles have a moderate directivity gain (at the expense of increased excursion compared to direct-radiators), while horns are even more directive and have better excursion control than direct-radiators.
This could be why bass horns with problems in the response (folded horns, for example) can still sound better than direct-radiators in a typical room. The response deviations of a "problem" horn are very likely not as large as what the room itself does to a direct-radiator. (That said, direct-radiator arrays have increased directivity, mostly in the vertical plane, and may also complex lobing patterns at the top of their working range.)
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Hello Lynn
I am having a problem seeing the difference between a corner horn and direct radiator also in the corner of the room. They are both playing into the same room so the standing wave issues based on room dimensions should be the same providing they are in the same location. The corner horns mouth is not large enough to make a significant difference as far as directivity below a few hundred hertz. Asside from a possible SPL advantage with the horn I don't see the advantage. What am I missing??
Rob
Hello Lynn
I am having a problem seeing the difference between a corner horn and direct radiator also in the corner of the room. They are both playing into the same room so the standing wave issues based on room dimensions should be the same providing they are in the same location. The corner horns mouth is not large enough to make a significant difference as far as directivity below a few hundred hertz. Aside from a possible SPL advantage with the horn I don't see the advantage. What am I missing??
Rob
For a corner horn, you are absolutely right. There's no difference in directivity between a direct radiator and corner horn, for the simple reason that everything is constrained to 90-degree radiation in every plane, no matter what kind of loudspeaker it is. A corner horn may be more efficient, but the directivity is exactly the same as a direct-radiator (in the same location).
The multiway horn system created by the original poster is not in a corner. Only a few hifi enthusiasts have the luxury of two symmetric corners in their living room, at the correct listening width, with the favored listening chair exactly between the left and right corners. For the rest of us, with rooms that are less symmetric, the speakers have to move a few feet into the room. Short of building custom rooms for hifi listening, we have to make-do with the rooms we have.
This is where the problem lies. For non-corner, non-rear-wall locations, there are strong reflections from the rear wall, side wall, floor, and ceiling. The arrival times from these reflections are not synchronous, and interfere with the direct sound from the loudspeaker. If the loudspeaker radiates less energy into the rear wall, side wall, floor, and ceiling, and more towards the listener, there will be less room interaction than a near-omni direct-radiator. Response will be flatter, with less severe peaks and nulls.
Direct-radiator bass arrays have increased directivity in the vertical plane, which cuts down on floor and ceiling reflections, but there is no difference for rear wall and side wall reflections, where the radiation pattern is close to omnidirectional in the 100 Hz to 500 Hz range.
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Lynn, I'm one of those lucky people with a good size, essentially symmetrical, room with two very usable corners. I currently use Lowther All Fun horns, the smaller brother of the BigFuns, driven by flea-power SET amps.
I like what Andrew has done with the Bass/Mid horn and, as I alluded to before, I've been wondering about possibilities around a corner firing derivative; it would seem possible that by exploiting the corners the bass cutoff point could be lowered a bit, than Andrew's 70Hz, without physically taking over the room. I have little knowledge or experience of speaker design and I'm looking for a steer on how one might develop the initial concept 'on paper'? Would something like HornResp be the place to start?
Just to add a little spice to the mix I'm fascinated by the possibility of a two way by utilising the ribbon mid/treble unit that DIYHiFiSupply use in their Crescendo speaker;
Crescendo Ribbon Horn Speaker
That would require a higher crossover frequency so the mid/bass would need to be extended upwards a little too. Is that asking too much?
I appreciate that there's a bit of work (and learning) involved and it could all go nowhere.
Thanks for any pointers.
Ray
I like what Andrew has done with the Bass/Mid horn and, as I alluded to before, I've been wondering about possibilities around a corner firing derivative; it would seem possible that by exploiting the corners the bass cutoff point could be lowered a bit, than Andrew's 70Hz, without physically taking over the room. I have little knowledge or experience of speaker design and I'm looking for a steer on how one might develop the initial concept 'on paper'? Would something like HornResp be the place to start?
Just to add a little spice to the mix I'm fascinated by the possibility of a two way by utilising the ribbon mid/treble unit that DIYHiFiSupply use in their Crescendo speaker;
Crescendo Ribbon Horn Speaker
That would require a higher crossover frequency so the mid/bass would need to be extended upwards a little too. Is that asking too much?
I appreciate that there's a bit of work (and learning) involved and it could all go nowhere.
Thanks for any pointers.
Ray
I was looking at that unit myself. Would they sell it separate? Either that, or build the Crescendo and use it with a good sub and high-pass it at circa 120Hz to 150Hz. Something like the 12" GR Research Rythmik Audio servo-drive kits might be good.
Ha, I built those bass horns for Ming Su...in 25mm Birch Ply, CNC'd. Sadly, I didn't have drivers (apart from some Tannoy Monitor Golds) to hear them.
I've thought long and hard about building some for myself.
Ming was after 35Hz to 350Hz.
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