Need help selecting drivers for DIY 3 way or 4 way music/home theater speakers

[saabracer23]

Hello all! First post here. So I’m strongly considering selling off my pair of L300s to fund a project I’ve been wanting to tackle for some time. These will be used for music a lot of the time, but also home theater so there will be 3 in total built (left-center-right). I have a number of drivers on hand which I was thinking I’d like to use to keep costs down, but if it seems like a bad idea and the Summits won’t cover the cost then I may consider selling my only other two pair of JBLs which are XPL200As and L7s. Hopefully I won’t need to though.

Anyways for top end, I was thinking of using the large Heil AMT. I have a pair of ESS AMT-1Ds which I’ll pull them from. So I’d have to source one additional one, hopefully with the original diaphragm. If this is a poor choice please do let me know. I see there is another member using the Heil in an 18” 3 way.

For the mid, I have a few option. I’m thinking I’d like to go with a 10” driver. I happen to have exactly 3 McCauley 6222. From what I’ve read this is supposed to be an excellent driver with good midbass. It’s the only 10” with a standard roll type rubber surround.



Another option for a 10 is the JBL 251J. These were pulled from a set of SK2-3300s. I have 6 in total, I thought maybe an MTM with the Heil would be cool, if not maybe just align them side by side as they did in the S2K-3300. If I should only use one per speaker let me know on that as well.



the other 10” option would be the JBL 2251J. Again with these I have enough to do 2 per speaker if that’s optimal. From what I understand these are the same as the 251J except that the 251J has aquaplas and is considered a bit better???

Onto the bottom end. This one is tricky for me. For home theater there will be a pair of 18” Dayton Ultimax woofers in large ported cabinets. So the mains won’t have to go super low, maybe cross at 50hz for home theater and full range for music.

I happen to have 3 JBL sub1500s (or W1500H?). My brother suggested I use them on the bottom end. I’m guessing something with a high efficiency would be better. I was considering doing something like the 2235 or similar 15 and then the sub1500 under it essentially making it a 4 way. The other option is to go with a trio of 18s, like the 2241h, or similar. If I go with an 18 I’d still like to use the trio of sub1500s, but more like true subwoofers for music duty. I posted some pics, in hopes to give folks an idea of what I have on hand. I want to make these the best they can be, so please let the suggestions roll.



Oh, for crossover, I’d likely go active to start off with and then if I can design a passive that does the speaker justice then I’d use it.


Thank you,
Dan

[Mr. Widget]

Welcome to the forum!

I'm a little surprised that no one has popped in with suggestions and comments. I have been meaning to, but am too busy to give your post the time it deserves.

I'll return to this in a bit. In the meantime, hopefully others will chime in.


Widget

[saabracer23]

Welcome to the forum!

I'm a little surprised that no one has popped in with suggestions and comments. I have been meaning to, but am too busy to give your post the time it deserves.

I'll return to this in a bit. In the meantime, hopefully others will chime in.


Widget

Thank you! Appreciate the welcome. I’d love to hear your suggestions when you have a moment to do so. Hopefully others will give their input too!

Dan

[grumpy]

Opinions and bench racing is easy from this end... sounds like a fun project.

My initial thought would be to go MTM with the 2251Js and Heil, if you have the space and won't be too close (listening position).
Keep the mid cones light and efficient to blend with the Heil unit better. That could all be crap if the 251J units suit you better.
I know Todd is enamored of his "Merman" system which transitions from a 10" to an 18" driver, but if you're expecting to add subs
(perhaps small distributed subs using the heavy JBL 15" units... sealed, with -significant- amps and EQ/limiting?) and other 18" driver systems,
you could likely use something smaller under the mid/hi units. A mid-bass unit can add a surprising amount of info to music ... e.g. compare
the JBL 240Ti vs L250Ti; both sound nice, but the 4-way makes a difference. Also, you wouldn't have to drive the 10" units as hard/low.
The Gauss units might work, if they spec out for such duty...might have to drive them separately.

I have a hard time imagining the work required to iteratively build, assemble, and test all of this with passive crossovers without a lot of experience
(which you may have), and some difficulty matching driver levels. A successful, complex, multi-way system from scratch is quite a challenge.
Will be interesting to see how this comes along!!

[saabracer23]

Opinions and bench racing is easy from this end... sounds like a fun project.

My initial thought would be to go MTM with the 2251Js and Heil, if you have the space and won't be too close (listening position).
Keep the mid cones light and efficient to blend with the Heil unit better. That could all be crap if the 251J units suit you better.
I know Todd is enamored of his "Merman" system which transitions from a 10" to an 18" driver, but if you're expecting to add subs
(perhaps small distributed subs using the heavy JBL 15" units... sealed, with -significant- amps and EQ/limiting?) and other 18" driver systems,
you could likely use something smaller under the mid/hi units. A mid-bass unit can add a surprising amount of info to music ... e.g. compare
the JBL 240Ti vs L250Ti; both sound nice, but the 4-way makes a difference. Also, you wouldn't have to drive the 10" units as hard/low.
The Gauss units might work, if they spec out for such duty...might have to drive them separately.

I have a hard time imagining the work required to iteratively build, assemble, and test all of this with passive crossovers without a lot of experience
(which you may have), and some difficulty matching driver levels. A successful, complex, multi-way system from scratch is quite a challenge.
Will be interesting to see how this comes along!!

Thank you for your thoughts. I’m assuming the 251J would have more moving mass, I don’t know of any T/S parameters for them, but in the SK2-3300 the 251J did play lower than any 2251J that I know of. (Which isn’t much as I’m not super familiar with this side of JBL, I’ve only had the L65, L300, L220, L7, XPL200A, and a couple other consumer products)

I was just wondering if since they put the 251J in such an expensive speaker if it might be a “super” 2251J lol.

The MTM is somewhat of a new though, I’m trying to play with the idea of what this speaker will look like and trying to keep the Heil at ear level. I considered using a waveguide or horn for the Heil, but not sure it would need it. It crosses low enough and is fairly efficient. If an MTM wouldn’t work I think the side by side layout like the SK2-3300 would look nice as well unless others tell me one would be better.

As far as adding the subs, I probably didn’t make it clear, but I’d like to limit the sub use for movies only, unless the sub1500 is used for sub duty, I’ve read it’s pretty clean and accurate. If I ran the sub1500 up to meet with the 10” midbasses then I guess they’d be used as woofers, I’m sure they’d offer plenty of low end, my only concern with them is efficiency and that thump you in the chest impact.

Of course if I can get away with a 3 way speaker where each driver is comfortably playing their frequencies and sounds as good as a 4 way that would be ideal. I’ve designed both 3 way and 4 way passives and 3 ways are definitely less complicated and easier to design. I figure the Heil could cross at 1000hz as it currently does in the AMT. I could play with 1200 or maybe even a little higher depending on the roll off (if I’m going active at first I’ll try 18-24 db per octave). I’d have to play with that once I have the cabinets built, I wouldn’t want to the 10s to get to “beamy” by playing them too high. I’ll have to do some research once the midbass is picked out and once the woofer is picked out to figure on the band pass of the midbass. No need to take this into account for an answer to my question, I’m just laying my though process out once drivers are selected.

You mention the “Gauss units might work” pardon my ignorance, what are you speaking of?

Thank you,
Dan

[RMC]

but am too busy to give your post the time it deserves.

+1

A successful, complex, multi-way system from scratch is quite a challenge.

+ 1

I usually try to help newcomers to this site, while some others may have less interest in that.

However last night i did look carefully at the post and came to the conclusion there's simply too much work involved here, LOT of time that i don't have unfortunately.

The poster has a bunch of drivers, each driver's specs need to be analysed for proper fit in his project, then explain to him the why of choices made. Its practically designing a system for him which is time consuming.

Moreover the OP will likely have a legitimate 2nd and 3rd round of questions to be answered. This can easily become quite a long ride... Sorry, for now.

Richard

[saabracer23]

+1



+ 1

I usually try to help newcomers to this site, while some others may have less interest in that.

However last night i did look carefully at the post and came to the conclusion there's simply too much work involved here, LOT of time that i don't have unfortunately.

The poster has a bunch of drivers, each driver's specs need to be analysed for proper fit in his project, then explain to him the why of choices made. Its practically designing a system for him which is time consuming.

Moreover the OP will likely have a legitimate 2nd and 3rd round of questions to be answered. This can easily become quite a long ride... Sorry, for now.

Richard

Well not really. I’m not asking for you all to design a crossover or design the speaker or anything like that. What I’m asking for is the knowledge of those who are fans of these drivers and who know these drivers. If someone thinks the 251J is clearly a better midbass than the 2251J that’s what I want to know. If someone thinks a JBL 18 handling the bottom end and would cross to the 10 better than the sub1500, that’s what I want to know. Can’t really think of any 2nd or 3rd round of questions I’d have unless someone’s answer provokes a question.

I’m not asking for a system design from the ground up, as my title states I’m just hoping to get suggestions as to which are the better drivers, which would you select for use. Once I have the drivers selected I’ll run them active, measure the drivers and mic them and slowly work on designing a passive crossover. I have a bit of experience designing crossovers and have access to some folks with more knowledge than I in that department. Though they don’t have knowledge of these drivers.

I see several threads in this area of people asking for recommendations on which drivers they should use in their build, this is the same.

Thank you,
Dan

[HCSGuy]

Sounds like a fun project

You may find researching the 251J/2251J a little frustrating, as there were several variants with really similar model numbers (I think they maybe did some -1 and -2 variants?) - it’s been so long I don’t remember them. I do remember that JBL modified the drivers for the SK2’s during assembly, using a heavier, aquaplassed cone, and a mass ring. I think that added 20g or so of moving mass total to the driver, to get the frequency response low enough to use in a THX home theater with a 80hz high pass crossover (I think the SK2’s fall apart somewhere around 65hz. I think the SK2’s drivers are the ones I would start with, as you know they’ve been used successfully in the same range before.

I’ll wait for Widget to chime in with more detail, as he as built some really nice music speakers with the SUB1500’s, but I don’t remember where he cuts them out. I’ve played with them, and would keep them low - low pass them at 100hz or 125hz. Also, as you may know, they had a problem with these drivers coming unglued, especially if you use them in a small, sealed enclosure with EQ. If you’re trying to do a 3way, using a 2216 woofer may be a better idea, though prototype with what you have first

Post pics as you go - I’d love to swing by when you have something to listen to - I’m just around the corner

[Ian Mackenzie]

I think you are asking the wrong question unless you can clearly advise a set of performance criteria?

Have you determined how loud you want this loudspeaker to go for a given amount of amplifier power?

What low frequency range are you aiming for and what box size can you tolerate?

Depending on what you want to your design to do some drivers might suit and some might not.

If you look at how JBL used these driver you have it will give you some glues on how best to use each driver. Jbl drivers are not general purpose. They are mostly designed for specific applications and are sometimes derived from other driver designs. So you are going to have to do a lot of research yourself.

From that step you might measure these drivers in a test box with REW and look at the real frequency response, the efficiency and the distortion level.

Then put these test boxes in a stack and start working on a practical design. You will find some drivers are chalk and cheese while others might be similar in some way. Only you can work this out.

I would think about the total box size first and keep it as simple as possible. Only use an additional drive if you absolutely have to. Tools like REW are your friend and will keep you thinking objectively while your ears tell you what you like more or less of.

As l recall all the ESS systems were two way designs or used passive radiators.

If box size is a criterion then the sub 1500 drivers can use used in compact enclosure but they are a sub woofer. The question then will be which of your other drivers will fit your design spec the best ?
Will a particular driver function properly down to a crossover point to meet the sub 1500 drivers?

You can simulate drivers with software and determine the limitations of a driver. Is a vented or sealed driver best or should you use one driver as a helper woofer (as JBL did in some of its Synthesis centre channel designs)?

I would steer clear of a D’appllito design until you have done some matter of fact tests with single drivers.

If you can obtain something like a JBL drive rack that will do your active crossover work.

Good luck with your project.

[saabracer23]

I think you are asking the wrong question unless you can clearly advise a set of performance criteria?

Have you determined how loud you want this loudspeaker to go for a given amount of amplifier power?

What low frequency range are you aiming for and what box size can you tolerate?

Depending on what you want to your design to do some drivers might suit and some might not.

If you look at how JBL used these driver you have it will give you some glues on how best to use each driver. Jbl drivers are not general purpose. They are mostly designed for specific applications and are sometimes derived from other driver designs. So you are going to have to do a lot of research yourself.

From that step you might measure these drivers in a test box with REW and look at the real frequency response, the efficiency and the distortion level.

Then put these test boxes in a stack and start working on a practical design. You will find some drivers are chalk and cheese while others might be similar in some way. Only you can work this out.

I would think about the total box size first and keep it as simple as possible. Only use an additional drive if you absolutely have to. Tools like REW are your friend and will keep you thinking objectively while your ears tell you what you like more or less of.

As l recall all the ESS systems were two way designs or used passive radiators.

If box size is a criterion then the sub 1500 drivers can use used in compact enclosure but they are a sub woofer. The question then will be which of your other drivers will fit your design spec the best ?
Will a particular driver function properly down to a crossover point to meet the sub 1500 drivers?

You can simulate drivers with software and determine the limitations of a driver. Is a vented or sealed driver best or should you use one driver as a helper woofer (as JBL did in some of its Synthesis centre channel designs)?

I would steer clear of a D’appllito design until you have done some matter of fact tests with single drivers.

If you can obtain something like a JBL drive rack that will do your active crossover work.

Good luck with your project.

Efficiency isn’t necessarily all that crucial. I’m sure anything that is built will be plenty efficient. The room is about 16’ wide and 23’ long. There is plenty of amplifier power, while running active each driver will have 300-400 watts each depending of the amplifier dedicated to that driver. If I get the passive crossovers setup I’ll then switch over to some Yamaha amplifiers I have rated at 925w at 8 ohms and 1400 at 4 ohms, so plenty of power.

Fir frequency response I’d like them to be a true full range speaker, for music my thoughts are running the speakers only so hopefully they’ll make it to 30hz (-3db) or so give or take a few hz. If I’m really in the mood for bass I can kick in the sub1500s as I’m sure they can do music justice. For HT the plan is to kick in the 18s and cross them to the mains at somewhere between 50-70hz. So these main speakers will start rolling off at that crossover point. Cabinet size would be whatever is optimal for the drivers picked. They’ll likely be behind an acoustically transparent screen/wall. The 18” sub cabinets will be 14 cubic feet afrer subtracting port and driver volume, so pretty large.


“Depending on what you want to your design to do some drivers might suit and some might not.”

Basically I’m after the 10” mid driver that will give me the cleanest most coherent midrange, where vocals will be as clean as possible. If at the same time they can give some good impact in the midbass region that would be a plus, but I’m sure the woofer they cross to can handle most of that if needed. Same goes for the woofer, I would hope for tactical clean bass with very little decay. I don’t want boomy, but I know that has a lot to do with the cabinet. On the tweeter, nobody has said not to use the Heil, so I may just go with that. I really like it, it’s fairly efficient and sounds good while being able to being able to cross low. I’ll have to double check, but I may have the mid and tweeter from the SK2-3300 as well, maybe those would be a better option than the Heil?

Indeed you are correct, building test boxes and taking measurements with REW would get me the answers I need. With twins that are a couple months old at the moment my time is externally limited, so if there was someone that had some time with these drivers I figured they might be able to save me time. Like I know there is a member here with a 3 way using the Heil with a 2251J and an 18 (not sure which 18). He could share his thoughts, cabinet volume, crossover frequency and slope, etc. Someone recently asked on another forum if there was anyone that preferred the midrange of the Scan Speak Revelator 12M4631 or the Seas W14CY001. I told him that sound is obviously subjective, but I much preferred the sound of the paper cone Scan. I shared my crossover info with him along with the other drivers used. Hopefully I was able to save him a bit of time. If I have some info he is looking for, why not share it?

Od course if in the end I can’t get definitive answers then I will indeed build test cabinets and measure, but it would greatly delay my progress. Do you happen to know if two screaming babies would mess up my measurements of the frequency response lol?

Yes, this Heil was used in a 2 way matching up to a 12” woofer and a passive. Most of the designs were 2 ways using a passive, but they did have the Rock Monitors like the Rock Monitor 3 which was a 3 way using a 6” mid.

Do you have any thoughts as to my question on my last response for the sub1500? As far as saving it from glue failure and truly the best cabinet alignment? I have DATS and a WT3, but again, if it can save me a little time…

Yeah, the MTM idea was just a passing though. Im not sure how the Heil would behave with a cabinet for the mids both on tap and below it, as it’s also rear radiating. Plus the center to center spacing on the 10s may not be ideal with the Heil between them. The more I think about it, the side by side may look better. Maybe make the front baffle as it was in the 2SK-3300, mounting the drivers on a slight slant away from each other. Did they do that to eliminate combing and improve horizontal dispersion? My last home speaker design was in a D’appolito configuration using a pair of 5-1/4” midwoofers and a 1” dome tweeter. So I was just curious if would work here.

I will keep my eyes open for a JBL drive rack, thank you!


Appreciate it!
Dan

[toddalin]

Never heard of a 251J and don't see specs on it anywhere though the cooling fins look to be substantially longer than the 2251J.

The 2251J is a nice match for the Heil and while an MTM would be cool, it is really not necessary. Run at its own impediance level (~3.3-3.7 ohms), the Heil will be a bit loud for one 2251J if it is not padded down a bit. It may be be just about perfect for an MTM arrangement without padding. BTW, the Heils really like/need a high current solid state amp.

Crossing the Heil over at 1kHz is a mistake. It's just too low and my Heil would "complain" where it interfaces with the 2251 at less than ~1,500 Hz. I bring it in at 2,150 hz and it really likes that. Keep it over 2kHz unless you use a steep slope on the crossover.

The 2251J has a natural rolloff below 300 Hz. Just forget about it going down to meet a subwoofer. Ain't gonna happen. Maybe this is where the 251J accels.

But, will the 251J run up high enough to meet the Heil at >2khz? The 2251J goes well over 4kHz and actually gets louder in this range so the 2,150 Hz crossover is no problem, and this is actually where the volume would normally be increasing. Still, there are those that would say that this is too high a frequency for a ~10" speaker based on the wavelength.

I subscribe to the theory that I always sit in the sweet spot and that crossing over @>2kHz keeps all of the fundementals in the 2251J adding a sense of coherency, soundstage, and imaging.

I like the 2241H for the bass because the accordion edge and relatively light cone give the woofer "speed" thereby letting the texture of bass instruments come through. The 2241H is actually rated from 30 Hz - 3kHz and I cross it over at 300 Hz. I run these as 2.5 ways and let the 2251 naturally roll off on the low end. I don't put the 2251 through a cap.

If you want to do this passively, this schematic will get you there. BTW, I typically run the L-pads at their max settings for the flattest response unless the music has lots of HF noise in which case I may turn down the Heil a bit.








This shows the nearfield spectrum for the 2251J. The dip at ~800 Hz is from a cabinet resonance/reflection, and I think a bit more insulation will take it out. It was much worse, with a subsequent peak, before I insulated the interior back of the cabinet, and I will try to do the sides in the near future to remove the remainder.

Typical 30 dB span:

[saabracer23]

Never heard of a 251J and don't see specs on it anywhere though the cooling fins look to be substantially longer than the 2251J.

The 2251J is a nice match for the Heil and while an MTM would be cool, it is really not necessary. Run at its own impediance level (~3.3-3.7 ohms), the Heil will be a bit loud for one 2251J if it is not padded down a bit. It may be be just about perfect for an MTM arrangement without padding. BTW, the Heils really like/need a high current solid state amp.

Crossing the Heil over at 1kHz is a mistake. It's just too low and my Heil would "complain" where it interfaces with the 2251 at less than ~1,500 Hz. I bring it in at 2,150 hz and it really likes that. Keep it over 2kHz unless you use a steep slope on the crossover.

The 2251J has a natural rolloff below 300 Hz. Just forget about it going down to meet a subwoofer. Ain't gonna happen. Maybe this is where the 251J accels.

But, will the 251J run up high enough to meet the Heil at >2khz? The 2251J goes well over 4kHz and actually gets louder in this range so the 2,150 Hz crossover is no problem, and this is actually where the volume would normally be increasing. Still, there are those that would say that this is too high a frequency for a ~10" speaker based on the wavelength.

I subscribe to the theory that I always sit in the sweet spot and that crossing over @>2kHz keeps all of the fundementals in the 2251J adding a sense of coherency, soundstage, and imaging.

I like the 2241H for the bass because the accordion edge and relatively light cone give the woofer "speed" thereby letting the texture of bass instruments come through. The 2241H is actually rated from 30 Hz - 3kHz and I cross it over at 300 Hz. I run these as 2.5 ways and let the 2251 naturally roll off on the low end. I don't put the 2251 through a cap.

If you want to do this passively, this schematic will get you there. BTW, I typically run the L-pads at their max settings for the flattest response unless the music has lots of HF noise in which case I may turn down the Heil a bit.








This shows the nearfield spectrum for the 2251J. The dip at ~800 Hz is from a cabinet resonance/reflection, and I think a bit more insulation will take it out. It was much worse, with a subsequent peak, before I insulated the interior back of the cabinet, and I will try to do the sides in the near future to remove the remainder.

Typical 30 dB span:

Thank you for showing me all of your work so far. Saves me a good deal of time. I’ve collected together my drivers. I have the 2242Hs (curious how they’d compare to your 2241s) and I’m really wanting to try the 251Js, I have all 6 on hand, I’m really hoping to use 2 per speaker. I’ll have to measure them, but it’s nice to see that the specs were posted. They seem to be a very nice driver. I should be able to cross them lower to the 2242 and they should hopefully still play cleanly up high.

Only reason I suggested the 1000hz crossover point to the Heil was because that is the crossover point it’s used in the AMT-1B. I’m not sure if the 251J could go to 2250hz. Really dig your setup!

Dan

[Ian Mackenzie]

Efficiency isn’t necessarily all that crucial. I’m sure anything that is built will be plenty efficient. The room is about 16’ wide and 23’ long. There is plenty of amplifier power, while running active each driver will have 300-400 watts each depending of the amplifier dedicated to that driver. If I get the passive crossovers setup I’ll then switch over to some Yamaha amplifiers I have rated at 925w at 8 ohms and 1400 at 4 ohms, so plenty of power.

Fir frequency response I’d like them to be a true full range speaker, for music my thoughts are running the speakers only so hopefully they’ll make it to 30hz (-3db) or so give or take a few hz. If I’m really in the mood for bass I can kick in the sub1500s as I’m sure they can do music justice. For HT the plan is to kick in the 18s and cross them to the mains at somewhere between 50-70hz. So these main speakers will start rolling off at that crossover point. Cabinet size would be whatever is optimal for the drivers picked. They’ll likely be behind an acoustically transparent screen/wall. The 18” sub cabinets will be 14 cubic feet afrer subtracting port and driver volume, so pretty large.


“Depending on what you want to your design to do some drivers might suit and some might not.”

Basically I’m after the 10” mid driver that will give me the cleanest most coherent midrange, where vocals will be as clean as possible. If at the same time they can give some good impact in the midbass region that would be a plus, but I’m sure the woofer they cross to can handle most of that if needed. Same goes for the woofer, I would hope for tactical clean bass with very little decay. I don’t want boomy, but I know that has a lot to do with the cabinet. On the tweeter, nobody has said not to use the Heil, so I may just go with that. I really like it, it’s fairly efficient and sounds good while being able to being able to cross low. I’ll have to double check, but I may have the mid and tweeter from the SK2-3300 as well, maybe those would be a better option than the Heil?

Indeed you are correct, building test boxes and taking measurements with REW would get me the answers I need. With twins that are a couple months old at the moment my time is externally limited, so if there was someone that had some time with these drivers I figured they might be able to save me time. Like I know there is a member here with a 3 way using the Heil with a 2251J and an 18 (not sure which 18). He could share his thoughts, cabinet volume, crossover frequency and slope, etc. Someone recently asked on another forum if there was anyone that preferred the midrange of the Scan Speak Revelator 12M4631 or the Seas W14CY001. I told him that sound is obviously subjective, but I much preferred the sound of the paper cone Scan. I shared my crossover info with him along with the other drivers used. Hopefully I was able to save him a bit of time. If I have some info he is looking for, why not share it?

Od course if in the end I can’t get definitive answers then I will indeed build test cabinets and measure, but it would greatly delay my progress. Do you happen to know if two screaming babies would mess up my measurements of the frequency response lol?

Yes, this Heil was used in a 2 way matching up to a 12” woofer and a passive. Most of the designs were 2 ways using a passive, but they did have the Rock Monitors like the Rock Monitor 3 which was a 3 way using a 6” mid.

Do you have any thoughts as to my question on my last response for the sub1500? As far as saving it from glue failure and truly the best cabinet alignment? I have DATS and a WT3, but again, if it can save me a little time…

Yeah, the MTM idea was just a passing though. Im not sure how the Heil would behave with a cabinet for the mids both on tap and below it, as it’s also rear radiating. Plus the center to center spacing on the 10s may not be ideal with the Heil between them. The more I think about it, the side by side may look better. Maybe make the front baffle as it was in the 2SK-3300, mounting the drivers on a slight slant away from each other. Did they do that to eliminate combing and improve horizontal dispersion? My last home speaker design was in a D’appolito configuration using a pair of 5-1/4” midwoofers and a 1” dome tweeter. So I was just curious if would work here.

I will keep my eyes open for a JBL drive rack, thank you!


Appreciate it!
Dan

I have no direct experience with that sub driver.

If you are intending to use massive sub enclosures then you are going to be limited to up to 80 hertz.
That means you will need a mid bass woofer to fill from 80 hertz up to 300 hertz to this JBL 10 in driver.

In 2SK-33300 one woofer only did up to mid bass frequencies. The other was driven up to the horn.
This is because a single woofer of this size was NOT going to cut it in so far as matching the output of the sub in the context of a HT system at 80 hertz.

This is where l was coming from. It’s simple physics in that a 10” driver doesn’t have the output to match a serious 15” or 18” sub crossing over at 80 hertz. If you try it you will hear the problem. But if you use 2 x 10” drivers you get a +3dB gain in sensitivity and +3dB in output. Guitar boxes use quad arrays of 10” drivers. Go figure.

The driver motor will run cooler and will have much lower distortion in the bottom octave of it range. You can try a vented enclosure which will give you higher acoustic output around 80-120 hertz.

I personally would be looking at the driver below in that you will have a much easier design to implement. Your set on using the Heil so it’s not a JBL based system anyways.

Earl Geddes used this driver in his famous loudspeaker designs. In just 85L it’s incredible. You won’t find a better driver. It’s smooth up to 2 khertz making it diy friendly and will give you an f3 of 46 hertz in compact enclosure. About the same size as the ESS tower design. They used CTS woofers. The B&C driver is light years better. If you crossover with 24db LR filters the Heil will perform better. I don’t think you will have a problem crossing over at 1500 hertz. You can contact Nelson Pass for tips on how to use the Heil. He designed the crossovers and was in R&D at ESS before he struck out on his own. He actually got fired from ESS so the story went over a few glasses of red….Lol.

https://www.bcspeakers.com/en/produc...ive/15rbx100-8

[RMC]

LOL. I stand by my initial impression and guesses about this driver... & I'd take that 2.5KHz upper 3dB spec with a grain of salt, and I've seen no response plots for the 6222:

"...Also, you wouldn't have to drive the 10" units as hard/low. The Gauss units might work, if they spec out for such duty...might have to drive them separately."

"Gauss? was thinking of that as the mid-bass element... I have no idea how/if it would match up with the Heil driver on it's own."

I don't see what's laughable about considering the McCauley 6222 as mid-bass/low-mid driver. Plus its somewhat insulting to the OP owning these drivers, as he wrote: "I’m thinking I’d like to go with a 10” driver. I happen to have exactly 3 McCauley 6222. From what I’ve read this is supposed to be an excellent driver with good midbass" Post 1

I'm certainly not trying to convince someone who doesn't want to be convinced, don't have time for this, but instead trying to "rehabilitate" drivers that appear to being "trashed". On the practical side having three can be useful, one being a spare in case of accidental overdrive or simply too much ambition.

initial impression and guesses about this driver are what you have, then a grain of salt about 2.5 khz and the absence of a response plot. Seems pretty thin.

One doesn't design or build boxes based on guesses and impressions. Need something more serious than this, such as data from a spec sheet. Not trusting the 6222 spec sheet upper response is your privilege but you have no other to offer.

A number of JBL systems and/or drivers don't show an official response curve and i don't recall you made a big fuss about those.

As for driving the 10" units as hard/low, that load would also apply to a Gauss, 251J or 6222. Which per se does not differentiate the situation. Looks like a non issue.

Simply throwing the Gauss name up in the air, with no specifics (e.g. suitable model number) doesn't help the OP moving forward, more so when he didn't seem familiar with Gauss.

Pic shows the original spec sheet for the Mc Cauley 6222, little better than the internet version (e.g. highest recom crossover). The 6222 is louder than 251 for the same voltage applied (251 being 16 ohms), the 251 is a 60hz driver while the 6222 is a 40hz, didn't see the 251 Pe and Xmax numbers (2251 are 388W, 5.7 mm) compared to 300W and 8.4 mm for the 6222, etc.

Sorry, but certainly not your most convincing post.

[grumpy]

Nevermind. Enjoy.