Great Scott! Retro Audio Rulz! Back to the Future, or Forward to the Past?

[JonMarsh]

After working far too hard this summer and year, one thing I've concluded is that it's time to do some things just for the pure fun of it!

What's really puzzling how some recent inspirations seem like rediscovering things done ages ago... literally decades!



I really have been questioning myself about posting about some of this stuff, seems like it could be early dementia sets in- and in this day and age, we have more than enough of crazy going around for all of us!






But it's almost like re-living my parts of my mis-spent youth...

Here's one example... a new woofer system design, based on one I did in the early 90's for Thomas Waale, using Audax Pro woofers. Heres an updated version modeled in VituixCAD, and driver is on the way to build one... have refined the design mathematics, and this is just about the perfect driver for doing what I specifically want here...

tip of the hat to Kimmo for being able to model this in what seems to be an accurate fashion in VituixCAD.




As you can see from the info pane, -3dB point is 26 Hz. Not an HT sub, but fairly compact and killer for music. Bandpass enclosures get a bad rep for what people do with them in car audio, cranking up the gain, narrowing the bandwidth, and having tolerating a lot of ripple in the response and really crummy transient response in order to play loud and louder... but as I started to figure out in the 70's, there are some interesting things you can do with them with the right driver and approach. Oh, and up to 107 dB with just 100W. But it takes a rather different set of driver parameters...



Here's something else that's been coming together in a remarkably brief period of time- like last week? having some right bits lying around, and stumbling on something new to make something old...

Note the system sensitivity- a 2.5 way could improve it another 3 dB and of course increase the acoustical output capability. But it would also make it much larger. The Satori woofer as measured is in just 1 cu ft. Two cu ft is about ideal for a ported setup. But 4 cu ft for two, i.e., 100L, does start to get a bit largish for a condo, where I'll be the next 18 months.

I should redo the driver measurements- they were done at different times with different angle increments, and the only ones that lined up were 0 deg and 30 deg. Things look pretty righteous out to 45 of axis, but then that's what you should get with a constant directivity horn and the right driver. Try to guess the crossover frequency.

HD is very low- the HF sensitivity is about 107 dB, and rated power handling is 200W. And this combo goes for about the same bucks as a premium dome tweeter. I would have killed to have these in my PA system back in the early 70's. Titanium diaphragm Neo magnet compression drivers from B&C.




Impedance curve - could be driven by a broken transistor radio, I think...




The give away of the test setup last week for driver measurements, but note there is a new waveguide already in development at SMJ... Will post the crossover as soon as I have the parts and know it actually works like the simulation!

[rick844]

Nice job putting this together. I would be lying if I said I understood it all, but I do get the point. I noticed you said it's not a ht sub, so it makes me wonder, what ht sub would you do (or do again) to fill a room that is 15 by 25? Form factor desired is less than 36 inches cubed. I have a 1000 watt pro amp. Looking to replace an existing ported 15 inch sub enclosure that does not pass the WAF.

[Zvu]

I love threads like this

.... Try to guess the crossover frequency....

Around 1000Hz ?

[JonMarsh]

I love threads like this



Around 1000Hz ?

Very close- 1200Hz!

About LR6 on the woofer, to keep the stuff higher up down in level, and Lr4 for the compression driver. Not quite a Harsch alignment, though that's something I'm going to look at also as an alternative, given the step back of the compression driver relative to the woofer. that might work better with a pair of Accuton AS190, but then THAT wouldn't be Retro! But I should investigate it, because developing transient perfect loudspeakers IS very retro- first one around 1978. Then the primary measurement tool is an oscilloscope! And that's certainly Retro!

Just 'cause it looks retro doesn't mean it has to have a fully retro technology approach.


The current networkignore the text about 2200Hz, that was left over from the file I started with for the development)








BTW, the driver is the relatively new (at PE, anyway) B&C DE990TN. It's kind of like a big brother and later development than parts like the DE500 that Geddes has used for his waveguides.


The design elves at SMJ have already been busy with their Fusion360 efforts (That's not Retro, either!)

[Zvu]

Old goals acomplished by new means - i love the idea.

It seemes that 3D printers will become obligatory tool in workshops in a few years. It makes development way faster.

[JonMarsh]

Nice job putting this together. I would be lying if I said I understood it all, but I do get the point. I noticed you said it's not a ht sub, so it makes me wonder, what ht sub would you do (or do again) to fill a room that is 15 by 25? Form factor desired is less than 36 inches cubed. I have a 1000 watt pro amp. Looking to replace an existing ported 15 inch sub enclosure that does not pass the WAF.

Rick, I hear you- and let me share a few thoughts first.

What is a music sub or an HT sub is sort of relative... my girlfriend Beverly, who passed away in January of 2018 from pancreatic cancer, had this tiny little Sony "HT" sub with an 8" woofer and I seriously doubt it could make 40 Hz at any significant level. But it had more low end than the mains and surrounds. At least she had those in a good location, up in the corners near the ceiling of this 35 x 25 ft room, with an arched high ceiling.

So, what I did for her was a Dayton UM15...

https://www.parts-express.com/dayton-audio-um15-22-15-ultimax-dvc-subwoofer-2-ohms-per-coil--295-514

In a Denovo knock down cabinet

https://www.parts-express.com/denovo-audio-knock-down-mdf-30-cu-ft-cubic-foot-subwoofer-cabinet--300-7087

That I veneered and made pretty (relatively) for her, with a Hypex DS 8.0 sub plate amp, which did the job nicely.





Now, it sounds like you had a fairly high end HT setup- and you know, even 10 years ago people were talking about how it takes 7.5Hz to reproduce some of the stuff on the U505 movie. Generally, I'd say a higher end HT setup target is about 10-12 Hz at least. Do you agree?

It's actually hard to do that with a ported or PR setup, because ported rolls off at 24 dB/octave and has a limited reinforcement range- PR rolls off at 36 dB/octave. The way to go is usually an IB manifold array (think a hole in your floor that goes down to the basement with a square but long form factor, something that could mount 3 12" long throw woofers on each side- that's what Thomas Waale put into his living room (former moderator here)

So, if you tune a ported setup for 12 Hz, you have very little reinforcement at 20 Hz and above.


So, early 2018, Peerless came out with a driver that is pretty interesting. I bought a pair from Digikey, because they were the only ones that had them in stock!

https://www.parts-express.com/peerless-by-tymphany-stw-350f-188pr01-04-15-high-power-subwoofer--264-1652

Take a look at it. Designed to play very low, very loud, and handle EQ for output extension in a smallish enclosure.


Because of all the upheaval in my personal situation and work situation, I haven't worked out what I'll do with the two I bought... and they're in climate controlled storage in Idaho, while I'm still working another 17 months in the SF Bay Area before I retire. When I unpacked one to look at it, I knew this was something a bit more extreme for a 15" driver.




I did some quick calculations back in 2018, and I think I got some 4 cu ft test enclosures to try out, but never got around to building them for test- it's all in storage in Idaho now. It's been 7 day weeks since mid April at work, but that is probably going to end next week. But these would demolish the condo I live in for now!

I'll run some numbers and see how they model and get back to you... might be interesting. Certainly can do something much smaller for you, and you say you already have a kilowatt amp- you'll need it!

[JonMarsh]

Hmmm, for the 2.5 way, imagine running two of the Satori WO24P-8 sealed, in just 2 cu ft- OK down to 55 or so, as you can see...

And setting that on tope of the bandpass woofer, which would have the driver vertical and the port firing down to the floor.... sensitivity should be good.


And to keep going retro, let's throw in another classic idea- Low Power Class A mono blocks.


With a modern twist, of course.

Pass Amp Camp. In balanced mono block configuration, 16W each .






OK, admit it, I know you saw it coming....


And I have a couple of these on the shelf waiting to be put together.

2010 was Summer Camp for the first Gen Ardent, maybe I can find some weekend time in August for Amp Camp Time!

[rick844]

Rick, I hear you- and let me share a few thoughts first.

What is a music sub or an HT sub is sort of relative... my girlfriend Beverly, who passed away in January of 2018 from pancreatic cancer, had this tiny little Sony "HT" sub with an 8" woofer and I seriously doubt it could make 40 Hz at any significant level. But it had more low end than the mains and surrounds. At least she had those in a good location, up in the corners near the ceiling of this 35 x 25 ft room, with an arched high ceiling.

So, what I did for her was a Dayton UM15...

https://www.parts-express.com/dayton-audio-um15-22-15-ultimax-dvc-subwoofer-2-ohms-per-coil--295-514

In a Denovo knock down cabinet

https://www.parts-express.com/denovo-audio-knock-down-mdf-30-cu-ft-cubic-foot-subwoofer-cabinet--300-7087

That I veneered and made pretty (relatively) for her, with a Hypex DS 8.0 sub plate amp, which did the job nicely.


[ATTACH=CONFIG]29575[/ATTACH]


Now, it sounds like you had a fairly high end HT setup- and you know, even 10 years ago people were talking about how it takes 7.5Hz to reproduce some of the stuff on the U505 movie. Generally, I'd say a higher end HT setup target is about 10-12 Hz at least. Do you agree?

It's actually hard to do that with a ported or PR setup, because ported rolls off at 24 dB/octave and has a limited reinforcement range- PR rolls off at 36 dB/octave. The way to go is usually an IB manifold array (think a hole in your floor that goes down to the basement with a square but long form factor, something that could mount 3 12" long throw woofers on each side- that's what Thomas Waale put into his living room (former moderator here)

So, if you tune a ported setup for 12 Hz, you have very little reinforcement at 20 Hz and above.


So, early 2018, Peerless came out with a driver that is pretty interesting. I bought a pair from Digikey, because they were the only ones that had them in stock!

https://www.parts-express.com/peerless-by-tymphany-stw-350f-188pr01-04-15-high-power-subwoofer--264-1652

Take a look at it. Designed to play very low, very loud, and handle EQ for output extension in a smallish enclosure.


Because of all the upheaval in my personal situation and work situation, I haven't worked out what I'll do with the two I bought... and they're in climate controlled storage in Idaho, while I'm still working another 17 months in the SF Bay Area before I retire. When I unpacked one to look at it, I knew this was something a bit more extreme for a 15" driver.

[ATTACH=CONFIG]29576[/ATTACH]


I did some quick calculations back in 2018, and I think I got some 4 cu ft test enclosures to try out, but never got around to building them for test- it's all in storage in Idaho now. It's been 7 day weeks since mid April at work, but that is probably going to end next week. But these would demolish the condo I live in for now!

I'll run some numbers and see how they model and get back to you... might be interesting. Certainly can do something much smaller for you, and you say you already have a kilowatt amp- you'll need it!

Wow, very educational. Yes, I would like to learn more for sure. Thanks for the feedback.

[rick844]

Based on the specs, I might need more amp to push this thing, which is ok. Im curious to see what you come up with.

Rick, I hear you- and let me share a few thoughts first.

What is a music sub or an HT sub is sort of relative... my girlfriend Beverly, who passed away in January of 2018 from pancreatic cancer, had this tiny little Sony "HT" sub with an 8" woofer and I seriously doubt it could make 40 Hz at any significant level. But it had more low end than the mains and surrounds. At least she had those in a good location, up in the corners near the ceiling of this 35 x 25 ft room, with an arched high ceiling.

So, what I did for her was a Dayton UM15...

https://www.parts-express.com/dayton-audio-um15-22-15-ultimax-dvc-subwoofer-2-ohms-per-coil--295-514

In a Denovo knock down cabinet

https://www.parts-express.com/denovo-audio-knock-down-mdf-30-cu-ft-cubic-foot-subwoofer-cabinet--300-7087

That I veneered and made pretty (relatively) for her, with a Hypex DS 8.0 sub plate amp, which did the job nicely.


[ATTACH=CONFIG]29575[/ATTACH]


Now, it sounds like you had a fairly high end HT setup- and you know, even 10 years ago people were talking about how it takes 7.5Hz to reproduce some of the stuff on the U505 movie. Generally, I'd say a higher end HT setup target is about 10-12 Hz at least. Do you agree?

It's actually hard to do that with a ported or PR setup, because ported rolls off at 24 dB/octave and has a limited reinforcement range- PR rolls off at 36 dB/octave. The way to go is usually an IB manifold array (think a hole in your floor that goes down to the basement with a square but long form factor, something that could mount 3 12" long throw woofers on each side- that's what Thomas Waale put into his living room (former moderator here)

So, if you tune a ported setup for 12 Hz, you have very little reinforcement at 20 Hz and above.


So, early 2018, Peerless came out with a driver that is pretty interesting. I bought a pair from Digikey, because they were the only ones that had them in stock!

https://www.parts-express.com/peerless-by-tymphany-stw-350f-188pr01-04-15-high-power-subwoofer--264-1652

Take a look at it. Designed to play very low, very loud, and handle EQ for output extension in a smallish enclosure.


Because of all the upheaval in my personal situation and work situation, I haven't worked out what I'll do with the two I bought... and they're in climate controlled storage in Idaho, while I'm still working another 17 months in the SF Bay Area before I retire. When I unpacked one to look at it, I knew this was something a bit more extreme for a 15" driver.

[ATTACH=CONFIG]29576[/ATTACH]


I did some quick calculations back in 2018, and I think I got some 4 cu ft test enclosures to try out, but never got around to building them for test- it's all in storage in Idaho now. It's been 7 day weeks since mid April at work, but that is probably going to end next week. But these would demolish the condo I live in for now!

I'll run some numbers and see how they model and get back to you... might be interesting. Certainly can do something much smaller for you, and you say you already have a kilowatt amp- you'll need it!

[Zvu]

Jon,

Do you plan to make the mid-hi part MTM ? That way you'd have symmetrical vertical lobe and since it will be largish system with quite low crossover point between midwoofers and tweeter it will not suffer from lobing at vertical axis.

Also, about reducing the port resonance - when i opened my LS50 i examined their flexible port. It could be done with classic BR tube by cutting windows at the flat part of BR pipe and gluing flexible material that will not leak air. Stuff Kef used is very similar to foam mouse pads only a bit thinner. As per their white paper and measurements, it absorbs part of the energy so resonance will be much lower in level. Combine that with down firing port and i think the problem is solved (if port resonance is low enough to make a problem in the first place). Hard plastic parts are there just for reinforcement so that port wouldn't change its length as the pressure builds up.

[JonMarsh]

Interesting ideas, thanks for sharing!

I hadn't really decided on MTM versus 2.5 way, was planning to simulate both, maybe even test both, as I can easily load drivers into the 1 cu ft Denovo "subwoofer" enclosures - they're great general purpose boxes.

I expect to have a single driver MT crossover going in a week or so, if I can just find time to order the parts and see what kind of lobing issues I do have. I have both 8 ohm and 4 ohm versions of the WO24P on hand, so literally "bread boarding" an MTM design is quite feasible....

I'd like to do part of the Facebook thing with this: "Move fast and break things"

Let's leave off the breaking things part...

Steve's getting a circular waveguide/horn design together, and I just sent him some 1/2 tooling phenolic to use as the base for driver mounting- a lot of details there to work out, but in the meantime testing with the constant directivity horns should be just fine...

A "full range" MTM or 2.5 way would "need" 4 cu ft. for a good ported setup. A sealed double woofer setup would work fine in 2 cu ft., F3 of about 50Hz. Enough for a lot of program material, but actually intended to use with an active crossover. A wide range single driver is 2 cu ft; that was the first concept. A single 4 ohm driver version sealed would just need 1 cu ft net, have to allow for the woofer and horn. that could be pretty compact.

It seems like there's potential for a whole interesting family. And that's not even counting doing a studio style monitor built into the upper angle/intersection of a front wall and ceiling, down tilt, no BSC.

And an idea I have is to do the bandpass woofer setup in the new laminated style enclosure, with a downward firing port; about 18-20" wide, and 30-32" tall to give enough length for the front loaded port firing down towards the floor. 100Hz and down. One on each side as stands for the "mains". I've got a Behringer analog electronic crossover I could throw on it for quick tests.

the B&C 15NW100 driver for the first test build was ordered Monday, should be here soon.

Now, what I really need is a week off from work, which is totally not possible with the stuff that has been going down. hah, I have the reverse problem of agism- two years past retirement age, and they want me to stay on another year... or more. Old school competence I guess.

[Zvu]

I understood that you'll make 2.5 way like this - 15nw100 in band pass as 0.5 part of the system, 2xWO24P in parallel as midwoofers and B&C horn in between to keep the sensitivity of the system at its max.

Now that i've read what you wrote more carefully, i see that you are in a condo and don't need large system as that at this point.

Still, it would be interesting to try a 2.5 system with 2xWO24P and B&C DE990TN in about 60 liters in MTM configuration. Adam does something similar with their model A77X: https://www.adam-audio.com/en/ax-series/a77x/

[Dave Bullet]

Jeff Bagby's Helios design had a single WO24-P in a smallish PR box matched with a waveguided Satori TW29BN - beryllium/neo dome @ ~ 1250Hz also. It's documented on the FB group DIY Loudspeaker project pad. Sadly I can't get a deep link to the project itself (thanks FB - not). I'd be happy posting a link, but not embedding actual design details here unless given permission.

PS: What CTC spacing will you end up with Jon? I can't recall lobing behaviour of various slopes in an MTM but by going steep will this allow you to avoid lobing issues or push the XO point lower given the waveguide / horn size?

What system sensitivity are you shooting for?

PS: Re work - have you thought about part time hours? Would that work for them and you? Keeps money trickling in for retirement projects and gives you time to actually do the projects!

[JonMarsh]

Jeff Bagby's Helios design had a single WO24-P in a smallish PR box matched with a waveguided Satori TW29BN - beryllium/neo dome @ ~ 1250Hz also. It's documented on the FB group DIY Loudspeaker project pad. Sadly I can't get a deep link to the project itself (thanks FB - not). I'd be happy posting a link, but not embedding actual design details here unless given permission.

PS: What CTC spacing will you end up with Jon? I can't recall lobing behaviour of various slopes in an MTM but by going steep will this allow you to avoid lobing issues or push the XO point lower given the waveguide / horn size?

What system sensitivity are you shooting for?

PS: Re work - have you thought about part time hours? Would that work for them and you? Keeps money trickling in for retirement projects and gives you time to actually do the projects!

Hey Dave!

When I say 2.5 way, it's one of the WO24P acting as a .5 woofer for the BSC comp, the other one running "flat" no BSZC. So, basically below 250Hz or so it's like an MTM, but above that the 0.5 woofer is tapered off. And the main woofer has no BSC, so the level at the upper crossover point is typically 4-5 dB higher than for a typical BSC comp crossover.

Now, with a 1200Hz crossover you can do things with the size of the vertical source you wouldn't want to do with a tweeter and two mid woofers. But if I use an MTM, the total height of the source in the crossover region is on the order of 25"! So although the symmetrical lobing of an MTM is desirable, it might be more desirable to have a single roughly 12" span to deal with. Now, since I've designed a 4 ohm woofer crossover (because I have some 4 ohm WO24P-4) I can use that to test a dual woofer MTM with WO24P-8 of course. So, as long as I'm willing to do the work, I don't have to speculate about what works best.

The bandpass woofer is sort of the auxiliary bass at this point- let's call it a music sub. Done right, it's VERY flat and neutral, and has quite tight transient response. But the cabinet stuff for bandpass is pretty finicky- you have to get everything just right, so I while I have an older test cabinet to try out, I may literally make a two piece text box, because getting the front volume and the port configuration just right is a big deal. Even trying to adjust the port parameters by increasing the area and the length simultaneously can upset the apple cart in ways you don't expect. Though VitruixCAD seems to have the theoretical modeling down. SO far, very good agreement between a target design done with old MathCAD docs and modeled in VituxCAD.

But it's the real hardware that counts... That woofer is coming three day select, it should be here today, tomorrow latest. I'm giddy with anticipation!

Hopefully it will work as predicted, and there will be no impact on Earths gravitational field locally, since it is a Neo motor woofer, and is not "Heavy!".

As to system sensitivity, well, we're limited by what the WO24P can do, but a single 4 ohm isn't bad, and two 8 ohms in parallel with BSC should still put things at around 92-93 dB with care, after BSC.

What would be fun is a Studio Monitor version, in a slope cabinet set up into the ceiling/wall boundary, as no BSC would be needed, and 95dB would be feasible. Then a little Pass Amp Camp mono block could really sing! I don't think I can put one of those in here... but after I move to Idaho, I hope to have a music room for all the guitars and keyboards and the Marshall stack, and a small digital recording setup. Then we shall see what we shall see...

Another big conference call today at noon, and I think we're getting things pretty close to things being ironed out, and the management tools and goals updated. It helps that I have things like full Gant chart plans and data six ways from Sunday, and the manager is riding a trike in comparison. So I will be going back to 5 day weeks starting this weekend...

I have a potful of money in deferred income, and finishing out one more year will make that pot a bit fuller for a home purchase in Idaho.

Progress! Need to get those crossover parts ordered!

[JonMarsh]

I understood that you'll make 2.5 way like this - 15nw100 in band pass as 0.5 part of the system, 2xWO24P in parallel as midwoofers and B&C horn in between to keep the sensitivity of the system at its max.

Now that i've read what you wrote more carefully, i see that you are in a condo and don't need large system as that at this point.

Still, it would be interesting to try a 2.5 system with 2xWO24P and B&C DE990TN in about 60 liters in MTM configuration. Adam does something similar with their model A77X: https://www.adam-audio.com/en/ax-series/a77x/

Interesting site! I'll have to look it over in more detail as soon as I have a little more time!

[JonMarsh]

About that STW-350F...

OK, I Refreshed my memory at lunchtime; I swear with the day job I have there is so much technical stuff cycling through all the time that something I looked at for speakers a year and a half ago can seem like quite a while ago...


First, here's a good capture from their technical brochure to keep in mind:




Part of why I got interested in this driver (besides how gnarly it looks!) is some of the off the beaten trail characteristics- some interesting tradeoffs and compromises were made in order to effect some specific characteristics....

• The length of BOTH the mangetic gap and the Voice coil is an unusual combination- the theoretical Xmax, where the gap is completely filled with coil is only 10 mm; but with the gap and coil being so long, there is a long region of gradually declining BL force where you still have a lot of drive. They quote 40mm usable excursion. I will be crious to see if that plays out.
• With the combined characteristics of VC, VC inductance, cone mass, mechanical Q, etc, and high electrical Q, the Qts is fairly high, and you sort of have this hump in the response that is always there in the 40-50Hz area. Good thing most people like bass in that area....
• The frequency response for different size sealed enclosures changes very little between 60L net and 150L net. I mean, VERY little. So, let's say you feel squeamish about just 60L net, go for an enclosure that is 4 cu ft gross, and you'll easilyi be safe for haivng 75L net. I really think that was my thinking back in January 2018, and I'm not just rewriting history. But since I bought enclosure kits that size, I think I have a good case for it.
• It is possibel to go ported. I'm not sure I would chose to do that, becuase below the tuning frequency things unload. With sealed, you have room gain and a slower roll off, and more proteciton for the driver.
• Without furthe adieu, I'll show some graphs....

60L



150L


Not really much different at 150L (5 cu ft) from 60L (2 cu ft)

Put an EQ lift of 8 dB from 40Hz to 20Hz and flatten it back out, and call it a day. THAT's where you're going to be using most of your power- at 84dB/2.83V, these aren't that bad as sensitivity goes. 80W to get to 100dB when you're not in the EQ range. So 1kW sounds pretty good.


Conventional Reflex, tuned to Fs


This is a conventional reflex alignment tuned to 23Hz. I'd put an 18-20Hz High Pass filter on the sub amp. Solid extension to 20Hz, but 165L is a big box!



EBS Alignment Reflex 165L


I'd put in a HP no lower than 15 Hz. But after thinking about it, I figured going sealed with two smaller boxes each half the size made more sense.

[rick844]

Thanks for presenting this and putting in the time. It means a lot for me (a newbie) to this world. I like (really like) the idea of have two smaller boxes instead of one really big one. Is there a benefit to limiting the HP if using for a LFE channel? Why not just allow the full range? Also, when using the 60l size sealed enclosure, it seems to be tuned to 34 hz, what is the realistic performance at say 15hz? I know what it says in the graph ~65 db at 15 hz, but how would this compare to a larger (less than 165 l, but more than 60 l) ported enclosure using the same driver? Im learning here, so sorry for the questions.

[JonMarsh]

Hi Rick,

What I'm going to do now is summarize what my thinking was (found some of my computer notes!) and explain how I think they intended these to be used in small enclosures.

In their overview technical paper, they show some simplified plots about the normal box response and the Eq'd response, but they're kind of glossing over points, especially considering that the actual raw driver response is not depicted accurately.





So, we've already seen what the calculated response based on T/S driver parameters looks like, and that looks a lot like the published driver data. So, a reminder, here it is again in 75L (my target net volume out of a 100L enclosure).






So, what we're going to do is hook up our virtual amplifier and EQ in front of that,





With a shelving EQ curve like many systems and dedicated plate amps like my Hypex DS 8.0 can provide... (and similar to what the STW-350F overview paper is describing)






Which should result in a net response about like this....




And this is pretty much what I was looking for. You know, with the power this part can handle and the excursion, you can probably even get by with just 3 cu ft gross volume, if space and WAF is a major issue. Do pay attention to the Overview paper's recommendation about an interior brace that the back side mounts for the driver bolts up to- you have to take that into account in designing the enclosure, though- being able to access things from somewhere to get to that, once the driver is in the enclosure!

[rick844]

Thanks Jon, again very educational. I was going over the secondary mounting in my head trying to figure out the logistics of getting in there. You almost have to use a removable rear baffle instead of a front one for this reason. I'm sure I could make something work. There are designs out there that indicate such a build, but the builders dont go to the level of detail that you have. Once I finish this Anthology build, my center mod is next. Then this will be my following project. When I get there, I will report how that goes and I will be in touch. Thanks again.

[JonMarsh]

Thanks Jon, again very educational. I was going over the secondary mounting in my head trying to figure out the logistics of getting in there. You almost have to use a removable rear baffle instead of a front one for this reason. I'm sure I could make something work. There are designs out there that indicate such a build, but the builders dont go to the level of detail that you have. Once I finish this Anthology build, my center mod is next. Then this will be my following project. When I get there, I will report how that goes and I will be in touch. Thanks again.

Sounds fine, Rick! We can touch base then, I think you're right about the removable rear baffle- the only other alternative I can think of would be something like Steve Mannings laminated enclosure designs, where the bottom can be the last thing you bolt on. It may take some pondering over a beverage or two (probably caffeinated!) in order to come up with something clever!

Good luck with your current builds!

[rick844]

Thank you sir. I started a thread on the anthologys.