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698K views 6K replies 208 participants last post by  Red Five 
#1 · (Edited)
The number of Devastator versions and the number of documented Devastator builds is multiplying, it would be nice if some of this information were kept more neatly in one place. This thread is a work in progress. I will add new variants to this thread and also builds and link them below. :cool:

As always, in the pursuit of performance from the use of wood! Wood is still cheaper than amps and sub woofers.... Let's not forget the other part of the Devastator formula, simplicity! (remember we are dealing with a band pass here, they are more complicated). No diagonals, all panels are on right angles to simplify the building process.

Note: there are also some guides linked below in this post. If you have questions about how to assemble a Devastator, there is a lot of good information in the builds, do this and do not this. That is on top of the build guide. Basic assembly works its way from the top and front panels, towards the back and downwards. Top hatches, rear panel vents, high compression fronts and Stepped fronts have all be added as the Devastator has evolved. Items are listed for the most part in Chronological order. Several members have put a lot of time in documenting the build process. Please check out their build threads!

Want to design a Devastator all on your own? The Hornresp tutorial is posted below. If you have design questions feel free to post them in that thread! There are tools for helping design cabinets in Google Sheets posted in that thread too.

With the addition of the Stepped front Devastators, responses can be mostly flat natively. Knowing your room and what can fit in a space are going to be key factors for selection vs trying to leverage the response shape in spot the suites the box well.

Suggestions for box selection: Devastators have seen evolutionary progress as time has gone on. The biggest factor for selecting a Devastator is the space available. That is one of the main driving factors for the wide array of designs beyond achieving more performance from the use of building material. Room size is another big factor. (I grabbed this from Audioholics)

Room
Dimensional Volume
Small Room​
< 1,500 ft^3​
Medium Room​
1,500 ft^3 to 3,000 ft^3​
Large Room​
3,000 ft^3 to 5,000 ft^3​
Extreme Room​
> 5,000 ft^3​

Small room, you can probably get away with a couple Micro 15" Stepped V1s. Medium room, you will need a couple 18"s at least. Large room - 21"s. Extreme, how many Fat Boy V5s can your marriage take? Other factors, is the room open to other areas and is it an odd shape? That can mess with the equation especially if sub placement options are limited.

Why bass physics suck:

Below is the Fat Boy Version 5 with the native 22Hz tune in gray and I tweaked the vent area down so it is now tuned to 18Hz. As you can see from the graph output takes a huge 5db hit from the lower tuning. In room that 22Hz box will probably stick with all the other Index Devastators down to 17Hz or 18Hz. That is a bit room dependent, so your mileage may vary. Also, remember 6db is the equivalent of doubling your sub system, amps, boxes and sub woofers, 3db from cone area and box displacement and 3db from the input power doubling.

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Now I am going to push this further down to 15Hz tuning on the rear chamber. As you can see we are down a solid 10db on the left corner from the original 22Hz tuning and another 5db from the 18Hz tuning.

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The important thing to know? Each octave (dividing a given frequency by 2) you descend in frequency will require 4 times the displacement to achieve a given level of output. Let's say when tuned 20Hz a box can hit 88db on 1 watt of power with 1mm of excursion. If we tune the box to 10Hz it would take 4mm of excursion from the woofer to hit 88db. This is an important fact when selecting a Devastator. There are three factors that will come into play. Output, Extension and Cost, those factors will always have to be balanced. You can chose 2, but you cannot get all 3 unless you are in a very small space that gains very well. A 7000 cubic foot room on a concrete slab is not a good place to chase extension. It would be better to go with higher tuned cabinets and gain the wobble effect from a BOSS platform. Unless you have the luxury of unlimited budget.

High Pass Filter Orders:

Real quick rundown, 6db of slope is an order. For example a 2nd order Butterworth filter will knock the response down 12db per octave. If set to 20Hz the response will be down 12db at 10Hz, assuming it is applied to a flat line. 2nd order filters can make integration easier in certain circumstances. Especially if the cabinet tunes have a wider range than just a few Hertz. Integration with sealed cabinets can be more tiresome and require a lot of trial and error. An 8th order 48db per octave slope on the sealed cabinet and then using a 2nd order HPF a few Hertz over tune on the Devastator can be a good starting point. Once again YMMV. If you do plan on using a 2nd order filter, go a little over tune with the filter to control driver excursion below tune.

Order: (typically you will not see a Dev go over a 4th order, just keep multiplying by 6 to go up)
1st 6db per octave
2nd 12 db per octave
3rd 18db per octave
4th 24db per octave

Why do we need High Pass Filters on a Devastator?

Below the tuning frequency of the Low Frequency(LF) resonator cone excursion goes out of control(see example below). The cone is no longer seeing a load like it would above the tuning frequency of the LF resonator. The cone movement would be similar to the sub being given power in free air. A pro driver can take several hundred watts in most cases in free air when sent a low frequency waveform. Doing that to a woofer frequently could A. damage the woofer over time and B. if sent a more powerful signal could bottom the woofer out immediately. The High Frequency (HF) resonator does present some load to the woofer below the LF tuning frequency, but it is not enough to control the cone movement. DO NOT RUN your Devastator without a protective high pass filter.

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As you see in the graph above, the cone motion with the 2000 watt input on this NSW6021-6 has the driver well outside of the 21mm xmax below 20Hz. Once a Butterworth 18Hz 4th order high pass filter is actived the cone is peaking around 19mm below 20Hz(light gray line) and that is inside the NSW6021-6's rated xmax.

Slang/Terms:

HCR - High Compression Ratio. This front has a bell curve, but is not quite as peaky as a lower compression front and uses less space. Good for shallow cabinets.
TR - Tactile Response
Stepped - A front quarter wave resonator with 2 or 2+ cross sectional areas. The response is typically more flat and they gain more low end output.
BR - Bass Reflex
QW - Quarter Wave resonator. These are typically referred to as horns. On a Devastator they do the high frequency lifting.
FPR - First Port Resonance
BB - Baltic Birch plywood. (not the veneer box store stuff, call a lumberyard)
BBv1 - Big Boy Version 1
MLP - Main listening position.
REW - Room EQ Wizard.
HPF - High Pass Filter.
BW - Butterworth.
LF - Low Frequency
HF - High Frequency
HO/SHO - High Output or Stepped High Output. Usually these cabinets have 22Hz tuning.
BMD - Beast Mode Devastator. Typically they are closer to 60" height vs 48"
FV - Finalizer. This cabinet started as a 48"x25.5"x34" cabinet with lower tuning. FV can be used for the 16Hz tuned rear chamber or the form factor
Dev - Devastator. Generally cabinets that are around 48" in height.
Mini - Typically this cabinet type is around 40" in height.
Micro - Usually in the above or around 30" in height.
Nano - Usually used for 12" cabinets.
FB - Fat Boy. Typically as deep as they are wide.
BAMF - Bass Ascension Module Five. Home music or PA cabinet with higher tuning and a Stepped QW resonator.
NSW - Eminence NSW6021-6
SAN - Lavoce SAN214.50 or the SAN215.30 is another good choice, but not usually that is referring to the 214.50.
DS - That could be a B&C 21DS115 or a 18DS100-4, both are great choices.
TBW - B&C 18TBW100 is usually the reference, but the 15TBW100 is another good woofer.
SAF - Lavoce SAF184.03
WAF - Should be the Lavoce WAF154.00
D21V6 - This would be an example the Devastator 21" version 6
M18V6 - This would be an example of the Mini Devastator 21" version 6
FB21V5 or FBv5 - Fat Boy Version 5
FV1 - Finalizer Version 1

Devastator response evolution:

The Devastator has seen developments over time. The examples below are on 48" tall cabinets to show the three main fronts and how they affect the response.

The Devastator 21" Version 1 is the first Devastator designed by John. As you can see the front HF QW resonator adds SPL across the entire frequency range, peaking in the mid bass region. Light gray is ported cabinet with the same vent length, vent area and chamber volume as the D21V1.

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Next up we have the Devastator 21" Version 5 with an HCR front. The HCR front has a smaller cross section area vs the lower compression front, but still adds output across the range and takes up less space in the cabinet. Once again dark gray is the V5 and light is just a basic BR chamber with the same specs.

Rectangle Slope Plot Line Font


Finally we have the Fat Boy Version 5 with its Stepped QW resonator that has multiple cross sectional areas. The higher tuning coupled with the design of the QW resonator makes the cabinet very flat and efficient. The higher tuning also allows the resonators to be spaced 1 octave apart in frequency without cutting our top end short, so this design can still crossover at 80Hz into a sound system.

Rectangle Slope Font Plot Line


Other advantages to having the front QW resonator:

Cone protection from curious children, pets and sometimes friends that are tipsy. Less rear chabmer/motor noise, the panels dampen noise that would otherwise find its way through the cone and into the room. Obviously the QW resonator eats up more space vs having nothing in front of the woofer, but the QW resonator has a few things going for it.

Construction/material/tips:

The preferred building material is currently expensive. Baltic Birch plywood (not the veneer stuff at box store, call a local lumber yard) is the preferred building material. 18mm is close enough to 3/4" not to mess up the building process. MDF is heavy and makes a big dust mess and does not take screws well, tends to crack. ACX plywood is lightweight, but has voids and a tendency to warp. BB is lighter than MDF and does not make the dust mess and is less prone to warping and also voids. MDF also sucks for using Kregs.

If you have router with a flush trim bit, it is not a bad idea to add 1/8" inch on the side panels and then clean it up after assembly.

PL3X is the glue of choice due to how forgiving it is with voids and set time. When using PL, wear gloves, you do not want that stuff getting on your skin and it will mess up clothing. If you are a fluent wood worker, you do not have to say no to tight bond.

Marking panels before assembly is another pro tip. I would also suggest marking up the woofer cutout and drilling all the holes for fastening the woofer before assembly. Marking the panel alignments/positions on the side panel, front panel and baffle are all good ideas. Measure twice, cut once is another good rule to live by.

Air leaks around the access panel are usually the number one issue once the box is together. Especially if the measured response looks weak on the left corner. If you want to make sure you have a good seal, turn off the lights, put a flashlight in the rear chamber. Button the hatch up and look for light coming through the hatch seal. Weather stripping or the PE gasket tape will work.

If you have a question or are unsure of something when putting the cabinet together, feel free to post the question in the Index. This thread has large following that is happy to offer tips!

Bracing - here is a good example of a common bracing mistake. The wider dimension should be adjacent to the outside panel, like in the photo below.

Driver mounting - Chris made this write up for his technique for securing the sub to the baffle - link



Threaded Inserts (Sub woofer mounting solution)

Panel Names?


Below is a reference image
Rectangle Parallel Font Plan Diagram


Rear Chamber Resonance/dampening material

Chris when testing the JBL Quad Devastator did some measurements with different pillow configurations in the rear chamber. We also reached out to a few members for measurements they took. It would appear standing waves in the rear chamber start to encroach on the passband somewhere between 40" and 48" of rear chamber length. Boxes close to 48" on up need pillows tacked onto the side panels to alleviate near past band resonance. The goal is having a clear path from the back of the woofer to the vent inlet. Air restriction will hurt low end output. However, if there is minimal restriction in air movement, a minimal loss in low end output will take place. Here are the links to the Quad testing.

Resonance Testing Pt1
Resonance Testing Pt2

Does my UM18/IB/high Qts Sub work in a Devastator?

The short answer is no, it does not work in a Devastator. This is a UM18 in a Mini Devastator 18 Version 6.



As you can see the woofer gets a very sharp peak at the resonant point of the front horn of the cabinet. You might be thinking why not just EQ that peak? Here is the problem, the UM18 will ring when loaded in a Devastator, the cone stays in motion after a impulse. This is the UM18 vs the 18TBW100, pink is the UM18, green is the TBW. Notice how the cone on the TBW stops moving relatively quickly. Some subs are designed to work well in higher order band pass boxes, others are designed to work in lower order band pass boxes. There is a simple method for finding a good woofer using a specific metric. Efficiency Bandwidth Product (EBP), the woofers Fs value divided by its Qes value. The Devastator starts working once a value gets around 70 or so. Values closer to 100 are better, but not absolutely necessary. If you have a woofer with a value higher than 70 and are curios to see how it looks, just post a message in the thread :)



Any Devastators optimized for music?

Yes, the BAMFs are designed to handle music duty/PA use. There are currently three different versions available with different tuning depending on the needs of your system. If interested I have a smaller design meant for an 18" that will definitely make some loud noise that has not been released yet.

I bought a Crown amp that has a network card, how do I manage it???
Chris made a nice write up concerning this situation, you can find it right here. You will need the Harmon Audio Architect software installed on computer that is on the same network as the USP card.

Reference Port Plug Design - link

Performance data (HR Estimations GP1m):
The Big Boy Family 21"s
The Fat Boy Family 21"s
The Finalizer Family 21"s
The Alpha Family 21"s
The BAMF Family 18"s + 21"s
The BMD Family 21"s
The Mini Devastator Family 21"s
The Devastator Family 21"s
The Mini Devastator Family 18"s
The Devastator Family 18"s
The BMD Family 18"s
The Micro Devastator Family 18"s

Shallow + Narrow 21" + 18" Devastators

Common 21 Comparison Graphic (shoutout to Chris for his help with this)
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Common 18" Comparison Graphic
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Current (9-1-22) top picks!
Colorfulness Slope Purple Rectangle Font

Note: The Alpha III and IV have narrow clones. The FBv6 has a narrower clone and the 18BMDSV2 has a clone.

PLEASE SHARE BUILDS IN THIS THREAD!!! (including pictures)

Designs (Guide is near the bottom of this post and see build links, a lot of go information in there.)

Broken down by woofer size:

24"
21"
18"
15"
12"
Build threads/other
Guides
 

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18
#4,082 ·
I'm gonna go out on a limb and say "all."
The measured results are pretty obvious that it is a benefit to the system as a whole. Just make certain to not block the ports. :)
 
#4,085 ·
Box height is the big factor. When dealing with 60" height boxes, the resonance is really close to the passband and creates a large null. 48" boxes is where things get closer the passband. I believe GSG has guidance in the manual on pillow placement.
 
#4,087 ·
@SaskCanesFan

Just to throw a fun wrinkle in the mix. I added a third fold on the horn in this baby. I made front calculator for tinkering with the third step. More low end could be had, but I would need more space somewhere....

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#4,088 · (Edited)
The Finalizer Version 5 HO

Show them the power of the Darkside with high magnitudes of EDM bass! (We can't repel firepower of that magnitude!) It can also do movies just as well, just use a BOSS platform because low hertz at this level can cause marital issues (disclaimer, I am not paying for counseling) or PO the natives(also, not paying for citations). The simulation is based on the NSW6021-6. I included the 1000 watt normalization data and a 2.33kw 21mm simulation, just under xmax. The HPF is a BW 18Hz 4th order. There was a discussion earlier on the bass that slams you and this thing is meant to hit very hard in the 25Hz+ range. Those gun shots we love in John Wick, yeah this thing is built for that.


Rectangle Font House Logo Electric blue


1000 watt normalization data

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Max SPL using 21mm (xmax) 94 volts (2.33kw)

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Font Material property Parallel Number Pattern


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#4,089 · (Edited)
Red...
How much damage can you do if 23" and somewhere between 60-72 were max parameters on two external dimensions? :D
It's kind of a silly question, but I think about the usage for people in tight spaces because I am one.

;)

Edit: I ask, also, because of all the HO work you've come up with recently. I can't help but wonder if a new look at the Narrow/Shallow concept might bear some fruit. Along those lines, I've seen the Front and Rear ports separated before... Is this problematic in actual response or ease of design?
;)
Thanks again for all you've done... pls feel free to tell me to take my limitations and p!ss off. :LOL:
 
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#4,090 ·
23" width, see the D18SV1. Depth can be more interesting. With a 21" 22" deep is possible. I haven't posted that box. The mouth distance would have to be huge. It's the fact most shallow boxes are because AT screen. A mouth firing into the AT screen is a new set of problems 😂
 
#4,100 ·
I appreciate the sentiment guys. With two young children I maybe watch one movie that is not a Pixar a year. My little project HT project list has not been touched. Move the Mini mouths in different orientations, take measurements. Tweak delays take more measurements. Move mains behind HT screen, so that would require building a shelf and maybe moving the screen about an inch. I was also hoping to connect my mains to one of the unused CTS2000s I have and then manually EQ the mains with my CSL mic and the DSP on the amp. Not sure when I will get to do any of that lol.
 
#4,107 ·
#4,108 ·
They are solid Italian drivers, they are pricey State side, so not often used. Especially with the price of the NSW over here. Are you not looking at 15"s?
 
#4,115 · (Edited)
Toy Story 2 and 3 are good for demos with the kids around! Toy Story 3 when Rex hits the ground in the intro would clip the MiniDSP. Which is another project, taking the boost PEQ filters off of the MiniDSP and then dumping them into the USP4 card. I have a feeling an expensive Crown DSP, is not going to hard clip. I did have the pleasure of showing my friends that help me build part of the subs the system finally this last Saturday. He has his own AVR and set up in his living room and could not believe how quiet -30db sounds on my system in a massive basement and how small the subs sound. He is currently building a room for HT in his basement, I might have a chance to corrupt him somewhat... The Micro Stepped 15"s should be good at that.

This was all before the second backup of the sewerage in the unfinished section of my basement happened on Sunday. Thankfully the JBL 12" I was given made it out alive, even though it was in the direct path, JBL had the wisdom of packing it inside a plastic bag inside the box. The first time this happened I was actually coming back downstairs to put a second coat of paint on the Minis, so November of 2019. Not a good explanation by the plumber as to why it happened then and even less explanation as to why it happened this time. The house was built in 07', so all PVC inside the house and outside. I will more than likely have someone come out and run a camera down the line.

My wife is now very much onboard with me never building a small theater room on that side of the house. Since it would be under the constant threat of disaster. That means there is more hope of some remodeling in the current space in the future. Currently the screen is on the west wall, I would like to build a new south wall with a home gym and a little office behind that wall. Then move the screen to that new south wall. I should be able to get 8 seats in the room easily, but it would make the space much less play room friendly... lol. Until then I have 3 nasty modes at the MLP.

Edit: my screen is 31" off the ground, I really like that Fv5, so I started tweaking on something similar with dimension that work better for me. The screen is 104.5" wide, so staying just under that is ideal. This comes in at 23.75 cubic feet and 48x28.5x30.

Rectangle Slope Font Plot Parallel
 
#4,122 ·
@Red Five Not sure how long you've been in IT. I have a friend that has been in it (I had to work that pun it!) for quite sometime, a very long time.
This is what you need to do: Build a separate building away from the house, build a large room inside the building for your Home Theater. Or, build the entire thing as a Home Theater!
I built an 18x12x8 room inside my 40x60x14 shop for my music.
My friend, well I think his building is 80 x 120. He can fit two tractor trailers with trailers attached in there and still have an entire bay left for his other toys. He has a lot of race cars, and a lot of money. I have two race cars, no money......... :)
But I do have my shop and my room to do whatever I like!

If you build a shop, don't put water out there, that will keep the wife away. Worked for me. ;)

 
#4,123 ·
My oldest loves building things, but she had a few years to go before she can help her dad in the garage with projects, we will get there!

HOA has a lot of limits as to what can go in the yard. Garages are outside of that. My best bet would be building a bunker attached to the basement and use the top as a patio. Sound won't make it in the house and does not violate anything in the HOA. Another option would be turning my stall in the garage into a theater room, then build an HOA friendly shed in the backyard for the stuff lol. I like the bunker the most...
 
#4,124 ·
Actually, we could use an NSW for testing purposes in the not too distant future. If would be a good data point along with the 21DS115-8, which is very similar to the SAN. Then when testing is done, I can use it in a Fat Boy or something similar...
 
#4,129 ·
Hi guys,

I have been researching about NSW 21" lately for my HT/Music use. My room is 5x7x3M. I will be using 4x subs in each corner of the room.

I stumbled upon devastator from a youtube video, it looks very cool. I have never heard bandpass sub enclosure. How is it differ from full marty?

If you use 4x full marty vs 4x devastator, and you eq them to have identical freq response (LPF at 80hz to main) and you only listen to max around 115db for all, can you tell the difference? Can you describe to me the sound characteristic?

Thank you
 
#4,130 ·
Hi guys,

I have been researching about NSW 21" lately for my HT/Music use. My room is 5x7x3M. I will be using 4x subs in each corner of the room.

I stumbled upon devastator from a youtube video, it looks very cool. I have never heard bandpass sub enclosure. How is it differ from full marty?

If you use 4x full marty vs 4x devastator, and you eq them to have identical freq response (LPF at 80hz to main) and you only listen to max around 115db for all, can you tell the difference? Can you describe to me the sound characteristic?

Thank you
From a sound signature perspective they sound more effortless vs a ported cabinet. My 21DS115 ported you could tell when the woofer was not happy, it sounds like it is trying when pushed with heavy EDM tracks. The Devs are for the most part, pet and child proof. Odds of damaging the cone are fairly low. Suspensions and motors make noise on subs, on a ported cabinet only the paper of the cone is blocking the noise. On a Dev you have a chunk of wood or two between the cone and the air.

It looks like you are sitting in 3700 cubic feet of space. 4 NSWs in that space should get the job done.

Now if you have time, please read through the first post. I have revamped it and there is a lot of information on these cabinets in there. Not all of the Devastators are created equal, please take a look at some of the performance comparison data. The stepped fronts will take the day. If you have some boxes you want to compare. Please reply here. I can make some graphs normalized at 1000 watts.
 
#4,145 ·
View attachment 3242041

Same graph as before, but I am throwing the Finalizer version 1 on it.
Thank you. Finalizer 1 looks good. I cant find build thread in page 1 , it has only Finalizer 3,4, and 5.
View attachment 3242041

Same graph as before, but I am throwing the Finalizer version 1 on it.
Thank you. I like the low extension of finalizer 1 although finalizer 5 have almost flat freq. Will they sound different if I eq them to be flat dan indentical? Does different model, only differ in SPL and response? Do they sound similar?

Btw, can I mix 2x full marty dan 2x devastator with NSW 21" in my room? do they have similar HPF,LPF, roll off ; so i can align the phase to be identical?
 
#4,141 ·
Can't help but snicker a little. I was in this trap at first, too.
We all want Dev output and ULF extension. And we want it flat.
Thus far, physics has continued its unrelenting assault on our Bass Fantasies and prevents any single solution from doing it all.

Hence we add Drivers and different cabinets to achieve the different goals of strong Infrasonic Output and Devastating "Mid-Bass." And of course, let's not forget the BOSS platforms. :D
 
#4,142 ·
An HO with a BOSS platform is the way to go. The only thing missing is the air pressure, which is usually bad for the structure and WAF. Just be happy with your insides getting pounded and the awesome wobble effects of the BOSS. Slam factor is not low frequency, it is where the HOs win.
 
#4,143 ·
@SaskCanesFan

Rectangle Font Line Parallel Slope


BW 14Hz 4th order HPF on for this sim. Velocity looks better.

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This cabinet after looking at it more closely is the Fv5 + 8inches of depth and 1.5" off the port height. The HF resonator works the best using the same cross sectional areas as the v5.
 
#4,147 ·
Since many on here have complained about not being able to find used high-quality amps at fair pricing, I’ll share a deal I found.

There is currently a lot of 8 crown dci 4/1250n’s available on ebay from a dismantled installation. Pricing is $1650ea plus shipping. Does have the make offer option, so you may be able to negotiate down somewhat.

In bridged mode, these amps will supply 2500w into two channels at 4,8,or 16ohm, plenty for a pair of 21” devastators driven to full potential. My sub stage is all powered by bridged analog 4/1250’s.

Amps appear to be in good condition, but the dust present seems to indicate they have significant hours on them. Listing indicates tested working.

I am not the seller, nor have I ever purchased from this seller.

These are the network amps with integrated powerful dsp, so some networking experience is recommended.

These are not fanless amps, and do have moderate fan noise. They are much quieter than a clone or inuke, but not silent like speakerpower or crown xls.

I won’t share a link, but search on ebay for “crown 4/1250n” and you’ll find them.

Chris
 
#4,150 ·
Since many on here have complained about not being able to find used high-quality amps at fair pricing, I’ll share a deal I found.

There is currently a lot of 8 crown dci 4/1250n’s available on ebay from a dismantled installation. Pricing is $1650ea plus shipping. Does have the make offer option, so you may be able to negotiate down somewhat.

In bridged mode, these amps will supply 2500w into two channels at 4,8,or 16ohm, plenty for a pair of 21” devastators driven to full potential. My sub stage is all powered by bridged analog 4/1250’s.

Amps appear to be in good condition, but the dust present seems to indicate they have significant hours on them. Listing indicates tested working.

I am not the seller, nor have I ever purchased from this seller.

These are the network amps with integrated powerful dsp, so some networking experience is recommended.

These are not fanless amps, and do have moderate fan noise. They are much quieter than a clone or inuke, but not silent like speakerpower or crown xls.

I won’t share a link, but search on ebay for “crown 4/1250n” and you’ll find them.

Chris
I second the Crown love. I bought three of the 4/1250 analog models when an eBay seller had a load of them in May of last year. $1162 each for factory refurbs with 3-year warranty. I later purchased an 8/600N for the remaining speakers. The DCI series are my favorite amps so far. They would have been out of reach financially if purchasing new. There are deals out there, but you have to look.
 
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#4,148 · (Edited)
To add onto Chris' suggestion, the Crown CTS-3000 is what Red Five recommended to me and it works great.

The CTS-3000 doesn't look as nice as the other amps, but in my experience, it will clip last out of the amp models below. I've actually only seen that red light on each of 3000s once and only for a fraction of a second. Most of these have a sticker on them from 2007 so they are old and almost always have wear and dust. Pre-pandemic these typically went for $350 shipped and the price seems to have come back down in that price range now. I hardly saw any of these on ebay before that, but the pandemic brought a lot of these out with people trying to cash in on them. I've owned each of mine for about 1.5 years and have had no issues with either. If you find ones that are new or open box, my guess is they might be with $600-$700 shipped. They are rated at 3000W into 4/8 ohms bridged.

The CTS-2000s are 2000W into 4/8 ohms and most of those typically sold for $260 pre-pandemic by resellers.

The fans on the XLS amps hardly ever turn on and whey they do, they are fairly quiet. The CTS fans are audible and were slightly distracting at times when they were in the same room. The fans on the clone amp are jet engine loud. I bought the FP22000Q from a fellow AVS'er more out of curiosity than anything, since it was new in the box and listed for a good price. I could probably eliminate 3 of my other amps by using the clone, but for now each sub is being driven by one amp.

Musical instrument accessory Audio equipment Electrical wiring Gas Electronic instrument
 
#4,149 ·
DCI’s replaced CTS as crowns top-tier installation amps. 2012 I believe, oldest DCI i have is 2013 build. DCI are still the current production.

I also own several CTS, can’t beat em for the cost.

The 4/1250’s I mentioned are equivalent to two cts 3000’s in one 2ru case, so that helps the cost differential.

Chris
 
#4,153 ·
@Red Five

I have been playing around quite a bit with Hornresp as well as created my own metric version of your spreadsheet (with a slightly different design).

Is this a viable setup?

Rectangle Slope Plot Font Parallel


(ignore the size in the description, I forgot to update it)
Rectangle Font Screenshot Parallel Pattern


Font Rectangle Parallel Pattern Slope


A lowpass filter is required (not figure out how to do it in Hornresp yet, nor how to see the port velocities).
 
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#4,154 ·
@Red Five

I have been playing around quite a bit with Hornresp as well as created my own metric version of your spreadsheet (with a slightly different design).

Is this a viable setup?

View attachment 3243841

(ignore the size in the description, I forgot to update it)
View attachment 3243842

View attachment 3243843

A lowpass filter is required (not figure out how to do it in Hornresp yet, nor how to see the port velocities).
One big limiting factor is the compression ratio. The most I will push that is around 3.2:1. If you hover over the Sd of the sub, HR will tell you what the ratio is. I think you are running 5.7:1, that will probably tear up the cone at some point. Love the work you put in!

The DS' get peaky with how strong the motors are and how compliant the suspension is. This is what I was working off of for rough numbers.

Rectangle Font Material property Parallel Pattern
 
#4,169 ·
#4,172 ·
Nice you got a USP card. I think the manual said 26db for both switches. Resetting it requires holding the preset button in while the amp turns on. I think the light should blink when the card resets. Once that happens it should automatically get an IP address on your home router. Then you can program it with Harmon Audio Architect software.

Edit: gain knobs full open for the USP3 to work right.
 
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