So I’ve done the fosi amp, 5.25” kickers and JBL sub on my GZ. Here’s my take. My guess is this setup sounds much like a pin woofer, probably better given the higher quality speakers. I’ve never owned pin woofer so take my statement for what it’s worth.

Yes my sound quality is a bit better than stick and I can feel the bass in my fingers while I play. I like that. It’s like a shaker on steroids. It’s also nice not to have a large Polk sub under the game. But the biggest drawback is you can only make it thump so much before you start getting rattles from the machine. More than just the glass, which is easily fixed with tape. This makes me nervous as I’d hate to create a cracked solder or mess up a node board. Maybe I’m overreacting.

If I had to do over I would continue with just adding the external sub. Crank it as loud as you want and zero rattles.

Maybe my equalizer settings are off with my current setup. I duplicated what I saw earlier in the thread and I don’t know enough about these settings to play around to optimize the sound. I’m running 8ohms everywhere and zero fade

Here what I went with;
Dayton DTA-2.1BT2
https://www.parts-express.com/Dayton-Audio-DTA-2.1BT2-100W-2.1-Class-D-Bluetooth-Amplifier-with-Sub-Frequency-Adjustment-300-3831

JBL STAGE 810 (2 pack)
Pair of JBL Stage 810 8" Car Audio Subwoofer Bundle https://a.co/d/6sHfGut

Already had backbox speakers installed, Rockford Fosgate R1525x2
Rockford Fosgate R1525X2 Prime... https://www.amazon.com/dp/B00BF6HX9E

BESIGN Ground Loop Noise Isolator... https://www.amazon.com/dp/B06XQYN77L

Grasshopper didn't mean to venture out in the wild without the Master.
I've been at it all week, so I'm going to do family thing this weekend and start back up on Monday.

PS. I have my Amplifier plugged into backbox service receptacle. I noticed that when I turned pinball machine off it switched from line input to Bluetooth. I did like that. Later

So the two sets of kickers I bought on ebay... those never shipped. I paid immediately on winning. Got a message saying they would ship the next morning, then nothing for over a week. Messaged twice asking for tracking. Then I got refunded out of the blue. The 8inch speaker I grabbed from amazon did show up. I will have to scrounge up another pair of 5.25 for deadpool.

I ended up going with a Lepai 168HA in my System 1 build because it's the only 2.1 channel amp I've found that doesn't have bluetooth. The last thing I need is some kid pairing his phone to my game at a show and playing something inappropriate. I'm sure it could be disabled by lifting a pin or cutting a trace between the BT chip and amplifier but I haven't looked into it yet.

Anyway, this review on Parts Express is super interesting but haven't found a complete writeup elsewhere on the web. The sub output is clipping hard almost immediately... how did Spooky ever manage to use this amp in TNA? Going to try the subwoofer distortion fix and see what I can figure out.

Reasonalbe low power stereo amp. Forget the subwoofer ouput.
WARNING – The outputs are all BTL (Bridged Transformer Less). This means that no outputs of the left, right, and subwoofer channels are common and MUST NOT BE EXTERNALLY CONNECTED TO EACH OTHER. Doing so will cause excess heating and distortion and may destroy the amplifier.

My intended use of this amplifier is for my bedroom TV. The TV has no external speaker connectors but it does have volume controlled line level outputs and the ability to turn off the internal speakers. This amplifier provides me with what I need. That is: clean power (less than 0.2% up to clipping), good frequency response, and 5 or so watts to drive the speakers. The sub woofer output will not be used.

Recently I have purchased a total of four of the amplifiers. I put the them all on the bench and ran power and distortion tests before use. I found that performance for all four to be almost identical and a long way from the specs.

STEREO AMPLIFIER PERFORMANCE:
Power Output – I measured single channel power output at 1KHz just below clipping and found that power output was 5.1 watts at 8 ohms, 7 watts at 4 ohms, and 5.2watts at 2 ohms. Power stayed within a few percent over the range of 20Hz to 20KHz.

Distortion – I checked distortion at just below clipping at 8 ohms. Distortion was 0.12% at 1KHz, 0.095% at 100Hz, and 0.25% at 20Hz. I did not check higher frequency distortion. Output power and distortion did not change significantly when both channels were driven.

Frequency Response and Sensitivity – With the tone controls adjusted for maximum flatness the outputs were 3dB down at 20Hz and 55KHz. With the volume control set to max (CW), 226mV was required at 1KHz to produce levels just below clipping.

SUBWOOFER AMPLIFIER PERFORMANCE:
Power Output – I measured the subwoofer power output at just below clipping at 20Hz, 50Hz and 200Hz. I measured 5.12 watts at 8 ohms, 6.76 watts at 4 ohms. At 2 ohms I measured 8.82 watts at 50 and 200Hz and 5.6 watts at 20Hz.

Distortion – I measured distortion at just below clipping from 20Hz to 200Hz. At 8 ohms, distortion was between 5.2% and 5.8%. At 4 ohms, distortion was between 10% and 11% over that frequency range. At 2 ohms, distortion was 21% at 50 and 200Hz and at 20Hz, output level was lower and distortion was 17%. I reduced the level to 1 watt into 8 ohms at 50Hz and still measured 5% distortion.

Input Sensitivity – With the SUB VOLUME set to max (CW), 15.6mV is required to produce levels just below clipping. This means that the subwoofer channel has 14.5X (23dB) more gain than the stereo channels. Sub-volume is not adjusted by the main volume control. Matching the two levels requires that the sub volume need only be turned a few degrees clockwise.

Frequency response – Maximum output was at 24Hz and relative to this frequency was 3dB down at 9Hz and 61Hz and down 17dB at 200Hz. Independent of the X-OVER control’s setting, the relative frequency response of the subwoofer channel did not change. Changing the X-OVER control from 40Hz to 200Hz instead resulted in an overall subwoofer output drop of 3dB.

Other – The subwoofer output is almost 180° out of phase with the stereo outputs. This is easily fixed by reversing the subwoofer leads.

OTHER ISSUES:
The LEDS are too bright.
The speaker connectors are poor. One broke and others are about to.
The Audio Input RCA jacks and AUX mini jack are directly paralleled.

CONCLUSIONS:
The power output specs for this amplifier are misleading. A total of 148 watts output are specified (40+40+68) while the power supply is rated at 12 volts at 3amps (36 watts).

HOW TO VOID THE WARRANTY – I searched for a schematic for this device and could not find one. I therefore captured it manually. The schematic allowed me to come up with mods to the circuitry to make it perform to spec.

1. Subwoofer distortion was mainly caused by inadequate power ground to the subwoofer output IC. After beefing this up, distortion is below 0.1% in the subwoofer channel.

2. Correcting the subwoofer frequency response required removing some capacitors and changing the values of others.

3. Tying the subwoofer level to the main volume level required changing resistor values and connection points at the volume control. This also made the subwoofer level control more friendly with levels matched at about mid-range.

4. I changed the series resistor for the blue LED to From 220 ohm to 10K.

5. I changed the series resistor for the red LED from 2.2K to 47K.

6. On one amplifier, I replaced the speaker connectors with 5-way binding posts.

FINALLY:
I hope others find this informative. Ignore the manufacturer’s specifications. If you need a low power, low distortion stereo amplifier, this is a reasonable choice. It has a nice look to it, but forget about the subwoofer output. Unless you have the knowledge to overhaul it, the subwoofer is useless. Also be aware that the speaker connectors are somewhat fragile.

Great run down. For TNA, the sub enclsore goes a long way to get the most sound out of that amp. It sounds good up to a point then it completely falls on its face and then full on clipping. The lowlights you list are exactly why I looked for an alternative . For about $25 more you can end up with the same car stereo solution that I settled on and have all the clean, distortion free power your ears can handle. On top of that you get much better noise rejection and crossover control. The 4ch amp I chose is flexible enough to allow either low-level (spike1/2) or speaker level (SAM, etc) inputs. I have this setup on 4 games so far and plan on at least 3 more. It would be interesting for you to try it out and give a back to back comparison.

https://pinside.com/pinball/forum/topic/improving-sound-quality-the-diy-route/page/8#post-6827701
https://pinside.com/pinball/forum/topic/improving-sound-quality-the-diy-route/page/10#post-6858259
https://pinside.com/pinball/forum/topic/improving-sound-quality-the-diy-route/page/11#post-6863467

That's interesting how you're using a 4 channel amp in 2 channel mode, correct? Does that put the subwoofer on only 1 channel or does it mix L+R?

No, I have it in 4 channel mode with the sub bridged on channels 3&4. Channels 1 and 2 are Left and Right back box speakers. I also have the RCA input to the amp split out and that goes to a powered sub to fill out the very bottom end.

How do you get to this screen? I can't seem to find it

I’m very happy to report back that my sound issues have been resolved by bypassing the Spike 2 amp chipset by using the Pinsound line out adapter.

I’ve installed the following in my Iron Maiden;
* Pinside line out adapter
* Ground loop isolater
* Lepai's LP-168AH 2.1 amplifier with 12V 5A adapter
* Kickers CSC5 as backbox speakers
* JBL Stage 810 as cabinet woofer
* KEF Kube 2 external sub

The sound is just incredible!! Many thanks for starting this forum topic, helped me a lot.

The only “problem” I have now is that I do hear some 50 hz noise coming from the power source. Any tips on buying a more silent power source for my amp?

Thanks in advance.

Did the LP-168HA ground mod... sub amp is a TDA7297. Didn't do an A/B test but it seems better?

"Upgraded" a System 11 game with speakers I had on hand.
Backbox: 2 x 6.5" full range speakers, 4 ohm. Wired in series. Didn't enlarge the tweeter speaker hole, just centered the new speaker over it.
Cabinet: 6.5" midbass woofer, 4ohm. Added a speaker crossover, as System 11 sends full range audio to the cabinet.

I added the 5.25 Kickers and the 810 JBL into a Jurassic Park with the movie code. Also, the pinnovators adapter out to an external sub.

I used the EQ settings shared by Dave in post #62 (https://pinside.com/pinball/forum/topic/improving-sound-quality-the-diy-route/page/2#post-6716867); 8 Ohm for both; Fade is at +5.

Problem is, the higher frequencies sound a bit strained/distorted or tinny at higher volumes, especially voice clips from the movie. I noticed this on Godzilla as well. I've played around with the EQ myself but really don't know what I'm doing and the system doesn't make it easy to test vocal frequencies within the UI, just that default soundtrack.

Can anyone advise how they've tweaked their EQ with a similar speaker setup on either JP or Godzilla? (if different from post #62) Am I the only one experiencing this? (Would also love any tips/sites/tools on how to learn about audio tweaking myself)

Side note: On Deadpool those post#62 settings sounded pretty good and I didn't change them.

Thanks!

I put a Pinwoofer kit in my Deadpool and am very satisfied with the results. Dan at pinwoofer answered my phone calls and helped me with very easy questions during installation. Things most dedicated pinballers would already know but I did not. Installation was not too hard and the results are amazing.

Wrong thread bro

Wrong Thread, this is DIY

If you want Phenomenal instead of amazing start at post #1 and read.

I saw you had done the rockford fosgate speakers (even saw your review on amazon ). Have you used any other speakers and if so, how would you compare them?

I would reduce the higher frequency EQ settings and also try increasing the Speech Attenuation if needed to fine tune to your liking.

Hope you seen my lame video too. Haha. Those Rockford Fosgate speaker have been in Aerosmth over a year now. I just recently installed subwoofer and amplifier.

Right now Aerosmith is the only game that I've had time to install Speaker, Amplifier, Subwoofer and box with port around sub. I've only played five game at the most. I don't think I have my settings correct as of now. So I can't give a deep review. I have more of all the above to do two more pins but with different speaker. I just haven't had the time.

But as far as putting box around subwoofer with port hole in bottom of cabinet and screwing it down. I'm sure I'll do it to all other pins from here on out. After I hear and feel the difference. I have no tape or anything around the glass and don't hear the rattle when the game get intense. I still have more to test when I get time.

Bought the jbl 810 but as you mentioned the bolts aren't long enough to hold it down, how do I replace the bolts in the cabinet? Is this easy to do? Any directions on this. Thanks

Get 1” #8 wood screws with washers, tap out the old screws. I put notes for myself here:

https://docs.google.com/spreadsheets/d/1hlTFVBtST1GRSl0kq-jK-J8W1xGTeZku11CP5Em-AFA/edit

Has anyone tweaked EQ settings and care to share what they've landed on for the 4" or 5.25" Kickers + replacement cabinet speaker (either 810 or Skar or anything)?

There have been a couple of people who have posted their EQ settings in the thread and one is even a key post stickied on the first page of this thread.

https://pinside.com/pinball/forum/topic/improving-sound-quality-the-diy-route/page/15#post-6942232

Thanks, yes that is the one I've been trying, but to me it often sounds worse than the stock setup, which makes me wonder if anyone else did further tweaking to those beyond the settings in post #62. (Or if others have even experienced what I'm talking about.. I'm assuming several folks in here all now have a similar setup thanks to dave's extensive research sharing)

I just put the 5.25" kicker, and a JBL 810 in my new GZ Pro, and one thing I did to adjust the EQ is to separate the backbox speakers from the cabinet speaker while adjusting the EQ by using the fader.

Set the fader full backbox to isolate them. Then adjust them using the EQ to your liking. I adjusted these to get clear, crisp mids and highs without distortion. These don't really offer anything down low, but on they're own they can sound pretty good.

Repeat for the cabinet speaker. This speaker I'm really just using for the bass to compliment the backbox speakers so anything above 500htz I'm turning way down on the EQ.

With this method after all the EQ settings are where it sounds good at any volume I can easily adjust how much bass and rumble I want by simply adjusting the fader. Want things to shake like a shaker motor? Fade higher to the cabinet, and turn it up!

Even at lower/normal volumes there's still a little rumble you can feel.

-Paul

Thanks so much, Paul, will give it a shot.

I like the Skar with the kickers better than the JBL. I bought both the skar and the JBL and returned the JBL. I think the skar filled out the mid range better. I think the only thing I changed was to make the cabinet and backbox 8 ohm and faded a little more to the cabinet.

Can anyone confirm if my sub on my Godzilla was hooked up correctly or not. I figured that the yellow black wire would go to the negative side of the speaker.

I got a new JBL and hooked it up the same way but just wanted to be sure.

Thanks

7524DD85-59A7-4046-A9F5-BCC2C550BA25 (resized).jpeg

I would be surprised if it had not been connected correctly originally.

However, if you want to check, it's simple enough: just look at the wiring at the CPU board. The connector labeled "CN4", found in the lower left of the board, is where the wires connect, and the board is labeled with + and - so you can see which wire goes to which terminal.

Thanks yeah looks like the yellow black wire is on the negative pin.

I’m gunna switch them around on the sub and see how that sounds.
41D601E7-89BF-4DA5-A745-AAC4CCA6AA16 (resized).jpeg

Thanks for the detailed breakdown, I ended up switching them anyway. I didn’t think anything bad was going to happen I just wanted to make sure I was getting the best sound I could.

Finding the recommended parts is proving complicated in France, at least for the sub.

I did find easily the Kicker CSC4 or CSC5, but JBL Stage 810 is not available except at Conrad (which is OK I guess but would not have been my go to choice for speakers). It might good if others could share their experience with alternative sub speakers that can be more easily sourced worldwide.

Also, has anyone tested the JBL Club 4020 and compared them to the Kicker or Alpine ? I've read the thread about Kicker vs JBL, but I'm not familiar enough with JBL linup to determine if the Club 4020 are the same category than the tested speakers.

Why these Club 4020 ? Because well... They look gorgeous Would fit very nicely using a round opening instead of the current grill opening

I thought I would mention, in case anyone's interested: the well-regarded Klipsch 12" subwoofer Costco sells is currently on sale for online orders, $80 discount from their usual $280 price.

I realize this isn't as great a deal as it has been in past years. I guess inflation is real? Imagine that! But it's still cheaper than other discounters I've seen for the sub.

I've been following this thread closely, reading all the guides, and when the parts come am planning to DIY a sound upgrade for my Rush pin. I'll post notes later once I've gotten it done. My goal is to do it as 100% DIY as I can; just speakers and standard cabling, making everything else myself. Nothing against the pin-specific companies making a dollar off upgrades; they provide a useful service. I just like the idea of doing as much as I can on my own.

Yup. Being able to read through the info here has made all the difference in my confidence in being able to do the upgrades myself. I really appreciate your efforts and that of others here in the thread to share all that info.

The speaker comparison was also really useful. I wound up going with the Alpine, in spite of the "rock-friendly" review for the Kickers, because my experience has been that I prefer the clarity and uniformity of a good reference speaker, over one that colors the sounds significantly.

I have been considering making ready to install wiring harness's for those wanting to upgrade their pins with components of their choosing. It could be a way of funding more product purchases for testing, reviews, and writeups etc. (I was spending a bit too much on products i was never going to use, and my Amazon returns were getting out of hand.. )

Honestly, that would be a big help. One of the things I'm DIY'ing is the connector for the CN5 line outs. I decided against the Pinsound part, only because it appears to use phono instead of RCA jacks, which isn't standard for any components I'd want to connect there, so I'd just have to be buying extra cabling to convert anyway.

But it turns out that female RCA jacks aren't easy to find as individual components either, nor are they all that inexpensive. I found some that looked like they'd work, but IIRC they were around $5-6 each $3 total. I wound up instead buying a cheap A/V cable, i.e. it has three RCA jacks on it going to a phono plug. I'll just cut off the plug and then wire the bare ends to the molex connector. The whole A/V cable was only about $6, so it made no sense for me to try to buy each of the three jacks individually and then assemble a cable myself.

But if someone were selling that whole assembly, molex to RCA jacks, for $15-20 with reasonable shipping, I probably would've just bought that on its own.

EDIT: Just double-checked my invoice, the $6 part was the three-connector all-in-one A/V cable I considered getting, but in the end I wound up getting one phono-to-single-RCA cable and one three-connector-phono-to-two-RCA cable, at a cost of $1.50 each.

Forgot to mention indeed that I do have an adapter ring I designed (3D printing) for these Club 4020. I just wonder for my newly arrived GZ if I should go to the Kicker or Alpine. Guess I'll try the Kicker, they are easily available (but they don't look as nice ). I do have also a few amps to test with (both with and without DSP)

I have this older Block Rocker we keep in storage when not in use, It would be great to store it under my Metallica and use it all the time. What do I need to get to connect it to the pinball machine?

20221024_115233 (resized).jpg

What a great thread, so much good information, but a little bit hard to keep track. I find myself looking back and forth to find information i remember and want to read again

I accidentially found that important post
https://pinside.com/pinball/forum/topic/improving-sound-quality-the-diy-route/page/9#post-6844596

You should edid your first post in the thread instead of somewhere in the middle.

I liked the information on making the CN5 adapter and all the references to great posts in rush or maiden threads.

I think i understand but can you confirm that the R and L out from the pinsound adapter are the signals that would go to the backbox speakers via a dedicated amp

The sub output is the mono signal that goes to the sub via another dedicated amp

Both signals are affected by the software 10way equalizer settings

So you mentioned somewhere that you use only the R + L output to drive backbox And cabinet speaker via one 2.1 amplifier. How would you account for the equalizer settings of the EQ then?

Or does the use of an external amplifier make the internal EQ obsolete?

Well, this thread has thrown me in a quandary. I do like sound and would normal put effort into something decent but I was previously thinking along the lines of a drop in solution "for not much money" as its not what I listen to music on.

Then I see these ideas of adding a BT amp and using it to stream music etc....
I also like the idea of 5.25" speakers but notice that there is more faffing about to get them mounted. Argggghhh! decisions decisions....

I do like the look of the adapters that davegauth made. Don't suppose they are available?? I have a friend with a printer.
I am leaning towards the alpine s-s but even the 4" would need a spacer so may as well make a 5.25" set fit.

FWIW, I have been working on a 3D-printed replacement for the mounting plate to support switching from the 4" speakers to 5.25". This is part of a larger upgrade project, which I'll eventually be sharing all the info I have, including STL for the new plate. But I'm happy to post the design somewhere for now if you want to try it out.

The plate is custom for the Alpine S-S50; I don't know enough about speakers to know if the mating surfaces would be compatible with other speaker designs, but since those are the speakers you're looking to get, that wouldn't matter anyway.

The Alpine speakers are not flush-mount -- the tweeter protudes a bit ahead of the woofer's cone, and the mounting tabs are behind the speaker assembly anyway -- so the plate has mounting bosses set back a bit to keep the tweeter clear of the surface of the plate (*). Also, the speaker has a sort of gasket around the perimeter, which I presume is to allow for the front and back of the speaker to be isolated (e.g. when mounted in a closed cavity), and the plate I designed includes a ring to match up with this gasket and preserve this isolation (though not sure just how important that would be in a pinball machine).

(*) Technically, I probably could've positioned the speaker more forward, allowing the tweeter to extend into the 1.4 mm thick space of the opening for the speaker, since the plate doesn't have the same grid across the front that the 4" plate does. But I wanted to be able to revisit the design later and add a grid (or something fun like the Rush starman logo), and so I kept the tweeter clear of the backplane of the mounting plate, even though there's not actually any material there that the tweeter would contact, just in case.

That said, I will say that the 3D-printed plate is not a painless approach. I will be using it, and I'm very happy with the way it turned out. But because of the geometry of everything, an all-in-one design obstructs access to the screws on the side that attach the plate to the metal frame of the pin's LCD display. To accommodate that, I had to switch to hex-drive screws (OEM are regular cross-point/Philips), and include a through-hole in the plate's structure so that I can put a hex key wrench through the hole to turn the screw. (I was hoping to find hex-head machine screws, so I could use a small wrench from the side to turn the screw, but for some reason while hex-head screws are available in both larger and smaller sizes, the 5-44 thread size the pin uses there isn't stocked by any of the stores I tried.)

I considered making an alternative design that was printed in two parts, where the base part could be installed with speaker mounting posts already attached, and then once that's all screwed to the machine, the second part along with the speaker could be assembled to the plate. But I couldn't see a way to make the design structurally sound enough while still providing the necessary clearance to access the side screws and at the same time keep the flush-front design (i.e. not have bolt heads protruding out the front of the plate). Everything just would've been too thin. So for now I've abandoned that idea.

I guess one could just not bother attaching those screws. But a) I feel like I ought to try to stick as closely as possible to the original OEM design as I can, and b) one of those four screws bonds the power supply's ground cable to the frame of the LCD display, and in my experience making sure grounds designed into an electronic component are preserved is important.

Your other options are the 3D-printed adapter to use the existing 4-inch plate (which it seems you've looked at already), or to buy the third-party 5.25" plates.

As far as the 4-to-5.25 adapter goes, the main issue as I understand it with that, is that it may reduce the clearance behind the speaker, which in conjunction with speaker light kits could be an issue with space between the rear of the right speaker and the power supply in the backbox. For me though (since I'm not planning to get any light kit), my main concern was that it seemed silly to mount a 5.25" speaker behind a 4" hole. I guess it would probably work okay, but it also seems intuitive to me that using a proper full-size hole for the speaker would be better.

As far as I know, Stern does not sell the 5.25" plates directly. However, I know of at least two places you can buy these from third-party sellers: https://www.pinballlife.com/stern-spike-2-speaker-plate-for-525-drivers.html and http://www.speakerlightkits.com/5.25-SPIKE-2-Speaker-Plates.html. About $50 for a pair from either source. These plates still have a slight geometry problem with respect to the speaker mounting posts being in the way of the side screws, but given that they are effectively identical to the 5.25" plate that Stern installs, I assume one can still get a screwdriver in, possibly at a slight angle, and get enough purchase on each screw head to secure it. For the Alpine speakers, you'd still need to get or print some kind of spacer or gasket to deal with the fact that they are not flush-mount speakers, but the overall installation would be closer to original factory design at least.

EDIT: in Europe, looks like pu-parts.com is a source for the 5.25" metal mounting plate: https://pu-parts.com/spike-2-speaker-plate

EDIT: Important, note that the screw size I state above is in correct. I apparently mis-measured the screw. I got what I thought was the right size today, the #5-44 screws, but it turns out that's wrong. The correct size is actually #4-48. Sigh. "Measure twice, buy once." Or something like that.

If one has access to a 3D printer, there are ready-made Stern mounting plates for 5.25" speakers on Thingiverse. I printed some for my GZ a few weeks ago. Works great.

Got a link? I looked but all I found were a couple of 4-to-5.25 adapters (not what I wanted), and this half-hearted attempt: https://www.thingiverse.com/thing:5208804

That one is missing side screw holes, as well as mounting holes, and from the description it sounds like the way they used it, the mounting bolt heads protrude out the front of the plate, which is "sub-optimal" to say the least.

Where's the one you used that works great?

Pablito350 I'm considering a similar change for my Godzilla. Couple of questions for you and others:
- Are you happy with the setup now that you've had it for a couple weeks? How does it compare to stock?
- How did you end up mounting the backbox speakers? Did you use an adapter or replace the speaker panel?
- To mount the JBL 810 sub in the cabinet, did you just get longer screws or did you need to do anything else?

Thanks!

That's the one - I also drilled the holes myself. I actually forked this design to add them, but the amount of time it was taking to measure and design wasn't worth it, vs. marking and drilling in 10 seconds. I had 2 different speakers I was considering (one set has tweeters across the cone and I wasn't sure if there was enough clearance so I had a backup), and it turned out they had slightly different placement for where the screws needed to be, so that ended up being a good thing.

The way it is described on the site to attach the speakers is to thread bolts through from the front (the grille and foam cover them up) and just use a nylon nut on the other side. That worked fine. I ultimately made standoffs for a future LED enhancement, and decided to melt the plastic and embed hex head bolts directly in the plastic, so they wouldn't move. So not plug and play, but it MAYBE took me 30 minutes tops.

Got it. Thanks. Glad that design worked for you. Definitely wasn't an option for me.

I used PU-parts metal speaker panel with a small 3d printed adapter for jbl club 4020, it looks very nice.

Also replaced the sub with a Pyle PLPW8D. It's a dual coil sub, which I wired in series to get 8 ohm. I used this one because it was easily available.

Out of the box, there is a far more distinct rumble in the cabinet. Now need to adjust the equalizer to get better quality out of the backbox speakers

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