Hey,
Planning on building the Paul Carmodys The Pit Vipers.
Built a couple of amps and pre-amps with a lot of help from this amazing forum.
Recently got a workshop in my possession so I think its time to make a couple of speakers now when I have the space.
The plan is to make something quite simple and I found the Pit Vipers which seem pretty straight forward.
I do have a few questions though. (probably stupid)
1. What is the best kind of material for this kind of speaker? MDF?
2. The plan that Paul Carmody doesnt specify the thickness of the material. Can I just assume the thicker is better? Thickness would change the volume but not to any large extent.
3. He is using a 6" PVC end cap on the midrange. Wouldn't be better to make a proper enclosure?
4. How much damping should be done? All sides, top/bottom?
Planning on building the Paul Carmodys The Pit Vipers.
Built a couple of amps and pre-amps with a lot of help from this amazing forum.
Recently got a workshop in my possession so I think its time to make a couple of speakers now when I have the space.
The plan is to make something quite simple and I found the Pit Vipers which seem pretty straight forward.
I do have a few questions though. (probably stupid)
1. What is the best kind of material for this kind of speaker? MDF?
2. The plan that Paul Carmody doesnt specify the thickness of the material. Can I just assume the thicker is better? Thickness would change the volume but not to any large extent.
3. He is using a 6" PVC end cap on the midrange. Wouldn't be better to make a proper enclosure?
4. How much damping should be done? All sides, top/bottom?
Torstensson,
Good questions 🙂. Some quick thoughts:
1. Material: MDF works, but nowadays many folks on the forum would prefer good quality plywood, as it is stiffer for the same thickness.
2. Material thickness: Thicker is not always better; rather, it is better to have a well braced cabinet. As Paul has mentioned, these are large cabinets, and without proper bracing they will resonate - which is not a good thing - so brace them well internally. if you are using good quality plywood, then 18-19 mm thickness material should be sufficient, and as mentioned before, use bracing throughout. It is also important to keep the width of the front baffle as close as possible to the original design. For the front baffle you can use 25 mm or 30 mm (glue together 18 mm + 12 mm material) to make it stronger.
3. Mid-range cabinet: By proper enclosure for the mid-range, do you mean one built with MDF or plywood? Such an enclosure would likely have thicker walls and take up more space inside of the cabinet - please keep that in mind.
4. Damping: Paul has some guidance on lining the inside of the back wall of the cabinet. In addition to that, maybe you can use 12-18 mm lining for the top and bottom too if you fancy. And if the bass feels a bit bloaty/congested, you can add some Dacron / hollow poly fill later.
Good questions 🙂. Some quick thoughts:
1. Material: MDF works, but nowadays many folks on the forum would prefer good quality plywood, as it is stiffer for the same thickness.
2. Material thickness: Thicker is not always better; rather, it is better to have a well braced cabinet. As Paul has mentioned, these are large cabinets, and without proper bracing they will resonate - which is not a good thing - so brace them well internally. if you are using good quality plywood, then 18-19 mm thickness material should be sufficient, and as mentioned before, use bracing throughout. It is also important to keep the width of the front baffle as close as possible to the original design. For the front baffle you can use 25 mm or 30 mm (glue together 18 mm + 12 mm material) to make it stronger.
3. Mid-range cabinet: By proper enclosure for the mid-range, do you mean one built with MDF or plywood? Such an enclosure would likely have thicker walls and take up more space inside of the cabinet - please keep that in mind.
4. Damping: Paul has some guidance on lining the inside of the back wall of the cabinet. In addition to that, maybe you can use 12-18 mm lining for the top and bottom too if you fancy. And if the bass feels a bit bloaty/congested, you can add some Dacron / hollow poly fill later.
+1. Not the "Birch Plywood" at Home Depot. A specialty lumberyard can help you with Furniture grade 11- or 13-ply Baltic Birch. And yes it matters. Not just for rigidity, but also for the cleanness of the cuts with a saw or router bit.
Thanks a lot! @zman01 @jayme
Cool, I was kind of looking into Plywood as well as I have been looking into horn designs as well (later project). Wasn't sure in this case.
Have found a place that sells high quality baltic plywood.
When reading up on damping, there were lots of comments on the importance of bracing, so will definately do my best here.
I have a festool tracksaw that should work good for the project. I don't have a router though, any suggestion for a good quality router?
I have looked into the crossover and I think I found a shop in Europe that have all the components.
If somebody has the time to take a quick look at the parts I found it would be lovely. Just wanna make sure I haven't done any major error on the parts.
Parts list / Link to part
Thanks
Cool, I was kind of looking into Plywood as well as I have been looking into horn designs as well (later project). Wasn't sure in this case.
Have found a place that sells high quality baltic plywood.
When reading up on damping, there were lots of comments on the importance of bracing, so will definately do my best here.
I have a festool tracksaw that should work good for the project. I don't have a router though, any suggestion for a good quality router?
I have looked into the crossover and I think I found a shop in Europe that have all the components.
If somebody has the time to take a quick look at the parts I found it would be lovely. Just wanna make sure I haven't done any major error on the parts.
Parts list / Link to part
Thanks
I‘ve shifted by method on cabinet material to a dual layer system. I build the initial box with standard 3/4 MDF and then laminate the entire box with 3mm HDF using outdoor carpet adhesive. The adhesive never hardens completely so it becomes a constraining layer and fully insulates the HDF surface from any vibration or resonance. The density of the HDF also produces excellent edges and surfaces which are perfect for veneer application. Constructing the main box is also easier and stronger as now I can use wood screws along with glue to build the box……the screw heads are all covered by the HDF layer.
If you take this route, make sure to flush mount your drivers and use a surface hole that is 1mm larger than the drivers mounting diamete. When installing the driver, use shims to fully center it this way the driver does not transfer energy to the HDF. Don’t worry about this with the tweeter though….it doesn’t matter with those high frequencies.
The PVC end cap is fine….no need to overthink things here
With the dual layer construction, I no longer have to ‘dampen’ the interior……a layer of 1/2” recycled denim insulation or similar is all that is needed.
Bosch power tools are readily available in Portugal at a competitive price….they make excellent routers.
Good luck with your build…..Paul has an uncanny nack for voicing a speaker as he spends a lot of time in the classic discipline of listening to his creations and tuning as needed. Generally speaking, musicians have a very well trained ear for this.
Torstensson,
Any particular reason you went for Mundorf coils? Here you go with links for Jantzen air core coils:
https://www.soundimports.eu/en/jantzen-audio-000-1239.html
https://www.soundimports.eu/en/jantzen-audio-000-1626.html
The 0.25mH coil you selected showing out of stock - here is another option:
https://www.soundimports.eu/en/jantzen-audio-000-1076.html
For the polypropylene caps, here are some less expensive options from Audyn:
https://www.soundimports.eu/en/audyn-q4-2-2-400.html
https://www.soundimports.eu/en/audyn-q4-6-80-400.html
Any particular reason you went for Mundorf coils? Here you go with links for Jantzen air core coils:
https://www.soundimports.eu/en/jantzen-audio-000-1239.html
https://www.soundimports.eu/en/jantzen-audio-000-1626.html
The 0.25mH coil you selected showing out of stock - here is another option:
https://www.soundimports.eu/en/jantzen-audio-000-1076.html
For the polypropylene caps, here are some less expensive options from Audyn:
https://www.soundimports.eu/en/audyn-q4-2-2-400.html
https://www.soundimports.eu/en/audyn-q4-6-80-400.html
Thank you, appriciate it!
No particular reason for the Mundorfs, read somewhere that they were good.
Will order everything this weekend.
Will try and remember to takes some pics and put them here for some feedback
No particular reason for the Mundorfs, read somewhere that they were good.
Will order everything this weekend.
Will try and remember to takes some pics and put them here for some feedback
Regarding routers - get one that has a 1/2" collet (takes bits with a 1/2" shank) which will also be packaged with a 1/4" collet. (Apologies, but I don't know if European routers list those in as metric). It also makes sense to get a plunge router, particularly for cutting holes for speakers. Also, I agree with previous comment and would recommend a Bosch. My local repair shop for tools has said that Bosch has been their most consistent supplier of service parts.
Sorry for my English, I wrote this text with a translator, unfortunately I don't speak English well. If it's wrong somewhere, that's why.
I plan to build a pair of Paul Carmody's The Pit Vipers speakers soon.
My question would be, if I were to install the midrange and tweeter pushed to the edge of the box (as for example with an ATC speaker), how much would that affect the sound and the sound stage? Also, if I put the reflex tubes on the back of the speaker? Is it possible that the sound quality deteriorates so much that it is not worth changing the original plans?
Thanks!
I plan to build a pair of Paul Carmody's The Pit Vipers speakers soon.
My question would be, if I were to install the midrange and tweeter pushed to the edge of the box (as for example with an ATC speaker), how much would that affect the sound and the sound stage? Also, if I put the reflex tubes on the back of the speaker? Is it possible that the sound quality deteriorates so much that it is not worth changing the original plans?
Thanks!
Another option for the box:
Buy good used speakers, add a new baffle (if necessary).
Add bracing, additional panel, etc- for your desired box volume.
Some examples:
Pioneer CSG7000
35.5"h x 15" w x 11 5/8 d
Kenwood Speakers
36" h x 15" w x 11" d
Infinity SM122 Tower speakers
35.5"h x 15" w x 13" d
=====
Radio Shack Realistic Nova 15, front baffle redo example-
(or biscuits, dowels, glue, etc).
http://woggmusic.com/supernova-minimus-speaker-build/
Buy good used speakers, add a new baffle (if necessary).
Add bracing, additional panel, etc- for your desired box volume.
Some examples:
Pioneer CSG7000
35.5"h x 15" w x 11 5/8 d
Kenwood Speakers
36" h x 15" w x 11" d
Infinity SM122 Tower speakers
35.5"h x 15" w x 13" d
=====
Radio Shack Realistic Nova 15, front baffle redo example-
(or biscuits, dowels, glue, etc).
http://woggmusic.com/supernova-minimus-speaker-build/
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Started the build of the Pit Vipers now. Still waiting for some things for the box but the crossovers are done.
Is there a good way test these? Besides connecting the drivers and see if everything works.
Is there a good way test these? Besides connecting the drivers and see if everything works.
I used .75 inch (3/4) MDF when constructing my pair. I also opted to utilize a double baffle for the drivers to mount on.
Paul's solution here is pretty straight forward and makes it even easier for a "new comer" to build the design. It also works exceptionally well. 🙂 I opted to make "support" rings out of MDF that the PVC end cap can slide into. I used E6000 adhesive to secure it. This allows more surface area when mounting to the rear of the front baffle. I used screws and glue to secure it baffle. As another measure, I covered the outer PVC end cap with "sound deadening" further reducing unwanted resonances. To answer your question though, you definitely could make your own enclosure for the MID chamber as others have done however, Paul's solution works just as well imo while being easier.
I used 2 window braces and lined the inner walls with convulted foam for the woofer section. The mid chamber I used a large handful of Polyfill.
These really are excellent DIY speakers anybody with a little ambition can build and enjoy. They're a blast to listen to and like to be played loud.
I hope this helps 🙂
I'm waiting for Mr Carmody to build something really large with minimum WAF.
The Pit Vipers are just a bit small for my own sense of the absurd.
The Pit Vipers are just a bit small for my own sense of the absurd.
Head on over to Paul's official forum post on parts express where I went in detail of the complete construction. I have the same user name.
https://techtalk.parts-express.com/...47-introducing-the-pit-vipers-ooh-yeah/page19
Moondog55,
I've been waiting for this myself! I have build quite a few of Paul's designs now and I love them. I was curious about scaling up the pitvipers to utilize double the subwoofers in each cabinet and an additional mid in MTM format.
My soon to be wife supports my fascination with speakers and encourages it so the bigger the better in my eyes 🙂 Paul always strikes an excellence balance of price to performance in most of his designs. I'd love to see what he could come up with in a Flagship tower design similar to the big names at HIFI shows.
Maybe one day if enough people are interested in it, he'll entertain the idea?
I've been waiting for this myself! I have build quite a few of Paul's designs now and I love them. I was curious about scaling up the pitvipers to utilize double the subwoofers in each cabinet and an additional mid in MTM format.
My soon to be wife supports my fascination with speakers and encourages it so the bigger the better in my eyes 🙂 Paul always strikes an excellence balance of price to performance in most of his designs. I'd love to see what he could come up with in a Flagship tower design similar to the big names at HIFI shows.
Maybe one day if enough people are interested in it, he'll entertain the idea?
I just emailed Paul and made an offer on monetary assistance to make something insanely large. Big woofers being the largest expense.
Maybe if a few of us sent him a few PE gift cards he'd accept the challenge?
I've never made any of his designs but I do use his pages for inspiration, many times in fact.
Maybe if a few of us sent him a few PE gift cards he'd accept the challenge?
I've never made any of his designs but I do use his pages for inspiration, many times in fact.
I made Pit vipers, really disappointed in them as they don't measure like Paul's sim. There's a large valley in the mid bass nearing 10db that his sim doesn't show. The lower mids sound quite sucked out and sound much better if brought back up with EQ. You can adjust a few xover component values to bring them back as well, but as it stands the speaker does not measure like his sim.
I ended up just gutting the passive xover entirely and running the speakers active. I also swapped the Peerless tweeter for an ND25FW which delivered much better results. I'm really not sure why he chose the D27, perhaps he already had some lying around. A waveguided tweeter is a much better option as it will hide the dome from the baffle to a degree. The porting in his design is also poor, one is much better off using a larger port and rear mounting it. This improves air turbulence quite a bit and helps keep the cabinets height related resonances from bleeding in the port and coming out of the front.
What I find most concerning is Paul has chosen to ignore my requests for an explanation on the differences between his sim and the speakers actual performance. This isn't the first time his designs have shown real world performance that differs significantly from his sims. The overnight sensation was measured on klippel and the differences were quite large, and Paul's response was quite disappointing. PE continues to sell the OS with a false response graph which I find to be just straight up false advertising.
TBH, designing your own speaker is really not that hard and my experience with Paul C's speaker sim discrepencies was actually a strong motivation for me to do my own designs. I've got a better Amiga crossover in the works that measures much better and so far, sounds much better as well. Hopefully I will finalize it soon and share that with the community. Paul is a hobbyist like many of us, so it's hard to be put too much pressure on his work, but this day and age I just find issues like the Pit Viper and OS response differences to be unacceptable.
I ended up just gutting the passive xover entirely and running the speakers active. I also swapped the Peerless tweeter for an ND25FW which delivered much better results. I'm really not sure why he chose the D27, perhaps he already had some lying around. A waveguided tweeter is a much better option as it will hide the dome from the baffle to a degree. The porting in his design is also poor, one is much better off using a larger port and rear mounting it. This improves air turbulence quite a bit and helps keep the cabinets height related resonances from bleeding in the port and coming out of the front.
What I find most concerning is Paul has chosen to ignore my requests for an explanation on the differences between his sim and the speakers actual performance. This isn't the first time his designs have shown real world performance that differs significantly from his sims. The overnight sensation was measured on klippel and the differences were quite large, and Paul's response was quite disappointing. PE continues to sell the OS with a false response graph which I find to be just straight up false advertising.
TBH, designing your own speaker is really not that hard and my experience with Paul C's speaker sim discrepencies was actually a strong motivation for me to do my own designs. I've got a better Amiga crossover in the works that measures much better and so far, sounds much better as well. Hopefully I will finalize it soon and share that with the community. Paul is a hobbyist like many of us, so it's hard to be put too much pressure on his work, but this day and age I just find issues like the Pit Viper and OS response differences to be unacceptable.