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.