Hello everyone! Longtime lurker first time poster. I have decided to start my second project.
The Paul Carmody Carreras! But after doing a bunch of research the last 6 months and looking at different projects (Mostly Troels) I have gathered some questions.
Thanks for a great forum and community!
The Paul Carmody Carreras! But after doing a bunch of research the last 6 months and looking at different projects (Mostly Troels) I have gathered some questions.
- Brackets
In some other large bookshelfs brackets is being used to increase rigidness, there is no mention of this in the carreras, should i add them?
- Capacitors
So some spend a whole bunch of money on pretty cylinders, is it worth it? I hear that you should have higher quality caps closer to the tweeter. My plan is to use Jantzen Cross or Standard for the majority and Superior where it is needed.
- Low-diffraction baffle
I realize that baffle and crossover goes hand in hand so I should not mess with it to much but would a low-diffraction baffle be better on the Carrera?
Thanks for a great forum and community!
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This kind of leads into answering your second question. The most important part of a crossover is integration. Sometimes the acoustic design is the primary limitation on success. You ask about capacitors, they can make a difference but if it isn't right on paper then it doesn't matter much what you do. Quality is worthwhile but don't expect miracles.
Porsche uses large rounds.... you could build a double thick front baffle and route 0.5" to 1" quarter rounds on the front baffle edges to smooth the SPL output. The rear baffle must be beveled cut behind the speaker to allow free air flow. Chamfer bass driver holes 45 deg. down to some 5 mm from edge of rebate.
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You mean internal braces? It's not a large box, but providing you don't go OTT, probably worth having at least one.
Here is a fact for you to consider: to the best of my knowledge, nobody has ever been able to consistently identify any difference between film (or film & foil) capacitors in a properly conducted blind listening test, once a reasonable quality level is achieved e.g. something like a Solen, Jantzen CrossCap / Standard Z etc.
If you're going to spend money on fancy caps, the tweeter circuit is probably the place to do it. Since the values aren't particularly large, if you've got the money to spend, I'd go ahead if it will give you peace of mind.
Leaving aside the idea whether something would be better if it was something different (my Vauxhall for example might be better if it was a Bentley), if you make any significant changes to the baffle shape / dimensions & the driver positions on them, you will change the frequency response and the crossover may require redesigning.
I've gotta agree with Scottmouse (sic) on capacitors. Any 400V MKP, like Solen, is quite competent.
No doubt aircoil inductors must work better than proveably non-linear ferrites. Resistors? Well a speaker voicecoil is just purish copper like any competent resistor. Matters of Constantan alloy aside, if they are sufficiently rated not to get hot, they do the job.
Rigid and heavy cabinets with braces is a bit of a can of worms IMO. Sturdy is good, but rigid and light but damped cabinets a la BBC LS3/5A work well too. With such a small box, it is hard to mess up.
Anyhoo, I think I prefer Paul Carmody's implementation over Troels here.
Carrera - undefinition
Ellam-XT
But not much in it, TBH. Some interesting variations by constructors in the Troels version.
No doubt aircoil inductors must work better than proveably non-linear ferrites. Resistors? Well a speaker voicecoil is just purish copper like any competent resistor. Matters of Constantan alloy aside, if they are sufficiently rated not to get hot, they do the job.
Rigid and heavy cabinets with braces is a bit of a can of worms IMO. Sturdy is good, but rigid and light but damped cabinets a la BBC LS3/5A work well too. With such a small box, it is hard to mess up.
Anyhoo, I think I prefer Paul Carmody's implementation over Troels here.
Carrera - undefinition
Ellam-XT
But not much in it, TBH. Some interesting variations by constructors in the Troels version.
I would agree regarding the advantages of air cores, assuming of course that there is physically sufficient space, as they are considerably larger than ferrites of equivalent or lower DCR, and the magnetic fields can become more problematic. Given the option, I'd always prefer them, though it's not always practical. Cored are usually OK for LF duties though, providing you don't push them into saturation.
I'm afraid, since I'm not the brightest, you'll need to explain that one Steve. The Latin adverb 'Sic [ erat scriptum ]' is typically employed within square brackets rather than curved, and used to indicate a misspelling in a piece of quoted text. That does not seem to be the case here since you were not making a quotation; however, by writing it you indicate you were aware you had misspelled my forum moniker. Notwithstanding the incorrect usage, if you had time to write that you self-evidently had time to spell it correctly (or even to use my name), so you presumably had some other purpose behind doing so which I have missed.
I'm afraid, since I'm not the brightest, you'll need to explain that one Steve. The Latin adverb 'Sic [ erat scriptum ]' is typically employed within square brackets rather than curved, and used to indicate a misspelling in a piece of quoted text. That does not seem to be the case here since you were not making a quotation; however, by writing it you indicate you were aware you had misspelled my forum moniker. Notwithstanding the incorrect usage, if you had time to write that you self-evidently had time to spell it correctly (or even to use my name), so you presumably had some other purpose behind doing so which I have missed.
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OP-
If you want to use more expensive parts than the normal, I recommend the Superiors of your listed types (I like the Silvers more) on the tweeter (both positions), and a 630V Solen (standard or silver range) across the woofer in the CR filter. I preferred the Solen standard 400V to the CrossCaps in a test I did, and the 630V to 400V in another build. The LCR filter is of less concern, centered at 800Hz and a narrow bandwidth. You could likely use a standard CrossCap there and be fine.
Mind you- none of these parts are bad to use, and I do rather like the Standard Z-Caps for a compact component that doesn't cost too much. The CrossCaps can tend to have fragile leads compared to the others, so beware of that.
That said- I heard the prototype of the Carrera with an OW3, and the xover used MR caps. Even though they are now NLA, that sounded quite good to me.
I heard Paul's too, and he sounded fine with whatever it was he used.
Later,
Wolf
If you want to use more expensive parts than the normal, I recommend the Superiors of your listed types (I like the Silvers more) on the tweeter (both positions), and a 630V Solen (standard or silver range) across the woofer in the CR filter. I preferred the Solen standard 400V to the CrossCaps in a test I did, and the 630V to 400V in another build. The LCR filter is of less concern, centered at 800Hz and a narrow bandwidth. You could likely use a standard CrossCap there and be fine.
Mind you- none of these parts are bad to use, and I do rather like the Standard Z-Caps for a compact component that doesn't cost too much. The CrossCaps can tend to have fragile leads compared to the others, so beware of that.
That said- I heard the prototype of the Carrera with an OW3, and the xover used MR caps. Even though they are now NLA, that sounded quite good to me.
I heard Paul's too, and he sounded fine with whatever it was he used.
Later,
Wolf
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