There is still a 12" version AFAIK. The problem being that the Peerless woofer has now almost $100, which can't really be called "Inexpensive" anymore.
Still....the build is quite reasonable priced! I've never built an OB before, and these are truly interesting price wise. Not having to build a complete box is a big plus as well!
The Ultra's woofer is still very reasonable, that's for sure!
Thank you for the fast answer.
Russellc
Yes, I would like more info on the trap mentioned in post 1217 for the woofer...like what gauge wire for coil and its resistance?
Russellc
Russellc
Manzanita status
Nice to know you enjoyed the thread! As Pano said, the GRS 15" version has been offered as a lower cost alternative to the Peerless 12". The 2.5-2.75 MH trap inductor should be an air core 14 ga. with a DCR of about 0.4 ohms. 16 or 18 ga. can work, but your DCR can approach 1.0 ohm and the trap just does not work as well... you can really hear the difference!
Good luck with the project! Please let us know how it works out for you!
John
Nice to know you enjoyed the thread! As Pano said, the GRS 15" version has been offered as a lower cost alternative to the Peerless 12". The 2.5-2.75 MH trap inductor should be an air core 14 ga. with a DCR of about 0.4 ohms. 16 or 18 ga. can work, but your DCR can approach 1.0 ohm and the trap just does not work as well... you can really hear the difference!
Good luck with the project! Please let us know how it works out for you!
John
Thanks, I will start acquiring the drivers and parts, I'm finishing up a few DIY Pass amplifiers from the Pass forum just now, but these drivers are very reasonable. Need some plywood and start planning the cuts.
Russellc
Nice to see that this thread is still alive! And forgive me it it is my porchlight that is a little dim, but I am a little confused:
In post 1217 John mentions a woofer trap:
"There is the option of adding a woofer trap in series with the woofer (coil - cap 15 uf & 0.40 mh in parallel with each other)."
But in post 1244 a 2.5 -2.7 mH trap is mentioned.
My questions are:
1) Does the trap apply to the Peerless 12" woofer or the 15" or both?
2) The inductance of the coil?
3) Is it a 15µF capacitor in both cases?
As I said: Sorry if it's just me being dimwitted.
In post 1217 John mentions a woofer trap:
"There is the option of adding a woofer trap in series with the woofer (coil - cap 15 uf & 0.40 mh in parallel with each other)."
But in post 1244 a 2.5 -2.7 mH trap is mentioned.
My questions are:
1) Does the trap apply to the Peerless 12" woofer or the 15" or both?
2) The inductance of the coil?
3) Is it a 15µF capacitor in both cases?
As I said: Sorry if it's just me being dimwitted.
Traps and more traps!
Hello all.... it seems I am the dimwit! I see trap and think of the original Vifa trap... not the later woofer trap. Post 1217 indeed deals with the later added woofer trap.
"There is the option of adding a woofer trap in series with the woofer (coil - cap 15 uf & 0.40 mh in parallel with each other). I have never posted this as it is part of the commercial crossover and it does add to the build cost. This trap does clean the upper end of the woofer band pass."
The woofer trap deals with the woofer break up and works fairly well on both the Peerless 12 and GRS 15.
The Vifa trap levels off the natural rise in frequency the Vifa exhibits.
I hope I have not caused anyone to purchase parts they did not need!
Hello all.... it seems I am the dimwit! I see trap and think of the original Vifa trap... not the later woofer trap. Post 1217 indeed deals with the later added woofer trap.
"There is the option of adding a woofer trap in series with the woofer (coil - cap 15 uf & 0.40 mh in parallel with each other). I have never posted this as it is part of the commercial crossover and it does add to the build cost. This trap does clean the upper end of the woofer band pass."
The woofer trap deals with the woofer break up and works fairly well on both the Peerless 12 and GRS 15.
The Vifa trap levels off the natural rise in frequency the Vifa exhibits.
I hope I have not caused anyone to purchase parts they did not need!
Is the crossover the same when using the GRS 15 instead of the Peerless or is there a revised one I missed?
Could you give the particulars of the coil in the woofer trap? gauge wire/resistance?
Thank you,
Russellc
That looks great.... nice job!
This one is on my list as well.
What is that monstrous amp under the TV?
Do u plan to move that couch away soon? 🙂
This one is on my list as well.
What is that monstrous amp under the TV?
Do u plan to move that couch away soon? 🙂
Russellc....
As is standard, the design uses a 14 ga. air core.. about 0.15 ohms. You can get by with 18 ga. (0.3 ohms) but there will be some degradation in the midrange. Not so much due to the higher resistance, it's just that the larger wire size produces less midrange distortion. You can really hear it. Have tried values as large as 8 ga. and it sounds the best, but just not justified due to crazy price and size. 14 ga. seems to be the best bang for the buck IMHO.
Another simple tweak to bypass the 15 UF cap with a Dayton 0.10. (P/N 027-452) This works well with any of the caps in my OB designs. Best dollar you can spend!
Best
John
As is standard, the design uses a 14 ga. air core.. about 0.15 ohms. You can get by with 18 ga. (0.3 ohms) but there will be some degradation in the midrange. Not so much due to the higher resistance, it's just that the larger wire size produces less midrange distortion. You can really hear it. Have tried values as large as 8 ga. and it sounds the best, but just not justified due to crazy price and size. 14 ga. seems to be the best bang for the buck IMHO.
Another simple tweak to bypass the 15 UF cap with a Dayton 0.10. (P/N 027-452) This works well with any of the caps in my OB designs. Best dollar you can spend!
Best
John
Nocrapman - sofa going tomorrow🙂 the amp is my first amp build... F5 class A amp, curtesy of the forum also.... Just building some chip amp mono blocks for these speakers, as the F5 does ok.... But... Well.. Just want to build something else🙂
Try also BA-3 with 32 volt rails...(24 + 24) considerably more gain than F-5....now I am doing F-6, as soon as DIYstore gets more chassis. Is that the 12" Peerless woofer? Nice build!
When using my F-5 with mid 80" efficiency speakers, I find I want extra gain. The BA-3 FE as pre amp solves this problem nicely. Gobs of gain, it will drive your F-5
like crazy!
Russellc
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