thaks Pano
yea the 10" spec sheet shows a very small rise in low bass as well but Qt is quite high at about 1.2
"no real low bass" , does that mean it had no sharp rise in low bass with nearfield measurment?
btw by "plump" Im assuming a humped up low end with respect to say a level midrange somewhat lower?
I guess im confused, thought all higher Q woffers tend tward a sharp rise in low bass on the order of 8 db or so
aiming for a very small dipole so really only want one woofer
response on this one looks right but twice as much money...
https://www.parts-express.com/pedocs/more-info/290-335-goldwood-gw-2128-more-info.pdf
yea the 10" spec sheet shows a very small rise in low bass as well but Qt is quite high at about 1.2
"no real low bass" , does that mean it had no sharp rise in low bass with nearfield measurment?
btw by "plump" Im assuming a humped up low end with respect to say a level midrange somewhat lower?
I guess im confused, thought all higher Q woffers tend tward a sharp rise in low bass on the order of 8 db or so
aiming for a very small dipole so really only want one woofer
response on this one looks right but twice as much money...
https://www.parts-express.com/pedocs/more-info/290-335-goldwood-gw-2128-more-info.pdf
It's funny that you mention the 12PF-8, I came here to ask if anyone had tried it! Looking at buying a pair and cannibalizing a pair of TC9FD19-08 out of an existing project. Might work well if you build it the same size as the 15" with just a smaller opening for the 12?
https://www.parts-express.com/GRS-12PF-8-12-Paper-Cone-Foam-Surround-Woofer-292-412?quantity=1
At a quick glance it looks similar enough to work with some work adjusting the crossover and level padding resistor of the TC9. I will be going active with line-level crossovers and separate amplification for each driver, so it wont be terribly difficult to play with the numbers. I also have a fountek FE83 pair on hand-
https://www.madisoundspeakerstore.com/approx-3-fullrange/fountek-fe85-3-aluminum-cone-full-range/
I also have a really cheap/nasty pair of 10" 4 ohm Titan woofers I can try in a super gross, junkyard attempt. I have a dozen partial sheets of 1/2" plywood that are otherwise trash- would cost me nothing but a couple hours in time to try out construction wise.
https://www.parts-express.com/Titan...Red-Surround-Woofer-4-Ohm-299-1018?quantity=1
https://www.parts-express.com/GRS-12PF-8-12-Paper-Cone-Foam-Surround-Woofer-292-412?quantity=1
At a quick glance it looks similar enough to work with some work adjusting the crossover and level padding resistor of the TC9. I will be going active with line-level crossovers and separate amplification for each driver, so it wont be terribly difficult to play with the numbers. I also have a fountek FE83 pair on hand-
https://www.madisoundspeakerstore.com/approx-3-fullrange/fountek-fe85-3-aluminum-cone-full-range/
I also have a really cheap/nasty pair of 10" 4 ohm Titan woofers I can try in a super gross, junkyard attempt. I have a dozen partial sheets of 1/2" plywood that are otherwise trash- would cost me nothing but a couple hours in time to try out construction wise.
https://www.parts-express.com/Titan...Red-Surround-Woofer-4-Ohm-299-1018?quantity=1
yea the baffles I have now are 22 inches wide and 29 in tall.
theres a ribbon of own making on top crossed at 650 2nd order linkwitz with level response at 86 db 1 meter.
On bottom is a single 12 inch low Q (.3) pro woofer ( sense 96db). It has a passive baffle step circuit for bass rise and then crossed at 650 2nd order
On this rather smallish? baffle tis quite good bass to around 40-50 hz (woofer within about 8 inches from floor) BUT the step circuit isnt ideal and thers a bit of fat in the 150-400 hz range
My intention was to 1st experament with some high Q woffers to hear the difference without the baffle step circuit. Some such as the goldwood I posted above show a nice rise starting at 150 hz that I believe would be a better match and may get rid of some of the thickness in sound between 150-400 hz?
theres a ribbon of own making on top crossed at 650 2nd order linkwitz with level response at 86 db 1 meter.
On bottom is a single 12 inch low Q (.3) pro woofer ( sense 96db). It has a passive baffle step circuit for bass rise and then crossed at 650 2nd order
On this rather smallish? baffle tis quite good bass to around 40-50 hz (woofer within about 8 inches from floor) BUT the step circuit isnt ideal and thers a bit of fat in the 150-400 hz range
My intention was to 1st experament with some high Q woffers to hear the difference without the baffle step circuit. Some such as the goldwood I posted above show a nice rise starting at 150 hz that I believe would be a better match and may get rid of some of the thickness in sound between 150-400 hz?
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12" Peerless Woofer Low Pass Crossover Questions....
The original Iron Core 20MH 16ga Low Pass Inductors (Parts Express P/N 266-960) are virtually impossible to source here in Australia, but I was able to source 10MH 18ga inductors (Parts Express Part #257-680), so I purchased 4 of these, with the intention of using 2 in series for each woofer.
I figure the ESR will be a bit higher than ideal, so what will be the consequences of using these and is there anything I can do to compensate?
If the impact of 2x 10MH chokes in series is too detrimental to the sound, is there an alternative?
Is there a reason why Iron Core inductors are specified?
And could I use DIY self-wound air-core 20MH inductors using 14-16 ga enameled wire?
Any help graciously appreciated, thanks!
The original Iron Core 20MH 16ga Low Pass Inductors (Parts Express P/N 266-960) are virtually impossible to source here in Australia, but I was able to source 10MH 18ga inductors (Parts Express Part #257-680), so I purchased 4 of these, with the intention of using 2 in series for each woofer.
I figure the ESR will be a bit higher than ideal, so what will be the consequences of using these and is there anything I can do to compensate?
If the impact of 2x 10MH chokes in series is too detrimental to the sound, is there an alternative?
Is there a reason why Iron Core inductors are specified?
And could I use DIY self-wound air-core 20MH inductors using 14-16 ga enameled wire?
Any help graciously appreciated, thanks!
https://speakerbug.com.au/index.php?route=product/category&path=59
Write to them. They are a distributor of Jantzen. They have perfect 20mH coils.
Write to them. They are a distributor of Jantzen. They have perfect 20mH coils.
It won't be detrimental if using 2 x 10mH in series instead of a single 20mH coil if they use the same wire diameter, therefore same DCR.
The ESR is determined by the length of the wire and its diameter, so the fatter the wire the lower the ESR, but the higher the cost. It's a no win situation.
Just arrange them in a way that it will resemble a single inductor, so maybe put them in line instead of side by side or on top of one another.
Iron cores are specified as it will be practically impossible to have an air core of that value, size and price wise.
An air core that will have the right inductance, 20mH and the low DCR will be humongous in size and weight, not mentioning the price.
I regularly use iron, and even ferrite core inductors with my projects and cannot hear or measure any ill effects, but I mostly use series crossovers, where the inductors are in parallel with the drivers and the interaction is different.
That of course is a different topic for discussion.
BTW, WES Components in Sydney sell 10mH inductors made by Dayton, check them out.
The ESR is determined by the length of the wire and its diameter, so the fatter the wire the lower the ESR, but the higher the cost. It's a no win situation.
Just arrange them in a way that it will resemble a single inductor, so maybe put them in line instead of side by side or on top of one another.
Iron cores are specified as it will be practically impossible to have an air core of that value, size and price wise.
An air core that will have the right inductance, 20mH and the low DCR will be humongous in size and weight, not mentioning the price.
I regularly use iron, and even ferrite core inductors with my projects and cannot hear or measure any ill effects, but I mostly use series crossovers, where the inductors are in parallel with the drivers and the interaction is different.
That of course is a different topic for discussion.
BTW, WES Components in Sydney sell 10mH inductors made by Dayton, check them out.
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Great, but have you checked the price?
You can buy a pair of secondhand KEF Q150 for the price of two of these.
The premise for iron core inductors is that whatever issues they have on midrange and high frequencies doesn't matter at low bass frequencies. I can't prove this but it's repeated often.
As mentioned before, cost is a big consideration as this build is supposed to be fast, fun and inexpensive. It must be true as it says so right at the top of this page.
As mentioned before, cost is a big consideration as this build is supposed to be fast, fun and inexpensive. It must be true as it says so right at the top of this page.
Two 18 gauge in series will have a rather high DCR. It will work, but won't be ideal. John Busch had some custom 14 and 12 gauge made, but his supplier refused to wind any more.
The cost of inductors wasn't too painful when we started this project. But they quickly thereafter went high and have stayed high. A source of good, reasonably priced 20uH inductors would be a great help to this project.
The cost of inductors wasn't too painful when we started this project. But they quickly thereafter went high and have stayed high. A source of good, reasonably priced 20uH inductors would be a great help to this project.
I never notice midrange / treble degradation with iron core In my speakers. My best midrange are with big iron core on my open baffle ! Better than air core with speakers in boxes with far expensive drivers...
See this link :
https://hificompass.com/en/projects/experiment/test-couple-iron-core-inductors
See this link :
https://hificompass.com/en/projects/experiment/test-couple-iron-core-inductors
In Poland 360 PLN = 125 AUD. In my opinion, this is a very important element that should not be skipped.
Thanks Arczar, the only 20MH coils speakerbug have in stock is P-Core 20mH 18AWG for AUD $36.66ea with 0.93Ω ESR
The four 10MH 18AWG inductors I bought (parts express Part #257-680) have an ESR of 0.78Ω each (2x in series =>1.56Ω ESR)
Am I right in assuming I'd be better off with 0.93Ω ESR than 1.55Ω ESR?
Would this make much of a difference in the big scheme of things? (i.e. would it be very audible?)
The C-core inductors are horrendously expensive and speakerbug do not have 20MH in stock, so again I would have to go for 4x 10MH which would be a total of AUD $660.00!!
At this stage if the P-Core 20MH inductors would be audibly better than the 10MH PE ones I have already purchased, I would certainly go for them.
Thanks Stanislav, sadly I cant use WES Components as I don't have a business or an ABN to set up an account.
I'm assuming the KEF's have 20MH indictors in their XO's?
I did a quick search on eBay...... the cheapest secondhand ones are $500+
Two 18 gauge in series will have a rather high DCR. It will work, but won't be ideal. John Busch had some custom 14 and 12 gauge made, but his supplier refused to wind any more.
The cost of inductors wasn't too painful when we started this project. But they quickly thereafter went high and have stayed high. A source of good, reasonably priced 20uH inductors would be a great help to this project.
Thanks Pano, I've even considered winding my own (having never attempted it before!), but from what I have read on googling the process it does NOT appear to be a simple task!
The four 10MH 18AWG inductors I bought (parts express Part #257-680) have an ESR of 0.78Ω each (2x in series =>1.56Ω ESR)
Would this make much of a difference in the big scheme of things? (i.e. would it be very audible?)
Cheers!