DE250 16 Ohm
Hi Earl,
Your kit webpage says that you use the DE250-16, which is the 16 ohm version of this driver(?). Is it a deliberate design choice to use 16 ohm versions? If so, for what reason/s? So if one is to source their own drivers (which I surmise are mostly 8 Ohms in the retail market), would a different set of crossover values be used?
Thank you.
Hi Earl,
Your kit webpage says that you use the DE250-16, which is the 16 ohm version of this driver(?). Is it a deliberate design choice to use 16 ohm versions? If so, for what reason/s? So if one is to source their own drivers (which I surmise are mostly 8 Ohms in the retail market), would a different set of crossover values be used?
Thank you.
jcx said:
then why the discussion of thermal compression and shorting rings?
I've already solved those problems.
chrismercurio said:I know it sounds crazy but maybe, if we just let Earl bring to market the kits he wants to bring to market as he is the expert on what he wants out of a loudspeaker, the results will be what they are supposed to be.
Best to all,
Chris
Thanks Chris, I can agree with this.
Re: DE250 16 Ohm
Yes of course its deliberate. The reason is that the voltage efficiency of the 8 ohm is too high so the higher Re helps. If you don't use exactly the same driver that the crossover was designed for it won't work properly. This is always the case.
fred76 said:Hi Earl,
Your kit webpage says that you use the DE250-16, which is the 16 ohm version of this driver(?). Is it a deliberate design choice to use 16 ohm versions? If so, for what reason/s? So if one is to source their own drivers (which I surmise are mostly 8 Ohms in the retail market), would a different set of crossover values be used?
Thank you.
Yes of course its deliberate. The reason is that the voltage efficiency of the 8 ohm is too high so the higher Re helps. If you don't use exactly the same driver that the crossover was designed for it won't work properly. This is always the case.
We used the Eminence 12 HO with the shorting ring in the ESP12 because we thought (based on some early tests and published specs) it did not have a small dimple in the woofers passband that the 12TBX100 had. But when we got the bulk shipment they all had the same problem as the 12TBX100. If the prices are comparable then I would opt for the B&C, but as I recall the price that I get on the Eminence was quite a bit lower than the B&C and since it worked about the same the Eminence was attractive. But this reduction is not $100, more like $50.
gedlee said:I've looked at their Neo woofers in the past. If weight is not an issue then the extra price did not seem justified to me. The 15NW76 does look very attractive, except that its efficiency may be too high to mate with the DE250.
I'll be using the DE250 with your 10" waveguide, what is the sensitivity after it's EQ'ed flat?
15NW76 does indeed look interesting, a bit high Fs and maybe a bit low Qts fore closed
How can a 100db woofer have too high sensitivity fore a 108db CD ?
How can a 100db woofer have too high sensitivity fore a 108db CD ?
augerpro said:
I'll be using the DE250 with your 10" waveguide, what is the sensitivity after it's EQ'ed flat?
It should be about 98 dB. That of course depends on the crossover.
Patrick Bateman said:The "real" Summa is a no-compromise design that mates a 15" waveguide & a 15" woofer. The achilles heel of the Summa is the woofer. There are only a handful of 15" woofers which can play into the midrange. The B&C 15TBX100 fits the bill, but it is E-X-P-E-N-S-I-V-E.
I know that others have mentioned the 15" Lambda designs, now sold by AE. I can tell you from personal experience that mine play and measure very well. I have the Lambda Apollo motor TDX, and they are expensive too. But I would guess that the main difference between the Apollo and the single shorting ring would be at very high SPL levels, so the Apollo is likely overkill here.
Sheldon
Re: Re: DE250 16 Ohm
Thank you Earl... So if used with an 8 ohm woofer, the woofer gets most of the power.
Some Summa pics from an old thread I found online: http://www.audiocircle.com/circles/index.php?topic=24627.0
gedlee said:
Yes of course its deliberate. The reason is that the voltage efficiency of the 8 ohm is too high so the higher Re helps. If you don't use exactly the same driver that the crossover was designed for it won't work properly. This is always the case.
Thank you Earl... So if used with an 8 ohm woofer, the woofer gets most of the power.
Some Summa pics from an old thread I found online: http://www.audiocircle.com/circles/index.php?topic=24627.0
I have a pair of DE250 - 8ohms and Nathan uses 16 ohms. Does anybody know if there is a difference between 8ohm and 16ohm version except the coil? Is it interchangeable?
As I said before I am interested in the 15" version (is it the Abbey ?), anyway let's call this the "director's cut" version of the kit, lol, if the shipping problems to euroland can be solved...
MethMan said:I have a pair of DE250 - 8ohms and Nathan uses 16 ohms. Does anybody know if there is a difference between 8ohm and 16ohm version except the coil? Is it interchangeable?
They are identical except for the number of turns on the VC and the wire size. Same performance. But unfortunately they are not interchangable because of the crossover design.
peufeu said:As I said before I am interested in the 15" version (is it the Abbey ?), anyway let's call this the "director's cut" version of the kit, lol, if the shipping problems to euroland can be solved...
The Abbey has a 12" waveguide, the Abbey+ is a 12" woofer and 15" waveguide. There are no current plans for a Summa replacement.
gedlee said:
They are identical except for the number of turns on the VC and the wire size. Same performance. But unfortunately they are not interchangable because of the crossover design.
I agree. I want to buy just voicecoils. 😉
MethMan said:
I agree. I want to buy just voicecoils. 😉
Do you mean diaphragms? You can buy these from B&C as replacements.
DE250
The DE250 is listed on the B&C website as an 8 Ohm driver, is the 16 Ohm version you use a special order item?
Nick.
The DE250 is listed on the B&C website as an 8 Ohm driver, is the 16 Ohm version you use a special order item?
Nick.
Re: DE250
No they stock them here in the US. It may be different in other parts of the world however. Its just a diaphragm change. 8 or 16 is pretty much arbitrary, but the 16 ohm keeps the pad resistors smaller. I used 8 for years and then switched to 16. It makes the other components in the crossover smaller and less expensive.
Grumpy_Git said:The DE250 is listed on the B&C website as an 8 Ohm driver, is the 16 Ohm version you use a special order item?
Nick.
No they stock them here in the US. It may be different in other parts of the world however. Its just a diaphragm change. 8 or 16 is pretty much arbitrary, but the 16 ohm keeps the pad resistors smaller. I used 8 for years and then switched to 16. It makes the other components in the crossover smaller and less expensive.
Re: Re: DE250
So it is, and not insignificant with low XO point
gedlee said:
I used 8 for years and then switched to 16. It makes the other components in the crossover smaller and less expensive.
So it is, and not insignificant with low XO point
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