Sreten, you mention attenuating with a series resistor. I've found various calculators to work out L-Pad attenuation, but how would you work out the resistance for a single series resistor.
Those Dayton ND20FB-4 look interesting. They are only 15W RMS, so could I use 2 in series, or because of their 90dB/W, would one be fine?
Those Dayton ND20FB-4 look interesting. They are only 15W RMS, so could I use 2 in series, or because of their 90dB/W, would one be fine?
Hi,
If you need a calculator, search on "voltage divider gain ", 4R in
series with 4 ohm gives an 8 ohm driver attenuated by -6dB, use
8 ohm to calculate the capacitor, and realise you've just doubled
tweeter powerhandling, though with a x/o at 10KHz, irrelevant *.
2R in series with 4 ohm gives a 6ohm driver with -3.5dB.
As stated the capacitor only method would do -6dB at 10KHz
by setting the cap for 4 ohm and 20KHz, same cap value in
fact as 8 ohm - 4R + 4ohm, the difference would be a rising
response in the top octave, that could work very well too.
Experiment I'd say.
rgds, sreten.
* The tweeters power handling is also irrelevant with a normal
x/o in the 3 to 4KHz range with a speaker of normal sensitivity,
say up to 90dB, for smaller lower efficiency speakers it goes
off the radar, it will have plenty in reserve with attenuation.
Last edited:
Thanks again Dave and Sreten. That was well explained. I think I may buy the Dayton's. They are cheap and are pretty small. And now I have a bit more info, I can at least experiment now and roughly know what to expect when inserting different values of resistors and caps.
On second thoughts, Dayton ND20FB-4 or the CSS ERT26? I'm leaning towards the Dayton's
On second thoughts, Dayton ND20FB-4 or the CSS ERT26? I'm leaning towards the Dayton's
Last edited:
Hi,
Make sure you can mount the Dayton properly.
rgds, sreten.
In fact the easier flush mounting version Dayton_ND20FA-6 (6 ohm) :
Dayton Audio ND20FA-6 3/4" Neodymium Dome Tweeter 275-030
Looks like it would suit the capacitor only approach much better for a 10KHz x/o.
(Noting a normal 10KHz x/o is -3dB @10KHz, designing for 20KHz is -9dB @ 10KHz.)
Its peak at 10KHz means you'll get a defined roll off at that point with whatever
capacitor value you choose for relative attenuation, probably the best option.
Make sure you can mount the Dayton properly.
rgds, sreten.
In fact the easier flush mounting version Dayton_ND20FA-6 (6 ohm) :
Dayton Audio ND20FA-6 3/4" Neodymium Dome Tweeter 275-030
Looks like it would suit the capacitor only approach much better for a 10KHz x/o.
(Noting a normal 10KHz x/o is -3dB @10KHz, designing for 20KHz is -9dB @ 10KHz.)
Its peak at 10KHz means you'll get a defined roll off at that point with whatever
capacitor value you choose for relative attenuation, probably the best option.
Last edited:
Hi,
My opinion is the flush mount will be better if 10KHz is the right
x/o point and you simply want to adjust the series capacitor
to effectively set the level of the supertweeter, not the x/o.
Its a minimalist approach. It will be flatter than the
rearmount just using a single series capacitor.
The rear mount is superbly flat, its more flexible, but more
complicated to use in some respects, but gives more options.
Me ? I think I'd go for KISS, and take it from there.
rgds, sreten.
My opinion is the flush mount will be better if 10KHz is the right
x/o point and you simply want to adjust the series capacitor
to effectively set the level of the supertweeter, not the x/o.
Its a minimalist approach. It will be flatter than the
rearmount just using a single series capacitor.
The rear mount is superbly flat, its more flexible, but more
complicated to use in some respects, but gives more options.
Me ? I think I'd go for KISS, and take it from there.
rgds, sreten.
Last edited:
I don't have any answers (probably more questions) but this thread is very interesting to me because just last night I was experimenting with adding some "air" to my dual EL70eN microTowers.
I had been considering getting some cheap piezos and playing with them, but last night I found a pair of old Sansui AA-2900 2-way speakers at the local thrift shop for $20 and bought them for sh!ts n' giggles.
First I just connected them up and tested them. They worked, so I went ahead and disconnected the woofers on each of them and ran them along side my EL70s just to see how much "air" the tweeters would add. Perhaps too much, so I aimed the tweeters at the ceiling and this provides perfect attenuation/dispersion.
About 30 minutes later, I had ripped (carefully removed, actually) the crossovers and tweeters out of the boxes. Now the raw tweeters are "mounted" (pointing straight up) with blu-tac on the top corners of my microTowers. The crossovers are just hanging behind the microTowers and I am running them on the "B" speaker leads so I can flip the "air" on or off with my remote.
I have no idea where the crossover is set but it is quite high. If I run just the "B" speakers (just the tweeters) it is really just the last octave I am hearing (I think).
Anyway, they do just what I figured they would do, add "air" and/or "sparkle" and they can keep up with the EL70 drivers with respect to power. Now I just need to make the whole thing a lot prettier.
Bonus: I now have 2 spare 6.5" woofers for another thrifty project.
I had been considering getting some cheap piezos and playing with them, but last night I found a pair of old Sansui AA-2900 2-way speakers at the local thrift shop for $20 and bought them for sh!ts n' giggles.
First I just connected them up and tested them. They worked, so I went ahead and disconnected the woofers on each of them and ran them along side my EL70s just to see how much "air" the tweeters would add. Perhaps too much, so I aimed the tweeters at the ceiling and this provides perfect attenuation/dispersion.
About 30 minutes later, I had ripped (carefully removed, actually) the crossovers and tweeters out of the boxes. Now the raw tweeters are "mounted" (pointing straight up) with blu-tac on the top corners of my microTowers. The crossovers are just hanging behind the microTowers and I am running them on the "B" speaker leads so I can flip the "air" on or off with my remote.
I have no idea where the crossover is set but it is quite high. If I run just the "B" speakers (just the tweeters) it is really just the last octave I am hearing (I think).
Anyway, they do just what I figured they would do, add "air" and/or "sparkle" and they can keep up with the EL70 drivers with respect to power. Now I just need to make the whole thing a lot prettier.
Bonus: I now have 2 spare 6.5" woofers for another thrifty project.
Last edited:
The KISS principle; Keep it Simple, Stupid!
Facing up is an easy way to attenuate and disperse, for those of us who are too lazy to learn electronics and/or find directional high frequencies annoying/distracting. I am a real "full range" fan, so facing the tweeters up adds the "air' without removing the full range "magic". I would think facing them up also tends to minimize or eliminate (or maybe just "mask") some of the pitfalls of multi-way systems, such as combing, timing issues, etc. (but I am just guessing).
Note: My dual EL70 microTowers already have one of the drivers facing up (and one forward, of course) so adding an upward-firing tweeter seemed obvious, especially when I felt the forward-facing tweeter was "more air than I wanted". Many might think "what a waste of a tweeter, to point it at the ceiling!", however I can assure you that the tweeter is very much a part of the sound experience in this configuration, without becoming a nuisance.
In your situation, orienting the tweeter in this manner might entirely eliminate the need for electronic attenuation, and might bring the added benefit of a more open, disperse airiness in the highs. Only trial and error, and your personal taste will tell...
Another option which I have seen is to add the tweeter to the back of the cabinet, using the rear wall as a deflector. I may play with this configuration as well.
Last edited:
Pictures? The one i found in a quick google was poor.
Looks like a 2.5" cone, likely XOed with a single cap -- how big is it.
I have a ton of little vintage tweeters that could be had for the price of shipping, some for a few coins or a bribe, and the ApexJr Audax & ERT26 new.
dave
PS: the 2 daytons are likely the same with different bezels for different aps.
Well, mine are already ripped apart, so pics wouldn't be very helpful, but here is a Kijiji add with an OK photo... SANSUI AA-2900 2-way speakers
Mine actually looked to be in better shape than those ones.
It's a 2.5" paper cone. The cabinets themselves are 9 3/4"W x 8 1/4"D x 19 3/4"H.
I will take a photo of my setup as it is, and the crossover, and one of you geniuses will be able to figure out where it is crossed
BTW, I have done a "ghetto eNable" on them; Mod Podge spray, and they look much better now
Mine actually looked to be in better shape than those ones.
It's a 2.5" paper cone. The cabinets themselves are 9 3/4"W x 8 1/4"D x 19 3/4"H.
I will take a photo of my setup as it is, and the crossover, and one of you geniuses will be able to figure out where it is crossed
BTW, I have done a "ghetto eNable" on them; Mod Podge spray, and they look much better now
Last edited:
OK. I think I will get the Dayton ND20FA-6 (can get them with shipping from a European audio shop with shipping for about £25) I have come up with a nice way to mount them also.....
I will get a short piece of hardwood mopstick handrail, like this:
hollow it out and mount the tweeter in the front and an aluminium disk on the back as a connection plate. As it will be hollowed out, I can put the various caps and resistors inside. The flat part of the handrail will sit nice on top of my speaker cabinet.
I was thinking how to connect this to my original speaker, so I thought about using an RCA connectors. I could cut a hole in the top rear of my cabinet and insert on of these:
Neutrik NF2D-0 Phono RCA Chassis/Panel Socket Black | eBay
and then use a standard one on the back of the tweeter's housing. Any thoughts on using RCA phono connectors? I checked a few on Farnell's website and they say they are rated to 5 amp. I would obviously make my own cables, not actually use standard RCA cables.
I will get a short piece of hardwood mopstick handrail, like this:
An externally hosted image should be here but it was not working when we last tested it.
hollow it out and mount the tweeter in the front and an aluminium disk on the back as a connection plate. As it will be hollowed out, I can put the various caps and resistors inside. The flat part of the handrail will sit nice on top of my speaker cabinet.
I was thinking how to connect this to my original speaker, so I thought about using an RCA connectors. I could cut a hole in the top rear of my cabinet and insert on of these:
Neutrik NF2D-0 Phono RCA Chassis/Panel Socket Black | eBay
and then use a standard one on the back of the tweeter's housing. Any thoughts on using RCA phono connectors? I checked a few on Farnell's website and they say they are rated to 5 amp. I would obviously make my own cables, not actually use standard RCA cables.
Last edited:
Hi,
KISS is "keep it simple stupid", if something simple seems to gel,
don't overcomplicate it, even if it doesn't work you'll learn a lot,
but most often it does work. Something more complicated may
or may not work, but being complicated its harder to learn from.
rgds, sreten.
Though I have to admit the simple scheme is better than
it might first appear due to relatively complex concepts.
KISS is "keep it simple stupid", if something simple seems to gel,
don't overcomplicate it, even if it doesn't work you'll learn a lot,
but most often it does work. Something more complicated may
or may not work, but being complicated its harder to learn from.
rgds, sreten.
Though I have to admit the simple scheme is better than
it might first appear due to relatively complex concepts.
Last edited:
I was going to do something similar for a co-ax mount T in the Pioneer B20. The tweeter fits perfectly on the end of an apprpriate diamter dowel and can be fixed to the end with a standard size chunk of shrink wrap. I have tweeters, dowel and shrinkwrap but i gave my B20s to GM
dave
Some interesting discussion in this thread http://www.diyaudio.com/forums/full-range/120224-adding-tweeter-full-range-3.html
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.