Horn response will calculate the cavity resonances or you can do the math. Math is determine the cross sectional area of the H or U frame. Convert the cross sectional area to an equivalent circle radius R. Find the depth of the cavity D. Find the Effective Length=EL= D + 0.6 x R. Convert to meters. Calculate the quarter wave frequency = 344m/s divided by 4 x EL
Cross below the quarter wave frequency or stuff (Cardioid) to avoid peaking FR.
I must admit that it seems odd/funny to me that there has been literally no mention whatsoever of this buyout Foster planar tweeter. Aside from looking like they'd be a pain to mount, what are some of the reasons nobody cares? https://www.parts-express.com/Foster-E100T10-Ribbon-Tweeter-8-Ohm-279-468
@dcibel said:
It starts to roll off at 6kHz. Recommended crossover at 6.5kHz really limits it's usability.
I'm not seeing the rolloff at 6k (if Fostex's specs are to be believed) but crossing at 6.5k leaves a pretty big hole to fill from a standard midrange up to that 6.5k number. Hello 4-way?
Might be a good tweeter on top of the Dayton Planar, but that puts you North of $80 all-in, and you have to ask yourself what kind of tweeters can be had for North of $80, that also do not result in increased complexity and cost at a crossover level.
I'm not seeing the value in it, to be honest. I mean, it is a cool option - but PE in the last several years has made a habit out of pricing buyout tweeters at ridiculously stupid levels and advertising them more as replacement parts and not DIY stuff. I mean, look at the pricing on those Jensen and Advent tweeters that they are never going to sell out of. Even the Ariel buyout tweeters are priced at $40 - you can buy some pretty badass tweeters for $40! No need for 20 year old NOS stuff. This little planar is a $12 tweeter, lets be honest here. For just a couple bucks more than the $25 Foster you can buy the GRS 3-1/2" planar, and odds are the Foster doesn't measure any better or more consistent between units.
Anyways, rant over. Modern tweeters from Tymphany are priced at such an attractive point that I don't see the need to wish for better buyout options. I sure miss the great buyouts, but I don't expect PE to continue the "buy a metric fuckton from a distressed company and price them to sell out in two weeks" approach any time soon.
@jr@mac said:
I sure miss the great buyouts, but I don't expect PE to continue the "buy a metric fuckton from a distressed company and price them to sell out in two weeks" approach any time soon.
Man I miss those deals too
Regarding the Foster planar... I know my alternate suggested tweeter is another $10 higher, and we DIY guys tend to be tight wads, but the RT1.3WE bests it in every way other than price. The RT1.3WE can be crossed an entire octave lower, it has a nice DIY friendly round faceplate (nice looking too), and it measures extremely well and sounds fantastic.
The more I think about it, the more I am starting to believe the Dayton DMA 4" might be the killer budget midrange of all time. I wish it had a round frame, but that is really the only thing (on paper) I can fault. On the plus side, it shares dimensions with one of the Beston ribbons.
@jr@mac said:
The more I think about it, the more I am starting to believe the Dayton DMA 4" might be the killer budget midrange of all time. I wish it had a round frame, but that is really the only thing (on paper) I can fault. On the plus side, it shares dimensions with one of the Beston ribbons.
I thought I had a pair of the DMAs, but can't find them now. Has anyone run a THD measurement on them?
But Chahly - Stahkist don't want speakers that look good, Stahkist wants speakers that sound good!
It has copper in the motor, well ventilated frame, very linear through the pass band, lots of neo in the motor - I think unless Dayton completely cocked up the gap or there is a bunch of offset in the motor, that it would measure pretty well. That motor appears to be very strong - the DOTD is a 4" 4 ohm driver with nearly 90db/2.83V. The 8 ohm variant is more sensitive than the 8 ohm TC9 as well. I think these might be legit, as much as I enjoy the TC9 the DMA seem to have a lot going for them (on paper).
Popped for 2 of the DMS 4 inch 4 ohm, figure I could always make (another) pair of near-field desktop computer speakers.
Also getting a pair of the DMS 2 inch, want to compare them to the Tectonics BMR 2 inch full range drivers.
But Chahly - Stahkist don't want speakers that look good, Stahkist wants speakers that sound good!
I remember seeing someone on another forum had done some testing and found them to not be an exact clone of the BG stuff, and had some minor to moderate consistency issues.
That being said, I imagine if you go active with the GRS (which looking at the published response curves seems to be a good idea), the GRS will work superbly.
38l tuned to about 25hz yields an f3 of 40hz and f10 of 22hz, or if you need a small cabinet 15l sealed with 750uf cap gives an f3 of 52hz with a steeper roll off.
@PWRRYD said:
Models pretty well in a 38 L sealed enclosure. F3 = 50 Hz, 25 Watt = 101 dB/m within xmax. Not sure I like the looks of that grill though.
I can't imagine an aluminum cone on a woofer would be so delicate that it needs an ugly grill. I agree with Nick - I think they're trying to make it look like a more expensive driver.
Comments
Horn response will calculate the cavity resonances or you can do the math. Math is determine the cross sectional area of the H or U frame. Convert the cross sectional area to an equivalent circle radius R. Find the depth of the cavity D. Find the Effective Length=EL= D + 0.6 x R. Convert to meters. Calculate the quarter wave frequency = 344m/s divided by 4 x EL
Cross below the quarter wave frequency or stuff (Cardioid) to avoid peaking FR.
Newark if doing 15% off online orders again.
It's your lucky week!
To celebrate St Patrick's Day we're giving you up to 15% off online orders*
Use Voucher Code: GREEN15
Ron
Can't believe I almost missed it - another lighting apparatus on PE!
Finally something decent.
C'mon, man! Just admit it's another $6 flashlight.
There must be really good money to be made selling flashlights. Wonder what their markup is?
@Tom_S said:
Check the prices for the same items on Aliexpress. Probably also large discounts for ordering in bulk.
This is starting to look more like a flashlight deal thread than a speaker deal thread
illuminating!
I must admit that it seems odd/funny to me that there has been literally no mention whatsoever of this buyout Foster planar tweeter. Aside from looking like they'd be a pain to mount, what are some of the reasons nobody cares?
https://www.parts-express.com/Foster-E100T10-Ribbon-Tweeter-8-Ohm-279-468
It starts to roll off at 6kHz. Recommended crossover at 6.5kHz really limits it's usability.
I'm not seeing the rolloff at 6k (if Fostex's specs are to be believed) but crossing at 6.5k leaves a pretty big hole to fill from a standard midrange up to that 6.5k number. Hello 4-way?
Might be a good tweeter on top of the Dayton Planar, but that puts you North of $80 all-in, and you have to ask yourself what kind of tweeters can be had for North of $80, that also do not result in increased complexity and cost at a crossover level.
I'm not seeing the value in it, to be honest. I mean, it is a cool option - but PE in the last several years has made a habit out of pricing buyout tweeters at ridiculously stupid levels and advertising them more as replacement parts and not DIY stuff. I mean, look at the pricing on those Jensen and Advent tweeters that they are never going to sell out of. Even the Ariel buyout tweeters are priced at $40 - you can buy some pretty badass tweeters for $40! No need for 20 year old NOS stuff. This little planar is a $12 tweeter, lets be honest here. For just a couple bucks more than the $25 Foster you can buy the GRS 3-1/2" planar, and odds are the Foster doesn't measure any better or more consistent between units.
Anyways, rant over. Modern tweeters from Tymphany are priced at such an attractive point that I don't see the need to wish for better buyout options. I sure miss the great buyouts, but I don't expect PE to continue the "buy a metric fuckton from a distressed company and price them to sell out in two weeks" approach any time soon.
Man I miss those deals too
Regarding the Foster planar... I know my alternate suggested tweeter is another $10 higher, and we DIY guys tend to be tight wads, but the RT1.3WE bests it in every way other than price. The RT1.3WE can be crossed an entire octave lower, it has a nice DIY friendly round faceplate (nice looking too), and it measures extremely well and sounds fantastic.
How about that $60 Acoustic Research 1" dome with an Fs of 1.5K?
The more I think about it, the more I am starting to believe the Dayton DMA 4" might be the killer budget midrange of all time. I wish it had a round frame, but that is really the only thing (on paper) I can fault. On the plus side, it shares dimensions with one of the Beston ribbons.
I thought I had a pair of the DMAs, but can't find them now. Has anyone run a THD measurement on them?
I wonder how the DMA 4" distortion compares to a TC9FD.
It has copper in the motor, well ventilated frame, very linear through the pass band, lots of neo in the motor - I think unless Dayton completely cocked up the gap or there is a bunch of offset in the motor, that it would measure pretty well. That motor appears to be very strong - the DOTD is a 4" 4 ohm driver with nearly 90db/2.83V. The 8 ohm variant is more sensitive than the 8 ohm TC9 as well. I think these might be legit, as much as I enjoy the TC9 the DMA seem to have a lot going for them (on paper).
Would make a great shootout!
Popped for 2 of the DMS 4 inch 4 ohm, figure I could always make (another) pair of near-field desktop computer speakers.
Also getting a pair of the DMS 2 inch, want to compare them to the Tectonics BMR 2 inch full range drivers.
Now this is a deal. https://parts-express.com/ultimate-speaker-kit?
Ron
4/7/2021: Bohlender Graebener Neo3 Driver with Deep Back Cup for SALE PRICE $83.98
Some of us may remember buying them for around $35 a pop. Has anyone tested the GRS knockoffs?
I remember seeing someone on another forum had done some testing and found them to not be an exact clone of the BG stuff, and had some minor to moderate consistency issues.
That being said, I imagine if you go active with the GRS (which looking at the published response curves seems to be a good idea), the GRS will work superbly.
I may be late to the party on this one, but did anyone see the new Fountek fw222. It looks kind of interesting.
Hey look - another LED light!
Models pretty well in a 38 L sealed enclosure. F3 = 50 Hz, 25 Watt = 101 dB/m within xmax. Not sure I like the looks of that grill though.
It looks like they were trying to make it look Accuton-ish.
38l tuned to about 25hz yields an f3 of 40hz and f10 of 22hz, or if you need a small cabinet 15l sealed with 750uf cap gives an f3 of 52hz with a steeper roll off.
I can't imagine an aluminum cone on a woofer would be so delicate that it needs an ugly grill. I agree with Nick - I think they're trying to make it look like a more expensive driver.
The new Fountek RD1.0 that Ron mentioned looks nice.