It depends where you're looking at: the 3.5 way or 4 way it can be done with the right drivers, but you have to fix the 'balance point'. Since the D54, which I guess you intend to use, is mid/hi sensitivity, you might choose the mid/hi sensitivity way, choosing a mid-woofer of about 95 dB/W/m.
There's no free lunch...as advertised: if you see the data that the manufacturers provide, you'll find diameter, Fs, sensitivity etc. etc. The distinction between Home speakers and Pro speakers follows the Iron Law: between going low, dimension and efficiency, you just pick two of them ( it was not well explained...go search! Hoffman's Iron Law). So having two 10" woofers, one 90 dB/W/m and the other 95 dB/W/m, the first will go lower in frequency.
SO for a 3.5 way speaker... you need a midwoofer that doesn't distort with low bass, 'coz it isn't high-passed
BUT there are many things to be considered before buying the speakers ( usually it takes some days to make the perfect configuration ). Crossover, the heart of a speaker, needs to be tailored to the specific models.
Tweeter: do you want it to stop at 18 kHz? Or go to ultrasonics ?
I did indicate a Dayton AMT-2...
So what's wrong with a 10" ? It's gigantic!
I'd keep the D54, put a Faital 6FE100 or 200 (double price! Why ?....search...) and a tweeter of the same ( sensitivity) league .
You'll lack bass. Wait! Before there's the construction of the crossover and the wiring...
Ok, now you lack bass, profound bass. Pick you're ol' cabinets with the Autobahn speakers and attach them!
There's no free lunch...as advertised: if you see the data that the manufacturers provide, you'll find diameter, Fs, sensitivity etc. etc. The distinction between Home speakers and Pro speakers follows the Iron Law: between going low, dimension and efficiency, you just pick two of them ( it was not well explained...go search! Hoffman's Iron Law). So having two 10" woofers, one 90 dB/W/m and the other 95 dB/W/m, the first will go lower in frequency.
SO for a 3.5 way speaker... you need a midwoofer that doesn't distort with low bass, 'coz it isn't high-passed
BUT there are many things to be considered before buying the speakers ( usually it takes some days to make the perfect configuration ). Crossover, the heart of a speaker, needs to be tailored to the specific models.
Tweeter: do you want it to stop at 18 kHz? Or go to ultrasonics ?
I did indicate a Dayton AMT-2...
So what's wrong with a 10" ? It's gigantic!
I'd keep the D54, put a Faital 6FE100 or 200 (double price! Why ?....search...) and a tweeter of the same ( sensitivity) league .
You'll lack bass. Wait! Before there's the construction of the crossover and the wiring...
Ok, now you lack bass, profound bass. Pick you're ol' cabinets with the Autobahn speakers and attach them!
Or you might choose to reduce its output via an L-pad and search for 90 dB drivers.
All my speakers have drivers that range from 85 to 90 dB, guess...the biggest woofer is a 6" !
(cheating: I have an ol' Vifa, well, two of them, that is a 8" ! )
I view a low efficiency speaker as 98 db 1w1m. My previous ones, stolen, were 101 db 1w1m. SP2-XT. OP has a big enough cabinet, just not wide enough for 15" woofers. OP would have to do some cabinet tricks like trapazoid cab and tuned padding to get 90 deg dispersion out of a 15", but a 12" it could be done in a parallelapiped cabinet.
That will be 250W "system power" not as often thought the power that the dome mid itself can absorb; if it is the IEC rating, that is with an appropriate crossover in front of it. So 15% of 250W = ~39W or so; the stepper the XO the more power it can handle in the long term
I'am not following you Moondog55.
Nominal power for D54 is given as 250W. That should be for driver itself in a given bandwidth, 800-7000Hz according to pdf datasheet.
Anyway, it looks much more robust to take 39W only.
Nominal power for D54 is given as 250W. That should be for driver itself in a given bandwidth, 800-7000Hz according to pdf datasheet.
Anyway, it looks much more robust to take 39W only.
Yes that "Driven" bandwidth is with the XO in front of it.
Fs is 350Hz so it's driven frequency is starting well above resonance. no way a dome with 1.5mm of X-Max can handle 250watts raw RMS. So 250Watts is total system power although it is rated at a 1000W system for transients that is again total system power.
People seem to be forgetting that the OP already has a pair of tweeters and his budget is extremely limited
Fs is 350Hz so it's driven frequency is starting well above resonance. no way a dome with 1.5mm of X-Max can handle 250watts raw RMS. So 250Watts is total system power although it is rated at a 1000W system for transients that is again total system power.
People seem to be forgetting that the OP already has a pair of tweeters and his budget is extremely limited
Still waiting on the box dimensions.
That woofer needs a big sealed box but in 120litres/150litres it models reasonably well, not really suitable for a vented box.
Qts of around 1 and about 105dB with 100 watts into it
I'd personally use it as a bass boost driver [ that .5 woofer] below 100Hz but the inductor wouldn't be cheap
That woofer needs a big sealed box but in 120litres/150litres it models reasonably well, not really suitable for a vented box.
Qts of around 1 and about 105dB with 100 watts into it
I'd personally use it as a bass boost driver [ that .5 woofer] below 100Hz but the inductor wouldn't be cheap
There are discrepencies between the .jpg d54af spec post #27, and the pdf file I downloaded. The pdf file indicates power handling of D54AF is ">100 watts IEC". I think IEC corresponds to AES peavey uses, but I'm not sure. Music power ratings in the US tend to be twice AES power.
On a more fundamental front, see post 42 of this thread https://www.diyaudio.com/community/...s-reflex-alignment.396836/page-3#post-7297494 by White Dragon who has been around the block. He is pessimistic of bass reflex box going on beyond Fs.
See this thread about "tight bass" of sealed versus boomy or whistling bass of reflex box. https://www.diyaudio.com/community/...gn-beginner.388191/page-4#post-7110089olsond3
In answer to post 128, box dimension is post # 6. Walls are 3/4" inside those. 160 L I estimate. Since OP listens to claasical tracks sometimes, I postulate system Q of 0.7 is best for him. Driver Qt is a driver spec, different than system Q, and determines how a driver fits sealed or bass reflex. Eminence states Qt< 0.4 vented only, >0.4 either way.
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Yes, there are discrepencies but both datasheets in #27 show DIN power ratings and lowest value I can see is 250W.
Honestly, I don't know how to turn DIN into IEC, but if someone has simple formula, please share.
And it looks like we need some clarification about that Dynaudio midranges. There are two versions:
D-54 AF is version without waveguide, flat front face. Given SPL is 94 dB/W/m.
D-54 is version with waveguide. Given SPL is 96 dB/W/m. Thats the one RevDev has, what his pictures show in post #9.
Except for waveguide (and different response as result), two versions are identical.
This is SPL (black line) and impedance (red line) chart from D54 pdf in post #27.
First on the left, from 0 to 50, are SPL values.
Zero level is 60 dB, as noted middle-below chart. For eg, 40 level is 100dB.
Second on the left, from 0 to 25 are impedance values, also written in red beside it.
From 2000-5000Hz SPL is 96dB.
At 1500Hz its 94dB
At 1000Hz its 89dB, and so on.
Its possible to cross D54 and Beta 12A at around 1500Hz with very nice results. I don't think 1500Hz is a problem for good 12in driver. Also, somewhat higher efficiency of Beta 12A makes simple to add around 3dB of baffle-step correction, just about right for average listening rooms.
With beyma, its possible to cross around 1100Hz, also with very nice results.
Even lower with Visaton.
Hello Indianajo, Davor D, Moondog55 and others. After reading and going back through I’ve decided to try the eminence beta12A woofers. Is there any chance you can help me know where and which crossover components I should select for this system? I have really no idea on mH or uF values, or even what type or vendor to buy through. I assume these woukd be relatively simple to recommend? I can see the above recommendation to cross the woofer over at 1500 Hz, but what do I need for that…and the for the tweeter? Thanks.
David Weems Designing Building Testing 4th ed suggests 1500 hz crossover 8 ohms 12 db/octave is 1.4 mH 10.6 uF Butterworth. 1.92 mH 7.5 uH Linkwitz-Riley. Inductor goes series woofer, capacitor parallel. Opposite tweeter.
Because of the 5 db rise 800-1500 hz I would have crossed the Beta-12a 6 db/octave at 1000 hz, but that is just my guess. That is 1.28 mH series 20 uf parallel. I would leave the D54AF 12 db/octave 1000 hz which is 1.8 mH 14. uf Butterworth and 2.56 mH 10 uf Linkwitz-Riley.
Actually what I would do is build the cabinet, run both pairs speaker wires out to the back. Then I would use the stereo channels of the power amp plus a graphic equalizer to set the best sounding or best measuring frequency response with the sliders of the equalizer. Then buy the expensive crossover components to see if I could replicate that. That way you can get back to one stereo amp.
I've picked up used 24 band stereo graphic equalizers for ~$60.
Because of the 5 db rise 800-1500 hz I would have crossed the Beta-12a 6 db/octave at 1000 hz, but that is just my guess. That is 1.28 mH series 20 uf parallel. I would leave the D54AF 12 db/octave 1000 hz which is 1.8 mH 14. uf Butterworth and 2.56 mH 10 uf Linkwitz-Riley.
Actually what I would do is build the cabinet, run both pairs speaker wires out to the back. Then I would use the stereo channels of the power amp plus a graphic equalizer to set the best sounding or best measuring frequency response with the sliders of the equalizer. Then buy the expensive crossover components to see if I could replicate that. That way you can get back to one stereo amp.
I've picked up used 24 band stereo graphic equalizers for ~$60.
I managed to make frd and zma files for Beta 12A and D54. When you decide on tweeter I can design you a custom x-over in Boxsim based on manufacturers measurements.
So, which tweeter you going to use?
The one from your post #36 looks good.
So, which tweeter you going to use?
The one from your post #36 looks good.
The scanspeak H2606 mounting diagram & description indicates it has to be loaded with a horn. May as well buy the horn at the same time to save shipping.
It is a horn tweeter, you don't have to buy the horn separately.
https://www.scan-speak.dk/product/h2606-920000/
https://www.scan-speak.dk/product/h2606-920000/
I don’t know if I need one. Someone had recommended a higher sensitivity one might match the mid and woofer better. I am ok with the Vifas or I can get a pair of the scanspeak. That doesn’t make much of a difference either way to me.
Perhaps DavorD would be kind enough to work out a decent XO for both options. The ScanSpeak is a re-work of an older Vifa model.