Hi everyone,
I have a plan to design an active 3-way using DSP. My reference is Genelec 1238. The speaker will be studio monitor for my upcoming studio.
I have success with 2-way system before using B&C DE250, B&C 12PLB100.
But 3-way is something more challenged that I am interested to try. Due to the unique waveguide of Genelec 1238, I dont think I can find a similar waveguide so I will rely on available parts on internet.
My general purpose is a speaker with:
1. High power handling to use as a main monitor (2-5m listening distance)
2. Accurate and effortless transient response in the whole frequency range
3. Using waveguide at least on HF unit to control directivity
4. Can reach down to 30Hz in-room effortlessly
5. It will be flushmounted in heavy brickwall
6. It can play really good at even low or medium SPL (75-95 dB SPL at the listening position)
7. Due to the room is normally small 20-35 m2 maximum, the speaker will never need to run at full power
My driver choice currently is:
1. 1" Compression Driver: B&C DE250
2. 8" Midwoofer: B&C 8PE21
3. 15" Woofer: This is the unit that I am not decided yet. My current selection list is: B&C 15TBX100, 15NBX100, 15NDL88.
4. Waveguide: I did not finalize on WG choice, too. My current plan is SEO-8 or SEO-10
Could you please help me to choose appropriate drivers and waveguide?
I prefer B&C drivers as I have great experience with them before. My budget for LF unit is around 200-300$. I prefer woofers with high motor strength, low enough moving mass, coated cone and has demodulation ring. I really need the dry, tight and focused LF transient sound.
Thank you very much.
I have a plan to design an active 3-way using DSP. My reference is Genelec 1238. The speaker will be studio monitor for my upcoming studio.
I have success with 2-way system before using B&C DE250, B&C 12PLB100.
But 3-way is something more challenged that I am interested to try. Due to the unique waveguide of Genelec 1238, I dont think I can find a similar waveguide so I will rely on available parts on internet.
My general purpose is a speaker with:
1. High power handling to use as a main monitor (2-5m listening distance)
2. Accurate and effortless transient response in the whole frequency range
3. Using waveguide at least on HF unit to control directivity
4. Can reach down to 30Hz in-room effortlessly
5. It will be flushmounted in heavy brickwall
6. It can play really good at even low or medium SPL (75-95 dB SPL at the listening position)
7. Due to the room is normally small 20-35 m2 maximum, the speaker will never need to run at full power
My driver choice currently is:
1. 1" Compression Driver: B&C DE250
2. 8" Midwoofer: B&C 8PE21
3. 15" Woofer: This is the unit that I am not decided yet. My current selection list is: B&C 15TBX100, 15NBX100, 15NDL88.
4. Waveguide: I did not finalize on WG choice, too. My current plan is SEO-8 or SEO-10
Could you please help me to choose appropriate drivers and waveguide?
I prefer B&C drivers as I have great experience with them before. My budget for LF unit is around 200-300$. I prefer woofers with high motor strength, low enough moving mass, coated cone and has demodulation ring. I really need the dry, tight and focused LF transient sound.
Thank you very much.
Sounds like a good plan. For your woofer look for the most xvar you can afford if sticking with B&C. The SW/TBW series has great specs but more expensive. LaVoce makes drivers nearly identical to B&C's performance for lower prices in some areas.
I would even go up to an 18" crossed between 200-300hz to the 8". 18TBW100 is a very nice driver.
Waveguide choice looks good.
Get your crossover right with real acoustic measurements and you'll have world class sound.
I would even go up to an 18" crossed between 200-300hz to the 8". 18TBW100 is a very nice driver.
Waveguide choice looks good.
Get your crossover right with real acoustic measurements and you'll have world class sound.
If you want best performance, speakers and room should work together. Do you have a floorplan for the studio? I'd imagine polar response should be dictated by the room dimensions and listening area.
Regarding drivers and horn, i'd have superior horn made, designed with ATH4 software found in another thread. Then a woofer that matches directivity of the horn at crossover and plays as low as possible in sealed enclosure with possible enclosure size constrains and third would be 18" subwooofer driver to get the low frequencies you desire. Pretty easy to build beside the horn, that could be cnc'd or even 3d printed.
All this because 8" driver I have and what other drivers spec sheets seem to indicate they have a lot of wiggles in impedance and frequency response smack dap the whole band they are supposed to cover and that feels silly. Not seen 8pe21 though. Only reason you need small driver is to be able to cross to a tweeter while maintaining the horizontal polar response smooth. But, a compression driver can be crossed lower to mate directly to a 12" or 15" driver. Now you are in the 2 way territory that can play to 100hz almost regardless of the chosen driver 🙂 Then a subwoofer driver, which has proper mass and thus low fs, and proper cone area to really properly go to the 30hz you want. I've got a 15" pro driver, that doesn't go low no matter the cabinet design and it doesn't even reach the datasheet spec in home use (low power). Use DSP crossover. If this feels overkill, I'd look for 6.5" mids and ~8" waveguide. Have fun!🙂
Regarding drivers and horn, i'd have superior horn made, designed with ATH4 software found in another thread. Then a woofer that matches directivity of the horn at crossover and plays as low as possible in sealed enclosure with possible enclosure size constrains and third would be 18" subwooofer driver to get the low frequencies you desire. Pretty easy to build beside the horn, that could be cnc'd or even 3d printed.
All this because 8" driver I have and what other drivers spec sheets seem to indicate they have a lot of wiggles in impedance and frequency response smack dap the whole band they are supposed to cover and that feels silly. Not seen 8pe21 though. Only reason you need small driver is to be able to cross to a tweeter while maintaining the horizontal polar response smooth. But, a compression driver can be crossed lower to mate directly to a 12" or 15" driver. Now you are in the 2 way territory that can play to 100hz almost regardless of the chosen driver 🙂 Then a subwoofer driver, which has proper mass and thus low fs, and proper cone area to really properly go to the 30hz you want. I've got a 15" pro driver, that doesn't go low no matter the cabinet design and it doesn't even reach the datasheet spec in home use (low power). Use DSP crossover. If this feels overkill, I'd look for 6.5" mids and ~8" waveguide. Have fun!🙂
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The waveguide seems too small. I would use either the parts express pt 12", jbl clone OR tbe b52 14" qsc clone. Both are excellent
I think the Seos 8 or 10 waveguide is large enough for a 8" mid, but the DE250 is not an "outstanding" 1" CD. Although if you like it...
Here is an 1" comparison test:
Grand Comparatif de Compressions 1 pouce - JustDIYIt !
Here is an 1" comparison test:
Grand Comparatif de Compressions 1 pouce - JustDIYIt !
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Thank you. I also noticed the TBW series. However, as you said, they are really expensive (especially when include tax and oversea shipping cost 😱 ). We are still debating about this woofer to see if it is really worth the additional cost.
You suggestion regarding go all the way to 18inch woofer is really great. It open up something we have not thought about. However, I guess it will make the cabinet much much bigger. 🙁
Thank you. We have some experience with acoustics design. Our recent studio has really really fast decay rate at LF and the frequency response is really flat down to 20Hz (dual 2x12 LAB12). We will try our best to have the best possible room for this speaker.
The most important thing for me when considering the 18inch is how they perform at low level. We, as mixing/mastering engineers, normally mix at 75-85dB SPL at listening position. Should a 18in driver work properly at that really low level for them?
At our recent studio, we installed our 2-way main (12PLB100 + DE250) with a pair of dual 2x12 LAB12 (which should match a pair of 18in sub), the sound is really good.
However, we want to have a complete 3-way main monitor option (not 2-way main + sub config) to try new things and to test if the mid come from true midrange driver can outperform the mid come from 12PLB100 or not.
Thank you for mentioning your waveguide. I will look for it soon.
We have here H290C, QSC 152 and Dayton's JBL clone horn, all are 12-15inch. However, they look ridiculus when pairing with a 8inch mid 😀
Thank you for great comment on B&C DE250 and the link to the great article. I am also testing CDX 1745 and CDX 1747, they perform really good compared to DE250.
Which 1" CD would you recommended for my application? Genelec 1238 use 1" metal dome tweeter, however, I dont know if their choice work with my particular case. 😕
Personally I recommend one of the 18sound Ti driver. These metal diaphragms with soft poly surround can do something.
I choosed the ND1090 because of the above linked test and it didn't disappoint. They simply amazing (although not inexpensive), my previous SS Illuminators went to the shelf.
Edit: there is a cheaper model with the same diaphragm as the ND1090 but with a ceramic magnet (and assuming a slightly simpler motor) instead of neo, the HD1050. This used in some commercial speakers like Unison Research Max 1 or so.
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Thank you for your suggestion, ND1090 is very good according to the article. However it is really hard to get in USA 🙁
Hi,
yeah it might be so that some/most PA drivers meet their specsheet performance with PA use and not in home use. At least the 15" PA drivers I have Fs should be 38Hz according to specsheet but actually is 48Hz when measuring TS parameters. Factory said it should be warm when measuring etc.. anyway, the point is by choosing proper subwoofer driver with way low Fs you should be quaranteed low end extension. Even if the Fs was above the specsheet value when listening at low SPL it still should be close at your 30Hz. I don't have experience on B&C drivers and not much experience in general how PA speakers measure. Anyway, buy drivers and measure the TS parameters and you'll see if they meet your design criteria. Buy another set if not. 🙂
About the waveguide, I haven't designed any yet. I would design if I was you 😉 The design program is by member mabat and there is lots of discussion about waveguides in the Ath4 thread. Worth checking if you have time. Otherwise I suggest buy some ready made waveguide you like to get the project going. Btw. 8pe21 specsheet curves look nice. Just build speaker version number 3 after this project, if not satisfied 😉 Good luck!
Check this shop, they ships to USA too:
Lean Business - Outstanding Audio, Guitar Speakers and PA Speakers specialist
I doubt you'll notice any deficiencies if you do your speaker processing eq at 80db at the listening.
18TBW100 is 344.00 free shipping at partsexpress.
Sound like a good plan!
With a well behaved midrange like that, the crossover becomes much easier. Easy is important even with DSP because a crossover can make or break a speaker. I know you'd like to keep it all in the B&C stable, but also have a glance at the Eminence Beta-8A which is a similar great sounding driver that is easy to cross.
With a well behaved midrange like that, the crossover becomes much easier. Easy is important even with DSP because a crossover can make or break a speaker. I know you'd like to keep it all in the B&C stable, but also have a glance at the Eminence Beta-8A which is a similar great sounding driver that is easy to cross.
Cone looks almost exactly the same between the Beta 8 and 8PE21
Except the B&C has copper in the motor. Or used to. Don't see it in the spec sheet anymore.
Except the B&C has copper in the motor. Or used to. Don't see it in the spec sheet anymore.
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If it has a copper shorting ring, that should help lower distortion. I can vouch for the Beta-8A being an excellent clean driver. It doesn't look fancy, but it sure sounds good. The B&C ought to be as good.
Both eminence an b&c have nice frequency response but lots of things going on in the impedance plot as well as other 8" pro drivers. Is there such 8" driver that didn't have any resonance from say 400hz to 1khz? I should try add some dampening stuff to the cone edge and see if there is any difference in inpedance plot.
6.5" drivers seem to have less resonance there, like this one B&C Speakers 6ndl38 or this FaitalPRO | LF Loudspeakers | 6RS140
6.5" drivers seem to have less resonance there, like this one B&C Speakers 6ndl38 or this FaitalPRO | LF Loudspeakers | 6RS140
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The 8PE21 is an excellent midrange driver, it's especially aimed at driving a horn. This means it has a strong motor and a mild sloping response to match. Although such things can be equalised, its efficiency comes at the expense of a smaller xmax.
Have you studied the JBL CMCD-82, an 8" compression driver which covers 200-2,000Hz in the JBL Progressive TransitionTM (PT) Waveguides.
PT-K95MH waveguide (90° x 50°, 18 x 18in, rotatable.
PT-K64MH Mid-High Frequency 60° x 40° rotatable.
I have seen used CMCD-82 on ebay.
JBL sells several products using the CMCD-82
JBL Powered 15 in. 3-way Integrated Loudspeaker System - VP7315/64DPDA
PT-K95MH waveguide (90° x 50°, 18 x 18in, rotatable.
PT-K64MH Mid-High Frequency 60° x 40° rotatable.
I have seen used CMCD-82 on ebay.
JBL sells several products using the CMCD-82
JBL Powered 15 in. 3-way Integrated Loudspeaker System - VP7315/64DPDA
The 12PLB100 I tested before with REW at both Low and High SPL show exactly the same frequency response. I also notice a little different of the sound between Low and High SPL playback, but I think it is mostly due to how our ears feel the sound at different SPL.
My skill and knowledge about waveguide is extremely limited so I rely a lot on well establish waveguide as they are easy to get or replace if I messed up something, lol.
Thank you, I found them before, too. However, when calculating shipping cost and tax, it is way above my intended budget for CD 😡
I tested CDX1745 today, it is almost the same as DE250. I hope CDX1747 will be better. In my place, I can get B&C, Eminence and Celestion quite easily.
Thank you, I have modeled the 18TBW100, it need really big enclosure. I dont even know how to fit that monster cab in my space 😀 That is one of the reason I want to go with a 15".
Thank you very much. I also tested several Emi drivers, They perform quite good on frequency response and THD. However, when listen to them, I still find them not satisfying as B&C. I have Emi 4012HO and B&C 12PLB100 in the same configuration with H290c horn and DE250, the 12PLB100 outperform 4012HO in every way. And 12PLB100 also sound much tighter and clearer. So this time, I want to put my risk on trying B&C drivers that I have never used before because I have more faith in them at the moment. I hope I will not have to pay big price or learn something hard way 😀
In description of Part Express, the 8PE21 has demodulation ring inside the motor. That is one of the reason why I choose it over Delta Pro 8A
Yeah, I think so.
Do you think 6.5" driver is suitable for my application? I thought in order to match with 15" LF unit, I have to use 8" mid if the mid driver is direct radiator?
Does it means that if I use 8PE21 as direct radiator, I have to cross it a little high (for example: 500-600Hz)?
Thank you for your suggestion, I would love to use JBL's waveguide too but I dont have plan to use JBL because their parts are not easy to buy and their drivers are generally on really expensive side. A 2" CD cover 200-2000Hz must be really really expensive @@. But I am pretty sure they sound really good.
15TBW100 is your next best choice for maximum output from a 15" at your price range from B&C.
https://www.parts-express.com/bc-15tbw100-15-professional-woofer-8-ohm--294-5991?__cf_chl_jschl_tk__=bd2ebd5ede4c7be856443b742a8401c6872b8b83-1588908349-0-ASoSCq0Av0pIXXN_sUQ6YSPnZWHLx7_g4lFucDlwNEXmjvrJwBHKoDOMZuVx_1VorpkDBGoSwA7sqFnJV8LS7LJrGwOG_Qr_1_02cog7-nZS3helNGvKuJmFFtmENdXRh8eshDm8wcbeN_Zz-klTapV4nYQoUXnUObJU3ubP2ZHIoir5AtPqNjP8tk1y02V_c3PbmHqDg6VMyATrG1bjXBWuK0i-_aDybGkpB9KObpPC7Zs56e-F3h2Js0ycYXj1N9mRPYcvlur7A0UVYnUjJQAT6EWkRAR9TNl6UeiKyJHAL72m7JzieIXRP3zUNWBB54dlB_p2D04a5A82wENBl5w
The 8PE21 will be fine crossed between 200-400hz to the 15" at the spl's you're looking at.