Hello to everyone! I'm really new to the building of loudspeakers and I've decided to build a 3 - way speaker. I picked my drivers from Dayton:
Subwoofer: RSS210HF-4 8" Reference HF Subwoofer 4 Ohm RMS: 280 watts
Mid: PM180-8 6-1/2" Neo Wideband Midbass Driver RMS: 30 watts
Tweeter: ND25FA-4 1" Soft Dome Neodymium Tweeter 4 Ohm RMS 20 watts
I designed my crossover on vituix and I've attached my design.
My questions are
1. What exact amplifier should I get? I've read so many articles about this and was still unsure: Some say 2 x the subwoofer (which in my case = 560 watts) I am afraid that it might burn my tweeter. I've originally decided to use one amp to power all but if not possible, will two amps affect my crossover? If two amps are a better choice, which ones should I get and how should I connect them together?
2. I've noticed that the lower end of my impedance dropped to about 3.5 ohms, Is that a bad thing?
3. Is my SPL curve good enough? IF not please let me know which part needs to be improved!
4. If there's anything ridiculously wrong in the charts please let me know that as well!
Thank you all for your time!
Subwoofer: RSS210HF-4 8" Reference HF Subwoofer 4 Ohm RMS: 280 watts
Mid: PM180-8 6-1/2" Neo Wideband Midbass Driver RMS: 30 watts
Tweeter: ND25FA-4 1" Soft Dome Neodymium Tweeter 4 Ohm RMS 20 watts
I designed my crossover on vituix and I've attached my design.
My questions are
1. What exact amplifier should I get? I've read so many articles about this and was still unsure: Some say 2 x the subwoofer (which in my case = 560 watts) I am afraid that it might burn my tweeter. I've originally decided to use one amp to power all but if not possible, will two amps affect my crossover? If two amps are a better choice, which ones should I get and how should I connect them together?
2. I've noticed that the lower end of my impedance dropped to about 3.5 ohms, Is that a bad thing?
3. Is my SPL curve good enough? IF not please let me know which part needs to be improved!
4. If there's anything ridiculously wrong in the charts please let me know that as well!
Thank you all for your time!
This is an unconventional 3 way design. Its more of a 2.5 way. A mid in a 3 way would normally be about 3 to 5 inches in diameter. You have attenuated the mid with a 15 ohm resistor then compensated with the woofer to bring sensitivity back up. The wideband mid-woofer has a rising frequency response which would be difficult to blend with the tweeter. It has higher sensitivity that the tweeter above 1kHz, normally the mid-woofer would be lower sensitivity than the tweeter then you would attenuate the tweeter to match. I would also look up 'baffle step compensation' (bsc) to incorporate into your design.
Thank you for your reply!
I’d like to know is it better for me to switch to a more mid focused driver instead of the 6 1/2 one? Did the SPL curve look weird to you (my humble knowledge only tells me the flatter the better)? What’s more could you give me any advice on the amp that I should use to power the drivers? It’s the part that I’m most confused and concerned. Again, huge thanks 🙂
I’d like to know is it better for me to switch to a more mid focused driver instead of the 6 1/2 one? Did the SPL curve look weird to you (my humble knowledge only tells me the flatter the better)? What’s more could you give me any advice on the amp that I should use to power the drivers? It’s the part that I’m most confused and concerned. Again, huge thanks 🙂
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I think you are running down a rabbit hole here with this question.
In your model, see how much power you need for what sound level you want.
Most people buy way too big an amp because "bigger is better" nonsense.
About any amp over 100W should be able to exceed safe SPLs in a domestics setting.
mili Ohm on the tweeter?
Pay attention to Stal
Have you read any of the SOP books on loudspeaker design or just dove in. Brave, but there is a reason we study the science.
You can't trust the advertised impedance and response curves, You need to measure the drivers yourself IN SITU.
I use a different tool, but your source impedance is not 4 Ohms. More like half of an ohm.
Are you aware that a 4 Ohm speaker causes much higher distortion in the amplifier, and most AVRs or less expensive amps are not stable into 4 Ohms.
The baffle design, dimensions and driver positions effect the crossover as well as offsets.
I recommend one's first project is to build a kit, but go through all the measurement and simulations the designer did. That gives you something to see what tradeoffs the designer made and you can verify your learning to measuring against a known result.
Might I suggest maybe using your mid-woofer and tweeter as a first project. Do a conventional 2-way monitor. Then think if you want to evolve it into a 3 way, or maybe build your woofer as a sub with a small plate amp. Another way to learn a bit more is to use a plate amp with DSP, so you are not dealing with passive crossovers first off. You may fond the "modern" way to be to your taste. You can manage the different efficiencies easier. Warning, even with it's own amp ALWAYS use a blocking cap in the tweeter.
In your model, see how much power you need for what sound level you want.
Most people buy way too big an amp because "bigger is better" nonsense.
About any amp over 100W should be able to exceed safe SPLs in a domestics setting.
mili Ohm on the tweeter?
Pay attention to Stal
Have you read any of the SOP books on loudspeaker design or just dove in. Brave, but there is a reason we study the science.
You can't trust the advertised impedance and response curves, You need to measure the drivers yourself IN SITU.
I use a different tool, but your source impedance is not 4 Ohms. More like half of an ohm.
Are you aware that a 4 Ohm speaker causes much higher distortion in the amplifier, and most AVRs or less expensive amps are not stable into 4 Ohms.
The baffle design, dimensions and driver positions effect the crossover as well as offsets.
I recommend one's first project is to build a kit, but go through all the measurement and simulations the designer did. That gives you something to see what tradeoffs the designer made and you can verify your learning to measuring against a known result.
Might I suggest maybe using your mid-woofer and tweeter as a first project. Do a conventional 2-way monitor. Then think if you want to evolve it into a 3 way, or maybe build your woofer as a sub with a small plate amp. Another way to learn a bit more is to use a plate amp with DSP, so you are not dealing with passive crossovers first off. You may fond the "modern" way to be to your taste. You can manage the different efficiencies easier. Warning, even with it's own amp ALWAYS use a blocking cap in the tweeter.
Hi! Fi
Hi! First of all I sincerely thank you for your advice. As for this project, I wanted to build a floor Bluetooth speaker with stand next to my TV in a room of 5 x 6 meters. The approximate size for the cabinet is around 60 x 40 x 20 cm. Do you have a recommendation of driver sizes(combination) for a 2-way or 3-way layout or any kits that you recommend? Thank you so much.
Hi! First of all I sincerely thank you for your advice. As for this project, I wanted to build a floor Bluetooth speaker with stand next to my TV in a room of 5 x 6 meters. The approximate size for the cabinet is around 60 x 40 x 20 cm. Do you have a recommendation of driver sizes(combination) for a 2-way or 3-way layout or any kits that you recommend? Thank you so much.
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If you have picked a cabinet size, then you need ot search for drivers that fit it. Usually, we select a driver , simulate it and then decide if it fits our needs. Now you have added i the requirement for BT, which changes any suggestion of amplifiers to one that has BT.
I am not sure why you want to take this on without doing a lot of study. Designing speakers is an engineering process. Might I suggest going to Parts Express, Madisound and Meniscus to look at their kits?
I am not sure why you want to take this on without doing a lot of study. Designing speakers is an engineering process. Might I suggest going to Parts Express, Madisound and Meniscus to look at their kits?
Thank you for your reply! I'm sorry if I am in a bit hurry of this. I'm an industrial design student and this is one of personal projects. I know pretty much nothing about electronics prior to this project and therefore trying to take some shortcut (preassembled board, kits, etc..). I understand it can take many years to understand the theories of sound and I've read through all your comments carefully. It's just that unfortunately I don't have enough time to learn more about the whole picture of loudspeakers. Thank you for all the information and I'll look into the kits on the websites u mentioned. 🙂
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tigerzhang, please don't quote the post directly above yours.
Back to original question. With that 3.5 ohm impedance, I'd buy an amp with at least 2 pairs output transistors per channel. Here in US used Peavey PV-4c and M-2600 are not too expensive. Overseas NAD C370 might work. If you want built in speaker protection relay a Peavey CS400 or QSC PLX1202 might be more the ticket.
Usually in a 3 way crossing the tweeter above 1100 hz is normal. This prevents it from consuming 40% of the power on pink noise. (AES rating) Power ratings of tweeters are usually much lower than mid or woofer. Incandescent bulb series tweeter for protection against huge pops is usual.
If I ever hosted a party I might want more power rating of the mid than 30 W. Say 100 W at least?
You've got as much money in your crossover (if MKP & 15 ga) as your drivers. A 2 way willl cover 54=20 khz and have 2 coils, 2 capacitors, and a tweeter resistor + protection. https://www.diyaudio.com/community/threads/efficient-2-way.380822/
Usually in a 3 way crossing the tweeter above 1100 hz is normal. This prevents it from consuming 40% of the power on pink noise. (AES rating) Power ratings of tweeters are usually much lower than mid or woofer. Incandescent bulb series tweeter for protection against huge pops is usual.
If I ever hosted a party I might want more power rating of the mid than 30 W. Say 100 W at least?
You've got as much money in your crossover (if MKP & 15 ga) as your drivers. A 2 way willl cover 54=20 khz and have 2 coils, 2 capacitors, and a tweeter resistor + protection. https://www.diyaudio.com/community/threads/efficient-2-way.380822/
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