Ok, so lately I've been mulling over the idea of making a floor standing 3 way speaker. I've played with too many 2 ways and I'm getting bored. Time to try something bigger!
I've still got a couple of Peerless 831759's available, and a couple of Vifa SC14SG-49 midbass and a couple of Vifa AC25TG05-04 soft domes.
I've considered crossover points perhaps 700/4000.
I'd like to make a fairly large cabinet with enough space (guessing 150L perhaps?) to use a 3"x 11" or so port for the peerless 10 to get it down somewhere in the neighborhood of 25-28 cycles.
Does anyone have any input on those crossover frequencies? I haven't tried to set out designing one yet (I'm usually pretty bad at it and would end up having to ask for help anyway!) but I'd really like to try my hand at a large, classic speaker, you know, the kind with terrible WAF.
Any comments, suggestions or fun-pokes are welcome!
I've still got a couple of Peerless 831759's available, and a couple of Vifa SC14SG-49 midbass and a couple of Vifa AC25TG05-04 soft domes.
I've considered crossover points perhaps 700/4000.
I'd like to make a fairly large cabinet with enough space (guessing 150L perhaps?) to use a 3"x 11" or so port for the peerless 10 to get it down somewhere in the neighborhood of 25-28 cycles.
Does anyone have any input on those crossover frequencies? I haven't tried to set out designing one yet (I'm usually pretty bad at it and would end up having to ask for help anyway!) but I'd really like to try my hand at a large, classic speaker, you know, the kind with terrible WAF.
Any comments, suggestions or fun-pokes are welcome!
Thank you Loren
I do have several such sites bookmarked that I use from time to time. They are a good starting point, but usually the finished crossover design ends up being quite a bit different
Thank you Loren
I do have several such sites bookmarked that I use from time to time. They are a good starting point, but usually the finished crossover design ends up being quite a bit different
Here are my observations/questions:
1. What is your selection criteria for 700 and 4,000 Hz as your crossover and how did you arrive at those numbers? Can yo
2. Why the shelf port versus a round port?
3. Why the large port area?
4. Have you calculated the shelf port length?
5. Why did you select 5.3 cubic feet for the box size? At 100 Watts you reach xmax at 45 Hz.
1.) Just from observation on frequency responses and what looks like good places to cross the drivers over before they start to get messy.
2+3+4.) It's a round port of PVC pipe, 3" in diameter and 11" long. I'm using it as a starting point because it's the same size and shape of a port used in a small cube subwoofer that was designed with this woofer that was tuned to 26 cycles. (well small, it's about 26"...let me go measure it....more like 22" square.)
5.) I'm not entirely sure what the size is going to end up being, I just had the looks of the box in my head and threw out that number, chances are it's going to be pretty different.
edit: 6.) You'll have to excuse my napkin scribblings, quite often I'll have a few beers and come up with something that I have to share, lol.
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I don't have your specific woofer on file, but I bet if I ran it in LEAP I would see some pipe organ effect on the port. It may not be big, but having such a high crossover for the woofer invites the possibility of port noises and issues with the woofer cone break up (wherever that really is for that driver).
What works well for a sub does not necessarily lend itself to a multiway speaker. Generally the sub uses larger port area to reduce port noise, but cut the woofer off early before pipe organ effects take place (i.e., below 200 Hz). For a multiway you have to balance port noise with the pipe organ effect (if present), so the design is a compromise either way.
One of the virtues of a 3-way is getting a lower crossover for the woofer than you would for a 2-way and letting a mid carry some of that load. 700 Hz may not work well in this case, but without going through a lot of testing and modeling I just don't know.
All of these things are just things you need to consider and are not necessarily gospel.
Right. I had not really considered this. Perhaps it would be better off sealed, or ported if I drop the crossover frequency down a bit.
Sealed might be the way to go, part of the reason I was looking to build a 3 way like this was to have great power handling by letting the large driver cover as much of the band as it could.
Yeah, I've got several designs here that use that driver, all of them are vented.
I didn't come up with them, and a lot of this stuff I'm still learning.
A 3 ways is an other playing game ! Less hard to make the crossover but is a nightmare to tune for a beginner. You will learn a lot of thing
The sound will be better. If it is easy to place a driver in box and make a crossover, it is more difficult to make a loudspeaker sounds well (it 's my opinion)
First advice, invest in a microphone and a soundcard (perhaps you have one)
You can use a software like HOLM or ARTA etc.
To simulate the crossover you can use speakerworshop or PCD
For me it is a reference project in the way to do :
http://www.diyaudio.com/forums/multi-way/140324-astasia-prject-3-ways-loudspeakers.html
Projet ASTASIA I -Seas CA22RNX + MCA15RCY + Vifa XT25TG30 - Enceintes
Sorry in French but you can see what he does if you browse the first pages (a translator could be used). I helped a little in this project. The first crossover didn't sound well at all, bad measurements and bad crossover slopes.
- Calculate the volume of the box
- Simulate the driver placement
- Do the measurements
- Choose the crossover point
- Simulate the crossover
- Make the crossover
- Listening to tune the different levels
etc.
Some links
http://www.diyaudio.com/forums/mult...designing-crossovers-without-measurement.html
FRD Consortium
Sorry but a lot of reading.
About your project and you drivers.
The sensitivities seem compatible. woofer 91dB midrange 87dB tweeter 90dB ?
WINISD said 36L@32Hz F3=40Hz (Fs 22Hz QT 0.28 Vas 121L)
Usually a 10" can go in 70L@32Hz F3=30Hz
port 4" x 10"I don't recommend to make a too big cabinet because you cross the 10" high 700Hz.
The crossover points without measurements are difficult to determine because you can have diffraction problems. 700Hz, 4kHz seem to me good points. I think you have a range 300Hz-4kHz.
Have a lot of fun
Have a lot of fun
Thank you again Jerome
I've still got the parts set to order for the 2 way you helped me with, that one will be done before this one.
I hope to be able to start on this one this month after I finish up the 2 way and get it perfect. It's already very good with approximate parts.
The links are great, I can read French
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