You are all very sweet for putting up with me for this long. It's greatly appreciated.
The JBL's are fine down to 130hz in a small open back enclosure (db drops off gradually from 130-60-ish hz).
Giving the timpano's a ported cubic foot brings to 54hz. So this was the idea...
3khz and 6khz are safe cutoffs but chosen arbitrarily.
Any tweeter Im looking at goes down to at least 3.2khz.
So... am I amble to keep the mismatched pair of woofers I have as long as each has a correct enclosure. That was always the plan all drivers are isolated within the enclosure.
The JBL's are fine down to 130hz in a small open back enclosure (db drops off gradually from 130-60-ish hz).
Giving the timpano's a ported cubic foot brings to 54hz. So this was the idea...
3khz and 6khz are safe cutoffs but chosen arbitrarily.
Any tweeter Im looking at goes down to at least 3.2khz.
Let's take that as a plan.
All you need now are:
All you need now are:
- The port dimensions (area and length).
- A 3-way or 2.5-way crossover network to suit your chosen crossover frequencies and driver impedances.
- Resistors to level match the JBL and the tweeter with the Timpano if necessary.
- A lot of luck!
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I'm sorry to be a butthead, I have read AllenB's tutorial as well as others. 3 more questions and I can start.Let's take that as a plan.
All you need now are:
How am I doing AllenB? Am I playing things too close to my chest?
- The port dimensions (area and length).
- A 3-way or 2.5-way crossover network to suit your chosen crossover frequencies and driver impedances.
- Resistors to level match the JBL and the tweeter with the Timpano if necessary.
- A lot of luck!
1) If using 12db highpass filter on the tweeter, 12db lowpass filter on woofer. Why use the same cut off frequency for both, as opposed to using the points where the DB balances out.
,,,If my thinking makes sense, In the example bellow, in example A, volume would be nearly twice as loud at 6khz (tweeter and woofer playing at the same db at the same time). In B, volume is half as loud using 5.25k and 7.5k cutoffs. So shouln't Optimal highpass cutoff be between 6k and 7.5k. and optimal lowpass be between 5.25k and 6k?
2) Should I start with 6db filters for the woofer filters and 12db for the tweeter's highpass filter (or 12db for everything?)
3) What is the safe db for a tweeter's Fs (ie if Fs is 2500, is -12db filter at 5000hz, AND -6db at 7500hz "safe") am I undersntading that correctly?
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- Crossovers calculators work on the principle that the the signal level will be -3 dB at the crossover frequency.
- Certainly use 12 dB/octave for the tweeter, the other drivers can be 6 dB/octave if you want to save on componentry.
- Crossover at least one octave above the tweeter's resonant frequency when using a 12 dB/octave crossover e.g. 5,000 Hz if fres is 2,500 Hz.
Yes. The midbass handles everything above 80, the subwoofer handles everything under. But it has a semi wide rolloff so the kids actually get down.
P.S. For completeness, when using a 6 dB/octave slope on a tweeter, the crossover frequency should be at least two octaves higher than the resonant frequency i.e. 10,000 Hz if fres is 2,500 Hz.
If I'm bugging you don't answer. 😛
Why did you choose that specific tweeter. I was considering Peerless BC25SC06 but there are a ton of options around that price point (only because the sensitivity is closest to be woofers).
understood thank you. I'll order the parts, slap this thing together then ask more questions or delete my account out of shame. 🤔
There's some really approachable information in this link about how to determine crossover frequencies:
https://soundcertified.com/how-to-determine-speaker-crossover-frequency/
Useful fact: In electrical power terms, the 3dB volume reduction point is the frequency at which the power to the speaker is reduced by 1/2.
https://soundcertified.com/how-to-determine-speaker-crossover-frequency/
Useful fact: In electrical power terms, the 3dB volume reduction point is the frequency at which the power to the speaker is reduced by 1/2.
I tried about a dozen different ones that were $10-$25ish price point. These just sounded the best to me. I have been trying different combos and crossover combinations for a few months to get to this design
I'll keep working with what I bought unless I hit a roadblock. Keeping the timpano's for sure (it starts getting little peaky at 4500hz, seems like a good choice no matter where I land).
I've heard a lot of bad coax speakers that I think the $30/pair JBLs are a hidden jewel in the budget speaker market. I need to plot it's response with the tweeters cut but I think they'll work fine, if they don't Ill save them for some other project.
The silk dome tweeters aren't loud enough they go back. So its between a pair of aluminum compression tweeters that have a 2.8-20k frequency that I haven't tried yet , or something new from parts express.
Senstitiviy on JBL and Timpano woofers is 94db, 95db on the tweeters. It might all come together.
Im doing a basic order from parts express. Then a bigger order when I come across inevitable issues. Tweeters can be swapped out then.
We're a month away from the annual bulk pickup day. Might get lots of new parts to swap with then.