By the way, before adding to the crossover the Rp1 Rp2 tweeter pad, also try an R1 with a higher value. Something between 27-33 Ohm 10W. That should lift the paralleled drivers impedance and open up the mids so the tweeter will not be sticking out that much anymore and the bass may seem less unruly in smaller spaces. The amp will like it better as a load too. In case you will not like it, simply stick to Vikash's schematic.
For the tweeter I wasn't going to use an actual L Pad, but rather wire in 2 resistors as per the schematic (1 x 1 Ohm & 1 x 10 Ohm).
Is that OK?
Let me understand your instruction.
Are you saying to discard the resistors in the tweeter circuit whilst trying out a 33 Ohm resistor inplace of the 10 Ohm resistor in the woofer circuit?
Thanks Salas.
My only problem is that I don't know what the tweeter crossover schematic was prior to Vikash's schematic.
Were there any R resistors in the circuit prior to the L Pad arrangement?
Only one parallel to the woofers I would understand. Did you find evidence of more in the speaker?
Good point. There is only one resistor in each of the crossovers.
So in summary, I'll remove Rp1 Rp2 from the tweeter circuit leaving it without resistors, and fit a 33 Ohm 10W Resistor in the Woofer circuit in place of the 10 Ohm resistor appearing in the schematic. Thanks
Yes, try that minimum modification first and if not satisfied apply the Vikash's schematic to the letter.
To finish my shopping list, I was hoping to get an understanding on Inductor selection.
Air core is preferable, but I need to get on top of best performance vs outlay.
The existing Inductor values are 243 uH & 633 uH.
From the availability list I'll be selecting 0.25mH & 0.65mH.
Which awg values do you recommend? 15awg or 18awg?
Air core is preferable, but I need to get on top of best performance vs outlay.
The existing Inductor values are 243 uH & 633 uH.
From the availability list I'll be selecting 0.25mH & 0.65mH.
Which awg values do you recommend? 15awg or 18awg?
Thanks, I missed that.
The crossovers are smothered in clear glue so I'll be working on disassembly so I can remove and measure the Inductors.
Not being a fan of iron core I'll probably be discarding these in favor of some decent air core replacements.
The square foam covers at the bottom front of the speakers are all missing.
For aesthetics what type of foam should I look for?
Something which won't affect sound reproduction.
thanks
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These covers probably play more than an aesthetic role. It could be needing their acoustic resistance. Use open cell foam. Also don't rearrange the internal damping material.
This speaker is not a true labyrinth one but more of an aperiodic vented approach. They called it RTL not TL. The clue is in the marketing details.
This speaker is not a true labyrinth one but more of an aperiodic vented approach. They called it RTL not TL. The clue is in the marketing details.
Thanks.
With the front covers, will 10mm thick open cell foam do?
The trouble with the existing internal damping material is that I don't know if someone has already rearranged it.
Also an earlier thread suggested additional damping should be placed around the tweeter as it tends to be on the sharp side.
Given your instruction should I not proceed with this?
These were made with little damping on the inside, a fairly budget model. Fish tank filter foam is suitable for the port covers
The tweeters were set too loud and the resistors were under-sized and tended to burn
The tweeters were set too loud and the resistors were under-sized and tended to burn
Thanks David.
I'll be omitting resistors in the tweeter section of the crossover and fitting a 10w 33ohm resistor on the woofer circuit.
The advice is that this should sort out the midrange hole and reduce the gap allowing the tweeter to blend in rather than stand out.
Thanks for the filter reference.
Just to clarify things regarding the omission of the tweeter Rp1 Rp2 tweeter pad.
One of the issues regarding the RTL3 is that the tweeter can be a little bright or sharp.
Your advice is to reduce the apparent brightness by filling in the hole in the midrange.
That due to the gap the tweeter sounds more prominent and placing the 33ohm resister in the woofer circuit may address this as well as impedance levels.
If the sound continues to be unacceptably bright, do I remove the R1 33ohm resistor from the woofers and fit the Rp1 Rp2 tweeter pad?
Hopefully the first scenario does the job.
Yes, if the first scenario doesn't do the job as well as you would like, you go with the Vikash's original scenario i.e. 10 Ohm resistor across the woofers and Rp1 Rp2 tweeter pad. The 10 Ohm better be 15W and away from the binding posts plastic cup. The 33 Ohm can be 10W as it will not dissipate nearly as much as the 10 Ohm.
Lets hope that the simple scenario will work out adequately since it has the benefits of better efficiency and an easier impedance curve.
If I need to revert to the Rp1 Rp2, I was looking at a high quality 10 ohm 10 Watt resistors which has the following specs:
10 Watt Wire Wound Resistor.
Tolerance 1%
Inductance below 0.7uH.
Wide temperature handling of -55C to +200C
Low linear temperature coefficient of +/- 300PPM.
Tinned Copper Leads.
Flame proof coating.
Do you think this will do the job, or is 15 Watt a must?
Also, if reverting to Vikash's schematic, is heavy duty (15 Watt) required for both R1, & Rp2?
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For the tweeter pad Rp1 1R & Rp2 10R you don't need serious wattage. 5W resistors will do.
For the woofers 10R if finally used, have 15W because it shares enough current with those.
Look into the Vikash link, there is a photo. He also used a >10W looking white sandcast resistor, the one held upright.
For the woofers 10R if finally used, have 15W because it shares enough current with those.
Look into the Vikash link, there is a photo. He also used a >10W looking white sandcast resistor, the one held upright.