Thank you.
What are your thoughts about what kind of xo and xo frequency between these two? 2nd L-R order and 1.7kHz?
Show me the measurements.
Low res youtube clips are worthless.
I'm not the best person to ask on passive xovers as I don't do them anymore. But as a start LR4 at 1k7 is a good starting point. My last 2 10" MR builds, both with CD/WG were 1.7kHz.
JBL2123 and AE TD10M.
Both excellent with the AE being the better. I looked at the 10NDA610 before the AEs were purchased but it was too hard to get and expensive here and it was also just released at the time, so no user data available.
Thanks.
Originally I was looking for an 8" to xo at 2kHz and the TD8M looked great, except the sensitivity wasn't high enough to be driven directly by a 45 or 2A3. The impedance is pretty constant though. Very nice driver.
Not so. At 2 kHz difference is about 6 dB, at 2.5 kHz difference is 10 dB. See the measurements.
Nonsense.
I agree. Once this is up and running it will be easy to test crossing the midrange over at different frequencies as the xo will be active and digital.
What I'm not experienced with is passive xo. Seems 1.7kHz is a good place to start. Do you agree 4th order would be advisable? For some reason I thought 2nd order.
While the TPL-150H can play lower, in the past several users noted it's best if used above 2kHz. Some measured increased distortion around 1.9kHz. Hence I was originally trying to xo at 2kHz, but likely a 10" won't be best at that point.
I understand this crossover is to tide you over while you build some amps. There are a few levels in finding a crossover point. The first would be an estimate to get you listening. The next would be after taking polars, dressing the TPL mouth/baffling to an appropriate level for this cross, and matching properly. The next may be after listening for some time and determining small adjustments after understanding the limitations.
These steps would seem useful regardless of whether you change to active, and whether you amp separately. Therefore I could see moving forward with them even though you might build an amp in the interim.
These steps would seem useful regardless of whether you change to active, and whether you amp separately. Therefore I could see moving forward with them even though you might build an amp in the interim.
Challenge accepted! LOL
I'm going to re-measure mine right now and convert the dB plots to percentages to see what is what.
Allen I agree 100%. In light of the slow process of trial an error with passive xo, and in light of my lack of experience, what I'm looking for is input from experienced eyes to establish a good starting point for the first estimation.
Seems the xo point should be 1.7kHz, give or take maybe 50Hz. What order and type would you suggest for the first estimation?
Point taken, Scott.
It is not only because of the high sensitivity. Sensitivity is important, though, as I intend to drive this drive directly from a 2A3 or 45 amp.
This driver exhibits also a very flat impedance, especially with AIC engaged, which is good for SETs.
Le is also super low.
The driver was designed as a midrange. Every comment I read from people who used the driver, or attempted to do, was about how good it sounded but difficult to deal with passive xo - an interim problem for me, but later with DSP a no problem.
It's unfortunate they didn't make it an 8" instead of 10".
I could achieve all of the above with a horn, but then center-to-center distance to the (already large) tweeter becomes an issue.
But I know you have a good point. Maybe I should consider letting go of the SETs constrain and allowing lower sensitivity, or using a horn and live with expected lobbing and reduce the xo point. A world of tradeoffs
Point taken, Scott.
It is not only because of the high sensitivity. Sensitivity is important, though, as I intend to drive this drive directly from a 2A3 or 45 amp.
This driver exhibits also a very flat impedance, especially with AIC engaged, which is good for SETs.
Le is also super low.
The driver was designed as a midrange. Every comment I read from people who used the driver, or attempted to do, was about how good it sounded but difficult to deal with passive xo - an interim problem for me, but later with DSP a no problem.
It's unfortunate they didn't make it an 8" instead of 10".
I could achieve all of the above with a horn, but then center-to-center distance to the (already large) tweeter becomes an issue.
But I know you have a good point. Maybe I should consider letting go of the SETs constrain and allowing lower sensitivity, or using a horn and live with expected lobbing and reduce the xo point. A world of tradeoffs
For the last couple on months, I have been driving my 99db/w horn-loaded cone mid-range from a Class A Triode-wired EL84 tube amp. It is however, a push-pull, as opposed to an SET. It does about 6 watts/channel. I have been investigating JUST how much power it takes, while I listen to music. I've been using a digital LED read-out volt meter, to determine this. 1/4 of a watt was the most I read. But, then (!!) I was properly scolded and told that my make-shift method leaves quite a bit to be desired. According to my amplifier gurus, the only *proper* way to measure would be to use an Oscilloscope. So, sometime in the future, we are going to adopt this method, to settle the science, once and for all. Further discussions have revealed that a low power SET amp (2a3) really can't put out much more than about 1 watt. As it turns out, old power ratings for these type of tubes were set with the understanding that 5% distortion was acceptable. What I can tell you, is this: For the most part, my little 6 watt job is adequate. Well, for 95% of music, that is. I do have some tremendously high-quality Stockfisch recordings that force the amp into clipping. As an alternate amplifier, I also have used a completely restored Ampzilla (200w/ch). This amp is a legendary performer, and probably among the very best sounding Class AB amp ever produced. Theory has it, due to the rather high bias, this amp stays in Class A mode for the majority of the time, when I use it. Having said that, I can tell you that the OPENNESS and unrestricted sense of power has been observed by every single guest listener, I have had over. Granted, the little tube amp is a marvel, and sounds ever-so-slightly warm, with that "tube glow", compared to the 'zilla, but it's not as dramatic a difference as one would think.
A-hA! Turns out you were completely RIGHT! LOL
At least it's mostly all 2nd order, and not 3rd order which stays just around 2% until under 1kHz.
I hear you. I have a McIntosh MC275 that puts out about 90W per channel and I would drive this tweeter + midrange combo with it. And in the process revisit my goal of using SETs. Could go up to 10W per channel and get FirstWatt SIT2, or go OTL and maybe 25W per channel.
BTW, Ralph Karsten, from Atmasphere, told me SETs have vanishingly low distortion if used well below their rated power. It's ideal to keep under 25%, and my plan is something that wouldn't need more than 50% of rated power. So 2W for 2A3 or 1W for 45. Of course these would only drive one fraction of the total bandwidth so it isn't like driving 20-20000Hz with 2W...my subs have their amps, my midbasses have 400W...
For now, I'll see how the MC275 does.
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