Lambda Series TD15H

[audiothings]

I was looking for a driver that can replace the JBL 2235H, and the AE Speakers Lambada Series TD15H has come up for prime consideration.

However, it has been suggested that there could be a mechanical resonance at 1.6 KHz due to the particular surround used. I am looking at the Reflexion Arts 234 speaker which uses an asymmetrical crossover - LPF is 12 dB @ 1000 Hz, HPF is 24 dB @ 1000 Hz.

How problematic is the 1.6 KHz resonance likely to be when the speaker is crossed over 12 dB @ 1000 Hz?

[Loren42]

Originally Posted by audiothings

I was looking for a driver that can replace the JBL 2235H, and the AE Speakers Lambada Series TD15H has come up for prime consideration.

However, it has been suggested that there could be a mechanical resonance at 1.6 KHz due to the particular surround used. I am looking at the Reflexion Arts 234 speaker which uses an asymmetrical crossover - LPF is 12 dB @ 1000 Hz, HPF is 24 dB @ 1000 Hz.

How problematic is the 1.6 KHz resonance likely to be when the speaker is crossed over 12 dB @ 1000 Hz?

I have 2235Hs that I replaced with TD15H in July. My crossover point is about 500 Hz. I have no issues with resonance. I can't say what it would sound like at 1 kHz.

I love JBL, but the AE TD15Hs are clearly superior drivers. I would not hesitate to do it all over again. I should sell my old 2235Hs since they are just sitting in cardboard boxes.

[audiothings]

Originally Posted by Loren42

I have 2235Hs that I replaced with TD15H in July. My crossover point is about 500 Hz.

What have you paired it with?

[Loren42]

Originally Posted by audiothings

What have you paired it with?

Audax PR170M for the mid and Morel MDT38 for the high end.

Crossovers are passive at 500 Hz and 2.5 kHz.

[audiothings]

Originally Posted by Loren42

Audax PR170M for the mid and Morel MDT38 for the high end.

Crossovers are passive at 500 Hz and 2.5 kHz.

Thank you for your quick response. For myself, I am looking at a two way system.

[Loren42]

Originally Posted by audiothings

Thank you for your quick response. For myself, I am looking at a two way system.

Yeah, looked at that idea long and hard a while back with no good alternatives that I liked then. The TD15H has a very high crossover point potential for a large woofer, so I was interested in seeing if I could do that.

The best way I could see doing a 15" 2-way was with a horn, but that is tricky to do and get good performance. The next choice was mating a full-range to the woofer, but that is a bit of a compromise, too.

What have you in mind to use?

[SunRa]

For a 1Khz crossover point, the TD15M might be a better idea. Especially if you already have some woofers around.


edit: I meant especially if you have some subwoofers around

[Brett]

I own and use the 15X and 2225/6 and agree with what the others are saying. I would either go three way in a WMT with the 15H or use the 15M if I were intent on using it like the RA234 speaker. Here the wide C-C spacing of the 15's especially if used that high could be problematic.

[LineSource]

I like the sound of the Lambda TD15S woofer and have built about twenty speakers with them. The TD15S with Qts ~ 0.37 and Fs ~ 22 Hz provides -3db at 25Hz in a 10 cu ft ported box before room gain. I think the low Qts TD15H is optimized for horn loading if you need under 40Hz with high efficiency.

If you want a high 1KHz xover plus high efficiency, the Lambda TD18H+ can be used with the Lambda TD15LO and a 1Khz controlled directivity 1" horn/waveguide. The TD15LO uses an under hung motor with the TD15M pleated edge cone.

I only design 3-way speakers and appreciate the upper midbass quality of the Lambda 15" woofers, but I seldom use bass crossovers over 160Hz. Hence, I have been watching for how new underhung NdFeB motor technology and carbon fiber loaded paper cone technology can deliver a high sound quality 18" woofer, but I have yet to find a genius solution for home audio. (90-100 gram Mms, underhung motor, 20Hz Fs, 0.37 Qts, 97 db/watt SPL, 200 watt compromise). An 18" with Qts ~0.8 also seems like the ideal choice for dipoles. With technology advancements, 18" is the new 15", and NdFeB is the new AlNiCo for bass.

[audiothings]

Originally Posted by Loren42

Yeah, looked at that idea long and hard a while back with no good alternatives that I liked then. The TD15H has a very high crossover point potential for a large woofer, so I was interested in seeing if I could do that.

The best way I could see doing a 15" 2-way was with a horn, but that is tricky to do and get good performance. The next choice was mating a full-range to the woofer, but that is a bit of a compromise, too.

What have you in mind to use?

I am looking for a suitable compression driver similar to the TAD2001 and I have found several links to pursue. 15" woofers that can handle ultra lows and be crossed over above 1000 Hz are harder to find.

Originally Posted by LineSource

I like the sound of the Lambda TD15S woofer and have built about twenty speakers with them. The TD15S with Qts ~ 0.37 and Fs ~ 22 Hz provides -3db at 25Hz in a 10 cu ft ported box before room gain. I think the low Qts TD15H is optimized for horn loading if you need under 40Hz with high efficiency.

Thank you very much. Exactly the kind of advice I am looking for. Hope John E Janowitz will chime in for some additional clarity. He compared the TD15"H" and the JBL 2235H here and they were almost identical in the LF region.

Originally Posted by LineSource

If you want a high 1KHz xover plus high efficiency, the Lambda TD18H+ can be used with the Lambda TD15LO and a 1Khz controlled directivity 1" horn/waveguide. The TD15LO uses an under hung motor with the TD15M pleated edge cone.

Somehow, I am currently set on two way speakers, but this may change by the time I build my pair.

Originally Posted by LineSource

I only design 3-way speakers and appreciate the upper midbass quality of the Lambda 15" woofers, but I seldom use bass crossovers over 160Hz. Hence, I have been watching for how new underhung NdFeB motor technology and carbon fiber loaded paper cone technology can deliver a high sound quality 18" woofer, but I have yet to find a genius solution for home audio. (90-100 gram Mms, underhung motor, 20Hz Fs, 0.37 Qts, 97 db/watt SPL, 200 watt compromise). An 18" with Qts ~0.8 also seems like the ideal choice for dipoles. With technology advancements, 18" is the new 15", and NdFeB is the new AlNiCo for bass.

It is refreshing to see somebody who is actually looking forward to new technology. I am meeting too many people who believe that the best days of hi-fi are behind us.