Jenzen Illuminator, built by Weisi, China
Copyright 2014 © Troels Gravesen


Dear Troels,
I hope this email could find you well.
First of all, I would like to thank you for showing your valuable speaker plans for DIY hi-fi fans all over the world. Recently, I followed your plan of Jenzen Illuminator to build a 3-way speaker. I chose the vented version and used exact crossover components you listed. Everything goes well except the treble. According to my listening, there is too much treble and the sound is so bright and a little bit harsh. I noticed that the tweeter attenuation used to be three levels possible (R1011=3R9, 4R7 and 5R6) and you finally decided as 2R7, 3R3 and 3R9. I try to adjust R1011 for many times, and I finally found R1011=7R2 (3R9+3R3) to be suitable for my system. The sound became balanced.
So, my question is: it this normal to set the tweeter attenuation as 7R2, which is quite different from your design. Do I need to adjust other component? Do you have any better plan to reduce the treble? Thank you so much!
I hope I can explain the situation well since my English is just entry level, I'm afraid.
Best, Weisi

Hello Heisi. 7R2 is indeed an extreme attenuation as the treble range will be some 6 dB below the midrange. I suggest checking the crossover once more - or try out different equipment to hear if this is persistent condition. There must something wrong.
Very nice cabinets, by the way! Best regards, Troels

Dear Troels,
Thank you so much for your reply.
I checked the wiring of the crossover and found nothing wrong. I think it might be my own problem of taste and listening habit. I like the so-called ‘analogue sound’, which is warm, ‘rich’ and ‘juicy’ in the midrange (NOT sure whether I am using the right words to describe it). I feel tired easily after hearing ‘bright sound’.
Plus, I am using a single-ended 211-tube amplifier, which is the best I have currently. It’s a very nice product by a personal workshop, using 5N OCC in all transformers. You know, tubes provide lots of opportunities or uncertain elements to the sound. All tubes I am using are NOS ones including GE211, Valvo E182CC, Brimar 6SN7, etc. NOS tubes give me a sound of darker, softer and smoother treble comparing with those modern tubes. That’s why I got confused with Jenzen Illuminator’s treble. Anyway, I feel so satisfied with it now and enjoy the sound, hah!
The cabinets were produced by a personal workshop located in northeast China. Production period was 9 months. I chose the red wood cover and piano coated. It costs me nearly 1,000 USD, which I think, is expensive but worthy.
Well, it’s not bi or tri-amp. I just put the crossover in the bass cabinet, using speaker cables to connect the upper cabinet. Just leave the possibility of toning by changing the cable, and it does sound different when they are changed.
For the source, I’m using a FAS (file as source) player and DAC converter. I have a CDPro2 transporter, but files are more convenient. Please see attached. Best, Weisi