Project with D130 LE175 (Potato Masher) and N1200 for low power tubes

[cwestman]

Hello,

Hope you are doing well, I just joined the forum because I am just starting a new project.
I got a DIY speaker based on JBL D130, LE175 Potato Masher and XO N1200. Enclosure is big, with a vent in front (but no port).

I got the set after auditioning because I saw potencial and because I need very high sensitivity speakers for my tube set amplifier.
The speaker sounds nice but not really flat. So I wanted your opinion about how much this can be improved.

My current setup is: Turntable Luxman Pd290 with Benz Glider L, SUT Cinemag 1254, phono EAR 834P, SET amplifier valve 71 with tango transformers, and mentioned speakers.




The speakers do some things really nice, it s clear in guitars, voices, piano... I really like the potato masher, the speakers gave a lot of detail and resolution in the mids but it's laking on the high and low frequencies (for instance drums). Jazz and acoustical material deliver with great sound. I am also not sure if the low mids are very correct in this setup. The 101db have gave a lot of breath to my weak amplifier.

So far I am wondering if I could do the following upgrades:
1. Add a JBL 2405 (any difference compared with the bullet tweeter 075?)
2. Also wondering if redoing the crossover with new components may bring improvements
3. The D130 is super shy in Bass, is it possible to put a port in the enclosure, or replace it with a modern cheap woofer and get quality results? I read the older D130 only handle 20W, so it's not recommended to put a bass reflex port, but I only have 1W of power and I am wondering if this might be a path to follow.


I just moved into Vancouver Canada, so I don't have tools to do a proper frequency measurement, I jut have a multimeter.

Do you see potencial to improve this so I can get the queality it has on the mids in a more extended range, keeping sensitivity high? What are your thoughts?

I love the look of classic and horn speakers, but also my main interest is to get better sound to listen to my music.

Many thanks in advance!
Carlos

[BMWCCA]

A bigger box would help but the D130 is never really going to be a "normal" woofer. Usually the LE175 is paired with the 130A which goes lower, but regardless it looks like your box dimensions aren't helping. If you haven't already, I'd try them on the floor which might help the low-end. I'm sure others with more knowledge will offer opinions.

I've had the D130 and 075 combination for 60-years. Most of the time I've used an EQ with them, though they aren't in a main system anymore.

Welcome!

[berga12]

check C38 baron from JBL
http://www.lansingheritage.org/images/jbl/plans/c35-c39/page2.jpg

Recapping the crossover might help, also Lpad...

box volume must be check, but D130 will not go lower than 45-50hz...

Reflex port have nothing to do with Power handling.

[cwestman]

I wanted to share , what was my approach.
Added a Beyma cp21F with a 1.5uf cap in series and an 80 ohms L-pad as attenuator.
The plant pot below has also cork and is to be nicer with the neighbours below and the bass.

I have spent a few days listening to records and playing with the control. I am very pleased with the sound.
I can't say often that a mod is an improvement, but this one, has been a dramatic improvement after adjusting the cap and lpad values for a while...

80730

[speakerdave]

A step-by-step process to get the sound you're after would be to switch from the D130/2135 to the 130A/2220, as a start. In any given size enclosure they will both reach about as low, but the 130A has a flatter response. The rising response of the D130 in effect buries the bass in over-abundant midrange. In the LH Library>JBL Library>Specs>Pro Components you can find data sheets for the two drivers with sketches of their frequency response. Even in your approximately five cu ft box you will hear better bass with the 130A/2220.

The second thing would be to get bigger boxes, 8 cu fit minimum. If shaped to fit into the corners of your room that would be even better.

Shoji "Shifty" Sugawari's Basie jazz club in Ichinoseki, Japan uses pairs of 130A's in 20 cu ft sealed enclosures. Someday, maybe you could do that. :p

Suggested reading: http://www.audioheritage.org/vbulletin/showthread.php?12206-Tokyo-Trip-Day-3

[cwestman]

Thank you Dave, That is very nice information. in particular about the woofer.

The speaker comes with the n1200 crossover that has 3 levels for the treble. I always used them at MAX but with the tweeter, I realized it blends really nicely with the N1200 at mid level. I suspect that relates with what you are describing about the woofer.

Which I had a microphone to measure what is going on. A colleague at work will show up eventually and we will be able to take some measurements.

Cheers,
Carlos