View Full Version : Reference 43XL - Monitors speakers designed by Willy PETERS

02-05-2011, 02:21 PM
Dear all,
I would like to share with you a great experience for an audio fan. After having spent many years with JBL 4425, 4430 and 4344, I had the opportunity to meet someone very special last year which made me change my mind on highend speakers.

He is a retired professional highend speakers manufacturer in Belgium. He was one of the most important JBL dealers in Europe in the 70's, created the brand Sandvoice many years ago.

His name is Willy Peters. He built an amazing system for a friend of mine in 2009. I was willing to upgrade my 4344 in that period (filters, internal foams,...); but after long reflexions and discussions on the subject, I made my choice: I decided to let Mr W.Peters make speakers for me. The mission was no that simple: replacing JBL 4344.

To make it shorter : here some technical data on the speakers

Name: Reference 43XL

- Type : 4-way floorstanding bass-reflex loudspeaker (*)
(*) 5 drivers are used as each speaker includes two 18 boomers set in push-pull configuration
- Frequency response : 22Hz 35kHz
- Sensitivity : 93 dB / 1 W. 1m
- Nominal impedance : 8 Ω
- Filtering frequencies :
- 18 boomer : 300 or 500 Hz at 6dB/oct. or 12dB/oct. with Phase adjustment: 0/-
- Medium: 300 Hz at 18dB/oct. with Phase adjustment: 0/+180
- Compression : 1 kHz at 18dB/oct. with Phase adjustment: 0/+180
- Tweeter: 7 kHz at 24dB/oct. with Phase adjustment: 0/+180
- Recommended amp power : min. 200W 1000W (8 Ω)
- Size (Height x Width x Depth) : 1100 x 820 x 620 mm
- Weight : 230kg

Drivers list
- Tweeter FOSTEX T500A MKII
- Compression: JBL 2420 (new) associated with hand-made carbon fiber horn
- Mid Range: JBL 2123 (new)
- Boomer: PRECISION DEVICES PD186 modified (*)
(*) special treatment added on cone for better low frequency response

Built details
Hand made cabinets, built in Padouk (more than 120 wood pieces per speaker)
Special internal absorption materials used to ensure no vibration are transmitted through the cabinets structure
Highend filters using state-of-the-art components coming from the professional market (most components used by Mr Peters are not available for sale in the public market)

My purpose is to get Mr Peters 's work better known. He is really an amazing person, with an extraordinary experience and knowledge in highend audio.
His aim is to built speakers with no limit or constraint in term of time, components quality, commercial margin which is totally impossible in the highend commercial audio market.

Detailed information available on www.refaudio.be (http://www.refaudio.be) (in French sorry).

The best way to give you an idea of this work is give you some pictures. Do not hesitate if you have any questions.


02-05-2011, 02:22 PM
Cabinet sides construction :

02-05-2011, 02:22 PM
Cabinets construction

02-05-2011, 02:23 PM
Front panel and isobaric enclosure for the two 18' boomers

02-05-2011, 02:23 PM
Filters construction

02-05-2011, 02:24 PM
I will add more pictures later
Kind regards

02-05-2011, 03:04 PM
Wow. How does it sound?

02-05-2011, 03:59 PM
Wow. How does it sound?

I suspect it's very boomy :D

I know that's the way they call LF drivers or woofers in Europe, but everytime it makes me smile, as if there's something you want to avoid in louspeakers, it's "boominess" :p

02-06-2011, 02:51 AM
Yes, I forgot the most important part: the sound.

The first point is to control the bass which are loud, so loud. The push pull configuration provides quick bass response, despite the heavy cones due to their 18' size. I have had the speakers since a few months now. I still need to optimize my room to limit the standing waves, but results are already amazing. Bass are loud but precised, quick. Dynamic is huge, seems to have no limit. Sound pressure is really far from what I had with my JBL 4344.

Low/Mid range is a JBL 2123/2421 so I find the JBL sound in this point. Dynamic, precision, not aggressive at all (thanks to the amazing filter).
The carbon fiber horn is very accurate, voices seem real; the association with the Fostex tweeter is superb. Soundstage is larger than standard monitor JBL; I was afraid the tweeter would be too directive (compare to the JBL 2405) but not a all. It is very sweet, detailed.
So delicacy in the upper band, and devastative power in the louds !

The most important is that the result is very musical (depending of the source, amps,... of course); they need big amps to work well (phase linear 700, Stratos Odyssey). I used also an ML23.5 but results were not that good. A very important point is that filters are like a piece of art; when you see them in the back of the speakers, it is very surprising.
Conception is the secret of Mr Peters; according to him, with such filters, there is no need to bi-amp the speakers. And the results show that this is true. I would be totally impossible to come to such results with mono amps on JBL 4344 or 45.

Thanks to the special internal absorption foams and cabinets' heavy weight, there is absolutely no vibration coming though the floor; I share the same wall with my neighbours, they would be dead by now with standard 18' speakers !)

If you come to France, near Paris, come for a visit !

02-06-2011, 10:28 PM
Yes, I forgot the most important part: the sound.

So delicacy in the upper band, and devastative power in the louds !

Wonderful craftmanship and attention to quality. Lot's of hours in the construction I would think.

02-07-2011, 12:28 AM
Excellent work:eek:
Any curves?:D

JBL 4645
02-07-2011, 03:39 AM
Wow that is juicy delicious.:rockon2: