All systems go !
All systems go !
DRIVE UNITS BY MANUFACTURER:
M21WG-09-08
Categories: 8-10 inch Bass Speakers Vifa Classic Drive Units
UK STOCK ITEM
Direct replacement for:
Heybrook HB1, JPW P1, JPW AP2, JPW AP3, Snell type K.
This classic 8" bass unit is designed for sealed cabinets of between 20 - 40 litres. It features a very high compliance suspension (Vas 81 litres), a magnesium chassis and a treated pulp cone. The highish Qms value gives the M21WG-09-08 a lovely open midrange sound hence it's popularity in various successful historic designs. One of the few excellent 8" drivers suitable for 2 way infinite baffle enclosures. New manufacture with improved foam surround.
These units are now manufactured at the Scanspeak facility in Denmark and may be badged as Vifa or Scanspeak.
Resonant frequency (fs) | 38 Hz | Nominal impedance (Zn) | 8 Ω |
Mechanical Q factor (Qms) | 4.9 | DC resistance (Re) | 5.6 Ω |
Electrical Q factor (Qes) | 0.82 | RMS power handling | 50 W |
Total Q factor (Qts) | 0.70 | Sensitivity (2.83V/1m) | 90 dB |
Equivalent volume (Vas) | 81L | Chassis diameter | 215 mm |
I want to first of all thank Will for his excellent advice and service.
I had noticed that my ebay purchased HB1s required a lot of volume to bring them alive so I thought it was time to replace the originals, rather than losing my hearing!
Having purchased a simple soldering set from Hifi Collective, I set about unbolting the original 8" speaker, saving its original plastic seal and discovered the loose wool inside which I replaced with a denser wool thickness whilst still leaving a hollow for the basket of the new 8" Vifa . I then notice that the latter was simply made of pressed metal, so it "rang". Consequently, I used finger-applied caulk over the reverse and rim of the speaker basket to damp the ringing. I also decided to replace the original tweeters with the recommended Morel CAT298 -104mm ; mention this at the same time as one needs access through the 8" speaker to accomplish this. The reason being that the contacts on the Morel are in one location whilst the originals are at either side of the tweeter enclosure . Consequently, unless one re-routes both cables through one of the original holes the new Moral won't sit flat on the internal wooden tweeter enclosure. So I threaded the brown wire (red) through the widened hole for the blue and filled the underside of the redundant hole with caulk. The Morel only has three bolt holes and these can only be fitted in Y-shape because of the lack of wood to hold them - so three extra holes require to drilled. NB the 94 mm faceplate is too small for the diameter of the HB1. it is the CAT298-104 mm that is needed, or at least it was for my HB1s. All of this had to be done before the actual connection of the new Vifa anf the Morels . I watched Danny Richie's excellent soldering tutorial on GR Research's Youtube channel and managed to make the connections.
Thankfully, the considerable effort involved, which was quite testing , has been worth it. The improvement was dramatically for the better - no longer deafened to get any bass response, no sub-woofer will ever be required! LP playback via Denon DL103 MC cartridge, Phasemation SUT 320 to MM phono stage of Marantz PM17 KI Sig. sounds warm and life like. For near-field listening Iturn the HB1s away from my seating position to avoid tweeter "sizzle". I was fortunate to purchase the HB1s with the original stands which are a perfect height for an Ikea Poang armchair.
I apologise for the length of this review and for including mention of the Morel CAT298-104 as well, but I couldn't find a step by step guide to the speaker replacement process and hope it may give non-tech audiophiles the confidence to improve their vintage speakers for themselves.
Highly recommend Willys Hifi for excellent service and advice communications.
Thanks for the comprehensive review !
Will & Caroline
Willy responded immediately to an enquiry I made about the speaker. Once ordered it arrived with 6-8 business days (UK to Canada) in fantastic condition. My JPWs are sounding beautiful once again. Thanks Willy.
Thanks for the review Daniel - enjoy the music !
Will & Caroline
My Heybrook HB1 speakers sound as good now, as the day I bought them. The new drivers are the same as the original ones and are worth every penny. Thank you Willys Hifi
Thanks for the review James !
Will & Caroline
Thanks for fast professional service arrived from England to toronto in 5 days and came as advertised would deal with you again for sure
Thanks for the review John !
Will & Caroline
Bought this to replace a damaged woofer in my Heybrook HB1 speakers, which I bought in 1985. The replacement is identical to the original and is a perfect fit in the cabinet. Communication was excellent, delivery to Australia was fast, and the woofers were very well packaged. Great service from Will and Caroline at Willys-Hifi. Highly recommend.
Thanks for the review David!
Will & Caroline
Friendly technical support
40+ years in the trade
UK family run business
Excellent customer service
Quick dispatch
Has fixed the slight grainy sound on my old Mission 771s. The tweeter had a stain on the back suggesting the fluid had escaped. Make sure you release(unsolder) the coil wires before splitting the tweeter. Audax have replacement tweeters TM025C1 albeit 8 ohm which is another way to go.
Couldn’t be happier, more detail, more clarity. Vocals massively improved and less harsh sounding. Thanks Willys hifi.
Very flexible and easy to work with cable. Made up 6.5m cables shielded with some faraday tape and added PET cable sleeving outer and terminations of ChordOhmic bananas . After about 25hr ‘burn in’ compared with my NAC A5. IMO a better sounding cable, definitely better soundstage.
1990 Linn Index II LS120 Crossover and wiring upgrade.
Truly Outstanding performance upgrade flying in the face of conventional wisdom.
The resistor value is increased from 2.2 to 2.7 and is an official Linn Service 'performance' upgrade.
HF
C1 3.9uF Jantzen Superior z-cap
C3 1uF Mundorf MCap EVO Aluminium Oil
R1 Mundorf M-Resist 5W 2.7 Ohm 2% MOX
LF
C2 5.1 uF split
3.3 uF Mundorf MCap EVO Aluminium Oil
1.8 uF Jantzen Superior z-cap
Carded lambswool replacing original poly wadding. Increased weight replacing 132g ea. for 215g ea. This was weighed out in stages and determined by sonic performance.
Small amount approx 15cm sq of Bitumen foam panel placed in two pieces in base of cab. (leftovers from another project.)
Jantzen solid core speaker cable AWG 17/ 1.15mm stripped of PVC outer sheath to leave only high performance PE insulation. Doubled and twisted Star-Quad. 2.3mm
x2 400mm lengths ea.
Replace binding post steel nuts and locking nuts on back of PCB with copper nuts x8 and locktight. (steel nuts in signal path???= Nuts)
Remove all Plastic front panels and rubber securing bungs. Seal air holes in front baffle sockets. (Holes!)
Total cost £190.00.
Worth every penny! The cost of replicating this level of performance will be many, MANY times this amount. This understanding determined my budget. Happy to spend £200 upgrading on a gamble for the knowledge and experience. The results are very serious for this money.
I purchased these new in 1990 and paid £220.00. They were never highly regarded but always delivered a satisfying sound I never bored of even though Bass is not a strong point in this sealed design. Proximity to rear wall is everything here.
No previous experience with crossover upgrades. Never built a PCB. Very limited knowledge of electronics A beginner !
Every sonic element is vastly improved. Detail everywhere, Soundstage opened up. Depth, Clarity, Definition, Truly remarkable the level of performance these 'nothing special' loudspeakers are now delivering. They are being driven by Oppo 105 upgraded, John Sampson upgraded Musical Fidelity A1. All solid core power/interconnect/speaker cables.
This project was only completed 'confidently' with the kind, generous help and insights from Willys HIFI who supplied all the excellent Mundorf components.
Cannot thank Will enough for his patience and knowledge. My lack of knowledge and understanding was never a barrier to success only because Will was so helpful, enthusiastic and interested in my enquiries. Will cautioned against my extravagant choice of caps. The results could not be predicted and so a more responsible and cost efficient choice was Will's sagely recommendation. Trustworthy, Knowledgeable and Approachable. How refreshing. My choice was a gamble to push the limits and the budget, the results are beyond my hopes and expectations.
Highly commendable service and support. Outstanding in the Audio/HiFi marketplace.
Thank you Will.
John.
1990 Linn Index II LS120 Crossover and wiring upgrade.
Truly Outstanding performance upgrade flying in the face of conventional wisdom.
The resistor value is increased from 2.2 to 2.7 and is an official Linn Service 'performance' upgrade.
HF
C1 3.9uF Jantzen Superior z-cap
C3 1uF Mundorf MCap EVO Aluminium Oil
R1 Mundorf M-Resist 5W 2.7 Ohm 2% MOX
LF
C2 5.1 uF split
3.3 uF Mundorf MCap EVO Aluminium Oil
1.8 uF Jantzen Superior z-cap
Carded lambswool replacing original poly wadding. Increased weight replacing 132g ea. for 215g ea. This was weighed out in stages and determined by sonic performance.
Small amount approx 15cm sq of Bitumen foam panel placed in two pieces in base of cab. (leftovers from another project.)
Jantzen solid core speaker cable AWG 17/ 1.15mm stripped of PVC outer sheath to leave only high performance PE insulation. Doubled and twisted Star-Quad. 2.3mm
x2 400mm lengths ea.
Replace binding post steel nuts and locking nuts on back of PCB with copper nuts x8 and locktight. (steel nuts in signal path???= Nuts)
Remove all Plastic front panels and rubber securing bungs. Seal air holes in front baffle sockets. (Holes!)
Total cost £190.00.
Worth every penny! The cost of replicating this level of performance will be many, MANY times this amount. This understanding determined my budget. Happy to spend £200 upgrading on a gamble for the knowledge and experience. The results are very serious for this money.
I purchased these new in 1990 and paid £220.00. They were never highly regarded but always delivered a satisfying sound I never bored of even though Bass is not a strong point in this sealed design. Proximity to rear wall is everything here.
No previous experience with crossover upgrades. Never built a PCB. Very limited knowledge of electronics A beginner !
Every sonic element is vastly improved. Detail everywhere, Soundstage opened up. Depth, Clarity, Definition, Truly remarkable the level of performance these 'nothing special' loudspeakers are now delivering. They are being driven by Oppo 105 upgraded, John Sampson upgraded Musical Fidelity A1. All solid core power/interconnect/speaker cables.
This project was only completed 'confidently' with the kind, generous help and insights from Willys HIFI who supplied all the excellent Mundorf components.
Cannot thank Will enough for his patience and knowledge. My lack of knowledge and understanding was never a barrier to success only because Will was so helpful, enthusiastic and interested in my enquiries. Will cautioned against my extravagant choice of caps. The results could not be predicted and so a more responsible and cost efficient choice was Will's sagely recommendation. Trustworthy, Knowledgeable and Approachable. How refreshing. My choice was a gamble to push the limits and the budget, the results are beyond my hopes and expectations.
Highly commendable service and support. Outstanding in the Audio/HiFi marketplace.
Thank you Will.
John.