Hi,
Utter nonsense. That is a BudP level of total misinformation.
No objective evidence = meaningless subjective drivel always.
rgds, sreten.
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Hi,
FWIW if considering having bespoke cabinets built, then
perhaps a better option is something with cabinet kits.
The way you seem to be going I'd suggest :
http://www.christienellis.co.uk/images/stories/ce/hificritic_trk1.pdf
http://www.christienellis.co.uk/images/stories/ce/hificritic_trk2.pdf
THE RHYTHM KING - TRK
FWIW the last time I looked at the hificritic site it was nowhere
as helpful as it claimed it would be, e.g. utterly no details about
active biamping, which can be done, but your on your own.
Also FWIW the Quad 303 is a much better amplifier when
used as a pair for 2 way actives, one per channel, due
to the regulated and current limited power supply.
rgds, sreten.
FWIW if considering having bespoke cabinets built, then
perhaps a better option is something with cabinet kits.
The way you seem to be going I'd suggest :
http://www.christienellis.co.uk/images/stories/ce/hificritic_trk1.pdf
http://www.christienellis.co.uk/images/stories/ce/hificritic_trk2.pdf
THE RHYTHM KING - TRK
FWIW the last time I looked at the hificritic site it was nowhere
as helpful as it claimed it would be, e.g. utterly no details about
active biamping, which can be done, but your on your own.
Also FWIW the Quad 303 is a much better amplifier when
used as a pair for 2 way actives, one per channel, due
to the regulated and current limited power supply.
rgds, sreten.
Utter nonsense
Current sets of objective evidence is very far from complete enuff to do anything but give you a small idea of what is happening -- it is often useful in tracking down gross performance deviations, but in the end final evaluation is always subjective because a well-trained ear is still our best form of test equipment.
dave
The days of human ears being better than test equipment probably ended in the 70s. One of the best speaker systems I've heard was designed by an engineer who famously didn't listen to it until it was in production - although this is unusual.
It's more a question of which tests to use and how to sensitively interpret them to match subjective impressions. Linkwitz, Geddes, Toole and the more science-based manufacturers such as KEF and B&W have been doing this for decades.
It's more a question of which tests to use and how to sensitively interpret them to match subjective impressions. Linkwitz, Geddes, Toole and the more science-based manufacturers such as KEF and B&W have been doing this for decades.
OP where are your thoughts at the moment?
Building a 70s transmission line will cost nothing more for drivers, £80 for a pair of crossovers from Falcon, £280 for wood plus £100 or so for bits and bobs. The last figure is of course something of a guess depending on what you already have to hand. Say £500 budget. This gets you a big fun speaker that is not quite what one would do these days.
If you can sell your drivers as a set for £200 then the question would seem to be can you get a better modern speaker for £700? Or is it? Better of course depends on your objectives one of which seems to be a bit smaller and possibly using a pair of Quad 303 amplifiers?
Is a design like this of interest? The SB Acoustic drivers are among the highest value for money drivers at present and are likely to be a bit, but not a lot, better than your 40 year old drivers for most objective parameters. The design is straightforward and I am sure quite a few speaker DIYers would look to make a few changes. I would suggest this is close to a modern equivalent of the KEFKit 3 and with the narrow front is often a bit more acceptable domestically.
Building a 70s transmission line will cost nothing more for drivers, £80 for a pair of crossovers from Falcon, £280 for wood plus £100 or so for bits and bobs. The last figure is of course something of a guess depending on what you already have to hand. Say £500 budget. This gets you a big fun speaker that is not quite what one would do these days.
If you can sell your drivers as a set for £200 then the question would seem to be can you get a better modern speaker for £700? Or is it? Better of course depends on your objectives one of which seems to be a bit smaller and possibly using a pair of Quad 303 amplifiers?
Is a design like this of interest? The SB Acoustic drivers are among the highest value for money drivers at present and are likely to be a bit, but not a lot, better than your 40 year old drivers for most objective parameters. The design is straightforward and I am sure quite a few speaker DIYers would look to make a few changes. I would suggest this is close to a modern equivalent of the KEFKit 3 and with the narrow front is often a bit more acceptable domestically.
I appreciate your suggestions (Tarkus, Sunflower, Zalph Audio zdt3.5 & The Rhythm King TRK) and certainly haven't dismissed them. I accept that modern drivers, crossovers and cabinet designs may well sound better than what I have got or plan to build. Your last suggestion is available as a kit from Wilmslow Audio (LINK) at a starting price of £708. Interestingly it is "CNC machined and rebated from 25mm MDF".
As it happens I already have all the drivers I need (i.e B139, B110, T27 and 4001G) and also a suitable Falcon crossover, built into my ancient, crude four foot high DIY cabinets. So the only additional costs from my point of view would be the (cut) MDF & battens, damping and filling material, wire (of which I have enough) and some hardware - plus blood, sweat and tears of course
Utter confusion! I almost wish I had never asked
I certainly don't think I would have to spend more than £400 to build a pair or HFA / R50 style speakers. I am sceptical that I would get £250 for my B139, B110, T27, 4001G and Falcon R50 crossovers. I know what my present system sounds like (good) and I anticipate that a new cabinet would only make it better. I could end up spending more than £700 on the off-chance that I would get a noticeably better sounding pair of speakers - or not.
At the moment I am trying to get a better price to get the MDF cut and rebated.
Sadly, nothing will ever be as good as the (prospective) purchaser listening to the speakers in their intended operating environment; failing that, listening in person in a quite listening room will probably be better than scientific objective tests. My son likes Drum & Bass, I like Classical music, Jazz & Blues - speakers that sound great to one of us may sound dull, harsh or artificial to the other.
I hadn't realized you had the drivers in working speakers which rather changes the relative costs. Is the main motivation to change the cabinets to get an improved sound or is it perhaps that you are unhappy looking at cabinets everyday that you consider a bit of a failure? If the former and the current implementation is reasonable then I doubt the cost and hassle will be worthwhile. If the latter, which I can empathize with having been there, then maybe depending on the condition of the drivers and crossovers. I built some Daline transmission line speakers in the 70s which I threw in a skip about 10 years ago when moving house. Had I retrieved the drivers, which I would have done had I had the time, I would have used them for playing around with but not to put in new cabinets because of their age. But people value things differently.
Since you'll build it then ùake sure that you add the correct amount of damping in the correct places, that will make a huge difference.
Now it must be said that since you have the speakers already up and running in a basic box, you should not expect the sound to be transformed. Only the bass will be different, hopefully better if correctly built, but the general sound will be similar.
I do agree with several others here that new (as in 40 years younger) drivers will make an enormous difference. These classic KEFs aren't as timeless as old Quad electrostatics.
Consider the Markaudio A12P full range driver in the superpensil box. For your taste of classical, jazz, blues, it will be a revelation.
Now it must be said that since you have the speakers already up and running in a basic box, you should not expect the sound to be transformed. Only the bass will be different, hopefully better if correctly built, but the general sound will be similar.
I do agree with several others here that new (as in 40 years younger) drivers will make an enormous difference. These classic KEFs aren't as timeless as old Quad electrostatics.
Consider the Markaudio A12P full range driver in the superpensil box. For your taste of classical, jazz, blues, it will be a revelation.
If I were in your shoes, I would work with particle boards and make only
a rebate for the tweeter. Veneering would be much less labor intensive than
painting.
To let OP off the hook … I think you should continue with the plan to use your existing drivers and try and get the best from them regarding cabinet. In that regard, my impression is that the design of TL's has got somewhat simpler in recent years, with less mystique surrounding them. The BJ Webb design looks fine if you don't want to generate your own design.
Regarding cutting materials, have a word with Farmwood Products here in the UK
Farmwood Products, Marine Plywood, Plywood Cutting
They cut panels to size and on their eBay page specify producing them for high end speakers. One of my Jordan customers has used them to built the VTL and was very pleased. I don't know if they do rebating but it's worth asking. They do high grade plywood too, so you'll have the opportunity to compare prices to MDF.
Regarding cutting materials, have a word with Farmwood Products here in the UK
Farmwood Products, Marine Plywood, Plywood Cutting
They cut panels to size and on their eBay page specify producing them for high end speakers. One of my Jordan customers has used them to built the VTL and was very pleased. I don't know if they do rebating but it's worth asking. They do high grade plywood too, so you'll have the opportunity to compare prices to MDF.
Thanks
Thanks for that, I will contact Farmwood.
As a matter of interest, what would be the effective difference in use between high grade plywood and MDF of the same thickness?
Next to the weight difference, many find that enclosures made from plywood sound better. The perceived effect would be more important in horns and TLs than in a simple closed or BR box.
I am personally still on the fence on that opinion however, I made a horn with mdf and there was nothing wrong with the result (except it being very heavy).
In theory, the extra stiffness of ply will benefit a horn or TL enclosure. If the design has lots of damping and/ or bracing, maybe less benefit. Using ply might enable you to use thinner material - 18mm ply rather than 22mm MDF.
Ply certainly weighs less and I find it's a more pleasant material to work with - the dust is less unpleasant and edges hold up better in ply. My own inclination would be to restrict MDF to smaller enclosures and use ply for larger, mainly for ease of handling.
Don't get too caught up, though. See what prices you get. And ask Farmwood the question - they use both materials every day.
Ply certainly weighs less and I find it's a more pleasant material to work with - the dust is less unpleasant and edges hold up better in ply. My own inclination would be to restrict MDF to smaller enclosures and use ply for larger, mainly for ease of handling.
Don't get too caught up, though. See what prices you get. And ask Farmwood the question - they use both materials every day.
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email sent to Farmwood - here's hoping - I also asked about Ply -vs- MDF
To kinda return to my original query, I am curious about the recessing of the drive units. I have read various posts about this - e.g. BBC mounting B110 behind the baffle in the LS3/5a, felt surrounding the T27 in the LS3/5a, speaker cabinet being wide enough that the grille frame would not distort the sound, etc.
With this TLS design:
To kinda return to my original query, I am curious about the recessing of the drive units. I have read various posts about this - e.g. BBC mounting B110 behind the baffle in the LS3/5a, felt surrounding the T27 in the LS3/5a, speaker cabinet being wide enough that the grille frame would not distort the sound, etc.
With this TLS design:
- is it actually, truly important to mount the various drivers flush with the baffle board?
- what impact on the sound will the frame of the grille have?
- should the baffle be mounted flush with the sides (as I plan to do) or should it be recessed?
I asked that question about rear-mounting here
http://www.diyaudio.com/forums/multi-way/247811-bbc-rear-mounting-drive-units-baffles.html
BBC speakers (and some of the recent versions such as Harbeth, Stirling and Graham) continue to use recessed baffles and grilles.
http://www.stirlingbroadcast.net/SB-88.jpg
Some of it may be the market they are aiming at, or the need to still rigidly to the original spec. Ultimately you're trying to get rid of as many potential sources of reflection on the baffle as possible. The ideal would be a flush-mounted speaker in an infinitely wide baffle. The BBC LS3/5a has a felt ring around the tweeter to reduce reflections.
You could surface-mount the drivers and then cut an additional baffle out of thin ply, with cutouts for the driver chassis, and mount that over the top. Or do the same with thick felt, cork or foam, if that saves the rebating. You might want a grille for sake of appearance.
http://www.diyaudio.com/forums/multi-way/247811-bbc-rear-mounting-drive-units-baffles.html
BBC speakers (and some of the recent versions such as Harbeth, Stirling and Graham) continue to use recessed baffles and grilles.
http://www.stirlingbroadcast.net/SB-88.jpg
Some of it may be the market they are aiming at, or the need to still rigidly to the original spec. Ultimately you're trying to get rid of as many potential sources of reflection on the baffle as possible. The ideal would be a flush-mounted speaker in an infinitely wide baffle. The BBC LS3/5a has a felt ring around the tweeter to reduce reflections.
You could surface-mount the drivers and then cut an additional baffle out of thin ply, with cutouts for the driver chassis, and mount that over the top. Or do the same with thick felt, cork or foam, if that saves the rebating. You might want a grille for sake of appearance.
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Read this:
zaph|audio
I reckon a hardcore audiophile would not settle for less than rebate
them all. It would be a lot of fun to double blind test it.
Yup, saw that. In fact it was that thread that made me wonder. I had also considered some sort of cut-out over the front of the baffle board but had dismissed it because of the differing thicknesses of the driver flanges and potential problems if it was not 100% stuck. Lojzek made the same point and has also provided a link to research on this topic.
I have thought about cutting square chunks out of my KK3 baffle where the drivers are flush mounted and fitting them into a TL baffle.
I will look into cork sheet.
It depends on the design, the crossover frequencies + acoustic & electrical slopes, time / phase alignment etc. Flush mounting eradicates a potential additional source of diffraction, but as noted there are other factors to consider; the BBC et al knew exactly what they were doing. In general, I prefer flush mounted units, but I wouldn't automatically rule it out either. Message is, go with what was originally intended for the drivers with that specific XO, baffle dimensions & the driver's positions thereon.
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I had a very informative reply from Antony Bull of Farmwood Timber Products Ltd.
Unfortunately he cannot help but he has given me a few contacts to try (Chop Shop CNC, Gee Cee Joinery & CNC Routing Services), I will try them and Google again for local CNC workshops as he suggested.
He also advocated the use of baltic birch plywood.
Unfortunately he cannot help but he has given me a few contacts to try (Chop Shop CNC, Gee Cee Joinery & CNC Routing Services), I will try them and Google again for local CNC workshops as he suggested.
He also advocated the use of baltic birch plywood.
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