Hi guys,
I did a lot of browsing lately, and I am now a bit more familiar to what's involved in building speakers.
I found a very interesting design (some of you may have seen it online), which looks fairly easy to build, and is completely calculated through.
(see link and image included).
Poor Man'
1) My first question is of a cosmetic kind.
As you can see on the image I provided, the baffle is covered in leather.
Now I know how to cover a plate of wood with leather, that is not a problem. What I dont know, is how I can cover a piece of wood with leather, and then mount it to the main speaker cabinet.
The way I see it, is that the leather will be folded over the back of the baffle, but this would likely interfere with glueing the baffle to the cabinet.
And if overlapping only the side of the baffle, that would most likely be about half an inch or so, assuming it is glued against another half inch plate behind it. Such an overlap probably would not hold well.
If the leather is only on a 2mm plate, there would be no grip at all.
Anyone any ideas on how this would be finished properly?
All I can think of is to first make the whole speaker cabinet, route out the area that will contain the leather-covered baffle (assuming paneling of 1" only about 0.5" would be routed), then use a plate of about 0.5", cover that with the leather, staple the leather to the front baffle on the sides of the board(!), and then glue the front baffle to the cabinet.
Another alternative would be to cut out the front section completely, cover a 1" board, again staple it on the sides, and then g;ue it to the frame. However, this could leave air gaps between the center section and the sides.
Anyone else some suggestions?
2) My second question concerns crossovers that are used by this guy.
Somewhere on his website he provides a cost calculation for the crossovers of a particular speaker. And this approaches the 200 US$ marker. Not cheap. Of course, as you can see on the ink I provided, the crossovers are rather high quality.
Blueran (Beyma > Beyma 6MI90 6" Driver ONLY £64.25) provides crossovers and filters that are much cheaper, but I wonder if the quality is going to be comparable (I can see the caps used are really quite different).
3) My third question concerns the difference between crossovers and filters. My understanding is that crossovers contain a split of frequencies between the drivers of a speaker, whilst a filter cuts out a frequency range for one particular driver. Is that correct? If not, could someone please explain the difference to me?
Also, could someone tell me when a crossover is used, and when it is better to use a filter?
Cheers!
K
I did a lot of browsing lately, and I am now a bit more familiar to what's involved in building speakers.
I found a very interesting design (some of you may have seen it online), which looks fairly easy to build, and is completely calculated through.
(see link and image included).
Poor Man'
1) My first question is of a cosmetic kind.
As you can see on the image I provided, the baffle is covered in leather.
Now I know how to cover a plate of wood with leather, that is not a problem. What I dont know, is how I can cover a piece of wood with leather, and then mount it to the main speaker cabinet.
The way I see it, is that the leather will be folded over the back of the baffle, but this would likely interfere with glueing the baffle to the cabinet.
And if overlapping only the side of the baffle, that would most likely be about half an inch or so, assuming it is glued against another half inch plate behind it. Such an overlap probably would not hold well.
If the leather is only on a 2mm plate, there would be no grip at all.
Anyone any ideas on how this would be finished properly?
All I can think of is to first make the whole speaker cabinet, route out the area that will contain the leather-covered baffle (assuming paneling of 1" only about 0.5" would be routed), then use a plate of about 0.5", cover that with the leather, staple the leather to the front baffle on the sides of the board(!), and then glue the front baffle to the cabinet.
Another alternative would be to cut out the front section completely, cover a 1" board, again staple it on the sides, and then g;ue it to the frame. However, this could leave air gaps between the center section and the sides.
Anyone else some suggestions?
2) My second question concerns crossovers that are used by this guy.
Somewhere on his website he provides a cost calculation for the crossovers of a particular speaker. And this approaches the 200 US$ marker. Not cheap. Of course, as you can see on the ink I provided, the crossovers are rather high quality.
Blueran (Beyma > Beyma 6MI90 6" Driver ONLY £64.25) provides crossovers and filters that are much cheaper, but I wonder if the quality is going to be comparable (I can see the caps used are really quite different).
3) My third question concerns the difference between crossovers and filters. My understanding is that crossovers contain a split of frequencies between the drivers of a speaker, whilst a filter cuts out a frequency range for one particular driver. Is that correct? If not, could someone please explain the difference to me?
Also, could someone tell me when a crossover is used, and when it is better to use a filter?
Cheers!
K
Attachments
Can the baffle not be inserted into a section routed out of a double-thickness wall on the side and stapled or bolted in place? Some caulk could take care of airgaps. It would essentially be a bit like bricklaying, with the center section overlapping a single continuous structure (with the driver holes, of course) behind it, which then extends and joins the sides together...
I guess there are several ways to skin this cat...but the original Strad is made as a sandwich with several layers of ply or MDF, - the wooden sides are laid up as lamels or tiles of rather thick veneer. The front panel is probably attached from the inside to an inner frame. This way it fairly easy to cover the front panel with leather - a small rabbet around the inner perimeter of the front panel will take care of the thickness of the leather . At least I think this is part of the truth. There was some links on the net to the building of the Amati, another of Sonus Fabers great lookers.......
I'm out of town on a job trip, and don't have my personal full link library on this PC.....
It suddenly struck me , what's the difference oof a crossover and a filter, - well a crossover is usually made of several filters.....
Since I detect som uncertainty, excuse me if I'm wrong though, but for a 3-way there is a lowpass for the bass, a bandpass composed of a low and a highpass to cater for the midrange, and then a highpass for the treble....
Concerning the price level, you'd have to expect that. Gravesens x-overs are not exactly simple, rather the opposite, and a lot of atention is given to details and corrections of small imperfections in the response and behavior of each loudspeaker element. Add to that the use of quality components, and you're in his ballpark. If I were rather inexperienced in loudspeaker design, and wanted to build the PMS, I'd follow his instructions to the smallest detail. I've actually been thinking of building a pair for myself.....
I'll see if I can dig out the link for the Cremona build,- at least when I get home next week......
Best regards
EDIT: I take it you have found the original???
www.sonusfaber.com look in the section "Collections" under "Homage"......
I'm out of town on a job trip, and don't have my personal full link library on this PC.....
It suddenly struck me , what's the difference oof a crossover and a filter, - well a crossover is usually made of several filters.....
Since I detect som uncertainty, excuse me if I'm wrong though, but for a 3-way there is a lowpass for the bass, a bandpass composed of a low and a highpass to cater for the midrange, and then a highpass for the treble....
Concerning the price level, you'd have to expect that. Gravesens x-overs are not exactly simple, rather the opposite, and a lot of atention is given to details and corrections of small imperfections in the response and behavior of each loudspeaker element. Add to that the use of quality components, and you're in his ballpark. If I were rather inexperienced in loudspeaker design, and wanted to build the PMS, I'd follow his instructions to the smallest detail. I've actually been thinking of building a pair for myself.....
I'll see if I can dig out the link for the Cremona build,- at least when I get home next week......
Best regards
EDIT: I take it you have found the original???
www.sonusfaber.com look in the section "Collections" under "Homage"......
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Hi again...
I found the links right away...
Here's a fellow countryman of you
The Amati Clone Project
and the Sonus Faber shop tour:
sonus faber amati fabrikage-nl
BTW : Sonus Faber makes excellent loudspeakers and the craftsmanship is quite outstanding, but don't believe all the fanciful claims and relations to the old masters of luthiery....marketing hype and pure **
I found the links right away...
Here's a fellow countryman of you
The Amati Clone Project
and the Sonus Faber shop tour:
sonus faber amati fabrikage-nl
BTW : Sonus Faber makes excellent loudspeakers and the craftsmanship is quite outstanding, but don't believe all the fanciful claims and relations to the old masters of luthiery....marketing hype and pure **
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Me thinks too, - this is not easy to do . Especially the transition edges towards the wood and the corners......
I've tried some furniture restoration, and without the tricks of my old mother who used work as a seamstress, I wouldn't have gotten away with it the way I did..... sometimes old moms can come in quite handy
I've tried some furniture restoration, and without the tricks of my old mother who used work as a seamstress, I wouldn't have gotten away with it the way I did..... sometimes old moms can come in quite handy
AuroraB, thanks for the links.
ACtually I was shocked to see that the drivers referred to, even in the clone project, are scanspeak's most expensive drivers! (well, maybe not most expensive, but when quoting 1000GBP fro drivers alone, I'm out..)
I was considering adapting this design (yes I like it over the PMS. Mostly because it's more convenient to place in my home), and using low end Eminence drivers and crossovers. That would keep it well within my budget. Although I do ofcourse have to recalculate volume space to match the Eminence drivers...
Just one question: If I were to follow the Cremona design, it uses 2 bass drivers. That means 4 units to drive with a 3-way crossover. Can the bass part of the crossover handle 2 bass drivers? It may be irrelevant considering that my tube amp can't output much more than 20W, but worth asking anyway...
ACtually I was shocked to see that the drivers referred to, even in the clone project, are scanspeak's most expensive drivers! (well, maybe not most expensive, but when quoting 1000GBP fro drivers alone, I'm out..)
I was considering adapting this design (yes I like it over the PMS. Mostly because it's more convenient to place in my home), and using low end Eminence drivers and crossovers. That would keep it well within my budget. Although I do ofcourse have to recalculate volume space to match the Eminence drivers...
Just one question: If I were to follow the Cremona design, it uses 2 bass drivers. That means 4 units to drive with a 3-way crossover. Can the bass part of the crossover handle 2 bass drivers? It may be irrelevant considering that my tube amp can't output much more than 20W, but worth asking anyway...
Basically it just means that the low pass section will have to be calculated for the correct impedance - 4 ohms for two 8 ohms elements in parallell. The refernce volume Vas also have to be doubled, since there are two elemenst working in a common volume- this means that when you calculate a box volume for one given element, the box volume has to be doubled if you use two,
As for the crossover for a Cremona clone, we don't know if it is a straight 3-way or maybe a 3.1, meaning the two bass elements have a filter section each, where only one element is operating in the lower mid range and the other is filtered off below mid range and working in the bass range only......
Anyone else have knowledge about this?
I've been following Troels Gravesens pages for a couple of years now, and his designs are not exectly shortcuts to an easy way out, - but quite the opposite - extremely well worked designs with a very close focus to the smal details that make a successful result. Thus the choice of top notch parts fully supports the results, - or rather is the basis of a well deigned product. Changing things in a given design will always change the end result - more or less.
There's nothing wrong with Eminence and the likes, although clearly designed for another niche in the market, - PA and band use mainly. OTOH - there are several designs on the net for HiFi. Since you want to use a 20W tube amp, you should be shooting for a design with a sensitivity of at least 94-95 dBs, which rules out most of the typical Seas, Scanspeak based designs, or rather most of the typical modern HiFi designs, which are almost all in the 87-89 dB range.
I'd recommend looking for a fullrange, or augmented fullrange - meaning an 8 inch FR with tweeter assistance, or FR with low bass assistance.
The OB 15" alpha with Fostex FR looks interesting. Planet10 and Scottmoose also have a lot of designs which shoud be excellent for a lower powered tube amp.
As for the crossover for a Cremona clone, we don't know if it is a straight 3-way or maybe a 3.1, meaning the two bass elements have a filter section each, where only one element is operating in the lower mid range and the other is filtered off below mid range and working in the bass range only......
Anyone else have knowledge about this?
I've been following Troels Gravesens pages for a couple of years now, and his designs are not exectly shortcuts to an easy way out, - but quite the opposite - extremely well worked designs with a very close focus to the smal details that make a successful result. Thus the choice of top notch parts fully supports the results, - or rather is the basis of a well deigned product. Changing things in a given design will always change the end result - more or less.
There's nothing wrong with Eminence and the likes, although clearly designed for another niche in the market, - PA and band use mainly. OTOH - there are several designs on the net for HiFi. Since you want to use a 20W tube amp, you should be shooting for a design with a sensitivity of at least 94-95 dBs, which rules out most of the typical Seas, Scanspeak based designs, or rather most of the typical modern HiFi designs, which are almost all in the 87-89 dB range.
I'd recommend looking for a fullrange, or augmented fullrange - meaning an 8 inch FR with tweeter assistance, or FR with low bass assistance.
The OB 15" alpha with Fostex FR looks interesting. Planet10 and Scottmoose also have a lot of designs which shoud be excellent for a lower powered tube amp.
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Initially I was looking at Beyma drivers, which tend to be very sensitive, 95dB plus, but I don't know how to design crossovers for them. I lack the professional equipment, and the knowledge that Troels has, so designing crossovers is a no-no for me. I was considering Eminence because they actually have their own brand crossovers (see blueran.co.uk), and naturally I assumed they would be compatible with their ownspeakers (however, I found they don't do normal tweeters...)
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