Hi,
This might sound daft!!
I've got a pair of Eltax Symphony 6 speakers, to my ears they sound ok/good.
The problem with them is that we have just moved to a smaller house and they are way too big for our sitting room.
Here's my plan...turn them into bookshelf speakers.
The cabinets have 2 speakers, a tweeter and a 6 1/2" bass/midrange and a port. I don't have the spec for either speaker apart from what is printed on the back of each speaker Music Power 150W, Sinus (RMS?) Power 80W.
I've come across several resources which deal with the design and construction of speaker cabinets but all need more in depth specs for the bass/midrange. This I don't have.
A few questions to get me started:
Where do I get the spec from?
Can I do some tests to get the spec I need?
Is there a generic model for people like me!?
Many thanks
Ron
PS I'm a furniture maker so the woodworking side is something I should be able to do.
This might sound daft!!
I've got a pair of Eltax Symphony 6 speakers, to my ears they sound ok/good.
The problem with them is that we have just moved to a smaller house and they are way too big for our sitting room.
Here's my plan...turn them into bookshelf speakers.
The cabinets have 2 speakers, a tweeter and a 6 1/2" bass/midrange and a port. I don't have the spec for either speaker apart from what is printed on the back of each speaker Music Power 150W, Sinus (RMS?) Power 80W.
I've come across several resources which deal with the design and construction of speaker cabinets but all need more in depth specs for the bass/midrange. This I don't have.
A few questions to get me started:
Where do I get the spec from?
Can I do some tests to get the spec I need?
Is there a generic model for people like me!?
Many thanks
Ron
PS I'm a furniture maker so the woodworking side is something I should be able to do.
Open them up and tell us what is printed on the back of each drive unit, particularly the woofer. Just be aware that you'll lose bass in a smaller box.
Probably Peerless woofers
Probably Peerless woofers
Common sense would suggest to keep the internal volume as the original.
You'd end with a much deeper enclosure if you keep the same baffle width.
Augmenting the baffle dimension would change the...uh...er...well, something changes ( they say...!)
Oh yes, it's the nature of the soundwaves and precisely, related to the low frequencies, the woofer emits frontally and the waves bend the speaker so we talk about BSC which is related to the transition from emispherical ( the baffle limits the radiation but forwards...) to spherical, so a certain amount of bass freq...😱
In general, also the crossover values should be related to what happens "outside" and not only "inside" ( the values that determines the Q of the filter and the Q in the box)
You'd end with a much deeper enclosure if you keep the same baffle width.
Augmenting the baffle dimension would change the...uh...er...well, something changes ( they say...!)
Oh yes, it's the nature of the soundwaves and precisely, related to the low frequencies, the woofer emits frontally and the waves bend the speaker so we talk about BSC which is related to the transition from emispherical ( the baffle limits the radiation but forwards...) to spherical, so a certain amount of bass freq...😱
In general, also the crossover values should be related to what happens "outside" and not only "inside" ( the values that determines the Q of the filter and the Q in the box)
The Eltax Symphony 6 lies very much in the budget camp so, in that respect, is a good candidate for experimentation.
However, its large size (see attached image) does not sit well with being converted to a bookshelf enclosure of the same volume.
The bass driver carries the following information:
Item No. 3284
Spec. 0610SY-B4
I don't think that will help much in the search for specifications.
However, its large size (see attached image) does not sit well with being converted to a bookshelf enclosure of the same volume.
The bass driver carries the following information:
Item No. 3284
Spec. 0610SY-B4
I don't think that will help much in the search for specifications.
Attachments
Thanks for all the replies, and thanks for the bass unit id from Galu. I'll take it that I've got the same speakers as yours in the photo. Googling this doesn't come up with much.
So what could possibly go wrong if I made up a couple of cabinets with the smallest baffle dimension to take the 2 speakers and I fitted the reflex tube in the back/side/underside?
The size would be a load less than the existing cabinets but what difference would I notice. Could I even be pleasantly surprised at how they sound?
I see that Eltax used to make smaller speakers with what looks like the same drive units. Presumably they worked okish?
Cheers
Ron
So what could possibly go wrong if I made up a couple of cabinets with the smallest baffle dimension to take the 2 speakers and I fitted the reflex tube in the back/side/underside?
The size would be a load less than the existing cabinets but what difference would I notice. Could I even be pleasantly surprised at how they sound?
I see that Eltax used to make smaller speakers with what looks like the same drive units. Presumably they worked okish?
Cheers
Ron
Given th ebox shape you would want to go from the MLTL to a BR. That should certainly be doable but we do need to know the driver specs.
You might well just want to move them on and start from scratch. Then you don’t have to burn or store the old cabinet.
dave
You might well just want to move them on and start from scratch. Then you don’t have to burn or store the old cabinet.
dave
Hi Ron! I'm going to assume your woodworking skills exceed your knowledge of reflex function. Tell me off if I am being presumptious! 🙂
The reflex tube acts in conjunction with the volume of the enclosure to tailor the bass response of the system. An enclosure of smaller volume would not be 'tuned' by the same reflex tube.
Without knowing the T/S parameters of the bass driver, it is not possible to suggest port dimensions which would tune your bass driver satisfactorily in an enclosure of reduced volume.
Without these parameters, we are working solely on guesswork.
Considering that you will expend a lot of time and effort employing your woodworking skills to build a smaller enclosure, modifying your current floorstanders doesn't strike me as the best option. Using an established enclosure design incorporating known drivers is the best recommendation. You could help finance the project by selling on your floorstanders.
If you do wish to continue with the mod, I suggest you do a mock up of a sealed enclosure of your required volume using stout packing box cardboard. That way you can judge whether the bass response is to your satisfaction or whether you have to think again.
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Dave, these are budget speakers and I'm sure they are bass reflex, not transmission line.
They may be called BR, but becaus ef the box geometry, ie one dimension consideralby larger than the others) it actually functions as an MLTL.
If they did a decent development job they would have had to lower the vent tuning from a BR sim. So they well could have built an MLTL without knowing they were. It happens a lot.
dave
If they did a decent development job they would have had to lower the vent tuning from a BR sim. So they well could have built an MLTL without knowing they were. It happens a lot.
dave
Thanks Dave!
That's all the more reason why using the current bass driver in a smaller box with the same reflex port is not such a good idea! 😎
That's all the more reason why using the current bass driver in a smaller box with the same reflex port is not such a good idea! 😎
If you tell us the internal dimensions of the box, and the length & diameter of the port, an estimate of the frequency the box is tuned to could be made, and from that dimensions of a new port for a smaller box could be made
Hi and thanks.
I did a bit more googling and found that this company Eltax made a bookshelf version which they called a Symphony 4.
The bass/mid and tweeter measure the same as the ones in my 6's. They measure 340mm high. 220mm wide and 240mm deep (this is the sort of size I had in mind for the cut-downs). The frequency response is quoted as 40Hz at the low end (35Hz for the 6's). From the photos I've seen the port diameter looks a little smaller than the 6's and is fitted to the back of the cabinet.
The easy thing for me is to copy this design....but that's not much of a challenge!!
Thanks PeterMck for the offer, I'll take you up on it once I have the speakers apart in my workshop. Could adjusting the port length/diameter improve the bass response, if it could then it would make the project well worth doing!
Cheers
Ron
I did a bit more googling and found that this company Eltax made a bookshelf version which they called a Symphony 4.
The bass/mid and tweeter measure the same as the ones in my 6's. They measure 340mm high. 220mm wide and 240mm deep (this is the sort of size I had in mind for the cut-downs). The frequency response is quoted as 40Hz at the low end (35Hz for the 6's). From the photos I've seen the port diameter looks a little smaller than the 6's and is fitted to the back of the cabinet.
The easy thing for me is to copy this design....but that's not much of a challenge!!
Thanks PeterMck for the offer, I'll take you up on it once I have the speakers apart in my workshop. Could adjusting the port length/diameter improve the bass response, if it could then it would make the project well worth doing!
Cheers
Ron
The best you can do is measure the drivers yourself or find someone in your region that can do that. Something like a DATS V3 or even REW with a diy rig (google that) can give you the necesairy info. With that info you can make a box and trying to keep the same front dimensions (as the crossover should be adapted to that). Without specs or measurements it's like shooting in the dark and hoping you hit the target...
Some practical advice: Measure the internal volume of the old floorstanding box and try to get as close to that as possible with the new box you make by extending the depth of the box. Keep the widht of the floorstanding box for your new bookshelf box and use the same chamfer at the edge. Place the tweeter at the same distance from the upper egde and side edges as in the old box. The distance between the bass and the tweeter should be kept as small as possible. Make the new box a bass reflex box by using a port/tube. Keep the diameter of the port minimum 5 cm and try different lengths of the tube. The existing crossover could probably be kept as is.
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Have you taken a drive unit out to check inside. I had some Eltax Floorstanders once and inside they were not floor standers. I.e. the box ended just below the port. The lower part of the box was just an empty stand. These might be the same and therefore you could re-use that volume.
Ok, I've taken out the reflex tube. The box is empty, no divider, free space from top to bottom. No damping/insulation material.
I know these aren't the top of the range speakers. They sound Ok but are just too big.
If I chop them down in height from 830mm to 350mm (to the size of the its smaller sibling) am I going to notice much difference in sound?
Should I line the inside of the box with some sound deadening? What is achieved by doing this?
How critical is the dimensions and position of the bass reflex tube?
Cheers
Ron
I know these aren't the top of the range speakers. They sound Ok but are just too big.
If I chop them down in height from 830mm to 350mm (to the size of the its smaller sibling) am I going to notice much difference in sound?
Should I line the inside of the box with some sound deadening? What is achieved by doing this?
How critical is the dimensions and position of the bass reflex tube?
Cheers
Ron
There will be a difference in sound, but the difference may be minimised by a new port design.
The walls of ported speakers can be lined with acoustic foam to help prevent the rear radiation from the speaker cone being reflected around the inside of the cabinet and then back out through the speaker cone and reflex port. Such reflections lead to a 'boxy sound'.
A dense material such as bitumastic damping sheet can first be attached to the enclosure walls to help reduce their vibration and make the enclosure acoustically 'dead'.
The dimensions of the bass reflex tube are very critical in determining the bass response and other characteristics of the system. Its position is not too critical.
Earlier, I suggested making a cardboard mockup of a smaller enclosure.
This is not such a daft idea, as it would let you know what you may expect sound wise before going to the lengths of chopping up your floorstander! 😎
This is not such a daft idea, as it would let you know what you may expect sound wise before going to the lengths of chopping up your floorstander! 😎
Hi,
Thanks. Tips understood.
Seeing as this is a "calculation free" cobbled together job how do I work out the best diameter/length of bass reflex tube? I suppose this is going to be a guess job by trying in various lengths of pipe that I've got kicking about and doing a listening test in situ.
My plan is to make the boxes with a solid dense homegrown hardwood like Ash, Elm or Oak. Is this the done thing or is MDF/Chipboard actually better?
Grill or no grill. What's the current thinking?
Cheers
Ron
Thanks. Tips understood.
Seeing as this is a "calculation free" cobbled together job how do I work out the best diameter/length of bass reflex tube? I suppose this is going to be a guess job by trying in various lengths of pipe that I've got kicking about and doing a listening test in situ.
My plan is to make the boxes with a solid dense homegrown hardwood like Ash, Elm or Oak. Is this the done thing or is MDF/Chipboard actually better?
Grill or no grill. What's the current thinking?
Cheers
Ron