I had heard the amp has very tight bass which is something I was after. My initial testing confirms this 
. It also has a good damping factor to help keep those DPC cone drivers under control (quite possibly part of the reason for the tight bass sound).
I don't know how they build those plate amps so cheap, makes you wonder whats really in them, but yet I sort of wonder how much difference it really makes. Either way I know whats in mine this way and am free to add EQ or extra power or whatever really quite readily.
Total cost must be racking up. Lets see;
PCB at £15 inc shipping
Parts to populate it around £20 (mainly the MOSFETS)
0.5degC/W heatsink £15
300VA transformer £14 (special saving day!)
4 x 10,000uf 63v caps, £1.70 each (on clearance!)
Filter components/electronics around £16
Fixings/connectors etc around £12
Around £100 I guess. I was happier not knowing 
Thats very impressive work on the 500W amp, I wouldn't be daring enough to try that without the PCB.
Heres a pic of the exposed side of the amp.
. It also has a good damping factor to help keep those DPC cone drivers under control (quite possibly part of the reason for the tight bass sound). I don't know how they build those plate amps so cheap, makes you wonder whats really in them, but yet I sort of wonder how much difference it really makes. Either way I know whats in mine this way and am free to add EQ or extra power or whatever really quite readily.
Total cost must be racking up
. Lets see;PCB at £15 inc shipping
Parts to populate it around £20 (mainly the MOSFETS)
0.5degC/W heatsink £15
300VA transformer £14 (special saving day!)
4 x 10,000uf 63v caps, £1.70 each (on clearance!)
Filter components/electronics around £16
Fixings/connectors etc around £12
Around £100 I guess
. I was happier not knowing Thats very impressive work on the 500W amp, I wouldn't be daring enough to try that without the PCB.
Heres a pic of the exposed side of the amp.
Attachments
Dr.EM said:
...am free to add EQ or extra power or whatever really quite readily.
Around £100 I guess
Thats very impressive work on the 500W amp, I wouldn't be daring enough to try that without the PCB.
Looks very clean.
. By EQ do you mean Linkwitz transform? Not sure if integrating it into a TL sub would be a good idea, maybe just a 3-6 dB boost at ~20 Hz, to avoid excess cone excursion.
As for power, that amp should be more than enough, with 275 watts into 4 ohms.
£100 is cheap for the entertainment value both in building it and in listening (plus bragging rights).
Thanks, that's my second version (first was 300 watts with only 6 output bjt's rather than the 10 pictured). Heat sink is homemade, and plenty big for a sub amp. It's all stuffed inside an old Fisher Audio receiver case with a new front. Also has a seperate +/- 15 volt supply for the Linkwitz transform plus a LED power meter.
That was a couple months worth of entertainment.
DR. Em,
You, Scottmoose and Planet10 seem quite good designing TL style enclosures. I was hoping that you would be so kind as to do a quick analysis for me. I do not have either the tools or the skill needed to do the analysis.
I purchased a group of HiVi A5+ drivers to be used four to a cabinet in a speaker design. My current plan is to build a ported enclosure tuned to ~50 hz yielding an f3 of about 48hz. When I read this thread it got me all excited about a TL. I have been reading about them for years, but have never heard one.
If these drivers seem suitable for a TL, then I can look at the rest of the design.
My main criteria is to keep the width of the cabinet about 8-1/2" wide and about 40" tall. There will be mids & tweeters above the HiVi A5's that will take up about 8" of baffle space near the top.
The specs on the drivers are;
*Power handling: 35 watts RMS/70 watts max *VCdia: 3/4" *Znom: 8 ohms *Re: 6.5 ohms *Frequency range: 55-6,500 *Fs: 55 Hz *SPL: 86dB 1W/1m *Vas: .22 cu. ft. *Qms: 5.91 *Qes: .47 *Qts: .44 *Xmax: 3 mm *Dimensions: A: 5-1/8", B: 4-1/4", C: 3-3/4".
The SD is about 15.9"^2 per driver, or about 60.36"^2 total for all four drivers.
Any help that you can offer in helping me decide if TL is a good fit for these drivers is greatly appreciated.
Paul
PS. I am not trying to hijack this thread, but I was very impressed with both the sub, and the quality of the design help I felt by posting here it might be noticed quicker. I can/will start a new thread if I do the TL.
You, Scottmoose and Planet10 seem quite good designing TL style enclosures. I was hoping that you would be so kind as to do a quick analysis for me. I do not have either the tools or the skill needed to do the analysis.
I purchased a group of HiVi A5+ drivers to be used four to a cabinet in a speaker design. My current plan is to build a ported enclosure tuned to ~50 hz yielding an f3 of about 48hz. When I read this thread it got me all excited about a TL. I have been reading about them for years, but have never heard one.
If these drivers seem suitable for a TL, then I can look at the rest of the design.
My main criteria is to keep the width of the cabinet about 8-1/2" wide and about 40" tall. There will be mids & tweeters above the HiVi A5's that will take up about 8" of baffle space near the top.
The specs on the drivers are;
*Power handling: 35 watts RMS/70 watts max *VCdia: 3/4" *Znom: 8 ohms *Re: 6.5 ohms *Frequency range: 55-6,500 *Fs: 55 Hz *SPL: 86dB 1W/1m *Vas: .22 cu. ft. *Qms: 5.91 *Qes: .47 *Qts: .44 *Xmax: 3 mm *Dimensions: A: 5-1/8", B: 4-1/4", C: 3-3/4".
The SD is about 15.9"^2 per driver, or about 60.36"^2 total for all four drivers.
Any help that you can offer in helping me decide if TL is a good fit for these drivers is greatly appreciated.
Paul
PS. I am not trying to hijack this thread, but I was very impressed with both the sub, and the quality of the design help I felt by posting here it might be noticed quicker. I can/will start a new thread if I do the TL.
For PixelPlay;
I'm finding the BurrBrown OPA2134's very suitable for these filters. The high pass section is using them and they sound totally transparent to me. I can hear more detail in my main speakers with this crossover implemented since neither the amp or speakers need to handle any low bass (sub 70hz).
aceinc, I think the Qts and Qes values may be a bit higher than optimum on those drivers, but hopefully one of the guys with the software might sim them and see what result they could give. I'd be interested to see the result
I'm finding the BurrBrown OPA2134's very suitable for these filters. The high pass section is using them and they sound totally transparent to me. I can hear more detail in my main speakers with this crossover implemented since neither the amp or speakers need to handle any low bass (sub 70hz).
aceinc, I think the Qts and Qes values may be a bit higher than optimum on those drivers, but hopefully one of the guys with the software might sim them and see what result they could give. I'd be interested to see the result
Hmm, well drivers arrived today. I'm not quite sure what to think yet, my initial impressions were that the mechanical handling was laughably poor but a few things are starting to show otherwise.
First test was run in free air as usual, doing this I had a bottoming out type noise at even VERY low levels but it soon became evident you must have these drivers away from the floor, ie not resting on the magnet; something to do with the vent mabye? Can't imagine why at these power levels (literally 1-2W out of the supposed 180W handling). Lifting them up improves it somewhat but you mabye get 1mm total Xmax before you get a sort of rattling sound, I did think it was faulty but both units are exactly the same. You are supposed to get 4.5mm linear each way, 9mm total. I next tried a good old cardboard box enlosure but its own rattinlg is uncontrollable so the only way I'm going to get any idea of what these can do it to fit them in the proper enclosure.
Perhaps they need an enclosure to keep them happy but I've seen many speakers run at high Xmax free air completely silently. Perhaps they need running in but this seems a bit of an extreme case? Or mabye they are just totally unsuitable and I've wasted a lot of money
Oh yes, some pics too:
First test was run in free air as usual, doing this I had a bottoming out type noise at even VERY low levels but it soon became evident you must have these drivers away from the floor, ie not resting on the magnet; something to do with the vent mabye? Can't imagine why at these power levels (literally 1-2W out of the supposed 180W handling). Lifting them up improves it somewhat but you mabye get 1mm total Xmax before you get a sort of rattling sound, I did think it was faulty but both units are exactly the same. You are supposed to get 4.5mm linear each way, 9mm total. I next tried a good old cardboard box enlosure but its own rattinlg is uncontrollable so the only way I'm going to get any idea of what these can do it to fit them in the proper enclosure.
Perhaps they need an enclosure to keep them happy but I've seen many speakers run at high Xmax free air completely silently. Perhaps they need running in but this seems a bit of an extreme case? Or mabye they are just totally unsuitable and I've wasted a lot of money
Oh yes, some pics too:
Attachments
Oh dear
Its all together now, the side is merely clamped on though. I've applied some damping (lambswool) to the front part of the line mainly.
As an enclosure design I feel it works well, it can hit some seriously deep notes that I've never noticed on my DM602's, but my driver choice is evidently a poor one. In the case they handle as they did in free air away from the floor, obviously it's louder in the case but overall it achieves a poor output, the drivers start making unhealthy sounds before my normal (very moderate) listening level and "cranking it" just isn't a possiblilty.
You can just about see the drivers moving as they start to go wrong, certainly no where near +/-4.25mm Xmax
I had heard about other/older Morel drivers having poor mechanical handling (here and elsewhere) but thought the new ones would be better and put a lot of that down to other peoples idea of "moderate". I actually don't know if mine are right or if I somehow got a faulty pair; they didn't come in manufacturers boxes and the dustcap on each has a small amount of marking (though that is possibly a consequence of the DPC process?). If anyone else has them I would be very pleased if you could describe thier performance!
Its all together now, the side is merely clamped on though. I've applied some damping (lambswool) to the front part of the line mainly.
As an enclosure design I feel it works well, it can hit some seriously deep notes that I've never noticed on my DM602's, but my driver choice is evidently a poor one. In the case they handle as they did in free air away from the floor, obviously it's louder in the case but overall it achieves a poor output, the drivers start making unhealthy sounds before my normal (very moderate) listening level and "cranking it" just isn't a possiblilty.
You can just about see the drivers moving as they start to go wrong, certainly no where near +/-4.25mm Xmax
I had heard about other/older Morel drivers having poor mechanical handling (here and elsewhere) but thought the new ones would be better and put a lot of that down to other peoples idea of "moderate". I actually don't know if mine are right or if I somehow got a faulty pair; they didn't come in manufacturers boxes and the dustcap on each has a small amount of marking (though that is possibly a consequence of the DPC process?). If anyone else has them I would be very pleased if you could describe thier performance!
They were from Wilmslow so I imagine its all as it should be. From what I've heard they are a quality company though a little overpriced (those drivers were better price than anywhere else mind with postage factored in).
It just seems bizarre to have 180W electrical power handling when the mechanical system can't handle more than 10W or so at low frequency (and low frequency response was a highlight of this model).
Although I haven't adjusted the stuffing in the enclosure yet I must say i'm very impressed with the enclosure design! It squeezes out very low notes even when the drivers are barely doing anything. Effortless reproduction of the kick drum and low electronic bass but the driver just limits the level you can use it (no chance of "feeling" the sound, have yet to try films too). My brother complanied about it from the next room and that was with about 2W so I guess its pretty efficient. It definately improves the listening experience to me, suprising how many songs have this low information. Generally the songs I had regarded as lacking in bass actually have rather a lot, but it was too low for my 602s alone so I never heard it!
I'll get some pics up later, admittably it does look rather huge in my small room so a more "normal" sized sub would have been very difficult to accomodate. I need to veneer it once the stuffing is adjusted and the side panel fixed on, should look respectable.
It just seems bizarre to have 180W electrical power handling when the mechanical system can't handle more than 10W or so at low frequency (and low frequency response was a highlight of this model).
Although I haven't adjusted the stuffing in the enclosure yet I must say i'm very impressed with the enclosure design! It squeezes out very low notes even when the drivers are barely doing anything. Effortless reproduction of the kick drum and low electronic bass but the driver just limits the level you can use it (no chance of "feeling" the sound, have yet to try films too). My brother complanied about it from the next room and that was with about 2W so I guess its pretty efficient. It definately improves the listening experience to me, suprising how many songs have this low information. Generally the songs I had regarded as lacking in bass actually have rather a lot, but it was too low for my 602s alone so I never heard it!
I'll get some pics up later, admittably it does look rather huge in my small room so a more "normal" sized sub would have been very difficult to accomodate. I need to veneer it once the stuffing is adjusted and the side panel fixed on, should look respectable.
Hi, Dr. Em. Your project is an intriguing one.
Have you taken great care to ensure that the line is properly sealed? If any air leaks exist, then the line no longer behaves like a line, and instead acts like a very leaky sealed box, or an improperly tuned reflex box. You could apply caulk to the insides of the box, and remove some of the stuffing (if you're using any).
Have you taken great care to ensure that the line is properly sealed? If any air leaks exist, then the line no longer behaves like a line, and instead acts like a very leaky sealed box, or an improperly tuned reflex box. You could apply caulk to the insides of the box, and remove some of the stuffing (if you're using any).
At the moment I guess it isn't. One side is held on with clamps alone so leaks are bound to exist (especially with only 4 clamps). It sounds good but the problem is poor driver excursion creating distortion at lower levels than I would want. The driver noise actually comes from the back opening in the line so must be emitted from the rear of the drivers only. Will a fully sealed line help this at all by loading the driver differently?
The side is clamped on while I adjust the stuffing. At the moment it is some lambswool behind the drivers and a tiny bit further down too, i'm likely to try more. Any ideas for good glue to hold the stuffing onto MDF by the way?
The side is clamped on while I adjust the stuffing. At the moment it is some lambswool behind the drivers and a tiny bit further down too, i'm likely to try more. Any ideas for good glue to hold the stuffing onto MDF by the way?
Actually, what I've found useful is placing a bead of silicone caulk along the outer edge of all the panels that form the line, as well as the outer panels, in order to create a seal between the side panel (which you say is just screwed on) and all the panels that form the line, so that when you put the side panel on, it self-seals. If you do this, be sure to take the drivers out, and let the caulk cure completely (usually 24Hr) before putting the drivers back in. The silicone caulk gives off gases while it cures, and these gases can cause the rubber surrounds to deteriorate. Also, caulk along all the joints in your box to ensure that everything is sealed and there aren't any air leaks. A transmission line actually generates quite a bit of pressure along its length that is enough to force air through tiny gaps.
As a side question, have you tried running the woofers at all without the side panel attached? I know there won't be any bass loading, and you won't hear any bass, but it's a way to rule out box vibrations as the source of the vibrating sound. Just start with the amp gain turned all the way down, and then turn it up slowly until you see the woofers having greater and greater cone displacements. If you hear clacking or vibrating, then just back down the amp gain. This is just to check that the drivers are reaching their own mechanical specifications. I'd expect those drivers to have a suspension-limited Xmax, since they've got such small surrounds. It could be that what you're hearing is actually vibrations from the enclosure itself.
As a side question, have you tried running the woofers at all without the side panel attached? I know there won't be any bass loading, and you won't hear any bass, but it's a way to rule out box vibrations as the source of the vibrating sound. Just start with the amp gain turned all the way down, and then turn it up slowly until you see the woofers having greater and greater cone displacements. If you hear clacking or vibrating, then just back down the amp gain. This is just to check that the drivers are reaching their own mechanical specifications. I'd expect those drivers to have a suspension-limited Xmax, since they've got such small surrounds. It could be that what you're hearing is actually vibrations from the enclosure itself.
I can't really comment on the physical properties of the drivers, as all I have / had to go on were the T/S parameters. Sounds like the power-handling claims were a trifle optimistic though.
A fully sealed TL, suitably damped, will have an FR like a ~optimum sealed box, but with a much milder impedence curve. Heavily damping an open line will result in ~aperiodic behaviour, with a similar effect, but often with a bit more gain.
A staple-gun holds damping down quite well btw... seriously.
A fully sealed TL, suitably damped, will have an FR like a ~optimum sealed box, but with a much milder impedence curve. Heavily damping an open line will result in ~aperiodic behaviour, with a similar effect, but often with a bit more gain.
A staple-gun holds damping down quite well btw... seriously.
Thanks for your replies
I reckon the box will be suitably sealed when the side is fixed. Like all other joints in the construction it will be fixed with a continuous bead of glue on every edge. I remember using bathroom silicone sealer on a sub some years ago, it still isn't dry
I will try the drivers without the side panel attached, perhaps a strobe will help see whats going on. I'm pretty sure its them at fault though but wonder just how far they get pushed with impulse type sounds without me really "seeing" it. The surrounds are quite small but are oddly shaped in that they stick forward quite a way, if the driver was limited by them alone I would be perfectly satisfied with them. I can't imagine what else is limiting them mind, it looks like a well built and fairly long throw motor system.
Either way I am impressed with your (collectively) design on this sub. Other than the limited output levels the sound is very impressive. Deep extension and fast reaction. It really reveals detail in bass rather than it just being a general rumble. I do love the sound of acoustic kick drums with it. Having used the drum kit at college many times I find this to be the only thing I've heard that really presents the sound as it should be.
I reckon the box will be suitably sealed when the side is fixed. Like all other joints in the construction it will be fixed with a continuous bead of glue on every edge. I remember using bathroom silicone sealer on a sub some years ago, it still isn't dry
I will try the drivers without the side panel attached, perhaps a strobe will help see whats going on. I'm pretty sure its them at fault though but wonder just how far they get pushed with impulse type sounds without me really "seeing" it. The surrounds are quite small but are oddly shaped in that they stick forward quite a way, if the driver was limited by them alone I would be perfectly satisfied with them. I can't imagine what else is limiting them mind, it looks like a well built and fairly long throw motor system.
Either way I am impressed with your (collectively) design on this sub. Other than the limited output levels the sound is very impressive. Deep extension and fast reaction. It really reveals detail in bass rather than it just being a general rumble. I do love the sound of acoustic kick drums with it. Having used the drum kit at college many times I find this to be the only thing I've heard that really presents the sound as it should be.
What you really need is one of these... 
This is what happens when Dave & I decide to have some fun. http://homepage.mac.com/tlinespeakers/FAL/box-plans/CSS-SD12-BIB-1v0.pdf The modelled response is with ~optimal damping applied as they're designed for corner-loading, so in room, they should be flat to about 19Hz. Reducing the damping will increase pipe-gain should no corner be available.
This is what happens when Dave & I decide to have some fun. http://homepage.mac.com/tlinespeakers/FAL/box-plans/CSS-SD12-BIB-1v0.pdf The modelled response is with ~optimal damping applied as they're designed for corner-loading, so in room, they should be flat to about 19Hz. Reducing the damping will increase pipe-gain should no corner be available.
That is a nice design and as it would happen probably would have been suitable since the footprint isn't all that huge. It would be located in a corner too.
I have 3 possible locations for my sub in my room. It'd either be forward facing on the left or right side of my desk or could be located facing the left wall (into a corner) placed lengthwise across the back of mk room. Only thing with that is the sound seems to dissapear when you get to the side/behind the drivers so forward facing is likely to work best.
I also realised that there are 4 mounting holes (for the amp) at the back of my sub. I need to place bolts through these to seal them too. I do kind of wish I'd used a seperate amp unit, mounting it to the sub is a bit untidy really. One of many things learnt through this project anyhow
Pic of unfinished sub. Once stuffing is adjusted box will be sealed and amplifier mounted before veneering and waxing to hopefully give respectable finish
I have 3 possible locations for my sub in my room. It'd either be forward facing on the left or right side of my desk or could be located facing the left wall (into a corner) placed lengthwise across the back of mk room. Only thing with that is the sound seems to dissapear when you get to the side/behind the drivers so forward facing is likely to work best.
I also realised that there are 4 mounting holes (for the amp) at the back of my sub. I need to place bolts through these to seal them too. I do kind of wish I'd used a seperate amp unit, mounting it to the sub is a bit untidy really. One of many things learnt through this project anyhow
Pic of unfinished sub. Once stuffing is adjusted box will be sealed and amplifier mounted before veneering and waxing to hopefully give respectable finish
Attachments
Hobbycraft is last hope for the tape it seems.
Playing with the drivers again since the box is being veneered now (side glued on at last after adjusting stuffing).
The rattling/distortion is definately somehow related to the pole piece vent. I was running it full range and experimenting, covering that vent immediately increases the rattling sound vastly. Obviously the noise is less evident when run full range as its masked by the higher ranges but as soon as you cover that vent you can hear it clearly over overything. The excursion looks clean in both the motor and suspension so this noise would seem to be generated somehow else. I was running with a small 14W amplifier too (yes, it runs out of mechanical handling even with that low power) so it's nothing like the voice coil overheating and somehow distorting. Any ideas, its got me stumped . If I removed the wadding in the back of the vent will it let too much dust in? I can't help feeling it is what is causing it as it must act as a partial blockage
http://eltimaudio.com/products/HU-series introduction.pdf
(you can see the wadding bit in those pics)
Playing with the drivers again since the box is being veneered now (side glued on at last after adjusting stuffing).
The rattling/distortion is definately somehow related to the pole piece vent. I was running it full range and experimenting, covering that vent immediately increases the rattling sound vastly. Obviously the noise is less evident when run full range as its masked by the higher ranges but as soon as you cover that vent you can hear it clearly over overything. The excursion looks clean in both the motor and suspension so this noise would seem to be generated somehow else. I was running with a small 14W amplifier too (yes, it runs out of mechanical handling even with that low power) so it's nothing like the voice coil overheating and somehow distorting. Any ideas, its got me stumped
. If I removed the wadding in the back of the vent will it let too much dust in? I can't help feeling it is what is causing it as it must act as a partial blockage http://eltimaudio.com/products/HU-series introduction.pdf
(you can see the wadding bit in those pics)
Check your tuning, the HU631 has an Fs of 44hz, I read somewhere in your post you were going for a tuning of 22hz, if so that is way below what this driver is capable of. I would be looking at a subwoofer driver with much lower fs, eg.
http://www.partsexpress.com/pe/pshowdetl.cfm?&Partnumber=264-854
Andrew.
http://www.partsexpress.com/pe/pshowdetl.cfm?&Partnumber=264-854
Andrew.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.