Tony
My curtains are extremely thin, virtually not even present. I suspect that you would have a very difficult time telling if they are there or not in a blind test. I can measure about 1 dB loss, but thats very difficult to hear. If you can readily hear the effect then the cloth is too dense. There are some very light weight fabrics out there. When held up to the light they almost appear transparent.
I have talked with customers privately about the difference in 1.5 vs. 1 uF caps in the crossover as having a roll off effect. I suppose I should post this in the manual. The ones that you are listening to have the slight roll-off I believe.
My curtains are extremely thin, virtually not even present. I suspect that you would have a very difficult time telling if they are there or not in a blind test. I can measure about 1 dB loss, but thats very difficult to hear. If you can readily hear the effect then the cloth is too dense. There are some very light weight fabrics out there. When held up to the light they almost appear transparent.
I have talked with customers privately about the difference in 1.5 vs. 1 uF caps in the crossover as having a roll off effect. I suppose I should post this in the manual. The ones that you are listening to have the slight roll-off I believe.
Thanks for the info.
When you say the larger ones are smoother, is that something to do with attenuating HOMs?
Would it be true to say that the larger diameter waveguides have deeper throats?
Would it be true to say that a deeper throat would enable the foam to absorb more HOM's? Or would the number of reflections being absorbed be equal and difference in HOM's are about equal?
Just curious if better HOM reduction is a property of the larger waveguides, as well as the better controlled directivity in terms of starting from a lower crossover point.
-Tony
When you say the larger ones are smoother, is that something to do with attenuating HOMs?
Would it be true to say that the larger diameter waveguides have deeper throats?
Would it be true to say that a deeper throat would enable the foam to absorb more HOM's? Or would the number of reflections being absorbed be equal and difference in HOM's are about equal?
Just curious if better HOM reduction is a property of the larger waveguides, as well as the better controlled directivity in terms of starting from a lower crossover point.
-Tony
Tony
I think that its all true. The larger waveguides have almost four times as much foam, if not more. Thats a lot more effect and if the effect is positive then thats a big benefit. But they also control the directivity better and do so to a lower frequency. The mouth is bigger so there is less reflection and diffraction. All in all bigger is simply better. But they are harder to make, cost more and are harder to package. There are no free lunches.
I think that its all true. The larger waveguides have almost four times as much foam, if not more. Thats a lot more effect and if the effect is positive then thats a big benefit. But they also control the directivity better and do so to a lower frequency. The mouth is bigger so there is less reflection and diffraction. All in all bigger is simply better. But they are harder to make, cost more and are harder to package. There are no free lunches.
CLD
Earl,
I'm progressing slowly but shurly with my Nathans (and multi-subs) and have a couple of quick questions. I had to do some minor surgery on one of the front baffles and need to ad some more of the glue that you used for CLD. For consistency would you mind sharing what type/brand you used ? After reading various posts it seems that you favor the "damped" vs "fixed" approach and im not sure if this is an epoxy or elmers poly glue.
Also as far as attenuating the HF response are you taking about changing the 1.5uf cap paired with the resistor to a 1.0uf cap ?
Thanks Earl.
Regards, Daniel.
Earl,
I'm progressing slowly but shurly with my Nathans (and multi-subs) and have a couple of quick questions. I had to do some minor surgery on one of the front baffles and need to ad some more of the glue that you used for CLD. For consistency would you mind sharing what type/brand you used ? After reading various posts it seems that you favor the "damped" vs "fixed" approach and im not sure if this is an epoxy or elmers poly glue.
Also as far as attenuating the HF response are you taking about changing the 1.5uf cap paired with the resistor to a 1.0uf cap ?
Thanks Earl.
Regards, Daniel.
What was the surgery, I'd like to know. I've had to sand down the edges of the inner board on the baffle to get it to fit right. Seems like this board is a few mils too big.
The glue that I use is a two part "soft" polyurethane that I buy in five gallon drums. I got this stuff for casting by mistake. Then I tried it as a glue and it works great. I got it at a company in lower MI. I don't think that anything comparable is available in small quantities. Use Liquid Nails for CLD and Elmers polyurethane (or any other brand its all the same) for the box.
Yes, the 1.0 uF cap will drop the HF response about 1-2 dB - just enough IMO. The 1.5 uF is flatt on axis, but the 1.0 has a flatter power response.
The glue that I use is a two part "soft" polyurethane that I buy in five gallon drums. I got this stuff for casting by mistake. Then I tried it as a glue and it works great. I got it at a company in lower MI. I don't think that anything comparable is available in small quantities. Use Liquid Nails for CLD and Elmers polyurethane (or any other brand its all the same) for the box.
Yes, the 1.0 uF cap will drop the HF response about 1-2 dB - just enough IMO. The 1.5 uF is flatt on axis, but the 1.0 has a flatter power response.
Surgery
Earl,
The minor surgery involved the lower half of the woofer cut-out on the inner layer of the front baffle. There was a visible air space between the two layers i'd guess from that poly glue pushing the boards apart or flowing downwards due to gravity as it dried. Basically the lower half of the inner baffle was not firmly attached to the outer baffle. Instead of trying to fill that air gap i elected to cut the lower half of the inner baffle away from the upper half. I then cleaned up the glue on both surfaces (to create a fresh glue joint/surface)and used dowels to keep the alignment and spacing as it was originally before making the cut. Now i just have to reglue the two layers back together and fill that small space i created with the width of the saw blade.
I would agree with you that the inner layer of the front baffle is just a hair wide. I started to sand it but decided that a single pass on a table saw would probably be a better option. Still waiting for my brother (pro cabinet maker) to help with that part so i'll let you know how that works out. Or if he comes up with a better alternative. It could be done with sanding but would just take a bit o time.
Thanks for the tip on the HF frequency response. Its nice to know there is some room to experiment if necessary.
Thanks Earl,
Daniel.
Earl,
The minor surgery involved the lower half of the woofer cut-out on the inner layer of the front baffle. There was a visible air space between the two layers i'd guess from that poly glue pushing the boards apart or flowing downwards due to gravity as it dried. Basically the lower half of the inner baffle was not firmly attached to the outer baffle. Instead of trying to fill that air gap i elected to cut the lower half of the inner baffle away from the upper half. I then cleaned up the glue on both surfaces (to create a fresh glue joint/surface)and used dowels to keep the alignment and spacing as it was originally before making the cut. Now i just have to reglue the two layers back together and fill that small space i created with the width of the saw blade.
I would agree with you that the inner layer of the front baffle is just a hair wide. I started to sand it but decided that a single pass on a table saw would probably be a better option. Still waiting for my brother (pro cabinet maker) to help with that part so i'll let you know how that works out. Or if he comes up with a better alternative. It could be done with sanding but would just take a bit o time.
Thanks for the tip on the HF frequency response. Its nice to know there is some room to experiment if necessary.
Thanks Earl,
Daniel.
So, would you say that the bond between the inner baffle and the outer one was not made well enough to hold? I usually glue these under pressure, but if there was not enough glue then even this would not help. Was there enough glue but not enough pressure, or the other way around? The boards are always glued flat so gravity is not the problem.
The table saw is exactly how I correct the inner baffle size problem. Much easier than sanding!!!
I've thought of supplying the HP caps as a 1.0 uf and a .5 uf. That way the three different combinations would give flat axial, flat power, and slightly falling power (more like a traditional tweeter if this is what you are used to). The user could easily mount a switch (or jumpers) on the back for the three settings.
The table saw is exactly how I correct the inner baffle size problem. Much easier than sanding!!!
I've thought of supplying the HP caps as a 1.0 uf and a .5 uf. That way the three different combinations would give flat axial, flat power, and slightly falling power (more like a traditional tweeter if this is what you are used to). The user could easily mount a switch (or jumpers) on the back for the three settings.
Surgery
Earl,
I think it was a combination of barely enough glue and not enough pressure on the lower part of the baffle. The upper part was perfect. The lower part was approximately 10% glue and 90% air gap starting at the mid-point of the woofer cut-out. It probably would have held thanks to the dowels but seemed problematic with that built like a tank B&C woofer. I figured it was worth spending an extra 30 minutes to get it right. If all goes well i plan on having an auto shop handle the painting so im gonna go slow to get the enclosure just right.
I've got the crossovers built and tested and am working hard on restoring a 50's stereo cabinet that will house a built in pair of 10 "subs so I've got my hands full. Not to mention the quartet of smaller subwoofers that are also waiting to find some time on the workbench. If only sleep wasn't a neccessity...
Glad to know the table saw idea will work. Just need some time to swing by my brothers wood shop to make a quick pass.
I like the idea of being able to tune the HF frequency on the fly. I'll wait patiently to see what you come up with (hint-hint)
Thanks Earl,
Daniel.
Earl,
I think it was a combination of barely enough glue and not enough pressure on the lower part of the baffle. The upper part was perfect. The lower part was approximately 10% glue and 90% air gap starting at the mid-point of the woofer cut-out. It probably would have held thanks to the dowels but seemed problematic with that built like a tank B&C woofer. I figured it was worth spending an extra 30 minutes to get it right. If all goes well i plan on having an auto shop handle the painting so im gonna go slow to get the enclosure just right.
I've got the crossovers built and tested and am working hard on restoring a 50's stereo cabinet that will house a built in pair of 10 "subs so I've got my hands full. Not to mention the quartet of smaller subwoofers that are also waiting to find some time on the workbench. If only sleep wasn't a neccessity...
Glad to know the table saw idea will work. Just need some time to swing by my brothers wood shop to make a quick pass.
I like the idea of being able to tune the HF frequency on the fly. I'll wait patiently to see what you come up with (hint-hint)
Thanks Earl,
Daniel.
Its not going to be in the kits, but I could describe how to do it easy enough. A couple of holes drilled in the back to bring out some wires and you just use a jumper to set the HF level. Easiest is a change from 1 uF to 1.5 uF. The three way setup is more complicated.
Did you find the HF content just a bit too much? Its flat on axis, but has a slight rising power response with 1.5 uF. So a live room can sound a little bright.
Did you find the HF content just a bit too much? Its flat on axis, but has a slight rising power response with 1.5 uF. So a live room can sound a little bright.
Did you see my email?
Unfortunately I didn't have a treble control on my system to try that. And maybe what I, and others, may hear is going to be a factor of synergy between my amplifier and speaker, rather than entirely the speaker itself.
-If you suspect that some others might find it too bright. Maybe, as an option or small upcharge, having the caps sold in the kit as the 1 and .5 values instead of a single 1.5 would be simple solution to assure that others, who don't have treble control, will make them to be more compatible with what they currently use.
-Tony
-If you suspect that some others might find it too bright. Maybe, as an option or small upcharge, having the caps sold in the kit as the 1 and .5 values instead of a single 1.5 would be simple solution to assure that others, who don't have treble control, will make them to be more compatible with what they currently use.
-Tony
Soon - no way. Possible - yes. But the 15" is impracticle to do as a kit because of its size and complexity. I could not send it overseas at any reasonable rate. To me the Abbey may be the end of the size growth as my next speaker will be even smaller than the Nathan. For the forseable future the full Summa will only be available assembled.
From my listening tests there the Abbey is the sweet spot.
From my listening tests there the Abbey is the sweet spot.
Right now the Summa15 is made in a composite plastic cabinet as it has been from the begining. Thats the only way I can do that one right now and that approach is not viable for a kit. There ARE a lot of advantages to the plastic cabinet, but cost is not one of them. So the other two models opted for a more reasonable cabinet design with a slightly lower performance. But I'd say that the performance of the Abbey is about 90% of the Summa at less than 1/2 the cost. I believe that's a pretty good trade-off . But if your want the Stadivarius then its the Summa.
Yes I've also noticed some glue oozing out between the the inner and outer baffle. I use polyurethane construction glue.
Also the holes for the woofer are to small. Some extra 'routering' was needed.
Perhaps also worth mentioning in the manual is the screws from the side panels to the front baffle are a bit to long.
I'm going to try the smaller cap since the Nathans are brighter then I'm used too.
Also the holes for the woofer are to small. Some extra 'routering' was needed.
Perhaps also worth mentioning in the manual is the screws from the side panels to the front baffle are a bit to long.
I'm going to try the smaller cap since the Nathans are brighter then I'm used too.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.