regarding the position of the Manzanitas, as I understand the stand at least 12" high is primary to limit the floor bounce in 100-400Hz region, and instead of a stand it is possible to make the wings longer, but wich is the difference in having also the baffle longer under the woofer only, making the Manzanitas kind of a smaller Ultra version? Is the longer baffle the problem or that one touching the floor that could be avoided putting some feet under the speakers? Also John said answering to a member about the baffle "16" baffle width is ok, wider is better actually", so could be even wider than the "standard" one? There is a correlation to height and width?
daide... Width is of more importance than over all baffle length. The baffle width (along with wing depth) sets both the potential efficiency of the system and F equal value. The crossover is designed around these two dimension values. You can extend the baffle down toward the floor, jusk keep the woofer and tweeter where they would be relative to floor distance if they were mounted on an 18" stand. With a longer baffle extending downward to the floor there may be a slight efficiency gain and a bit more floor refelction issues at certain listening distances. Some builders run the wings all the way to the floor, as in 18" of added vertical length. Hope this all make sense. Please let us know what you do and how it works out! J
xover location...
The crossover location should not be an issue. Just make sure all of the crossover parts are securely fixed. Given the mechanical forces the woofer puts on the baffle, anything that can move or vibrate, well, will move and vibrate! Let us know how your Manzanita works out for you! J
The crossover location should not be an issue. Just make sure all of the crossover parts are securely fixed. Given the mechanical forces the woofer puts on the baffle, anything that can move or vibrate, well, will move and vibrate! Let us know how your Manzanita works out for you! J
well OBs are usually down to the floor with the LF driver getting some boost from the boundary condition (to prevent LF wrapping around and canceling like around the width).
When I started experimenting to get a taste of the OB sound, I could get it to measure flat on axis with just a 15inch and a 4inch (SS 10F/4424). However, inserting an 8inch in between made a HUGe difference in terms of sound quality. They ended up looking like this:
Kick@#! winged OBs for pick up in Ontario
After I switched the 8incher from Visaton B200 to AL200 they became just fantastic.
Someone asked about the cone size: the bigger cones are also deeper and beam sooner so you are likely to end up crossing from a beaming driver to a wide dispersion smaller driver which is not a good thing for off-axis performance.
Honestly I was surprised by how much I achieved with my OBs. They only had one downside which was their size and low WAF. The dispersion was not quite as good as in Linkwitz speakers when one starts to move around but for my listening positions they sounded better since they were 3-way driven by smaller class A amps and the drivers were less damped than the curved Seas cones which SL used. I made his speakers to have a comparator.
When I started experimenting to get a taste of the OB sound, I could get it to measure flat on axis with just a 15inch and a 4inch (SS 10F/4424). However, inserting an 8inch in between made a HUGe difference in terms of sound quality. They ended up looking like this:
Kick@#! winged OBs for pick up in Ontario
After I switched the 8incher from Visaton B200 to AL200 they became just fantastic.
Someone asked about the cone size: the bigger cones are also deeper and beam sooner so you are likely to end up crossing from a beaming driver to a wide dispersion smaller driver which is not a good thing for off-axis performance.
Honestly I was surprised by how much I achieved with my OBs. They only had one downside which was their size and low WAF. The dispersion was not quite as good as in Linkwitz speakers when one starts to move around but for my listening positions they sounded better since they were 3-way driven by smaller class A amps and the drivers were less damped than the curved Seas cones which SL used. I made his speakers to have a comparator.
Yes, a nice 6-8 inch wideband driver works well for a 3-way OB. John has made some rather good ones as have some other friends - and I've built a few that were not too bad. I like the Eminence Beta-8 a lot as an OB midrange driver. Very clean driver.
But that's a little outside the scope of this thread.
But that's a little outside the scope of this thread.
Out of curiosity, on page 66 post #651 John wrote a summary of tweaks, talking about inductors, he said that using higher values of L2 will make the Viva darker and he was settled with 2mh for L2 and 15Ohms for R1, why on the GRS crossover L2 becomes 4.7mh?
And about inductors, John said "higher value, fuller midrange, lower, thinner and brighter", on the new Peerless and Grs crossover this is still valid?
And about inductors, John said "higher value, fuller midrange, lower, thinner and brighter", on the new Peerless and Grs crossover this is still valid?
A higher value L2 inductor will result the trap operating at a lower frequency, so you will hear a bit more lower mid range in the over all system tonal balance. My perception of this was a some what darker sound. Just my personal experience. Traps are tricky and small changes in the value of the components can make a significant difference.
As for the GRS trap... I really don't remember working the Vifa trap out. I would guess there must be some mid frequency issues with the GRS that were affecting the system tonal balance and or creating a bumpy frequency response. To my ears at the time, the 4.7 MH at L2 solved the probem.
One nice thing about the Manzanita is one can adjust the crossover to suite their personal taste. In the case of L2, you can buy a 5 MH inductor and unwind it until you ger the value that works for you. J
As for the GRS trap... I really don't remember working the Vifa trap out. I would guess there must be some mid frequency issues with the GRS that were affecting the system tonal balance and or creating a bumpy frequency response. To my ears at the time, the 4.7 MH at L2 solved the probem.
One nice thing about the Manzanita is one can adjust the crossover to suite their personal taste. In the case of L2, you can buy a 5 MH inductor and unwind it until you ger the value that works for you. J
2.0mH I think about aircore:
Cewka powietrzna 2,000mH - 0,363ohm - 1,60mm - LoudSpeakerShop.eu
But 0,4mH? Aircore or core coil?
it was clearly written on this topic so I ordered an ERSE. I only had doubts about the other two coils. Thank you very much for the answer because I'm just shopping
2nd question:
the default resistor values is R1=4.5R and R2=8R. I have 3.9R and 8.2R at home. What values to order for trial? I will buy ceramic 5W for testing. Are cheap, so I can buy more, but I don't know what "jump in value. Min. 2,5R, max. 15R? But what in between?
Good question and I don't have a very good answer. The easiest of course is that have a variable resistor in there. Once you find a value that works you replace it with a normal resistor. You could order two of every value between about 3R and 15R, but that might be a bit much. 
If you order some higher values you can put them in parallel to achieve a variety of lower values. For example: 8R with 16R in parallel = 5.33 ohms.
You should end up somewhere around the nominal values, so concentrate your resistors around those values.
If you order some higher values you can put them in parallel to achieve a variety of lower values. For example: 8R with 16R in parallel = 5.33 ohms.You should end up somewhere around the nominal values, so concentrate your resistors around those values.
Some idea I had for a little time. And I do not know if this will work OK or not, or if it creates more problems than it solves.
In regardes of doubling up the woofers (Peerless or GRS) with the Vifa, the problem is always the powerhandling of the Vifa.
Would it be possible to wire up 4 Vifa’s in series/parallel with no change (needed, I think) in the filter as the impedance will stay the same, but the power is then shared by all 4 Vifa’s
Like in this picture.
And if this could work, what would be the best config, make an array from top to bottom with as centerpoint the centerpoint of the origional 1 Vifa
Or maybe arranged in a cirkel around the centerpoint of the origional Vifa?
Yes, this will cost more than with one Vifa per speaker, but as the cost of the Vifa still being as low as it is (at least in Europe) I personally do not find this an issue.
Or would this create the lobing I have read about?, and make things worse?
In regardes of doubling up the woofers (Peerless or GRS) with the Vifa, the problem is always the powerhandling of the Vifa.
Would it be possible to wire up 4 Vifa’s in series/parallel with no change (needed, I think) in the filter as the impedance will stay the same, but the power is then shared by all 4 Vifa’s
Like in this picture.
An externally hosted image should be here but it was not working when we last tested it.
And if this could work, what would be the best config, make an array from top to bottom with as centerpoint the centerpoint of the origional 1 Vifa
Or maybe arranged in a cirkel around the centerpoint of the origional Vifa?
Yes, this will cost more than with one Vifa per speaker, but as the cost of the Vifa still being as low as it is (at least in Europe) I personally do not find this an issue.
Or would this create the lobing I have read about?, and make things worse?
4 Vifa's series - parallel
A couple of thoughts….
There are a host of things that would change and require a near complete rework of the design with 4 Vifa TC’s per channel.
You can double up on the woofers (either one). Assuming they would be wired in parallel. You can get by with a lower value of iron core low pass inductor with the lower 4 ohm load. Around 14-16 Mh will work OK if I am remembering some of my initial experiments.
If you retain the current baffle width and wing depth all you will gain is being able to play another 4-6 db louder from the low pass crossover point on down. That 4-6 db is the effective pad value being used on the Vifa in the original design.
A single Vifa, given it is being crossed over rather high can play surprisingly loud without much complaint.
It would be easier to run a pair of the Vifa’s in parallel and rework the crossover values to accommodate the new 4 ohm load. There will be some comb issues, but with the center to center distance of only 4” or so it shouldn’t be too bad.
A couple of thoughts….
There are a host of things that would change and require a near complete rework of the design with 4 Vifa TC’s per channel.
You can double up on the woofers (either one). Assuming they would be wired in parallel. You can get by with a lower value of iron core low pass inductor with the lower 4 ohm load. Around 14-16 Mh will work OK if I am remembering some of my initial experiments.
If you retain the current baffle width and wing depth all you will gain is being able to play another 4-6 db louder from the low pass crossover point on down. That 4-6 db is the effective pad value being used on the Vifa in the original design.
A single Vifa, given it is being crossed over rather high can play surprisingly loud without much complaint.
It would be easier to run a pair of the Vifa’s in parallel and rework the crossover values to accommodate the new 4 ohm load. There will be some comb issues, but with the center to center distance of only 4” or so it shouldn’t be too bad.
Yes, good points. When I did a big baffle with 2xGRS15" woofers in parallel the poor Vifa could hardly keep up. I ended up using a 6.5 or 8" fullrange instead.
However, one could imagine using two Vifas in a sort of 2.5 way configuration. Low pass one Vifa so that it contributes only in the lower register and not up high, run the other one all the way up thereby avoiding most of the comb filtering. It would take a good bit of work and experimentation with the crossover but might work well to get more low end grunt out of the Vifa.
However, one could imagine using two Vifas in a sort of 2.5 way configuration. Low pass one Vifa so that it contributes only in the lower register and not up high, run the other one all the way up thereby avoiding most of the comb filtering. It would take a good bit of work and experimentation with the crossover but might work well to get more low end grunt out of the Vifa.