Hello all, I haven't been here in awhile so sorry if this topic may have been talked about before.
I'm currently planning to a Jim Griffin's Line Array using the Dayton Audio DMA105-8 4" driver. I will be doing a Power Taper using his guide on the white paper to get 8 Ohms or slightly over. Now my question is even though these are Full Range speakers with 70Hz- 20Khz range, can I get away without a Crossover? I do have 2 Monolith THX 10" 500W subs to use in cause it does need lower end help.
I will be doing a 12 driver per side build. hopefully I will not need too much help in that part. I do have Xover Pro software to help if i do need a Xover to help this build.
Anything else I may need that I may be missing?
I'm currently planning to a Jim Griffin's Line Array using the Dayton Audio DMA105-8 4" driver. I will be doing a Power Taper using his guide on the white paper to get 8 Ohms or slightly over. Now my question is even though these are Full Range speakers with 70Hz- 20Khz range, can I get away without a Crossover? I do have 2 Monolith THX 10" 500W subs to use in cause it does need lower end help.
I will be doing a 12 driver per side build. hopefully I will not need too much help in that part. I do have Xover Pro software to help if i do need a Xover to help this build.
Anything else I may need that I may be missing?
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You probably won't need a crossover as is (since you would require something to cross over to 😉 ) -but you may need some midband - HF EQ due to the destructive interference inherent to the configuration. It's not necessarily guaranteed nor the extent as it depends on the on & off-axis FR of the drivers and the exact configuration, sitting position etc. & the degree of power-tapering you end up using. However, X-Over 3 Pro may not be much use as it can't model passive shelving filters and its impedance model is derived purely from T/S parameters & the Le spec., (which are often at variance to the reality) -you can't import impedance data, and its ability to model FR is limited as it does not take phase into consideration.
Scott, Thank You for the reply and info. On the midband - HF EQ, can a true Parametric EQ like the SAE 2800 work in this regard?
VituixCAD can model line arrays very well. There are several threads around here that discuss both the theory and actual implementations of line arrays. Search for ‘TC9+line array’ in Google.
With the 4” drivers, you may be able to get away without subs but you will need EQ to flatten and extend the reaponse.
Good luck! Line arrays are fun!
With the 4” drivers, you may be able to get away without subs but you will need EQ to flatten and extend the reaponse.
Good luck! Line arrays are fun!
ra7, Thank You for the info. That software looks really interesting.
The subs "If Needed" are not an issue. I have subs to use with the Line Array. 🙂
The subs "If Needed" are not an issue. I have subs to use with the Line Array. 🙂
The theory says that once the drivers start to comb you will get a 3dB/ocatve fall-off due to destructive interference. Tapering the line will change that.
And the room. Build & measure, them EQ. SAE may work, IME not the best electronics thou.
dave
And the room. Build & measure, them EQ. SAE may work, IME not the best electronics thou.
dave
How is that applied? (or do you have a link to the paper?)
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@Davey thanks.
I'm thinking the shading scheme has not been defined very clearly. It seems to me that when the line is to be varied in length with frequency, the middle of the line for power shading should be at a different height varying with frequency. This also seems to suggest that when the transition is wanted to be kept within a certain region, eg the lower midrange, the overall length of the line should be tested for suitability.
I'm thinking the shading scheme has not been defined very clearly. It seems to me that when the line is to be varied in length with frequency, the middle of the line for power shading should be at a different height varying with frequency. This also seems to suggest that when the transition is wanted to be kept within a certain region, eg the lower midrange, the overall length of the line should be tested for suitability.
Are you conflating tapering and shading?? They are two different things, in my opinion.
The Linus array is power-tapered, in one option.....and non-tapered in the other.
A shaded array was demonstrated by Jim (and others) in various other projects.
Dave.
The Linus array is power-tapered, in one option.....and non-tapered in the other.
A shaded array was demonstrated by Jim (and others) in various other projects.
Dave.
Perhaps. We could be talking about level or delay. It could be frequency dependent. Manipulation could be for diffractive purposes or directive reasons (acoustic transition) or I've seen it mentioned for single spot purposes (focus).
In any case this is a fullrange project and besides, Jim does mention shortening the array. This would put it to the floor at only the lower frequencies.
If I were the OP, I'd not power-taper the line and wire series-parallel to obtain the same drive to all transducers.
I built the Linus array many years ago and wired it both ways to evaluate. I much preferred the non-tapered scheme in my setup. But, of course, that was a two-way configuration, and not the full-range scheme planned here. 🙂
For a full-range scheme, the IDS-25 seems a better approach, to me.
Dave.
I built the Linus array many years ago and wired it both ways to evaluate. I much preferred the non-tapered scheme in my setup. But, of course, that was a two-way configuration, and not the full-range scheme planned here. 🙂
For a full-range scheme, the IDS-25 seems a better approach, to me.
Dave.
The Cab will but I'm thinking of having the last driver at or around 12" from the floor. The reason is I will not be anywhere close to that low for listening.
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Davey, was the IDS-25 from that engineer that worked for McIntosh?
I do have plans when I do a trail run to do both Tapered and Non tapered and let my ear and sitting position determine which will work better. I do know I want the over all impedance to be around 8 ohms, but if lower it will be no problem as both my Latino VTA-120 and Edge M8 will handle it that load with no problems.
I do have plans when I do a trail run to do both Tapered and Non tapered and let my ear and sitting position determine which will work better. I do know I want the over all impedance to be around 8 ohms, but if lower it will be no problem as both my Latino VTA-120 and Edge M8 will handle it that load with no problems.
I thought I'd provide a demonstration on the problem of not running your line to the floor.
(I've put two on the same screen, the vertical line through the middle is the floor in both cases and each room is simulated on it's side so they fit on the screen. The left one shows the source to the floor and the right one shows a gap between the source and the floor.)
Of course the interest in this may vary in a number of ways at different frequencies.
(I've put two on the same screen, the vertical line through the middle is the floor in both cases and each room is simulated on it's side so they fit on the screen. The left one shows the source to the floor and the right one shows a gap between the source and the floor.)
Of course the interest in this may vary in a number of ways at different frequencies.
Allen, Thank You for the demo. Very interesting, now is this example of a non tapered?
I currently run a MTM design from Clearfield Continentals by Counterpoint designed by Albert Von Schweikert back in the early 90's (still an awesome speaker) it was the Grandfather to their VR-33 speaker.
I currently run a MTM design from Clearfield Continentals by Counterpoint designed by Albert Von Schweikert back in the early 90's (still an awesome speaker) it was the Grandfather to their VR-33 speaker.
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This example is not tapered, but for that matter the floor end shouldn't be tapered. The left example would be upset by tapering on the floor end at lower frequencies, but the open end is a different story and it's your choice.
My first try will be the 3/3/3/3 configure and see what I get. So you suggest having the last driver all the way to the floor? If so, then I will have to go with more Full Range drivers because I would like the speaker to be at the same height or slightly higher than my Clearfield Continentals which are 52" and their bigger brother the Metropolitans are 62". So something around that height.
Like I mentioned I do have a SAE 2800 that I upgraded/modded so it sounds nothing like the stock version, I wanted to use that if I need any help with flattening out the response. I also have a Carver Speaker System Control that has adjustable Q, Sonic Holography and other stuff for the speakers to play with. 🙂 I also upgraded that unit as well.
Like I mentioned I do have a SAE 2800 that I upgraded/modded so it sounds nothing like the stock version, I wanted to use that if I need any help with flattening out the response. I also have a Carver Speaker System Control that has adjustable Q, Sonic Holography and other stuff for the speakers to play with. 🙂 I also upgraded that unit as well.
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