Maybe a well damped plane wave tube?.....would certainly be able to construct easily and control the HF rolloff with damping material. The length would determine the phase at the exit?
Way way too big in my opinion. One of those is equal to ten of what I an using in terms of radiating cone area. Keep in mind you will be playing the driver through a tiny port.
I was hung up on bigger is better too until I saw what the numbers were telling me and the design packaging compromises with bigger drivers became apparent.
Think small.
The little drivers I picked are unusual in that they have big 32.6 mm (1.25") diameter voice coils and enough excursion to crossover at 300 Hz at 120 dB SPL.
My design posts start at #854.
Just for fun, I got an instant online quote of roughly $200 each for these in ABS plastic from zoomrp.com. You can get next day delivery. Wonder what the printer itself costs?
Hulkss am I assuming the adapter covers the CD and you just attach that to the horn?
Was wondering how big they were. I dont see any mid ports so I figured they were small but couldn't tell from the picture.
And are you saying to look at 2" mids?
I was thinking 5's if I could find them but I am only going buy other designs is all.
Was wondering how big they were. I dont see any mid ports so I figured they were small but couldn't tell from the picture.
And are you saying to look at 2" mids?
I was thinking 5's if I could find them but I am only going buy other designs is all.
Look here: Throat Adapter
I have been posting design details beginning at #854 of this thread. Have a look.
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So how high is the port tuning for the SH type horns? Port tuning for the bass drivers in a 3way?
It seems like it would be pretty high considering how small the port length is. It also seems like some people have used 2, 4 and 5" mids successfully. Just makes my decision harder to choose.
Although maybe I can design two different designs for my application.
It seems like it would be pretty high considering how small the port length is. It also seems like some people have used 2, 4 and 5" mids successfully. Just makes my decision harder to choose.
Although maybe I can design two different designs for my application.
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That was for your mids. I was still wondering how to tune the bass section of a 3 way. Seems like the ports aren't that big and only 3/4" length. I just cant get my head around the fact that the ports dont get over ridden by air from the woofer. That and it would seem like a high tune of maybe 100hz or higher was all. IDK
Either way I thank you for the link. I keep re-reading this and think I will just try and test my 10" midwoofer I have with a similar small port and small amount of volume. I will have to use what I have though which is just a PHL3451 woofer. Not ideal maybe but something to try and start off with. I have some 8a's from Eminence also that will be going in another build. I also have a pair of 18 Sound NLW 9300 15's that I could try and see how the bass section would work.
Either way I have a lot to learn and maybe just trying things out will be the best answer.
Either way I thank you for the link. I keep re-reading this and think I will just try and test my 10" midwoofer I have with a similar small port and small amount of volume. I will have to use what I have though which is just a PHL3451 woofer. Not ideal maybe but something to try and start off with. I have some 8a's from Eminence also that will be going in another build. I also have a pair of 18 Sound NLW 9300 15's that I could try and see how the bass section would work.
Either way I have a lot to learn and maybe just trying things out will be the best answer.
I couldn't agree more.
The thing that's important is *output* level, not sensitivity.
For instance, the Aura Whispers have a sensitivity level that's something like fifteen decibels lower than an Alpha 6 closed back midrange. But the Whispers have an xmax of 3mm and the Alpha has an xmax of 0.2mm.
Crazy, huh? Aura's tiny little computer speaker has an xmax that exceeds Eminence's prosound midrange by a factor of FIFTEEN.
Of course, the Alpha has higher power handling, right?
Not so fast... While the Alpha is a much larger driver, the voice coil is virtually the same size. 37.5mm on the Alpha and 33mm on the Aurasound.
Add all this up and I think there's a compelling case to be made for using small midranges like the Aurasound. (Full disclosure... I think Peerless makes a handful that are competitive with the Aura, as well as Tang Band and Dayton as well. And the laptop loudspeakers that DB Keele uses as tweeters in his CBT array look compelling too.)
For a speaker to hit 135db how much do we ask from the mids? Do they need to be 135db capable?
In regards to the air pocket, Tom stated that the pocket of air acts like a Hpass so is this amount just simulated to see what volume cause s what Hpass or do I just need to build one and then measure?
In regards to the air pocket, Tom stated that the pocket of air acts like a Hpass so is this amount just simulated to see what volume cause s what Hpass or do I just need to build one and then measure?
You can answer your questons by downloading and using Hornresp software: Hornresp
These are the best midrange drivers I know of for a Synergy Horn if you need over 120 dB: TF0410MR
If you search around you can find the values to input to Hornresp. Red Spade is developing a design with them here: Red Spade
After further search it would appear I have to talk to Paul in order to get the Celestion drivers. I will also look at budget when it comes to this design verse a dual 8"/CD design like the SM95. Two goals in mind are the SM95 and SH64. I would use the 4" mids for the 64 and probably the PHL 2011 8's for the 95.
Either way thanks Hulkss. Sorry if all these questions have already been posted. I try to keep up but when reading so many forums and builds I get lost.
Either way thanks Hulkss. Sorry if all these questions have already been posted. I try to keep up but when reading so many forums and builds I get lost.
Will have to find another 4" midrange driver.
The astigmatism is not caused by the slot loading, it is per Hughes, "caused by different horizontal and vertical apparent apices". This does occur in slot loaded horns and others.
Here is an illustration of the problem:
It is easy to see in this 90 x 40 conical horn image that the side and top walls have different apices which will cause astigmatism in the radiated wave pattern of the horn. This happens because the walls are shifted along the horn axis to make a square throat. If the horn walls make a rectangular throat like the horn mouth, they meet at the same point with no astigmatism in the horn.
In my case, the Quadratic Throat is a transition from a rectangular horn to a round compression driver. Square throats are correct when the horn mouth is square.
Can you hear the benefits of a Quadratic Throat Waveguide?
From testing by Hughes: "Where the Quadratic-Throat Waveguide® really outperformed the standard constant-beamwidth coverage horn was in harmonic distortion. At several power levels and across all frequencies, the 2nd harmonic distortion level was almost uniformly 3 to 4 dB better. And finally, the 3rd harmonic distortion, the most irritating for the listener, averaged about 9 dB better than the conventional design. This is an easily discernable sound quality difference over the older designs."
That is enough of a potential benefit to me to be careful to produce accurate horn wall and throat geometry designed to generate a spherical wave front with minimal distortion.
I've looked at this throat adapter several times but cannot find the similarities to the pictures on page 10 of this:
http://aaassets.peaveyelectronics.net/pdf/qwp1.pdf
Your throat adapter rounds out the walls of the adapter and theirs seems to fill in the corners. Your corners continue to the base, theirs do not.
Is that intentional?
I expected to see something like this:
And to follow the exit angle of the compression driver you could use rails in the corners to follow that angle for the first part of the transition. That's how I interpret that Hughes paper you linked too.
Obviously I just threw together this shape but the point is the corners seem to be rounded on the Hughes examples, both drawing and picture. There is some cut out on the walls that I didn't do but a loft + rails should be able to get you there.
I'm just wondering how you came to your hood lens shape without the rounded corners?
And to follow the exit angle of the compression driver you could use rails in the corners to follow that angle for the first part of the transition. That's how I interpret that Hughes paper you linked too.
Obviously I just threw together this shape but the point is the corners seem to be rounded on the Hughes examples, both drawing and picture. There is some cut out on the walls that I didn't do but a loft + rails should be able to get you there.
I'm just wondering how you came to your hood lens shape without the rounded corners?
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I'm with you on those Celestion. Today I test violin trough Aura drivers -(I got Synergy horn with them) and it sound compressed. So here we come again... We can measure things that we are know...
And there are a lot of things that we don't know yet.