It appears to be 'buried' in the ~400 Hz dip when in actuality it should be down around 200 Hz in the 3rd harmonic dip.
GM
The driver's response looks almost too good to be true........ How close did you measure from?
GM
Hmm. Agreed, especially in the HF where Dayton indicate a major resonance at ~16KHz: http://www.parts-express.com/pedocs/specs/295-378-dayton-audio-rs100-4-specifications-46166.pdf What mic. is that Tom?
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Well, truthfully, it was a sloppy measurment from 2 meters, mostly on axis. I'll run another one today. When I ran that it was late and I had just fired up the equipment which I hadn't used in 5 years. It's the bheringer mic by the way. Let me see what I can do. To be honest though I wasn't paying a huge amount of attention to the upper band, I did notice it was awfully flat.
Tom
Tom
I just pulled readings from 6 set positions on axis in 1 foot increments. 1 foot from the driver the null points recede quite a lot and 6 feet they are very pronounced. At 1 foot the upper range is still smooth but the 16 k peak is much more noticeable. I think overall my readings are correct. Let's also remember I am not calibrating the amp that feeds the speaker so there may be some variation due to that. I don't think it's a drastic enough variable though. Any thoughts guys?
Tom
Tom
For the sake of completeness, here is 1 meter on axis. The speaker is close to in the corner of my office which is 10 foot by 20 foot in size with quite a bit of junk in it. Now, can this be solved through damping or placement? Both factors I will play with when I have time.
Tom
Tom
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Hi,
I love this crazy driver !
I build a straight TL, below mesurement smoothed 1 meter axis :
No very big hole under 200 hz.. What is the height of your driver and ceiling ?
Phil.
I love this crazy driver !
I build a straight TL, below mesurement smoothed 1 meter axis :
An externally hosted image should be here but it was not working when we last tested it.
No very big hole under 200 hz.. What is the height of your driver and ceiling ?
Phil.
Phil, the driver height is 32 inches. Slightly angled ceiling from 8 up to 9 feet. I agree, this driver is dare I say one of if not the best FR driver I have ever experienced. Granted my experience only goes through the fostex line, low end and tang band and The ANS8. but none of the high end tang band line or lowther stuff. Any way you cut it, this is an amazing driver for the money or even 3 times the money. My horn/TL is performing exceptionally well to my ears. The graph may not be perfect but that is frequently the case on many good designs. I do want to try and work out the issues though.
Tom
Tom
I do wonder if that 430 Hz dip is my placement. I am going to rearrange my space and see if it changes. I need to get in the studio now guys. I also need to go for a ride on the harley! It's actually quite nice out here in DC so I am going to take advantage of that.
Tom
Tom
We should sit down and have a listen when you are in town! Message me and I'll get you my information!
Tom
Tom
Hmm, 1130/2/32 = ~212 Hz dip, so a driver/floor eigenmode and since this is a 1/2 WL resonance there should be a peak at ~424 Hz, but we have a null, so this is apparently the acoustic XO point.
GM
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Thanks GM. I will go back and look at my numbers again and figure out where I went wrong. I don't mind building another set at all, I just ant to make sure I know where I made the wrong turn before I do.
Tom
Tom
Hi,
Maybe this driver is not a good candidate to BHL.. Qts is too hight.
Perhaps adding a BSC can change sounding.
6 db attenuation near 750 hz, 1 mH and 5.6 Ohm.
Phil.
Maybe this driver is not a good candidate to BHL.. Qts is too hight.
Perhaps adding a BSC can change sounding.
6 db attenuation near 750 hz, 1 mH and 5.6 Ohm.
Phil.
Qt on the Dayton is fine for a back horn; assuming no assistance from the amplifer it's actually better suited to such use than a lot of drivers with a lower Q & similar Fs since it allows a lower acoustic XO.
Hi,
TS and impedance curve of mine, Qts is 0.611
Phil.
TS and impedance curve of mine, Qts is 0.611
An externally hosted image should be here but it was not working when we last tested it.
Phil.
What were the voltage conditions used for the measures (T/S parameters vary with voltage drive -under low voltages you'll see Q, Fs rise, Vas reduce etc.).
Be that as it may, your measures indicate a mass-corner frequency of 242.286Hz, which is fine for back-horn use.
Be that as it may, your measures indicate a mass-corner frequency of 242.286Hz, which is fine for back-horn use.
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