Hornresp

[bjorno]

Originally Posted by amjulio

..I made my math...

Hi amjulio,

You certainly did it!

Here's a picture in order to explore your design: I think using adequate (max rec. BW) filters and a ~20 mS signal-delay line is necessary to make your design peak in performance:

b

[amjulio]

Originally Posted by bjorno

Hi amjulio,

You certainly did it!

Here's a picture in order to explore your design: I think using adequate (max rec. BW) filters and a ~20 mS signal-delay line is necessary to make your design peak in performance:

b

Hi, Bjorno

Yes about BP filters. What did you mean with "max rec."?.
I'm absolutely ignorant about delay issue, do you mean I'd lag bass channel 20 ms respect to medium and high frecuency bands?.
Spectrogram: thinking about what information spectrogram gives us my conclusion was: acustic energy at 100Hz decays 25dB 20ms after electrical power input stops. Higher frecuencies damp much before and lower ones doesn´t matter because our ear is not so sensitive. On the other hand I believe my room will have a reberveration time larger, so horn reverberation time wouldn't be an issue.
What do you think?. I have not experience in audio so your warnings and feedbacks are welcome.

[Patrick Bateman]

Originally Posted by Kolbrek

Patrick: by substandard results, do you mean because of the elaborate horn, or because of the driver?

amjulio: I would say that if you put that much work into building a horn subwoofer, you really owe yourself to drive it with a high quality woofer that can provide enough volume displacement. 3mm can work if the diaphragm area is large enough, but an 8" driver is too small for subwoofer use, even with a horn.

I have built horn subwoofer using single 10", 15" and double 12". Use 15" or (double) 12", 10" is too small. Maybe one of the long-throw woofers could work, but I would rather go for smaller displacement and larger area.

Regards,
Bjørn

Exactly what you said - if you're going to go to all that trouble, use a woofer with some displacement.

[amjulio]

Originally Posted by Patrick Bateman

Exactly what you said - if you're going to go to all that trouble, use a woofer with some displacement.

Well... personally not too much trouble, actually I have a couple of masons building my house, my work is not to much and lot of fun reading and simulating with Hornresp.

Patrick, Why should I get a better (more displacement) imported driver if the one I can get not too far from my home gives more acustic power than I need?

[bjorno]

Originally Posted by amjulio

Hi, Bjorno

Yes about BP filters. What did you mean with "max rec."?.
I'm absolutely ignorant about delay issue, do you mean I'd lag bass channel 20 ms respect to medium and high frecuency bands?.
Spectrogram: thinking about what information spectrogram gives us my conclusion was: acustic energy at 100Hz decays 25dB 20ms after electrical power input stops. Higher frecuencies damp much before and lower ones doesn´t matter because our ear is not so sensitive. On the other hand I believe my room will have a reberveration time larger, so horn reverberation time wouldn't be an issue.
What do you think?. I have not experience in audio so your warnings and feedbacks are welcome.

Hi amjulio,

First: When your numbers are put into HR it returns a promising sub with good possible performance and that is IMO admirable 'per se'.

With max rec. BW I meant you should restrict the lower FR boundary to ~30 Hz for either of the suggested drivers, possibly even moved a bit lower, for what it's worth, that only if using the recommended Bw4 HPF.

In my simulation: For the upper FR boundary I recommend not to XO higher than 145 Hz for possible localization issues that surely will appear if passed and if using a LR2 filter at 80 Hz would be safe too.

250 Hz is then – 20 dB down when a LR4 or a LR2 filter is used. It is possible to XO as high as 180 Hz if using a brick-wall filter LP slope but then the sub should be centered between the Main Speakers but I do not recommend this approach.

The excess group delay for you sub-horn is ~20 mS that has to be taken into consideration if you want a smooth XO integration with your mains. The cure here is to signal delay your Mains correspondingly otherwise you will hear bass/mid-bass not in sync with the higher registers.

As I can see there are no issues when looking at the wavelet spectrogram, it's almost flawless or a textbook case for a perfect IR.
You're right your room IR (best illustrated in a ETC graph) should dominate by totally masking the sub's IR and adding more than10 times of room amplitude response decay. No worries here..

Concerning the sub-horn dB SPL capability, I find your design capable enough with an IMO healthy SPL margin I wouldn't exceed for esthetically reasons, especially if listening to the kind of ' acoustic' music i prefer.

Movie sound (Ka-boooom!!!) do not impress me at all, often not proportional to the visual content but instead very exaggerated just to impress people not grown up enough or addressed to faint hearted .. like teens who almost wet their pants for a sudden unreal designed sound.

b

[amjulio]

Aspect Ratio

Doy you think aspect ratio of the horn not square could cause some trouble?. Please, answer here: Horn HOM & aspect ratio

Originally Posted by bjorno

Hi amjulio,

Movie sound (Ka-boooom!!!) do not impress me at all, often not proportional to the visual content but instead very exaggerated just to impress people not grown up enough or addressed to faint hearted .. like teens who almost wet their pants for a sudden unreal designed sound.

b

I strongly AGREE. Exaggeration is The Word for home teathre sound system.

[blo06]

Hi everyone,

first thing first : Happy New Year !!

then, question :

how to simulate two ou more box in HR when it' s done for one ?

Is it possible ?

Cheers.

[David McBean]

Originally Posted by blo06

how to simulate two ou more box in HR when it' s done for one ?

Hi blo06,

Either select Tools > Multiple Speakers or press Ctrl+K from the SPL Response window.

Kind regards,

David

[blo06]

Hi David,

does Multiple Speakers give the output for 2 speakers in the same box or 2 similar boxes with one speaker ?

Or is it the same ?

What I'm looking for is the response for 2 similar boxes with one speaker.

Cheers.

[David McBean]

Originally Posted by blo06

Hi David,

does Multiple Speakers give the output for 2 speakers in the same box or 2 similar boxes with one speaker ?

Or is it the same ?

What I'm looking for is the response for 2 similar boxes with one speaker.

Cheers.

Hi blo06,

The Multiple Speakers tool will enable you to find the response for two similar boxes, each with one driver. Please note that there is currently some question as to the accuracy of the Hornresp multiple speaker predictions at higher frequencies.

Single sheet TH challenge

The Driver Arrangement tool (accessible from the input parameters screen when in Edit mode) will enable you to find the response for one box with two drivers.

Kind regards,

David