TOPIC:

Hello Hadi,

having watched your tutorial videos and being quite impressed by the software, it seems that FilterHose is relatively straight forward to use and actually quite tempting! But from the available info so far, it also seems that the application is solely aimed at amplitude/phase equalization of a user selectable frequency range.

While this is very useful already, I'm actually wondering how the shown equalization could be combined with a linear phase / FIR cross over (ideally also designed with FilterHose)?

Please be so kind inform the community about the way to combine FIR equalization and FIR cross-overs using FilterHose.
I.e. how could e.g. a 3-way or 4-way FIR devided and filtered system be desigend using FilterHose?
This combined with hints at measurements (like you did) and how to optimize for e.g. miniSHARC or openDRC-DI or openDRC-DA8 would lead at least take me long ways toward investing into a license.

Thanks a lot for meaningful answers!
Best Regards,
Winfried

@ Winfried,

Great question.
Worth for you to maybe email Hadi from his website and prompt him to check the website for a reply here. I'm not sure if he's subscribed to the whole subsection of the forum to receive a notice.

DevTeam

Hi Winfried,

Correct, for now Filter Hose only corrects mag/phs at a certain range (target is a flat phase/mag). We are still developing the part of creating crossover or custom EQ. This may still take time since it requires a different structure in the program (that is different from what Filter Hose originally intended to do - quick correction and quick filter edit).

Filter Hose provides convolution between input and the filter. Hence, you can combine filters.I have experimented with a simple electrical loopback measurement on a regular DSP (IIR filters) and load this filter measurement to FH. To convert a minimum phase filter to a linear filter, FH can do it easily by selecting the phase = 0 target. By doing convolution (step 4), you get the new linear phase filter. Let's say you measure a butterworth 8th order high pass filter, measure the transfer function and linearize the phase with FH. Step 4 will give you the final result.

On the other side, you can measure that component and create another filter to flatten the mag/phs in FH, and create another FIR filter.

Load both FIR (one being the input, and the other one in step 2), and hit convolve. Step 4/output is the combination of the FIR EQ and your linearized IIR HPF.

I understand it is not the best way to create a FIR HPF, but this is a work-around before we have the feature implemented.

Another application is to implement the high pass and low pass as IIR, and measure per component with all IIR filters in it. Then use FH to linearize the mag and phase of component+IIR. The FIR created in FH will then fix the phase drop from the IIR.

I hope I understand and answer your questions correctly. If not, please ask again.

Best,

Hadi

Note: To moderator: I do check forum regularly every few days.

Very good answer Hadi. Thanks for sharing how to use your great software!
Here is btw a way to subscribe to your whole forum section: minidsp.com/forum/filter-hose

You can then click on subscribe and you'll receive emails asap someone is posting to this section of the site.

DevTeam

Thank you. I have just subscribed to the forum. One question: do I need to subscribe per thread for reply notification? I am curious if sub forum subscription only applies for new thread only?

Hadi

Hadi,. if you subscribed to the whole forum section (as per our link), any post in that section will get you a warning in your email address.

Devteam

Update:
Filter Hose v2 is currently (March-April 2016) in beta testing period.

The new version will include user defined filter, including HPF/LPF, and also user defined target. User defines curve using biquad input. This will address the original question of this thread. More information about v2 will be posted when it is released.

Thank you,

Hadi

Very cool update Hadi! Hoping to see more of all this.

DevTeam

hadisumoro wrote:

Update:
Filter Hose v2 is currently (March-April 2016) in beta testing period.

The new version will include user defined filter, including HPF/LPF, and also user defined target. User defines curve using biquad input. This will address the original question of this thread. More information about v2 will be posted when it is released.

Thank you,

Hadi

Good day sir,
My name is Andrew , I'm thinking about purchasing filter hose here in the next week or so. I'm currently using re-phase with 2- 2x4HDs in my car.

I'm pretty new to making filters. I think it's going to be a long time affair for me, I find it very fun to have completed freedom over the signal for a car environment.

Do you think filter hose will be able to work good. The catch is I will have to do in-car measurements. I saw on the hx page that you have to take initial measurements outside. I won't be able to do that. I am also running all high efficiency drivers and compression drivers.

Will I be able to use filter hose effectively and successfully doing it this way?

Cheers,
Andrew

Hello Andrew,

Thank you for your interest.

It is recommended to measure the loudspeaker free from reflections to do phase linearization. Inside a room, or confined in a small room such as car, a lot of reflections will be included in the measurement and windowing may not be that helpful. This will require a lot of smoothing. Yes it can be done and good result can be achieved, but has a lot of limitations.

Creating FIR (please note Filter Hose is just a tool to create FIR) in a car can be done in several ways. First, you can measure in different positions and average the magnitude only (this has to be done in your measurement software). You can export the magnitude only to Filter Hose and create a linear phase FIR filter to flatten the average freq responses. Linear FIR filter will not change the phase response of the loudspeaker. Save this filter and you can listen to it by implementing it to MiniDSP.

Second, you can do another measurement (per speaker) without doing averaging. You can inspect the phase response (how badly it is affected by reflections). Do windowing (such as MZTW short) and 2-3 times smoothing, and then create a filter to linearize the phase (called phase = 0 in Filter Hose). You may need to experiment this with different kind of measurement position.

Load the first filter (to flatten the mag only), and load the second filter (to flatten the phase only) in Filter Hose. Convolve the to make a new filter, and you can listen to the result. You can redo the second filter as much as you want to get the good result. Room reflections that are not properly taken care of can make the final result hollow or weird.

The effectiveness of the FIR depends on the measured data or how the measurement is done. From other user experiences, some stated that Filter Hose helped them to create FIR filter quickly but the measurement process, filter creation and trials can take a while to get a good result. I trust Filter Hose can do a good job in providing FIR filter, but user needs to be aware that the measurement is the key to everything and the process of creating the FIR (including measurement) has a lot to do on the final result.

I hope this gives insights to you. Thank you for your interests in Filter Hose.

Best,

Hadi