New DIY Mid High (90deg) - AKA PM90

Jason Joseph

Sophomore
Sep 27, 2011
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New York
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what configuration you decide on should be based on the amp power you will have.. Once you decide that then you can do the simple math of 1.5 times the rms power to ensure you are at the right place.. 1.5 times is just to get you in the right region and is subjective in itself..
 

Peter van Gils

Freshman
Mar 3, 2013
130
16
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Netherlands
www.plugingeluid.nl
Yes, and hence my question is: Are there any concerns with using 2x 16 Ohms in parallel = 8 Ohms for the mids, in contrast to 2x8Ohm=4Ohms?
I can get my hands on the 16Ohms version, but can't happen to find an offer for the 8 Ohms version. Just want to doublecheck before spending 700+ Euros on the wrong mids.
Do you want to run 1 or 2 cabinets per side?

2x 16 Ohms requires a very beefy amp: it needs to be able to deliver > ~2.5 kW @ 8 Ohms if you want to utilize the full capability of the cabinet. Running 2x 8 Ohms can save you €€ on the amps.
 

jami schorling

New member
Aug 21, 2019
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Thanks for your answers. Amp power is definitely an aspect of consideration. If there isn't any other that could make a difference (e.g., different TS-parameters on the 16 Ohm version), that would not be my biggest concern. Though I read something somewhere sometime about sensitity issues with the 16 Ohms configuration, but I can't remember right.
 

Chris Burns

Freshman
Nov 13, 2016
74
3
8
Connecticut
This isn’t a PM specific question, but you guys will have the experience and data,

I’m swapping out my XT1464 for HF950s to broaden the horizontal coverage in my HT LCR build I did a few years back. Switched from 1st gen 4594 to DCX464s and due to the high freq narrowing of the 1464 I’m switching.

Two questions, has anyone run a DCX yet with the HF950, how has the performance been and;

How does the 950 load and perform in terms of distortion down to a 450Hz XO?

Thanks gang


Sent from my iPhone
 
Jan 19, 2011
1,001
59
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Oslo, Norway, Norway
drbentsen.no
This isn’t a PM specific question, but you guys will have the experience and data,

I’m swapping out my XT1464 for HF950s to broaden the horizontal coverage in my HT LCR build I did a few years back. Switched from 1st gen 4594 to DCX464s and due to the high freq narrowing of the 1464 I’m switching.

Two questions, has anyone run a DCX yet with the HF950, how has the performance been and;

How does the 950 load and perform in terms of distortion down to a 450Hz XO?

Thanks gang


Sent from my iPhone
I'm working on DSP settings for a speaker using HF950 with BMS4590.
Initial measurements suggests that the 500hz XO I target is doable in terms of dispersion, it's pretty even with the LF section there.
But, I haven't done any distortion measurements...
 
Oct 25, 2018
124
18
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60
Bideford, Devon. UK
As one always keen to spend as little money as possible to achieve my goals (ok, a cheapskate...) I am using Behringer crossovers and EQ, lamenting the inability to implement phase correction. However, I came across three tantalising videos on YouTube - search 'All Pass Filter BEHRINGER DCX2496' - showing it used as an all-pass filter using just the individual channel phase adjustment features. It all appears to be in Portuguese with little on-screen activity, but I get the gist of it. Comments, please, good people.

 
Dec 13, 2021
5
2
1
56
California
Hi Guys. I don't want to be a party pooper but am I the only one who is concerned about really high 2nd harmonic distortion of BMS4594HE in the high frequency region, where it's most noticeable/audible? The THD is -20dB or 10%, huge! It's shown in green on the picture
1643226453814.png

There is a research that claims even -40dB distortion is noticeable at 10KHz:

1643226242041.png

The question is does single-point source worth living with this level of THD, especially considering the price of the driver? My much cheaper Selenium D3300TI for example has THD at around 2% or less in the same HF region...
 
Dec 13, 2021
5
2
1
56
California
As one always keen to spend as little money as possible to achieve my goals (ok, a cheapskate...) I am using Behringer crossovers and EQ, lamenting the inability to implement phase correction. However, I came across three tantalising videos on YouTube - search 'All Pass Filter BEHRINGER DCX2496' - showing it used as an all-pass filter using just the individual channel phase adjustment features. It all appears to be in Portuguese with little on-screen activity, but I get the gist of it. Comments, please, good people.

it looks like DCX2496 should support phase correction. From the user manual:
1643248346125.png
It's also possible to use CC caption on youtube, with auto-translation to english. I found is useful more than once.
 
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jami schorling

New member
Aug 21, 2019
7
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31
germany
it looks like DCX2496 should support phase correction. From the user manual:
View attachment 209559
It's also possible to use CC caption on youtube, with auto-translation to english. I found is useful more than once.
Did exactly that, and from what I understood, it is an adjustable All Pass Filter that you can use to correct the phase. It applies a 360° shift at the frequency that the High Pass filter is set to, even If you dont use it. If put intelligently and depending on the phase behaviour, you could flatten out some of the phase by doing that. But quite surely you can't accomplish the same as with FIR?
 
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Dec 13, 2021
5
2
1
56
California
Did exactly that, and from what I understood, it is an adjustable All Pass Filter that you can use to correct the phase. It applies a 360° shift at the frequency that the High Pass filter is set to, even If you dont use it. If put intelligently and depending on the phase behaviour, you could flatten out some of the phase by doing that. But quite surely you can't accomplish the same as with FIR?
The explanation of Polarity/Phase adjustement in the user manual is 0 to none. But it's definitely not a simple delay (delay is described in the next chapter, 4.5.5) so should be All Pass Filter with the phase control for all frequencies. Unfortunately for me I don't have enough knowledge of DSP to understand the implementation.
 
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