Electrical Crossover and Acoustical Response

[Hillbilly SQ]

Here's something that's been on my mind about the sub crossover. Numerous people have said boosting or cutting the sub level will hurt phasing. If you boost the sub level for extra boom wouldn't it be roughly the same acoustical phase at +12 vs zero or anywhere in-between with just the sub being louder or quieter? Does taking away the smooth transition between sub and midbass have something to do with it by creating a potential cliff and a new out of phase cross point on the lowpass?

[Jdunk54nl]

https://www.audiofrog.com/community/...he-bass-right/

[Justin Zazzi]

Here's something that's been on my mind about the sub crossover. Numerous people have said boosting or cutting the sub level will hurt phasing. If you boost the sub level for extra boom wouldn't it be roughly the same acoustical phase at +12 vs zero or anywhere in-between with just the sub being louder or quieter? Does taking away the smooth transition between sub and midbass have something to do with it by creating a potential cliff and a new out of phase cross point on the lowpass?

In short, yes it it not ideal to boost only the subwoofer because it changes the relationship between the subwoofer and the midbass speakers. The relationship between speakers is where phase matters, so you want to preserve that relationship between speakers once you get it correct. It would be better to boost the bass in all speakers at the same time so the relationship between the speakers is unchanged. However, not many pieces of equipment have a global bass boost knob so this is a hard thing to do in practice.

The link above that jdunk posted is a good demonstration of this concept and Andy has a clever way to approach the problem.

[Brego]

Wouldn't a Shelf Filter work to do the base boost, just Link Mid-base with Sub(s) and boost?

[Stycker]

I'm no expert, but I would think that a shelf filter would in turn mess up the relationship between midbass and midrange in the same manner. Back when I used the MS-8, it used a shelf filter for boosting bass and midbass at the same time. There may have been an algorithm in there to compensate for that very issue.

[Brego]

You may be correct, but I was thinking if the Shelf-filter was used in the lower-to mid freq range of the Mid-base bandpass. Example : Say your MId-base is bandpassed is 80-350, and then apply a Low Shelf filter at around 125. Then only freq's below 125 are boosted, and would not effect the relation between Mid-Base and Mid-Range.....

[jtrosky]

I wish the Helix remote controls would allow you to control more items with their URC.2/3 remote "knobs" - such as self filters, augmented bass parameters, tone controls, particular EQ band, etc. They only allow you to assign a VERY limited number of things with the knobs...

[SkizeR]

I wish the Helix remote controls would allow you to control more items with their URC.2/3 remote "knobs" - such as self filters, augmented bass parameters, tone controls, particular EQ band, etc. They only allow you to assign a VERY limited number of things with the knobs...

okay, I'm just gunna say it.. You are out of your mind if you really expect this from an analog controller that costs like 60 bucks lol. Get the director or wifi module. They can do almost all of this and more. It can do anything you really need it to besides tune

Sent from my SM-G975U using Tapatalk

[jrwalte]

It is not unreasonable at all. It is software based on what parameter that analog pot can control - solely limited by the intent of the developer to make you want to buy the Director instead. I've seen it many times in German engineering in R/C as well. Limit software controls in one device and offer it in a more expensive add-on. To me it just seems to be a common practice of German companies.

[SkizeR]

the urc.3 is 55 dollars and only has 2 pots and a button. If you want rear attenuation, augmented bass parameter changes, tone controls, eq, shelf filters, etc (all the things the director does, and for 55 dollars via 2 pots and a single botton)... then yeah. you are absolutely unreasonable. in every URC.3 setup ive done its either been main volume and sub volume, or digital/hec volume and sub. the only time i can picture getting rid of sub volume is if you already have a separate gain knob for your sub amp. but then your just getting a bit ridiculous on the knobs. If you want all of this your dash is going to look like you have one of those typical half din in-dash 7 band eq's lol. Just get a director or wifi module.

seriously, reading stuff this crazy reminds me that i need to step away from forums