Any easy inexpensive way to high pass mains?

[ksneote]

Wanted to give an update on my attempt to find some sort of high pass. As per a Psycoacoustics suggestion, I actually managed to find a Velodyne CHT-8 subwoofer for $30. While searching Parts Express I came across some new Tang Band amps, with built in high pass/low passes/subwoofer amps. Funny that I found the perfect solution right after I bought my sub haha.

https://www.parts-express.com/tang-band-kit0058-2-x-5-watt-full-range-speaker-module-amplifier-with-bluetooth--264-966

https://www.parts-express.com/tang-band-kit0060-1-x-30-watt-subwoofer-module-amplifier--264-970

https://www.parts-express.com/tang-band-kit0059-2-x-10-watt-full-range-speaker-module-amplifier-with-bluetooth--264-968

[Millstonemike]

I was planning on using the subs plate amp as a LP. Would there be any issue with having a plate amp LP and the amplifiers built in one? As I'll probably have the sub LP set to a lower frequency

Really depends on each system's LP. Not your case, but as one example ...

Take a plate amp with an 80 hz 12 dB LP fed with an AVR LFE output. The LFE LP output is set to 300 Hz 24 dB LP and the plate amp would just cut everything above the filter's 80 Hz corner freq.

At the other extreme, a plate amp with an 80 Hz 6 dB per octave Butterworth LP (Q=.707) and a feed with another 80 hz 6 dB per octave Butterworth LP will yield an 80 Hz 12 dB Linkwitz-Riley (Q=.5) LP filter - cut starts a little earlier with a gentler slope than a 80 Hz 12 dB Butterworth LP.

[ksneote]

I looked at the amp. The only way to use a PLLXO is with analog inputs. That amp only has one analog input, the 3.5mm Aux input. So if you plan on using any of the digital inputs your back to Chris with a passive high pass in the Quarks.

And the spec.'s for the amp's woofer LP filter are 200 hz, 24 dB per octave. It seems to be fixed so your stuck crossing higher.

Ah right, I nearly forgot about that. I couldn't use the built in DAC. I'd probably purchase another SMSL amp without a built in DAC.

I was planning on using the subs plate amp as a LP. Would there be any issue with having a plate amp LP and the amplifiers built in one? As I'll probably have the sub LP set to a lower frequency

[Millstonemike]

Is there an easy way to measure the impedance of an amplifier? I checked the specs, and no where did it mention that unfortunately.

Chris's high pass seemed too, well, high. I was under the impression that one should cross a subwoofer at 80hz and below, as the sound is harder to localize at those frequencies.

I looked at the amp. The only way to use a PLLXO is with analog inputs. That amp only has one analog input, the 3.5mm Aux input. So if you plan on using any of the digital inputs your back to Chris with a passive high pass in the Quarks.

And the spec.'s for the amp's woofer LP filter are 200 hz, 24 dB per octave. It seems to be fixed so your stuck crossing higher.

[ksneote]

Is there an easy way to measure the impedance of an amplifier? I checked the specs, and no where did it mention that unfortunately.

Chris's high pass seemed too, well, high. I was under the impression that one should cross a subwoofer at 80hz and below, as the sound is harder to localize at those frequencies.

[Millstonemike]

PCD has a line level calculator in the additional circuit calculators tab

A couple of notes ... as shown in the pic of the calculator, you want C2 to be one tenth of C1 lest the second stage impacts the first stage of the 2nd order HP. And you don't need R2', you can just use the impedance of the amp.

The problem with FMODs is they don't specify the impedance assumed for the amp. Hence I assume they are using low values for Rs and Cs so that the amp's impedance has minimal impact on the advertised XO point. And that may be a strain on the signal stage driving the PLLXO - you don't know without values.

Earlier in the thread Chris mentioned a adding the HP to the Quarks passive XO. I had thought that was a good idea as they become "universal" independent of the feed. You could always add a switch to enable/disable the HP portion of the added components.

And, of course, the Voxel feed has come from before the PLLXO implementation.

[jhollander]

PCD has a line level calculator in the additional circuit calculators tab

[DanP]

The Fmods work fine, you just have to know the input impedance of your amplifier to predict the cutoff frequency properly. Taking it a step further, you can design and make your own for less than $1 per channel. I don't have the link but someone had posted something here that showed how to calculate values for a passive line level filter, which is what Fmods are. Cheap, easy, small... perfect.

Dan

[ksneote]

Sorry for the late response everyone, I was in the middle of moving.

Thanks for all the suggestions, they were very helpful. Unfortunately, most of them were either expensive, or large/bulky (I'm moving to a pretty small apartment). It seems like my best option is either to get the Velodyne 8" sub as Psycoacoustics suggested, or finding a sub plate amp from a commercial manufacturer to put into the Voxel. I'm probably going to lean towards buying a used small format sub that has a built in high pass.

On that note, does anyone have any suggestions for small, commercial subs that have a built in high pass? Aside from the aformentioned Velodyne.

[ngjockey]

http://www.hsuresearch.com/products/high-pass-filter.html

[Psycoacoustics]

It seems that once home theater receivers took off the subwoofer manufactures began eliminating the high pass outputs. Probably to save money, but also because the receiver can do the same job.

That doesn't help people like you and me. I like my Vintage gear!

I use a small Velodyne CHT 8 that high passes @ 80 hz. It works well for me.

When I thought I was going to build a new sub I searched and searched for something to do the same thing to no avail! I was able to find a used CHT series amp on eBay. I can't remember what I paid, but it was cheaper than PE's new dsp plate amp.

With that said, I think PE's new amp would be just what you need and quite frankly, seems to be very reasonable priced! With your description of what your looking for,,,,,, I'd save my penny's and buy that.

Good Luck, Mark

[hcruz]

...Can you control the high-pass frequency?

According to the manual yes you can but it doesn't mention much detail about it. Default seems to be 100hz.

https://www.pioneerelectronics.com/StaticFiles/Manuals/Home/VSX-530-K_OperatingInstructions060115.pdf

[GTPlus]

You could use one of these too. http://www.parts-express.com/Search....itesearch=true

[philthien]

Instead of the SMSL I would get this if you don't mind losing the the USB part of the DAC.
https://www.amazon.com/Pioneer-VSX-5...2GDAMF1NCGMRB4

It would give you an appropriate high pass for the woofers, Bluetooth, additional analog connectivity and room for surrounds later on.

Edit: And you also get a remote

Edit: I get it, he is using separate amplification for the sub.

Alright, the Pioneer may be a better choice.

Can you control the high-pass frequency?

[brkitup]

You could also do it electronically as well.

I won't link to another site per the rules, but if you search for this at Amazon: SSL SX310 2/3-way Pre-Amp Electronic Crossover with Remote Subwoofer Control

it looks like it will do what you want. Probably costs a bit more than the passive solution, though... and it needs a 12v brick to power it.

This one would do it for $9: https://www.parts-express.com/factor...-plug--129-219

Just another option to think about. I'd probably go with Chris's suggestion as it will never "Go Bad"... as in no power supply or electric components to deal with. Who knows what you're going to get with some of these unknown brand electronic doo-dads from other countries.

I agree with you... there does seem to be a lack of small size 2.1 amplifiers with real-world high/low-pass crossover capabilities built-in.

A 30 watt per channel stereo section with an adjustable high-pass like you need.... along with an adjustable subwoofer low pass crossover line-output for a sub plate amp or amp board would be great. Wonder why there are so few?

TomZ

I was wondering the same. Is there really not a market for 2.1 channel receivers? I don't like the fact I'm forced to go for a home theater receiver if I want these capabilities. My Harman/Kardon receiver has decent crossover adjustments, but I'd still love a high quality, simple, 2.1 channel integrated amp with a basic high-pass crossover. I know Outlaw makes one, but it's slightly pricey.