Observed something tonight that has me confused, concerning crossover point of front speakers

[Robert D]

Im running two Prodigy speakers as front mains on my Marantz receiver along with an Aaragon amp to power them. I am also using a depth i subwoofer. I set it up using Audyssey. Tonight I was messing around with the crossover point for the front speakers, Prodigys which are supposed to go down to 28 HZ, and noticed that if I move the crossover point up from 40 HZ to 80 HZ or more that the base becomes greater and more defined. Audyssey set it to 40 HZ. I have the sub set to LFE + main so that it gets a signal from all the speakers and the mains are set to Large.

This is going against what I thought should happen. Somehow setting the crossover higher on the mains is giving me more base, even though the subwoofer is already set to LFE +main. When its set to LFE + Main doesnt that mean that the sub is already getting as much signal as it can? I figured having the mains set to 40 HZ would give more bass since its covering a wider frequency range on the front speakers and that some of that would overlap with the sub since the sub crossover point is set to 90 HZ.

I thought that when the front speakers are set to large and the sub is set to LFE + Main, the sub woofer would get the whole lower frequency range up to 90 HZ from the mains . It seems like when I set the main's crossover from 40 HZ up to 80 HZ that the sub is then getting a stronger signal somehow. The sub is blended in well enough that I am unable to tell where the extra base is coming from when I move the crossover point up. It sounds like there is more base coming from the Prodigys, but that makes no sense since the crossover is set higher and cuts off at 80 HZ.

I unplugged the sub and now I can tell that the extra base is indeed coming from the sub when I turn up the crossover point on the mains. I then changed the crossover point on the mains setting it all the way from 250 HZ down to 40 HZ and the base coming from the Prodigys didnt change at all. Makes no sense. I tried this with Audyssey turned on and off. The woofers are moving and producing bass, just not very much. Both are the same.

I feel like an idiot. Any idea what the deal is? With the mains and sub running at the same time it sounds great so i guess i dont really have a problem. Its just that you would think the Prodigys would produce good base since they are supposed to go down to 28 HZ. Maybe something is wrong with them?

 

[JonFo]

Prodigys which are supposed to go down to 28 HZ

Hum, maybe at 85dB they might reach that, but forget >95dB, the THD would be in the double-digits.
And, that 20-year old driver is likely on its last legs. Time for a replacement, or relieve it from stress.

I have the sub set to LFE + main

That combo is generally not recommended, as it over-boosts the low end. You are doubling-up on the low frequencies. Set the sub to just LFE.
The crossover from speakers should be set to small (and ALL speakers should be set to small) even the Prodigies, will direct the below-crossover point to the sub, which is desired.

Somehow setting the crossover higher on the mains is giving me more base, even though the subwoofer is already set to LFE +main. When its set to LFE + Main doesnt that mean that the sub is already getting as much signal as it can?

With the higher crossover, the added bass you are perceiving is probably due to two factors: A) the sub is much more cable bass reproducer, and B) It's location in the room is better for the frequencies being delivered. ESLs are located to make the panels sound good, but that generally is not aligned with good low-end performance. So shifting the 80Hz and lower to the sub is the right thing.

 

[Robert D]

Hum, maybe at 85dB they might reach that, but forget >95dB, the THD would be in the double-digits.
And, that 20-year old driver is likely on its last legs. Time for a replacement, or relieve it from stress.


That combo is generally not recommended, as it over-boosts the low end. You are doubling-up on the low frequencies. Set the sub to just LFE.
The crossover from speakers should be set to small (and ALL speakers should be set to small) even the Prodigies, will direct the below-crossover point to the sub, which is desired.


With the higher crossover, the added bass you are perceiving is probably due to two factors: A) the sub is much more cable bass reproducer, and B) It's location in the room is better for the frequencies being delivered. ESLs are located to make the panels sound good, but that generally is not aligned with good low-end performance. So shifting the 80Hz and lower to the sub is the right thing.

I have a feeling that the age of the woofers may be why they aren't putting out large volumes of bass. The sub sure does. Going to leave the crossover set to 80 HZ. For whatever reason, the setup isn't doubling up the low frequencies like I thought it was. I just feel like I may be missing out on some mid bass.

If those woofers are truly shot and the panels, it's probably not wise to replace them since the cost would be prohibitive? The theater center I have is probably the same age too. I did have to already replace a woofer on that, but cost was low. I spent about $3500 buying the prodigies and the theater center channel. Buying new that is comparable isnt something i want to do right now i think.

What fronts and center do you think ML has now that would be comparable and not a step down?

That sale they have now is good and ends soon, but cost is still high to me.

The store I buy from could put mine up for sale for me.

 

[JonFo]

What fronts and center do you think ML has now that would be comparable and not a step down?

Those prodigies can be made to work, just takes a bit of effort. But not much more coin.

Now, the center is a BIG deal, and the new Focus C18 is an amazing unit, buy that now that it's on sale (you have two more days).
Sell your old center to offset the cost.

 

[Robert D]

Sadly the center channel speakers aren't on sale.
https://www.martinlogan.com/en/category/our-speakers
$3500 is a bit much right now in the midst of this covid-19 crap. Not sure how much I'd get for the theater. Anyone know?

The store I buy from usually gives me a discount on new items. That would help some. That speaker is really that much better than the theater? The theater Electrostatic panels look like they are bigger, but is bigger always better?

Not sure why ML didn't discount those 2 center channel speakers.

 

[Robert D]

anyone own the c18 that could chime in? Wondering how it compares to other speakers you have owned, such as the ML Theater.

https://www.martinlogan.com/en/product/focus-esl-c18

 

[JonFo]

anyone own the c18 that could chime in? Wondering how it compares to other speakers you have owned, such as the ML Theater.

See this thread: Thinking of upgrading to ML Focus ESL C18 - help?

My impression from others is that the C18 is a step up from all prior models. Based on the design alone, my thoughts are it will be better.

 

[Chops]

The reason you started getting more bass output once you moved the crossover frequency up on the Prodigy is because they are not in proper phase with your subwoofers, so where the two were overlapping down to 40 Hz, they were cancelling each other out. Now at 80 Hz, there's a lot less overlap, hence a lot cancellations.

Also, the age of the woofers have nothing to do with their current performance. The only time this would be of issue would be if the surrounds were failing and causing the driver to sag (a.k.a. - foam surrounds or torn surrounds) and the voice coils to rub in the pole gap. Driver output does not degrade with age just from normal use.

The other loss of output from a woofer would be if it used an alnico magnet which over time loses its strength and needs to be recharged.

However, if you play the Prodigy's be themselves and have lower bass output, it's likely due to the Prodigy's location in the room and/or your listening position, not aged woofers.

 

[Robert D]

The reason you started getting more bass output once you moved the crossover frequency up on the Prodigy is because they are not in proper phase with your subwoofers, so where the two were overlapping down to 40 Hz, they were cancelling each other out. Now at 80 Hz, there's a lot less overlap, hence a lot cancellations.

Also, the age of the woofers have nothing to do with their current performance. The only time this would be of issue would be if the surrounds were failing and causing the driver to sag (a.k.a. - foam surrounds or torn surrounds) and the voice coils to rub in the pole gap. Driver output does not degrade with age just from normal use.

However, if you play the Prodigy's be themselves and have lower bass output, it's likely due to the Prodigy's location in the room and/or your listening position, not aged woofers.

Once I get everything up and running again, im having the Prodigy panels refurbished now, I will mess with the phase dial on the Depth i and see if that helps. Right now I have the dial set at 90 degrees. I guess that is something that I will just have to adjust and listen. Maybe I got it wrong.