My apartment setup

[Brandon Hartwick]

This isn't my drawing or design, but after talking with some more experienced builders this sounds like the best way to go.

I will likely be using 4 10" woofers per channel instead of 6 7" woofers, this will better match the 4' height of the panel I'm using. I'm going to run both the woofers and the ESL panel with active crossovers for now to get a feel for what frequencies I'm after.

I think before I dive in with both feet I'm going to build an active set of bookshelf speakers with some parts I have laying around. This will give me a better idea of how to use the DSP unit.

 

[Robert D]

This isn't my drawing or design, but after talking with some more experienced builders this sounds like the best way to go.

I will likely be using 4 10" woofers per channel instead of 6 7" woofers, this will better match the 4' height of the panel I'm using. I'm going to run both the woofers and the ESL panel with active crossovers for now to get a feel for what frequencies I'm after.


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I think before I dive in with both feet I'm going to build an active set of bookshelf speakers with some parts I have laying around. This will give me a better idea of how to use the DSP unit.
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Sounds really exciting. Keep us posted on how it turns out.

 

[Brad225]

Did you ever look at JonFo's SLX project for center channel?

 

[Brad225]

Photo of what it looks like. It is part of the X-Static Theater in his home.
Coned mid range and infinite baffle sub into the floor.

Check out the construction thread it is a great view and read.

 

[JonFo]

This isn't my drawing or design, but after talking with some more experienced builders this sounds like the best way to go.

Nice, but I'd suggest adding a 'wing' to the right side of the ESL to mitigate the dipole cancellation. It could be the same width and angle as the side of the woofer tower.

What 10" drivers are you considering?

Not many will go clean to >500Hz, which is why the 7" or 8" drivers are usually used.

 

[Brandon Hartwick]

Nice, but I'd suggest adding a 'wing' to the right side of the ESL to mitigate the dipole cancellation. It could be the same width and angle as the side of the woofer tower.

What 10" drivers are you considering?

Not many will go clean to >500Hz, which is why the 7" or 8" drivers are usually used.

Thanks for the tip, I'll definitely look into adding a wing to the side of the panel.

For woofers I was looking at the paper cone Dayton Reference woofers, the frequency response looks pretty good on those.

 

[Brandon Hartwick]

In other news, I got my bookshelf speakers together last night but ran out of time to setup the DSP. One thing is for sure, I will never be a carpenter...

600V rated industrial cable for speaker wire for you wire enthusiasts

Also added another set of binding posts to my Aerius speakers so I can bypass the passive crossover. To do this you need to splice into the black/red and green wire off the step up transformer.

 

[Robert D]

In other news, I got my bookshelf speakers together last night but ran out of time to setup the DSP. One thing is for sure, I will never be a carpenter...


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600V rated industrial cable for speaker wire for you wire enthusiasts
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Also added another set of binding posts to my Aerius speakers so I can bypass the passive crossover. To do this you need to splice into the black/red and green wire off the step up transformer.
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Tell us how they sound! I see your cat likes to help out. Mine is like that!

 

[Brad225]

We all started in woodworking with what we felt was less than perfect. It doesn't look as you describe it.

Are you going to round over the outside horizontal and vertical outside corners? I believe it is a type of standing wave issue.
Someone here will provide the proper verbiage.

Look forward to hear how they sound.

 

[Brandon Hartwick]

Adventures with DSP and active crossovers

I'm a believer, this unit is amazing. With 4 inputs and 8 outputs you have a huge amount of flexibility. It's wild being able to sit on the couch and dial everything in on the fly with a laptop.

Last night I got the bookshelf speakers setup and we're they ever harsh, with all levels equal they were pretty brutal. But with a little level adjustment between the tweeter and woofer they're actually really good, very smooth and extremely detailed, probably the most detailed small speaker I own. At some point I'll bring them back to my shop and finish them for real.

I also decided to hook up the Martin Logan's directly to the amps and bypass both internal crossovers completely. The old Jeff Rowland amp handles direct driving the panel with no problems at all, even at high volume. Using 24bd/octave active crossovers at the stock 450hz gave best results and the speakers sound as good or better than running with the passive X over. Tonight I'll play around with it some more but this looks very promising.

Those of you still running passive bass sections are really missing out big time. I'm never going back.

 

[Robert D]

What software are you using for the crossover and DSP? That looks really nice.

 

[Brandon Hartwick]

What software are you using for the crossover and DSP? That looks really nice.

It's Dayton Audio software to pair with the DSP-408 unit. It's really easy to use and setup, I highly recommend it and so far it also seems sonically transparent. Pair this with Room EQ Wizard you could really dial things in exactly how you like it, last night I had really good results just doing adjustments by ear.

 

[JonFo]

I installed a giant stack of subwoofers this weekend. This actually works extremely well, the bass is fast, clean and you can feel it in your chest. This sounds way better than the single 12" I had previously.

Nice, that forms a line array that should improve far-field energy in the upper ranges of the subs, and better distribute vertical room modes (vs a single sub on the floor). You definitely have much more 45 - 120Hz energy in the room, which is why you get more chest-slam.

I would use REW to measure that you do not have room modes from the single location. Maybe more subs just to balance out might be required, or tons of acoustical treatments.

 

[JonFo]

I highly recommend doing the active crossover modification on any Martin Logan speaker that uses a passive woofer crossover, the improvement is huge.

+10

Been saying this since the forum started back in 2005, even a less than ideal active XO beats passives. A well tuned DSP XO is another world.

With the Monolith III, it's even a piece of cake, as the speaker binding posts are post XO (Monolith Passive is in an external box), so zero mods.

 

[JonFo]

I told myself I wouldn't do this, but here we are.

I am soon to acquire a pair of nearly new panels from a pair of ML Quest's, I already have the electronics I need minus crossovers. I will be designing woofer enclosures and panel frames from scratch out of laser cut steel.

Oh, that looks very cool, and using metal for the frames is the hot ticket.

Let's hook up via PM to discuss a future project I have in mind for the next iteration of life for my Sequel speakers.
I plan to repanel them in 2023, and the old Nextel-covered boxes are pretty tired after 29 years, the cost of stripping and refinishing is not worth it, plus I want to match my center setup with a line array of mid-bass drivers. Oh, and the panel will be in a monopole enclosure. You know, kind of like my Monoray design

 

[JonFo]

Using 24bd/octave active crossovers at the stock 450hz gave best results and the speakers sound as good or better than running with the passive X over. Tonight I'll play around with it some more but this looks very promising.

Those of you still running passive bass sections are really missing out big time. I'm never going back.

Yep, simply bypassing the passive woofer XO is the low-hanging fruit for these older models, no mods are required on most of the models either, just disconnect the straps briding the terminals.

Steep crossovers on the high-pass panel are key, and 350 to 500Hz is the range, depending on the panel and room setup. Yes, even the massively huge Monolith panels should only see 330Hz at the lowest but work best at 350 to 400Hz. Most of the others are where you wound up with yours, Brandon, at 450Hz.

Do use REW to measure the impulse responses of each driver individually and time-align if the DSP has that adjustment and sufficient resolution. The sloped SL3 might not need it, but vertically aligned models (Sequel, Monolith) do need 1.xms of delay to the panel.

Also, use Group Delay curves to time align the subs to the mains. What you are looking for is the least variation across frequencies. The curve will never be flat, but removing any peaks/troughs is a win, indicating better phase alignment across the system. Changes in delay as small as 1ms have measurable impact. And if set correctly, the result is some of the best overall bass response ever.

 

[Reverb]

Adventures with DSP and active crossovers

I'm a believer, this unit is amazing. With 4 inputs and 8 outputs you have a huge amount of flexibility. It's wild being able to sit on the couch and dial everything in on the fly with a laptop.

Last night I got the bookshelf speakers setup and we're they ever harsh, with all levels equal they were pretty brutal. But with a little level adjustment between the tweeter and woofer they're actually really good, very smooth and extremely detailed, probably the most detailed small speaker I own. At some point I'll bring them back to my shop and finish them for real.

I also decided to hook up the Martin Logan's directly to the amps and bypass both internal crossovers completely. The old Jeff Rowland amp handles direct driving the panel with no problems at all, even at high volume. Using 24bd/octave active crossovers at the stock 450hz gave best results and the speakers sound as good or better than running with the passive X over. Tonight I'll play around with it some more but this looks very promising.

Those of you still running passive bass sections are really missing out big time. I'm never going back.

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Nice looking custom sound boxes. I bet they sound nice too, right?

 

[Brandon Hartwick]

Oh, that looks very cool, and using metal for the frames is the hot ticket.

Let's hook up via PM to discuss a future project I have in mind for the next iteration of life for my Sequel speakers.
I plan to repanel them in 2023, and the old Nextel-covered boxes are pretty tired after 29 years, the cost of stripping and refinishing is not worth it, plus I want to match my center setup with a line array of mid-bass drivers. Oh, and the panel will be in a monopole enclosure. You know, kind of like my Monoray design

I'm really good at working with metal so for me it's an easy decision. I also have access to a laser cutter so I can make basically any design I dream up.

I'll shoot you a PM later this evening when I'm back at my hotel. Your design sounds very interesting and I'd like to learn more.

 

[Brandon Hartwick]

Yep, simply bypassing the passive woofer XO is the low-hanging fruit for these older models, no mods are required on most of the models either, just disconnect the straps briding the terminals.

Steep crossovers on the High-pass to the panel are key, and 350 to 500Hz is the range, depending on panel and room setup. Yes, even the massively huge Monolith panels should only see 330Hz at the lowest, but work best at 35 to 400Hz. Most of the others are where you wound up with yours, Brandon, at 450Hz.

Do use REW to measure the impulse responses of each driver individually and time-align if the DSP has that adjustment and sufficient resolution. The sloped SL3 might not need it, but vertically alinged models (Sequel, Monolith) do need 1.xms of delay to the panel.

Also, use Group Delay curves to time align the subs to the mains. What you are looking for is the least variation across frequencies. The curve will never be flat, but removing any peaks/troughs is a win, indicating better phase alignment across the system. Changes in delay as small as 1ms have measurable impact. And if set correctly, result is some of the best overall bass response ever.

Yes I still need to bust out REW at some point when I get back and get some real measurements. I'm sure this would help flatten out the bass response of my tower of subwoofers.

 

[Brandon Hartwick]

All the components I was waiting for have finally arrived so work can now begin on my custom ESL build

Quest panels make my Aerius I's look tiny. Since I have no wiring diagrams on how the power supplies and crossovers go together I need to trace back all the wiring and make some myself. Hopefully later this evening I can start to get this sorted out, otherwise I'll have to bother Martin Logan again.

I would like to give a huge shoutout to Ron over at Martin Logan for all the help he's provided in answering all my questions and sending me all the information he had at zero cost. Without his help this project would not have been possible in the first place.

Leave it to Martin Logan to find the cheapest woofers available, as per usual. These probably will just go up for sale as I will be using 12 7" woofers for the line arrays.

These are the front, side and top sketches for what I have done so far. Nothing is final as of yet.