Boomer1950

The EQ settings I'm currently using in the Crown amp DSP are as follows: 24Hz +9dB 27Hz -9dB 40Hz -11dB 45Hz +4dB 58Hz +15dB 73Hz -10dB 88Hz +11dB 99Hz -3dB It seems to me some of these adjustments are rather large, but what do I know? I made smaller adjustments at first & found myself making larger ones to get results closer to what I thought I wanted. I was attempting to moderate some of the extreme peaks & valleys of my "No EQ" measurements. I would appreciate any advice concerning these EQ settings.

I'm back after working a few hours with REW & the DSP in my Crown amp. I think I was able to generate more accurate measurements. Here is the graph of the performance of the sub without any adjustments made through the amp DSP: and the waterfall: The Crown Cdi1000 has a few DSP functions - delay, limiter, & EQ. I'm allowing my AVR set the delay & I haven't used the limiter. In the DSP section you also choose Stereo/Bridge-Mono. I've set it to Bridge-Mono which produces 1100W @4 ohms. The EQ function allows for 8 different adjustments at whatever frequencies you select. You can make .5 db adjustments up to +/-15 db. The Harman-Kardon software to control the amp functions is called Audio Architect & it only has a Windows version. So, after I took some measurements in REW on my MacBook, I took screen shots of my graphs, transferred them to my iPhone, rebooted into Windows to open Audio Architect, made 8 adjustments (best guess), rebooted back into Apple, opened REW & took new measurements to see how my adjustments effected the performance of the sub. Rinse & repeat. Maybe I should've used the Windows version of REW... Anyway, after multiple attempts to adjust the DSP here is the graph that was produced: and the waterfall: This is the comparison of the 2 graphs: I just realized I don't have the settings I used to produce the graph in blue. I'm going to post this info, so I don't lose it when I reboot into Windows. I'll come back with the EQ settings

Here is the graph before I applied any EQ adjustments:

I also produced a Waterfall graph from REW, but I am not able to determine what it means. I've added it below for any comments from you guys:

I bought a Dayton UMM-6 microphone in order to do some REW measurements. Then I learned a little about Hi-Q Architech which is the program used to adjust settings on a Crown (or Harman Kardon) amplifier with DSP like my CDi1000 amp. After a couple of efforts to make adjustments to the EQ output of the amp I was able to produce the following graph from REW: I don't know if I should try to flatten this curve beyond this. I wasn't sure how to interpret the "phase" aspect of the REW results, so I included this graph with the phase element added: I thought it was necessary to get some measurements done in order to see the performance of the sub I built. Any comments or recommendations would be greatly appreciated. It's been a pleasure working with all of the knowledgeable people on Data-Bass. I couldn't have done this without your detailed advice. Thanks very much!

@SMEI've been looking into getting a miniDSP to better fine tune my sub, so your recommendation for a HPF to protect the driver will move that decision along. I have a tone generating app that I used to do the test you suggested to find the tuning frequency. It appeared to be about 21-22Hz. By 18Hz the cone was moving quite a bit again. I was shooting for 20Hz, so it will be interesting to see what it actually is, when I do measurements with REW. Listening impressions - During the build I tried to give my wife an idea of what to expect from the new sub. It was always a difficult topic, because I wasn't completely sure what to expect. But now that it's playing in my living room, the new sounds I'm hearing are a little easier to describe. Both music & movies are dramatically different. With music there is a "presence" of bass that can't be ignored. It's not totally volume, but rather how the bass now seems to fill the room. As the bass line gets lower there is no obvious reduction of volume which, of course, makes it louder in the lower frequency ranges & that increase in volume comes with an increase in chest-thumping vibrations. Listening to music is a much more visceral, immersive experience now. Even at moderate volume the ability of the sub to reach down & hit the lowest notes with authority is impressive. Movie viewing has been radically changed - especially action movies with Dolby Atmos soundtracks. However refined & musical it's capable of being, start Mad Max Fury Road & it becomes a sledgehammer - seriously rocking us during explosions. The ability to reproduce loud explosions, gunshots or car crashes is stunning. The sub never seems to be pushed anywhere near its limits - even when the soundtrack is as loud as I can stand (the ultimate measurement of the volume capability of your system - it's louder than you can listen to it) . I don't want to sound too giddy, but I'm more than pleased - I'm thrilled.

Thanks, @SME for the kind words. I had planned to buy a Crown XLS amp, but before I bought one, I found a Crown CDi 1000 at a great price. I have some questions about setting up the DSP correctly. First question is about High Z & Low Z. Here is the relevant section of the manual: Output Mode: The options are: • 70V (70V/high-Z mode for Ch. 1 or Ch. 2) • High Z – Channel is configured for 70V/high-Z loads. (A 70Hz high-pass filter is automatically enabled whenever 70V is on.) It is a 24 dB/octave Linkwitz-Riley filter in the crossover section. • Low Z – Channel is configured for low-Z loads. From what I've read "Low Z" would be correct for the 4 ohm (two 2 ohm voice coils wired in series) SQL-15 driver. Is that right? I am running it in "Bridge Mode." My choices for Crossover settings are: XOV (Crossover): The available crossover frequencies are: OFF, 90 Hz, 100 Hz, 1200 Hz, 1500 Hz, 2000 Hz, 2-CH SUB, CUSTOM. With my old sub I set the crossover on the sub as high as it would go & let the AV receiver set the crossover. What do I select as the crossover for the Crown amp? I set the EQ to "Out" bypassing the EQ. I set delay to "Off" letting the setup function in the AV receiver set the delay. There are options for a "Limiter" setting: OFF, -3dB, -6dB, -12dB. I'm not sure which setting would be best. Comments & advice are greatly appreciated.

Oh yeah. I signed the back & put a couple of coats of gloss polyurethane over it. Doesn't everyone?

Thanks @maxmercy. I really wanted this to look nice, because the plan was to have it front & center in my living room - which it is. My wife loves the way it looks & definitely prefers the "no grill" look. But, the chances of me going further down this rabbit-hole - or opening Pandora's Box wider - aren't very good. I can't imagine starting another project like this. I'm thrilled with the way it turned out, but it's a "one-hit wonder." Subwoofer building is very much a solo project & my wife & I don't do many of those anymore. It took what felt like an unnatural amount of time away from her to get this done. The good news is we like doing everything together.

It's hard to believe, but I've finished my subwoofer - global pandemic be damned. It seems like it took forever, but at some point you just have to stop. Painting the box the way I did greatly increased the time it took. Leaving it square & painting it with truck bed liner would've saved me weeks. No matter now. Here's the finished box. Just so someone will know I painted the bottom the same way... here's the bottom. Because I have a dual 2 ohm voice coil driver, I wired it in series. I ran one wire to connect the negative of one coil & the positive of the other voice coil. Then the internal wire was split with the positive to one coil & the negative to the other. My concern over getting the driver positioned correctly so I could get the screws through the holes in the baffle was unnecessary. With only a slight bit of adjustment the screws lined up & the driver was tightened into place. Sliding the ports in & attaching them with 4 screws was even easier. Voila! I couldn't let a comparison with my former 100 watt 12" Polk sub be overlooked. I took a picture of my entertainment center with the Polk sub in place. Now with my new SI SQL15 sub with a 1100 watt Crown amp - with & without speaker grill: It sounds absolutely wonderful, but I don't have a microphone I can use to give you any kind of performance data. I'll get to that soon. But I want to thank all the people who helped me get through this process - especially @dgage who helped me set up a visit with Nick at Stereo Integrity along with other good advice. Everyone was so gracious to this old man that I can hardly express the extent of my gratitude The picture of my MDF was taken on Jan 21. On June 5 I hooked it up & listened to it for the first time. Worth every minute.

Thanks, @dgage. I'll look into making the hole bigger using those router bits.

The SQL-15 is here. It looks great & I can hardly wait to hook it up - but I will wait a little. I added the plastic ties to give me something to hang onto. I decided to see how it fits in the box. It looked good at first, but then I noticed it wasn't going into the recessed driver support (inner baffle). I removed the plastic ties to make sure they weren't keeping it from fitting. That wasn't the problem. I assume the hole I cut is slightly small. This picture shows the edge of the driver sitting on the edge of the hole. My first thought is to hand sand around the inside of the hole & regularly check to see if I've made the hole big enough. If you guys have any suggestions about how to handle this problem, they would be greatly appreciated.

My driver from SI is arriving today!! Nick called yesterday to let me know he was shipping it. Obviously, the trip from Claremont to Burlington is a quick one for FedEx.

The world has certainly gotten crazy since my last post. My wife & I have been "sheltering in place" for the last 3 weeks. Although I have plenty of time now to work on the box, I failed to buy the color paint before the quarantine started. Being in the high risk group (senior citizen) has kept me from doing any shopping in-person. I ordered some paint online from Home Depot, but it's taking them forever to ship it. More waiting... Some good news: The Stereo Integrity SQL-15 drivers have arrived in NC! They're being shipped now, so it could come to me sometime soon. I have finished the primer painting & sanding. It looks pretty good to me. I haven't shown a picture of the finished grill attached to the front of the box with the magnets I embedded in the front baffle & the speaker grill - so, here it is: The grill fits exactly as I had planned. I wanted the front face to show above the grill - it fits the same way at the bottom, but it's hard to see with the shadow there. I intend to paint the box gloss black, but I've been wanting to have a two-color scheme - just to be a little different. My current speakers are cherry wood & I thought a reddish brown accent would help the subwoofer match my other speakers somewhat. In order for me to get some idea about how it would look I put yellow masking tape on the box where I intend to have the brown color. The rest of the box with be gloss black. I've already received the gloss topcoat that I'll apply to the entire box. The stripe will go around the box - down the front, across the bottom & up the back. After I paint the front baffle black with the brown stripe I don't believe you'll see through the speaker grill - as you can in this picture. But now, I wait - for the paint on order & the arrival of the driver. I'm very happy with the box at this point. Everyone stay safe. Wear a mask in public to protect the people you might meet. Everybody needs to wear a mask in public. Please. Help protect the most vulnerable in society - those with underlying health issues & the elderly - like me & my wife!

Just a quick update. I have attached the front baffle, so all of the construction is over. Here's a pic of the completed box with the grill frame attached by magnets. It was at this point that serious sanding began. I decided to take the edge off of the sharp edges of the corners. I used a sanding block to "blunt" those edges. After a lot of work I had barely changed the shape of the corners. I knew after I used a router once that I would not be able to use a router indoors - the blizzard of dust would ruin my house. I realized that using a round-over bit once the box was built was out of the question. My wife & I are not able to pick up the box & take it to the carport to mitigate the dust in my house - remember, I'm 69 & my wife is 70. I have no idea how much this box weighs, but I guess it's easily over 125 lbs. I had never used a plane while working with MDF (hell, I've never sanded this much either), but I decided to give it a try - starting on the bottom of the sub in order to "hide" any screw-ups. I liked the early results so I continued to the rest of the box. I'm pretty happy with the results so far. Some more sanding to go before I start applying oil-based primer. I took the sub off of the saw horses because I need to roll it around to work on the various sides. Taking it off the saw horses was an exercise of "controlled fall." No damage to the sub, the room, and most importantly, no damage to me.