2001 Honda Accord DIY SQ

[jsun_g]

Glad it's working out for you after all that effort. I hear ya on the 0.4 cubes...my sealed kickpanel enclosures are about 0.2 cubes and ideally I need double that. I have been contemplating Juan's suggestion of venting into the car frame and ditching the large enclosures.

I'll be looking forward to the RTA specifically of the midbass drivers unequalized.

BTW Juan nice to see you on here. I bought some subs (Petras Prowlers) off you oh about 14 years ago (remember UPS mangled one of the subs and the cardboard box looked like hammered $hit...).

Originally Posted by keep_hope_alive

good. they play low (good 'ol OZ) and have an expected peak (around 125Hz). ideally, I would have a sealed enclosure for them, about .4 cu. ft. or so. for now, the vent is sufficient. what i may play with is filling the irregular cavities to direct more flow out the vent. right now i have some corners that i will fill with modeling clay. i'm just getting everything dialed in, shelving here and there, playing with crossover settings. they did fine with a 50Hz HPF at 18dB/oct. right now i think i have them up at 63Hz and 24dB/oct as i was able to get the JL to blend with the front stage a bit higher than expected.

we sent our Sound Devices USBPre back to have the headphone pot replaced. when that comes back i'll be able to RTA each driver (which i will share on here). we use that as our mic preamp/sound card. we have an Earthworks M50 measurement mic to go with it (as well as a much cheaper Behringer ECM8000). the interface is a laptop dedicated for Goldwave and True RTA. we are looking for better software for data acquisition and RTA.

i have a lot of tuning left, a lot of fabrication left, but at least i'm enjoying it.

[OldOneEye]

Yeah, I remember that one. One of the few shipments that went haywire for me. I started working for RPS shortly there after and I don't think I've ever shipped something that heavy ever again (4 15" woofers in one box?!? what was I thinking?) They made the mistake of giving me a managers name so I think they gave up trying to hide from me and just paid the claim.

Juan

[jsun_g]

Not to hijack the thread but just a quick note on that shipment...
I went to the UPS distro center directly after the 15's came in and took the damaged sub and box with me. I convinced them to ship a replacement sub from you overnight at no cost. I think the shipping alone came to $160. LOL.
Good times...

Originally Posted by OldOneEye

Yeah, I remember that one. One of the few shipments that went haywire for me. I started working for RPS shortly there after and I don't think I've ever shipped something that heavy ever again (4 15" woofers in one box?!? what was I thinking?) They made the mistake of giving me a managers name so I think they gave up trying to hide from me and just paid the claim.

Juan

[keep_hope_alive]

Originally Posted by OldOneEye

Great work. Just curious why you vented into the exterior versus maybe venting into the frame rail/channel that runs under the doors (its supposed to be a big cavity).

Juan

two reasons:

1. access - i found some frame cavities, but the one was shared with the mid cavity (outside of each mid) and the other was under the car (just to the inside of each midbass). but to make a clean hole into either would either force my enclosure to take up floor space or cut away even more metal.

2. structural - i didn't want to do anything to reduce the structural integrity of the frame. ideally, you'd reinforce the hole in the frame with some plate steel, but i can't weld (yet).

i did not want to sacrifice any safety. the hole in the floor was an empty cavity anyway, no harm done. the hole in the side kick is an arguable weak point, but since i didn't extend the hole around the sides i feel it's just as strong (plus, it's a small hole).


after i made the vent i made it a mission to find as many deep puddles as possible to check for water infiltration. i still have a factory drain hole as well as the vent, and i did not find any wetness despite deep puddles. i feel the drivers will be safe. i also used fiberglass since it's not organic, and won't support mold as easily. if it does get damp, it can dry out easily.

[keep_hope_alive]

thanks for the comments. i'm still not 100% sold on the off-axis midrange drivers.

i will be testing an active 2-way as well as the 3-way, since the midbass location is near ideal. a second set of OZ tweeters would be nice, located in the kick.

if i cut away more metal, reinforce with steel, i know how i can get the kick mids on axis (in front of, and outside of the midbass drivers).

[Megalomaniac]

Why do you want to put a 2nd set of tweets?

[keep_hope_alive]

Originally Posted by Megalomaniac

Why do you want to put a 2nd set of tweets?

a second set down by the midbass drivers would let me experiment more. apillar vs kick. it would also let me increase the apillar tweeter HPF above 6-7kHz (just for stage height) and decrease the kick tweeter HPF to counter beaming..

my understanding is that with the separation of the tweet to the apillar, i should keep the HPF at or above 4kHz (i know i misspoke earlier by saying 2kHz). however, the midrange may start beaming before 4kHz. while I know the off-axis midrange isn't ideal, but if it can win world championships, it must work somehow with some drivers.

also, a set in the kicks would let me experiment with a simple two-way using the 6.5". Until I RTA I won't know the true upper limit of that driver.

Something to consider is the impedance curves of the drivers.

[keep_hope_alive]

RTA Results December 5-6th 2009

Behringer ECM8000 (with correction file)
Rohls mic preamp/phantom power
TrueRTA
Creative Audigy PCIMA sound card
(the better RTA kit is occupied currently)

First pass after initial install.

I varied the used of 1/3rd oct. and 1/24th oct depending on what i wanted to see. 1/3rd oct helped with my 1/3rd oct eq adjustments.

also, i counted comb filtering by moving the mic around the head location during the measurement. this proved helpful in determining what was interference with a single mic location, and what was actual system response.

not the scales change in the tuned versions. my goal was a 5dB variance, which i mostly achieved. the midbass was hot in the 125Hz area, which i do like a boost there, but not as much as there was. i also notice some areas that seemed more sensitive to my ears than others.

background noise:


driver midbass with mic in the kick, eq flat, 63Hz HPF






driver midbass with mic at headrest, eq flat, 63Hz HPF, mic was fixed position


driver midrange with mic at headrest, eq flat, 100Hz HPF, mic was fixed position




driver midbass, flat eq, mic at driver headrest, moving mic
notice the 15dB variance was reduced to about 5db.


driver midbass tuned, mic at driver headrest, moving mic






driver midrange, eq flat, mic at driver headrest, moving mic
notice the 15dB variance was reduced to about 5db.


driver midrange, tuned, mic at driver headrest, moving mic






both tweeters tuned, mic at drivers headrest, moving mic
no before pic, it wasn't too far off actually



at this point i started playing with crossover settings, slopes, gain adustments, and doing some tuning by ear. played several tracks from the JL Labs Tools CD 2 and some music i'm familiar with. i have done some more adjustment since then. it's a better starting point than it was.
all speakers, crossover points are 315Hz and 4kHz, mic at passenger headrest

[jsun_g]

Looking good...
Noticed the ~125Hz peak in the midrange as well as the midbass, so it may not be a midbass or midbass enclosure cavity issue, maybe more of a matter of general speaker placement and car dimensions coming into play.

[keep_hope_alive]

good point. i can also hear that hump, even before the RTA i was attenuating the 125Hz band and neighboring bands.

[keep_hope_alive]

Got the kicks cleaned up. Modified the factory kick panel cover. The future for these speakers is a fiberglass grille, i'll use the factory cover as a mold. For now, it's better than it was - even with a black marker outline. :O New carpet is totally flush with factory (and is open weave - acoustically "transparent") BTW the factory carpet was stained when I got it.










Temporary bass provided by JL12W3D4 running sealed with the same baffle as before.


Not sure if I shared the 1/0 wiring upgrade, and battery wiring. It's a bit cleaner now. Fuse holder is bolted to the metal battery mount.

[GlockandRoll]

Great work, man would I love to hear that car!!!

[sydmonster]

good to see progress in the project....

(unlike mine)

[keep_hope_alive]

Originally Posted by sydmonster

good to see progress in the project....

(unlike mine)

Despite it being below 20 degrees every night, i'm trying to make progress here and there. Garage stays around 30 if the heater is running. :P

It sounds pretty good. I've been playing with it a lot. Doing a lot of back and forth with presets, experimenting with how crossover settings change the sound stage. While running it as a two-way (mid off) has a much more solid stage, the Oz 180's doesn't have enough output at 4kHz for my tastes. I much prefer the overall sound of the 3-way with mid/midbass x-over anywhere between 360Hz and 500Hz. Surprisingly, despite being off axis like they are, the Oz 100's do a great job up to (and above) 4kHz.

I am excited about getting the IB wall built. I have the wood, pattern, materials, tools, etc. just waiting. All I need is the time and a warmer day (i'll take 40 deg).

[jhmeg2]

awsome install. I know how you feel, working in the cold... It was -3* when I was working on my a-pilliars, finished them and drove the car out of the shop, and the glue and vinyl came lose. Now I'm in FL. with no where to work, and I need to re-wrap my pillars, and finish a few trim panels. any one in the Fort myers area can help me out!!!. keep up the work. Maybe some time I can drive down to Ill. and get a demo.

[sydmonster]

Originally Posted by keep_hope_alive

I am excited about getting the IB wall built. I have the wood, pattern, materials, tools, etc. just waiting. All I need is the time and a warmer day (i'll take 40 deg).

hmm cold, indeed. (not that I experiance it that much)

When i went IB in my Accord I wasn't 100% sure what I was getting into (as it wasn't regular IB). But now that its done, the low end of it is addictive. IB and in particular, IB with clean power and a LARGE driver is awesome.

[ryan s]

How did I miss this update?

Now those locations I could live with. The standard "kickpanel" install intrudes into the dead pedal area too much, IMO.

Although I'm wondering...can the speakers still get wet through the carpet and grille cloth? The midbass on the floor is exactly where I rest my foot and you know all about winter, as well... With a metal grille in place, I wouldn't be scared to put my foot through the speaker, but moisture would still concern me...

[keep_hope_alive]

^I have been checking on the floor mounted midbass drivers throughout the winter - we had a decent amount of steady snow on the ground this winter. The drivers were good to go - they did have some light dusting on them, that was with the waffle grills. Now I have the actual Oz Audio grills. We'll see if this prevents as much ingress.

I'm really happy with how it's coming along. I have more tuning to do to achieve a rock solid two seats. One seat is fairly easy to get a great sound stage. All of the locations are working out great. I am still comparing 3-way vs. 2-way with presets on the H701. It's nice having that functionality. The Oz don't play as high as i'd like for a great 2-way given my tweeter locations.

Did some cleaning up tonight. I installed the Oz Audio grills, and adjusted the polyfill inside the cavity. I'm still getting a resonance at 125Hz that I can tame with the EQ, but it's a noticeable loss in midbass at that band. I have some ideas for ways to eliminate it. For now, it's still imaging great and sounds very good. I know it's enclosure, it's the only tone that vibrates the floor. The baffle is rock solid, I'm going to try filling in some of the corner voids in the cavity.







Next, I experimented with covering the Apillar with fabric - this is a fleece type material. I chose black so that they would be less noticeable from outside - blends with the tinting and tweeter. not sure i'm a huge fan of the color since nothing else is black. i'll experiment more with other fabric colors, grill cloths, etc. for now, it's certainly better than it was. In the end, I may go with a matching color and figure out a way to cover the tweeters without reducing high frequency output (i.e. non-absorbing). Since they are way less obvious from outside the car - i consider it mission accomplished. That was the #1 goal anyway.








Next I need to figure out what i'm doing in the trunk. I now have the pair of 300H's and a pair of 250L's. I'm thinking about the 250L's in the rear corners. Then I need to relocate the amps. I also picked up a second 3300c, so my amplifications options have increase (as well as required floor space). I'm not 100% sold on the IB wall yet. I like the idea, but i'm really happy with placing the JL Audio 12W3 in a sealed enclosure at the rear passenger corner of the trunk. Decisions, decisions. I think some testing is in order...

[keep_hope_alive]

Another task is to fix the HU mount by making it a single opening. And I need to make a panel to close off the driver's side under dash. I'm sure i'm getting a pathway from the driver's kick drivers up through the dash.

Any ideas/experience using materials to close off the under dash cavity? Obviously, it needs to be removable, but rigid. 1/2" MDF?


I also want to add some 2" acoustical foam to the center console sides, try and absorb some upper midrange reflections. I also want to repaint or cover the door speaker grills - nothing there anyway (blanked off for road noise).

I am also looking into some dash pads.

It'll never end.

[bikinpunk]

Have you considered ordering new automotive carpet to cover the floor and hide midbass?
In the pictures it sticks out like a sore thumb.

[keep_hope_alive]

Originally Posted by bikinpunk

Have you considered ordering new automotive carpet to cover the floor and hide midbass?
In the pictures it sticks out like a sore thumb.

oh hell yea. it's hideous. i can't decide if i want to put a layer of new open weave carpet on the existing carpet, or buy new. the reason i would layer is so i can leave the factory cut out and put the open weave on top - sew the edges and glue the center.

if i buy new carpet, i'll still need to cut out for the speakers since the factory carpet has a rigid backing, and i'm in the same spot i am now except maybe, just maybe, it will be a close match (unlikely).

the factory carpet is stained anyway, bugs the hell out of me.

or, i buy the open weave carpet i like, and put a mass loaded vinyl barrier with a decoupler down - and just ditch the factory carpet altogether. that way i can have a seamless appearance (desired) while controlling what is acoustically transparent.

[keep_hope_alive]

for an underlayment i'm looking at Vibramat from SoundSense
http://www.soundsense.com/pdfs/Vibramat.pdf

SoundSense has some nice products (I usually specify them for commercial buildings)
SoundSense, LLC - Acoustical Engineering and Design Specialists - Products

or Acoustical Surfaces has good products.
Mass Loaded Vinyl Barrier with Decoupler

If I had been thinking, i would have been using GreenGlue to adhere my kick baffles - as a viscoelastic adhesive.


Yes, I know Luxury Liner Pro is a very similar product. I'm taking that into consideration also. I'll be contacting Ant for the transmission loss data associated with his product.

[bikinpunk]

personally, I'd just buy carpet that matches the OEM carpet in color and put it down on the floor. Cut to desired shape, and stitch together.
non-backed carpet can lay over the midbasses without any effect on their FR.

I did this, though I couldn’t find a good OEM match. I just laid it down on the floor, stapled some spots in and called it a day. At some point I want to find a closer match, but so far I’ve had no luck and quite frankly don’t care enough to bother right now.

[keep_hope_alive]

all new OEM carpet is $450 (#3 below). for that price i'd make my own out of MLV, closed cell foam, and automotive carpet. Honestly, i'll probably use the same unbacked automotive carpet you see in the pics in front of the speakers, and recover the floor. that should look much nicer and cost less than 10% of the OEM replacement.

[bikinpunk]

right, I didn't say buy the OEM carpet. I said buy some that matches the OEM carpet color.
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