hawk 7

iTrader: (2)

I have thought about placing a sub or subs in the storage bin compartments. I've done a search and it seems as if that is not a great idea. I was wondering if anyone has any real experience with the difference between having a sub in the storage compartment versus having them in the hatch area. I understand in theory you will loose the trasfer function (I think) but is it noticable??

Icemark

I have only experiance on the FC, but I have tried to make the bin location work at least a dozen times on multiple cars.

Yes the bin location is less than optimal. Not saying it can't be done. It just takes lots of power, a perfect enclosure to sound even half as good as a single 10 in a bandpass or custom enclosure in the back of the car.

The bins are not far enough back to develop a good low wave form, as well as the roof tends to cause a poorly modified standing wave if the woofers are facing up.

yes it is the perfect stealth location, but even custom fiberglass won't sound great there.

So you need to determine, if sounding okay is acceptable or if you ned your bass to be accurate and good, before you put woofers in the bin area.

brownmound

so if the storage bins are no good, have you had any experience with building subs in some other stealthy location. i know someone on this board has put 8" in the space between the back carpet and the tail lights, but i doubt they were subs.

right on-

Icemark

Different on the pre-86 cars...

The first gen cars sound great with 4 eights over their storage bins. Little f'glass to seal the bins and a nice carpeted panel and a first gen sounds great. This is where the idea of subs in the bins on RX7s first came about.

But on the FCs; they just suck for the sound in the bin area. Removing the spare and building a f'glass enclosure there for a 10" or 12" is the best bet or a small tight 8" or 10" bandpass loaded to fire towards the rear.

But back on a first gen, putting a sub into the spare tire area there sucks big time as well.

So it really depends on the body style

brownmound

I was planning on making a box for a single 8 or 10" (depending on what i can get to fit, based on the required air) and putting it in the driver side storage bin area. the box would be mdf, sealed and bolted to the frame of the car. It wasn't clear if this is what you had done in the past or if you had just let the space in the bin be the sub box, which I doubt.

So, what do you think the results would be of a single 8" or 10" JL sub in a sealed enclosure in the driver side bin? Power?

Thanks

jizzajuice

Here's what my friend did for the enclosure and it works awesome. I'm running an 88 GXL 2 seater so it's got the two bins instead of the two 'seats' you gotta be an acrobat to get into. ^_- Anyways, we did a Kicker Solobaric 10inch behind the passenger seat and we angled it towards the back so we didn't have to reflect the sound off the roof. To power things we made an amp rack for two amps: 1)Rockford 550Watt 2)Alpine 450Watt. Two different amps because of application and to keep costs down. *Sale and what not* Alpine is running the lone sub, and the Rockford is running the mids and tweats. Well, it's hard to describe the sound but I'll just tell you the kind of music I listen to and I THINK you'll get a descent picture. I'm a Eurobeat/House dance music type of guy and sometimes I'll listen to classical and ballads. However I absolutely cannot STAND rap so heavy bass is NOT my thing. Well hope this helps and good luck!

Peace,
AJ ^_^

Icemark

Actually that was the first thing I tried in my 87 sport...

I made a 3/4" fiberglass bottom and sided enclosure with resin bonded and coated 3/4" MDF for a top/mounting surface. It came out to just about 1CF.

An eight was useless, more bass out of the 7" ScanSpeaks I put in each tower. The 10-inch was better, but still didn't get below 45hz.

A JL 12W6 and a Gous 12inch (both about the same) sounded best, but still had a weird standing wave, even with a custom vent tube (similar to transmission line or a small vent side of a band pass) added on later. Tune porting while increased the upper end volume also increased the low end cut off. Both woofers I should say needed at least 400-watt mono or sub amp running them.

After getting frustrated with that (I didn't think accurate and low bass was too much to ask) I tried a JL 10W6 in fiberglass and MDF enclosure in the spare tire well. This was the magic number.

I had since tried two 10s and 2 12s replacing the bins with band pass, f'glass/MDF, Plexi, Plexi/MDF/Dynamat, and conventional only MDF and conventional Birch ply only enclosures in multiple FCs, and they always never compared to a single 10 or 12 in the spare tire well. I even tried transmission lines in there.

In the various enclosures, I have tried JL, Alpine, Gous, Kicker, Eclipse, Earthquake, Lanzar, almost every woofer available for both home and car audio... Only the JL consistently gave me reasonably accurate bass, that had some snap to it.

Hell in desperation I once even used 4 IB (Infinite Baffle) 10s across the top of the bins on a birch ply shelf, and it still didn't sound as good as a single 10 ported in the spare tire area.

I really want the bin area to work... it is the perfect spot... it just doesn't. Kinda like its tough to get bass in a 93-98 accord sedan... something about the car just doesn't allow decent bass unless you use an un conventional location. The bins are conventional.

Now remember the SA models are different. The whole bin design has different accoustics. One of the best sounding 81's I ever did had just woofers mounted on a panel and the panel replaceing the bin lid.

smnc

Really? I'm working on my stereo this winter and I was thinking of mounting a 10" Kicker Solo-Baric in the drivers-side strage bin location.

You're saying that it would sound better with NO box?

Icemark

I have not tried that woofer free air... I thought it worked better in vented enclosures, but if the Theil Smalls work for it to be free air you could try it. The supports/bracing for the SA bins are better than the FC anyway.

Whats the worst that could happen? If you just remove the bin and screw it onto a panel back over the bin access.

brownmound

House, yes. And Hall and Oates.

Sooo...what I am gathering here, and it seems like we have some experience to draw on (thanks Iceman) is that it may in fact be possible to build a box in the storage bins of an FB and get decent sound. I'm not looking to disturb the local starbucks patrons when I drive by, I'm just looking for some good, tight, punchy bass to replace the 18 year old system. In fact a good pair of 6 1/2's and a decent amp would probably keep me happy, but I know I'll be needin that low end fill. The stereo upgrade is my planned winter project also. I would really like to keep the sub in the storage bin area, conventional maybe, but a great freaking solution none the less. It's hard enough to find any decent head unit to match the FB (you've all heard me bitch and whine before).

I was going to go JL for the sub...now I need to get the bin out and take a look around to see what kind of shape I am dealing with in there. Do I gather that it is best to aim the sub towards the rear of the car? I have zero experience in subs.

Thanks, and right on-

dnewman

Icemark,

You said you tried transmission lines? I have a couple of questions about that. How in the hell did you ever find the space in an RX7 for a transmission line? I've only built one (for 2 12s) and the enclosure was enourmous. And I didn't even build it as large as it was supposed to be as the cross sectional area of the TL was only about 70% of the speakers Sd. It was about 3 feet tall 4 feet wide and 30 inches deep.

Also, you mention a custom vent tube similar to a transmission line. I can't for the life of picture a modified port that would have any similarity to a transmission line. Can you describe it more for me?

Thanks!

dnewman

Damn! That's a lot of woofers! I have used 30-40 in my day and haven't even scratched the surface of all the woofers available. There are too many hundreds of speakers available that i don't have the financial resources to ever attempt. I'm kinda shocked that you found the JL the best sounding. I'm not doubting that you are telling the truth, but there are so many woofers that are better than the JLs.

Have you ever tried the following subs?

Adire Audio Shiva
Dayton DVCs
Titanic 1000
NHT 10"
Lambda Acoustics SAL (PL) series
Stryke SB series
Stryke TC15HE
Blueprint 01 and 03 series

They are all excellent drivers that you should really try since you seem to have an open mind. They are all technically superior to the JL W6 series and in most cases quite a bit cheaper. Check them out if you get a chance.

Icemark

Yes I have tried the Dayton and NHT, but the others have not been accessible to me. I doubt that I will be able to get a hold of them, as I have since left the car audio/electronics biz. I am working with DSL and the next gen VDSL now.

A lot of the woofers out there are made by only a couple of companies. For example when I was with DEI one of the many companies we went to was Eminence (who builds about 30% of the worlds woofers or parts for the woofers) and said we need a woofer that meets these specs. They would ship it too use and we would play with it, and try to blow it up. My RX7 was one of the cars we used as a test bench. I used both an enclosure for a 12 where the bins were and a couple of spare tire enclosures. We figured if we could make a woofer sound good in the bin area of a FC that that woofer would sound good anywhere. Because of all this testing, we tried everyone’s woofer we could get a hold of. By weekly I had a different woofer to compare. Kinda cool not having to pay for a woofer and try to blow it up, as well as make it sound good. At the time I was with them DEI decided to go with a off shore company that allowed them to do some really different speakers on final assembly. But again like most speaker companies out there, they used off the shelf parts from various speaker manufactures all put together to make one speaker in final assembly.

I personally always wanted the bins to work. Its the perfect spot.

Yes the transmission line was truly a bitch. The vent/line on it was more than 15ft long. I wish there was a good 'puter program for building one (like there are a couple for band pass, vented, sealed, etc. enclosures) as we maybe made 3 different ones before we got one to work right. That’s a lot of MDF (and even if you use the formaldehyde free pinks stuff and a mask, it still is a lot of dust in your lungs). I would only consider this design in the future for home speaker systems. I'll see if I can dig up some pics to post. The line raised the whole back floor up about 4 inches. The Bose system in the FD is also a transmission line, but granted for just 6" speaker size.

I agree that there are some better speakers than the JL out there, but they (JL speakers) are easily found, and in most cases sound good in many different applications. They are a nice mid-upper end speaker that doesn't cost an arm and leg, and you must admit that is night an day better than the average Kicker or Sound Stream out there.