Need help finding a shallow midbass

[owdi]

I'm looking for a driver with some very specific attributes, and I'm beginning to feel it does not exist. This is what I need:

1) Mounting depth no more than 2.25" (57mm)
2) Cutout no larger than 5.25" (133mm)

I would also like

3) price <$50 per driver
4) vented motor
5) low distortion between 80hz and 2000hz
6) 4+mm xmax

If you haven't guessed yet, this is for my car. I want to take what I've learned building home speakers and apply it to car audio. I have all necessary equipment to take measurements, as well as a box full of leftover crossover components to experiment with.

I would love to use the Dayton RS150-4, except it is too deep :-(

Dan

[servicetech]

Will the drivers be going in a box or in a door?

[augerpro]

The Peerless HDS Nomex 832873 is 2.25" deep, maybe a sixteenth more.

EDIT: also it is low distortion, easy to cross using an active xo, needs little space, comes in $51.70, BUT the xmax is 3.5mm, I don't think it will go to 80Hz with authority, and it's not a vented polepiece.

Really you'll have a tough time finding a true midbass that will fit in that space.

[owdi]

servicetech - they will go into my door.

augerpro - Great find, I hadn't even looked at the Peerless HDS Nomex due to price (everything else in that price range was 75+mm deep). The mounting depth of 61.5mm/2.4in is barely workable, and 3.5mm xmax is fine. An abundance of available measurement data doesn't hurt either.

I called PE tech support to get some more info about the RS150-4. Apparently, with the rubber boot removed from the magnet, the driver is 65mm/2.56in deep. That is so close I may try it.

Just to clarify, I will use an active XO between the subwoofer and woofer, and a passive XO between woofer and tweeter.

Dan

[augerpro]

I would use a passive notch filter if you go with the RS150, otherwise I'd use the Peerless. How low do you need this woofer to play?

[servicetech]

Since the driver is going in a door, you will need a driver with a relatively high QTS. I once made the mistake of using a driver with low QTS in a door and the bass response was weak. Remember the driver thinks it's running "free air" while mounted in a door.

For the money you plan on spending I would just pick up a quality component set. I've found the driver and crossover quality to be very good even on the sets under $100. The drivers are made to go in a vehicle (shallow depth, high QTS, water resistant), and the crossovers are custom designed for the drivers. Typically the grilles are included to protect the drivers, and they even come with all the wiring. The crossovers come in a little box that is easy to mount.

[owdi]

augerpro - I have not decided on a crossover frequency yet, it will depend on in-car measurements. If I go with the RS150, I will definitely use some type of notch. The HDS Nomex could probably be used without a filter, since I will always be listening 45* - 60* off axis. I haven't decided on a highpass frequency yet, but it will probably be 3rd order butterworth @ 90hz.

servicetech - Good point, but I don't want to limit myself to high QTS drivers this time around. If in-car measurements reveal midbass is too lean, I'll either EQ or add series resistance. I don't want to buy a component set, because I think I can do better.

Dan

[jp88]

Dan,
Are you sure you cant fit anything bigger? Maybe by using a spacer ring or something like that. I just mounted rs-180's in my doors behind the factory grills on my 96 grand Cherokee. I had to make a 3/4 inch spacer (I had about the same depth before hand as you aprox 2.5" I only had to make on minor modification to get my door panels over them which involved dremeling a small raised area about 1/4"x1/2 inch long.

maybe not the case in your situation but I figured Id throw it out there.

joe

ps if your interested I could maybe pull my door panel off this weekend and snap a few pics

[owdi]

Dan,
Are you sure you cant fit anything bigger? Maybe by using a spacer ring or something like that. I just mounted rs-180's in my doors behind the factory grills on my 96 grand Cherokee. I had to make a 3/4 inch spacer (I had about the same depth before hand as you aprox 2.5" I only had to make on minor modification to get my door panels over them which involved dremeling a small raised area about 1/4"x1/2 inch long.

maybe not the case in your situation but I figured Id throw it out there.

joe

ps if your interested I could maybe pull my door panel off this weekend and snap a few pics

I wish I could fit the RS180's, but I've done my research and I know I can't. I have an '02 Subaru Impreza WRX, which has about 1.5" of clearance. After adding a .75" spacer, and sanding down some plastic, I get about 2.5" to work with.

Source 1

Source 2

Source 3

I'm going to fabricate spacers from .75" MDF, which will look like these. The only way I can get more is by redoing my door panels, or rigging my windows so they don't roll down all the way.

Dan

[Jonasz]

I have an '02 Subaru Impreza WRX

You don't need a sound system with a sweet sounding car like that!! :P

[subynube]

I have an 02 WRX as well. These door card extension pins can take out the door card further to fit larger speakers. You then can make a speaker spacer/ring larger than .75 inches, maybe even a full inch with these door card extensions. I know that we have very shallow doors, but a lot of people do get by with getting some big stuff in there :T

edit: I just re-read your post and it looks like you are already aware of these. Well, good luck anyway!

[owdi]

Jonasz - I do when I'm stuck in traffic.

subynube - what do you have in yours?

In my quest to find a good shallow midbass I've ventured into the dangerous and filthy world of car audio. It's been painful, but I found a ray of hope in the Zapco i-502 coaxial. What made these speakers stand out was posted FR and T/S parameters. I doubt they will outperform the Peerless HDS Nomex, but they do come with a tweeter.

The Zapco RH-16.2 set looks like it has a midbass comparable to the HDS Nomex, but it's too deep, and costs $859.

Dan

[servicetech]

How will the tweeters be positioned in your door? If they are near your feet forget about decent sound quality unless they can be aimed up to your ears somehow.

[subynube]

subynube - what do you have in yours?

I did have exile audio components, which I put in the stock location. They were super shallow speakers, approx 1.8 inches deep, so I just did a .5 inch MDF spacer and no other modification. But, the mid bass was quite weak and I took it all out, sold it, replaced it back with the factory stereo, and bought equipment for home audio :T

[owdi]

servicetech - the tweeters are just in front of the armrests, much closer to my ears than the mids.

subynube - did you treat the doors at all? There is nothing inside the door to absorb sound, and there are many holes which allow the back wave to cancel the front.

I took my door apart today so I could start making the spacers. There is little chance the Dayton RS15-4 will fit, and even the Peerless HDS Nomex 832873 would be extremely tight. I haven't found anything shallower than the HDS, so it's the winner.

Dan