Digger8 Sub - diggity dig it all the way to 20Hz

[fastbike1]

Re: Digger8 Sub - diggity dig it all the way to 20Hz

Thanks for the extra info. I'm still not getting close to your sim though. Really academic though. The GTO 804 is pretty appealing with either model. At any rate, I'd use measured params and WBCD which works particularly well for modeling PRs. FWIW, this box model shows flatter response and lower F3/10 if tuned to 27Hz (~340 gms on the PR). 575gms puts F3 @ 29 and F10 at 20 because it starts a gradual rolloff at ~60 and the has the knee at ~22. The 27Hz tune puts the knee pretty much at Vb.
There has been a fair bit of love for the Infinity 1260W and it looks like the GTOs are in the same vein. I'm seeing GTO 804s at ~$55 shipped.

The PR is a Dayton 12" SD315 (I should've noted that...will edit now).
Vb = 24L
Added mass = 575g (what I currently have in there, LOTS of washers!)
LPF @ 100Hz LR2 (I usually have it set around 80-100Hz for HT and about 70-80Hz for music)

PR will reach xmax well before the JBL, but so far I haven't had to put enough power through it to have it hit xmax yet. I know my hearing doesn't go to 20Hz. Hearing damage from when I was younger playing with too much bass in cars. There's plenty of output at 20Hz...so far, there's nothing in the performance to make me think the model is much off.

Kevin -
Multiples of these would be perfect as it would help address nulls in the room from a single sub. And for the cost and size, you can both afford to buy/make and fit more in whatever room you choose.

[jsr]

Re: Digger8 Sub - diggity dig it all the way to 20Hz

Bryan,
I'm not worried about the electronics. Theyre quite tough. And most plate amps have exposed electronics with no problems.

Fastbike,
I'll post up screen shots of my modeling on friday. I'm not working tomorrow and WBCD is only installed on my work computer. I get flat response down to 20Hz. You may be using some wrong values. I'll try tp get clear shots of the screen. If not, I'll post up all the values. My work greatly limits my web browsing capabilities, so posting pictures and screen shots are actually difficult.

Johnny,
Yeah, the old Infinity looks very similar aside from a few changes. I like the look. And performance has been great so far.

[Kevin G.]

Re: Digger8 Sub - diggity dig it all the way to 20Hz

Any thoughts on finishes yet?

[jsr]

Re: Digger8 Sub - diggity dig it all the way to 20Hz

I'm thinking about just using a vinyl in all white. I'm not good with finishing and my painting sucks. Just need to even out the wood as none of the panels lined up perfectly (i.e. the top left of the baffle is slightly high while top right is slightly low...either that or the sides wouldn't line up). All the panels are like this. It was a bit frustrating putting it together and lining things up the best I could. These were CNC'd. So I just plan on using some wood filler and sanding the best I can and covering with a vinyl.

[ontariomaximus]

Re: Digger8 Sub - diggity dig it all the way to 20Hz

the JBL driver looks pretty good for $47! Did you measure it or take JBL's specs? What are the specs? Can't read em at Amazon

[bkeane1259]

Re: Digger8 Sub - diggity dig it all the way to 20Hz

the JBL driver looks pretty good for $47! Did you measure it or take JBL's specs? What are the specs? Can't read em at Amazon

http://www.jbl.com/estore/jbl/us/product/productDetails.jsp?pid=GTO804

Just scroll down till you hit the T/S parms

[jsr]

Re: Digger8 Sub - diggity dig it all the way to 20Hz

I used JBL's specs as Bryan found. I think JR mentioned his old Infinity measured pretty close to mfr's specs. All are Harmon, so their testing and consistency should be the same. They have some nice low end umph while watching movies.

[jsr]

Re: Digger8 Sub - diggity dig it all the way to 20Hz

Here's the WBCD captures for the TyKy Digger8.

LR2 used for model because the Yung amps use a 2nd order filter. I don't know the type, so just LR since it's typically the most popular.

I'm really "diggin" this sub...so far it's been great with the LFE on movies. I haven't had a chance to run much music through it at decent volumes since my baby is usually sleeping in the same room.

[dougc]

Re: Digger8 Sub - diggity dig it all the way to 20Hz

I dont know if their still available but I use the Peerless XLS 12" passive with the Dayton RSS315. The Peerless passive is awsome.

[jsr]

Re: Digger8 Sub - diggity dig it all the way to 20Hz

I like the specs on the AE PRs and will likely go that route if I find I hit xmax too often on the Dayton. The AE's prices are more reasonable for me. Just their leadtimes are long (and often much longer than their quoted times). The Peerless doesn't seem available anymore unfortunately.

[fastbike1]

Re: Digger8 Sub - diggity dig it all the way to 20Hz

The difference in our models is that I habitually use a highpass filter. If you look at your excursion plot you will see that it looks pretty ugly for the PR below ~25Hz and similarly ugly for the JBL below ~20 Hz. If you're running the sub to waht the amp is capable of, you are likely to shred the PR.

Here's the WBCD captures for the TyKy Digger8.

LR2 used for model because the Yung amps use a 2nd order filter. I don't know the type, so just LR since it's typically the most popular.

I'm really "diggin" this sub...so far it's been great with the LFE on movies. I haven't had a chance to run much music through it at decent volumes since my baby is usually sleeping in the same room.

[johnnyrichards]

Re: Digger8 Sub - diggity dig it all the way to 20Hz

It is important to remember that most, (if not all) plate amps use some kind of rumble filter. I think the Dayton uses a 2nd order centered at 19hz, for example. It is not a spec they usually advertise, either.

[jsr]

Re: Digger8 Sub - diggity dig it all the way to 20Hz

Yeah, I mentioned a few times that the PR will reach xmax before the JBL, and that I have another PR I'm looking at should the Dayton not work well. So far I've not had a problem with excursion. The amp was chosen because it's not much more cost for much more power. It's not getting used at full amp power, but I have more power should I repurpose the amp.
I didn't use a HPF in the model because the Yung amps don't have one per info on PEs site...what PE tech said.

[upsman]

Re: Digger8 Sub - diggity dig it all the way to 20Hz

JSR, Any idea how these would sound sealed. Amazon reviews say you can put into .3 ft/3 and get excellent results, dont know how deep they would go but maybe two for music might do the trick....I bought one to try out with a Bash amp.....


BobC upsman

[jsr]

Re: Digger8 Sub - diggity dig it all the way to 20Hz

Hi Bob,
They only get to around 40Hz F3 without EQ in a 0.3cf. The recommendation online is for a car and doesn't quite work as well at home. I'll model it tomorrow to see how well it will do in a sealed box, but it will be larger. Or you can go with about 0.6 cf box with a PR...I think I modelled one that did pretty well.

EDIT:

Here's what I get for a 8.5L (0.3cf) net sealed enclosure with no EQ:
F3 = 37.8 Hz
F6 = 30 Hz
F10 = 23 Hz

With +4dB boost at 35Hz, you get an F3 = 31.4 Hz, but without EQ, it doesn't go very deep. I had the Infinity REF860W in my car in a ~0.3cf box (was about 0.28cf net) sealed and while it sounded good, it really didn't extend very low (and my car is small so I don't get too much cabin gain at the really low frequencies). Most car audio guys like a strong output around 40Hz, so most recommended tuning for car setups tend to either heighten that area or are fine with it rolling off immediately after that. I prefer it extending to at least low 30s in the car (but my current setup still doesn't due to space constraints).
The Infinity is very similar to the JBL...you can swap the 2 and not notice a difference. The Digger8 can be made with the REF860W also and have almost identical performance numbers.