HD15 Simplification

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   Firstly, thanks for an excellent resource!

I would like to make a HD15. Unfortunatly I am inexperienced in carpentry so am trying to simplify the plan as much as possible.

Would either of these modifications be sensible, how much would they damage the performance of the speaker?

- Replace the curved section with 3 pieces cut with angled (mitred?) edges to simulate a curve

- Have the back or base removable for driver access

Of course, if all go's well; I will want to make more than one  

Matt

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matt andrews Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 15 September 2004 Status: Offline Points: 501	Post Options Post Reply Quote matt andrews Report Post Thanks(0) Quote Reply Topic: HD15 Simplification Posted: 15 September 2004 at 4:37pm
	Firstly, thanks for an excellent resource! I would like to make a HD15. Unfortunatly I am inexperienced in carpentry so am trying to simplify the plan as much as possible. Would either of these modifications be sensible, how much would they damage the performance of the speaker? - Replace the curved section with 3 pieces cut with angled (mitred?) edges to simulate a curve - Have the back or base removable for driver access Of course, if all go's well; I will want to make more than one Matt

biotec Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 07 June 2004 Location: United Kingdom Status: Offline Points: 2932	Post Options Post Reply Quote biotec Report Post Thanks(0) Quote Reply Posted: 15 September 2004 at 4:50pm
	I know andrew made the modification where he had the hatch as the whole back panel and I think he found it worked fine. I think replacing the curve with mitred angles will ruin the sound of the cabinet unless you completely redesgned it. The curved section is actually not too difficult to do, its just hard work and time consuming.

norty303 Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 18 August 2004 Location: Eastbourne Status: Offline Points: 8806	Post Options Post Reply Quote norty303 Report Post Thanks(0) Quote Reply Posted: 15 September 2004 at 5:09pm
	I'd suggest reading Dom's step-by-step build for the HD15 on speakerplans. I'm sure the curved section isn't as difficult as you think. It's just the waiting for each layer to set... (says he, never having touched a sander!! )
	My laser stuff: Frikkin Lasers

Dom Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 25 February 2004 Location: United Kingdom Status: Offline Points: 1700	Post Options Post Reply Quote Dom Report Post Thanks(0) Quote Reply Posted: 15 September 2004 at 6:43pm
	Personally I think if you haven't much experience then you'll be much better off building the curved section, as all you have to do is bend the wood. The only thing is waiting for the layers to dry. Much easier than cutting accurate mitres if you haven't got a table saw... I hadn't got any carpentry experience when I built my first hd15 cabs so just give it a go...

whitehousejamie Members Profile Send Private Message Find Members Posts Add to Buddy List Young Croc Joined: 08 March 2004 Location: United Kingdom Status: Offline Points: 1485	Post Options Post Reply Quote whitehousejamie Report Post Thanks(0) Quote Reply Posted: 15 September 2004 at 6:53pm
	Hi, Just wondering, do you have to use thin layers of wood for the curve, or is it possible to bend an 18mm sheet by steam? How about when using MDF? Cheers Jamie

matt andrews Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 15 September 2004 Status: Offline Points: 501	Post Options Post Reply Quote matt andrews Report Post Thanks(0) Quote Reply Posted: 15 September 2004 at 7:20pm
	Excellent, thankyou for all the support guys I reckon im gonna drive straight in and just get on with it, time to take some measurements to my local wood shop.. (when i get paid) Just a couple more questions for now For the curve, should I get the laminates cut to size to take into account the radius gaining 3mm each time eg 472 x 597 472 x 602 472 x 606 472 x 611 472 x 615 472 x 620 Also, I would like to run one of these (just to play with for now) on one channel of a QSC RMX 1850HD (360W @ 8ohms). Will i get anything usefull out of the PD154 driven with this little power. The other channel will be used for my existing full range boxes. Matt

whitehousejamie Members Profile Send Private Message Find Members Posts Add to Buddy List Young Croc Joined: 08 March 2004 Location: United Kingdom Status: Offline Points: 1485	Post Options Post Reply Quote whitehousejamie Report Post Thanks(0) Quote Reply Posted: 15 September 2004 at 7:25pm
	The best driver to go with, if you are only going to use 1 is the P-Audio BM15LF, and its cheaper too. You would be ok with 360watts going into it, although ideally you would want 500 - 600 watts. Jamie

matt andrews Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 15 September 2004 Status: Offline Points: 501	Post Options Post Reply Quote matt andrews Report Post Thanks(0) Quote Reply Posted: 15 September 2004 at 8:00pm
	Once i have one working, I intend to build 3 more and invest in a hefty amp, somthing like the QSC RMX4050HD or one of the new voids everyone is talking about. Are the P-Audio's as good as the PD's in stacks (4 upwards). I can see this getting rather expensive and being hard work; but equally rewarding.

whitehousejamie Members Profile Send Private Message Find Members Posts Add to Buddy List Young Croc Joined: 08 March 2004 Location: United Kingdom Status: Offline Points: 1485	Post Options Post Reply Quote whitehousejamie Report Post Thanks(0) Quote Reply Posted: 16 September 2004 at 12:16am
	The best driver to use in bigger stacks is the P-Audio C15-500LF, which is little over �100. The PDs are excellent drivers, but you need a lot of power to run them properly. Jamie

Andrew Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 10 March 2004 Location: United Kingdom Status: Offline Points: 669	Post Options Post Reply Quote Andrew Report Post Thanks(0) Quote Reply Posted: 16 September 2004 at 7:10am
	The removeable back approach has still to get the Rog 'seal' of approval. One day, hopefully at the Soundoff, Rog will be able to compare HD15 units built in different ways. My approach is to glue/screw the four sides and baffle, and then start on the curved section using load straps to hold the wood down. Would definitely recommend doing the curved section rather than a load of mitres. Having a removeable back enables a top hat to be bolted in where the door is on the plans.

Jogge Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 09 August 2004 Location: Belgium Status: Offline Points: 63	Post Options Post Reply Quote Jogge Report Post Thanks(0) Quote Reply Posted: 16 September 2004 at 7:36am
	When doing mitres, the chance of airleaks will be bigger. I personaly would go for a nice smooth curved section.
	Always listen to experts. They'll tell you what can't be done and why. Then do it.

Andrew Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 10 March 2004 Location: United Kingdom Status: Offline Points: 669	Post Options Post Reply Quote Andrew Report Post Thanks(0) Quote Reply Posted: 16 September 2004 at 8:41am
	Also, I tend to use a tube of Gripfill per cabinet, mainly to glue down the first curved section from the inside, and thereafter any other inside edge, including the baffle. The first unit I built, the curved section was made from 2mm MDF, nice and flexible, with lots of thin strips, like a roller blind/door, effectively lots of mitres, between layers. Would definitely go the thin ply route, but the first layer is a bit tricky to bend. Thereafter you just need to ensure that there are no air gaps between layers.